Mobile Salt Research Articles

Per aqueous liquid chromatography of Radix hedysari polysaccharides and Au nanoparticles co-functionalized stationary phase and its application in the determination of iridoids and phenylethanols

BackgroundHydrophilic Interaction Liquid Chromatography (HILIC) is an outstanding strategy for the challenging analysis of hydrophilic and polar components. Nevertheless, analysis under HILIC mode typically consumes 70%–95 % acetonitrile with the disadvantage of high analytical costs, being environmentally unfriendly and causing biohazards, which is not in line with the concept of green chromatography. Research has shown that Per Aqueous Liquid Chromatography (PALC) simultaneously emphasizes efficient analytical performance for hydrophilic analytes and green analytical concepts. The development of new PALC stationary phases with superior performance is necessary. ResultsIn this paper, silanized silica was sequentially subjected to esterification reaction, polymerization reaction and covalent bonding through five steps to obtain SiO2-RHP-AuNPs material, which was prepared as a novel stationary phase for PALC. Comprehensive characterization of the materials by means of Fourier transform infrared spectroscopy, Transmission scanning electron microscope, Elemental analysis and Thermogravimetric analysis showed the successful bonding of the functionalized groups on the original silica. The polymeric stationary phase based on Radix hedysari polysaccharide and Au nanoparticles had higher density of hydroxyl and ester functionalized groups. The Au nanoparticles upgraded their mesoporous structure and thermal stability, providing exceptional chromatographic performance and selectivity for chromatographic analysis. The influence of mobile phase water content, salt concentration, pH and column temperature on the retention behavior was evaluated. The novel Column was found to exhibit a dual mechanism of hydrophobic interactions/ion exchange interactions in a mobile phase with high water content. Significance and noveltyThe separation efficiency and selectivity of SiO2-RHP-AuNPs columns for synthetic pigments and organic acids in PALC mode were superior to those of commercial HILIC and C18 columns. In addition, a method for the determination of seven active ingredients in Fructus Ligustri Lucidi by SiO2-RHP-AuNPs column in PALC mode was developed. The method had good stability, reproducibility and accuracy, which was capable of realizing the quality evaluation of Chinese Materia Medicas.

Late quaternary morpho-stratigraphic record of diapir rise in the Cardona salt extrusion, NE Spain. Halokinetic sequences, raised terraces and uplift rates

Active diapirism has received very limited attention from the geomorphological and Quaternary Science perspective, despite the role played by this ground deformation process in the development of landforms and sedimentary environments, and the important practical implications associated with mobile salt structures (e,g., mining, hydrocarbon production, geostorage). The Cardona salt extrusion (NE Spain) was initiated in late Quaternary times from the post-shortening unroofing of the crest of a salt anticline by the entrenchment of the transverse Cardener River. Detailed mapping, outcrop analysis, geophysical data and trenching indicate that the diapir-flanking deposits show halokinetic complexes comprising two types of morpho-stratigraphic units: (1) an older flap of coarse-grained drapefolded colluvial deposits; and (2) younger lacustrine and fluvial deposits in peripheral depressions confined between the upturned colluvial flaps and the country rock slope. These synkinematic units record an overall relief inversion and correspond to the so-called wedge and hook halokinetic sequences, recording ratios between diapir rise rate and sedimentation rate lower and greater than 1, respectively. The radiocarbon ages obtained from several raised late Holocene strath terraces carved in the salt indicate uplift rates within the range of 36.5–12.1 mm/yr, consistent with geodetic data. The spatial variability of the uplift rates can be related to increasing flow rates towards the axis of the salt wall and potential along-strike variations. The relatively high diapir rise rates observed at Cardona diapir, unaffected by contractional displacement loading (tectonic squeezing), is attributed to the youthful stage of the salt extrusion and the low dynamic viscosity of the Cardona Saline Formation, with a low proportion of impurities and a significant amount of potash salts.

Mechanistic modeling of empty-full separation in recombinant adeno-associated virus production using anion-exchange membrane chromatography.

Recombinant adeno-associated viral vectors (rAAVs) have become an industry-standard technology in the field of gene therapy, but there are still challenges to be addressed in their biomanufacturing. One of the biggest challenges is the removal of capsid species other than that which contains the gene of interest. In this work, we develop a mechanistic model for the removal of empty capsids-those that contain no genetic material-and enrichment of full rAAV using anion-exchange membrane chromatography. The mechanistic model was calibrated using linear gradient experiments, resulting in good agreement with the experimental data. The model was then applied to optimize the purification process through maximization of yield studying the impact of mobile phase salt concentration and pH, isocratic wash and elution length, flow rate, percent full (purity) requirement, loading density (challenge), and the use of single-step or two-step elution modes. A solution from the optimization with purity of 90% and recovery yield of 84% was selected and successfully validated, as the model could predict the recovery yield with remarkable fidelity and was able to find process conditions that led to significant enrichment. This is, to the best of our knowledge, the first case study of the application of de novo mechanistic modeling for the enrichment of full capsids in rAAV manufacturing, and it serves as demonstration of the potential of mechanistic modeling in rAAV process development.

Tectono-stratigraphic evolution of salt-influenced normal fault systems: an example from the Coffee-Soil Fault, Danish North Sea

We explore how the relationships between fault activity, salt movement and sediment loading affect the stratal geometry of the hanging wall throughout the evolution of a salt-influenced normal fault system. We examine a c. 65 km long portion of the Coffee-Soil Fault System in the Danish North Sea, the hanging wall of which has been partially influenced by a pre-rift unit of mobile salt. To constrain the tectono-stratigraphic evolution of this fault system, we combine structural observations with seismic stratigraphic analysis of the hanging wall growth strata. We find that the hanging wall of the Coffee-Soil Fault System shows major depocentre shifts through time, along with marked variability in the along- and across-strike stratal geometries. We explain how the development of these characteristics is influenced by: (1) the segmentation and linkage history of the fault system; (2) the evolution of the salt-cored cover monoclines above blind basement fault segments; and (3) changes in the location and rate of accommodation generated by the load-driven withdrawal of salt up the dip-slope of the hanging wall and by fault-related subsidence. Our findings have implications for structural and stratigraphic studies in salt-influenced rift basins, as well as for understanding the potential distribution of geo-storage and hydrocarbon reservoirs in such settings.

Lubricant‐Interface Induced Mobile Crystallization for Hypersaline Wastewater Management

AbstractHypersaline wastewater management is a crucial issue for water‐energy nexus. Evaporation‐based zero liquid discharge (ZLD) desalination shows great promise to detoxify the hypersaline wastewater. However, salt formed on the evaporation surface compromises the efficiency and continuity of desalination. Here, the study reports a photothermal lubricant‐infused surface (PLIS), capable of inducing mobile salt crystallization and eliminating salt scaling during desalination. Few nuclei initiate away from the PLIS, followed by migration inward as salt growth, leading to compact crystal. The final dewetting process leaves only scattered protrusions from crystal bottom contacting with the PLIS. Such a converged small area plus pinpoint contacting mode produce an ultralow adhesion of salt to the substrate (≈2 mN mg−1), ≈40 times lower than that on a regular‐used hydrophobic surface. The salt crystal precipitated on the PLIS can be blown off easily by air flow, refreshing the evaporating surface for continuous desalination and realizing ZLD.

Discharge Monitoring in Open-Channels: An Operational Rating Curve Management Tool.

An aspect correlated with climate change is certainly represented by the alternation of severe floods and relevant drought periods. Moreover, there is evidence that changes in climate and land cover are inducing changes in stream channel cross-sections, altering local channel capacity. A direct consequence of a significant change in the local channel capacity is that the relationship between the amount of water flowing at a given point in a river or stream (usually at gauging stations) and the corresponding stage in that section, known as a stage-discharge relationship or rating curve, is changed. The key messages deriving from the present work are: (a) the more frequent and extreme the floods become, the more rapid the changes in the stream channel cross-section become, (b) from an operational point of view, the collection and processing of field measurements of the stage and corresponding discharge at a given section in order to quickly and frequently update the rating curve becomes a priority. It is, therefore, necessary to define a control system for acquiring hydrological data capable of keeping river levels and discharges under control to support flood early warnings and water management. The proposed stage-discharge management system is used by the Civil Protection Service of the Marche Region (east-central Italy) for the monitoring of river runoff in the regional watersheds. The Civil Protection Service staff performs stage-discharge field measurements using water level sensors and recorders (e.g., staff gauges, submersible pressure transducers, ultrasound and radar sensors) and a current meter, acoustic doppler velocimeter, acoustic doppler current profilers, portable mobile radar profiler and salt dilution method equipment, respectively. Power functions are fitted to the stage-discharge field data. Furthermore, extrapolation is performed to cover the full range of flow measurements; in general, extrapolation is not an easy task because of sharp changes in the stream cross-section geometry for very high or very low stages. In the present work, we also focused attention on the application problems that occur in practice and the need for frequent updating.

Phosphorus-doped deep eutectic solvent-derived carbon dots-modified silica as a mixed-mode stationary phase for reversed-phase and hydrophilic interaction chromatography.

In this work, phosphorus-doped carbon dots (P-DESCDs) were successfully prepared using choline chloride/lactic acid type deep eutectic solvent and phosphoric acid as ingredients, and (3-aminopropyl) trimethoxysilane was used as a bridge to graft P-DESCDs onto the silica surface to obtain a new mixed-mode stationary phase (Sil-P-DESCDs) for reversed-phase and hydrophilic interaction liquid chromatography. The successful preparation ofthe stationary phase was confirmed by laser scanning confocal microscopy, elemental analysis, and Fourier transform infrared spectrometry. Interestingly, the doping of phosphorus greatly improved the separation performance and hydrophilicity of the Sil-P-DESCDs column. The Sil-P-DESCDs column was found to have certain hydrophobicity, hydrogen bonding ability and shape selectivity by Tanaka and Engelhardt standard test mixtures, and a series of hydrophilic and hydrophobic compounds such as alkylbenzenes, polycyclic aromatic hydrocarbons, sulfonamides, aromatic amines, phenols, flavonoids, nucleoside bases, and alkaloids. In addition, the effects of mobile phase ratio, column temperature, flow rate, salt concentration, and pH on the retention of analytes on Sil-P-DESCDs columns were investigated. Finally, the Sil-P-DESCDs column was applied to the qualitative and quantitative analysis of calcein-7-glucoside in the real sample of medicinal Astragalus pellets, and it was found at a concentration of 0.02mg/mL.

Annular Creep Barrier Evaluation and Qualification Using Ultrasonic Measurements

Summary It is well-known that formations that exhibit active creep behavior under downhole conditions, such as reactive shales and mobile salts, can form annular barriers across uncemented or poorly cemented annular sections behind casing strings. Such creep barriers can simplify well abandonments, particularly in high-cost offshore environments. Evaluation and qualification of creep barriers in the field, however, have proven challenging and labor-intensive when casing is perforated, and annular rock material is pressure-tested to verify its sealing ability. This work seeks to eliminate the need for pressure testing by allowing the barrier to be qualified using only casedhole log measurements. Sophisticated rock mechanical laboratory experiments under realistic downhole conditions were conducted to investigate the formation of creep barriers by North Sea Lark shale. The experiments evaluated barrier formation while varying annular fluid chemistry and temperature. Measurement parameters included creep rate, pressure transmission across newly formed barriers, pressure breakthrough through the newly formed barriers as well as ultrasonic responses by the shale. It was found that the Lark/Horda shale has a distinct anisotropic ultrasonic wave velocity profile that uniquely characterizes it. This can be used to identify its presence in an annular space when contacting the casing. A main conclusion is that a Lark shale barrier can be qualified through casedhole sonic and ultrasonic logging alone without the need for pressure testing if (1) the magnitude of the wave propagation velocity of the shale behind casing can be confirmed (2077 m/s for Lark shale); (2) the characteristic velocity anisotropy profile, unique to the shale (~10.1% for Lark shale), can be verified; (3) good contact with/bonding to the casing is observed; and optionally (4) anisotropy in the time behavior of the shale contacting the pipe is observed when the barrier is stimulated artificially. If these conditions are met, then our experiments show that the barrier will have excellent hydraulic sealing ability, with a permeability of a few microdarcies at most and a breakthrough pressure that approaches the minimum horizontal effective stress value. Additional findings are that shale heating will accelerate barrier formation but may damage the shale formation in the process. Extraordinary fast annular closure and barrier formation with evident shale rehealing was observed by using a concentrated KCl solution as pore fluid, showing the merits of barrier stimulation by chemical means. This result can be explained by considering the effect of solutes on shale hydration forces.

Assessment of automated off-line solid-phase extraction LC-MS/MS to monitor EPA priority endocrine disruptors in tap water, surface water, and wastewater.

EPA method 539.1 recently introduced an expanded list of priority endocrine-disrupting compounds (EDCs), some of which were also included in the Unregulated Contaminant Monitoring Rule 3 (UCMR3). Though standardized methods are available for drinking water, analysis of steroid hormones and bisphenol A (BPA) at the ultra-trace level remains challenging. This study set out to evaluate the suitability of automated off-line solid-phase extraction (SPE) liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) for the determination of EPA-priority EDCs in environmental water matrixes (tap water, surface water, and wastewater influents and effluents). The target molecules included 14 steroid hormones (altrenogest, androstenedione, equilenin, equilin, α-estradiol, β-estradiol, estriol, estrone, ethinylestradiol, levonorgestrel, medroxyprogesterone, norethindrone, progesterone, testosterone) and BPA. Factors that may influence the analytical performance were assessed. This involved, for instance, testing combinations of SPE materials from different brands and protocol variations. Several materials presented absolute extraction efficiencies in acceptable ranges. Initial sample pH, nature of reconstitution medium, and mobile phase salt concentration were among the potential factors affecting analyte signal. Storage conditions (different preservative agents) possibly exerted the strongest influence, in agreement with the literature. Limits of detection were in the range of 0.03-0.5ng/L in drinking water, 0.1-0.5ng/L in surface water, and 0.16-1ng/L in wastewater. Method validation also involved testing linearity, accuracy, and precision in reagent water and matrix-matched extracted calibrants. The method was applied to field-collected water samples in Eastern Canada. Summed EDC concentrations remained low in tap water (<LOQ-0.92ng/L), while higher detection frequencies and contamination levels were reported in riverine surface waters (2.6-37ng/L) and municipal wastewaters (10-424ng/L).

Source apportionment of PM2.5 in Seoul, South Korea and Beijing, China using dispersion normalized PMF

East Asian countries experience severe air pollution owing to their rapid development and urbanization induced by substantial economic activities. South Korea and China are among the most polluted East Asian countries with high mass concentrations of PM2.5. Although the occurrence of transboundary air pollution among neighboring countries has been recognized for a long time, studies involving simultaneous ground-based PM2.5 monitoring and source apportionment in South Korea and China have not been conducted to date. This study performed simultaneous daily ground-based monitoring of PM2.5 in Seoul and Beijing from January to December 2019. The mass concentrations of PM2.5 and its major chemical components were analyzed simultaneously during 2019. Positive matrix factorization (PMF) as well as dispersion normalized PMF (DN-PMF) were utilized for the source apportionment of ambient PM2.5 at the two sites. 23 h average ventilation coefficients were applied for daily PM2.5 chemical constituents' data. Nine sources were identified at both sites. While secondary nitrate, secondary sulfate, mobile, oil combustion, biomass burning, soil, and aged sea salt were commonly found at both sites, industry/coal combustion and incinerator were identified only at Seoul and incinerator/industry and coal combustion were identified only at Beijing. Reduction of the meteorological influences were found in DN-PMF compare to C-PMF but the effects of DN on mobile source were reduced by averaging over the 23 h sampling period. The DN-PMF results showed that Secondary nitrate (Seoul: 25.5%; Beijing: 31.7%) and secondary sulfate (Seoul: 20.5%; Beijing: 17.6%) were most dominant contributors to PM2.5 at both sites. Decreasing secondary sulfate contributions and increasing secondary nitrate contributions were observed at both sites.

Using Shale as a Barrier Simplifies Well Abandonment

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 199654, “Simplifying Well Abandonments Using Shale as a Barrier,” by Eric van Oort, SPE, and Maria Juenger, The University of Texas at Austin, and Munir Aldin, SPE, Metarock Laboratories, et al., prepared for the 2020 IADC/SPE International Drilling Conference and Exhibition, Galveston, Texas, 3-5 March. The paper has not been peer reviewed. The complete paper presents the results of an investigation into the creep behavior of North Sea shales and their ability to form effective annular barriers. The large-scale laboratory results show that Lark-Horda shales will form competent low-permeability annular barriers when left uncemented, as confirmed using pressure-pulse-decay measurements. Experimental conditions were found to influence the rate of barrier formation. Higher effective stress, higher temperature, and beneficial manipulation of annular fluid chemistry all have a significant effect. Introduction An alternative to traditional plug-and-abandonment techniques presented it-self more than a decade ago, with observations that formations such as mobile salts and shales could creep into uncemented annular spaces and form competent annular barriers that could be identified on sonic and ultrasonic bond logs and verified using pressure testing. Shale particularly has the necessary characteristics that several guidelines require of a good barrier, being largely impermeable, nonshrinking, ductile, and resistant to chemicals and substances, all of which help provide long-term integrity. Shales that appeared to be particularly well-suited to beneficial annular creep behavior were characterized by low strength and high ductility, high clay content with relatively high smectite content, low levels of quartz and carbonate cementation, relatively high porosity and low compressional wave velocity, and a tendency to yield wellbore instability problems while being drilled. Mechanisms other than creep were considered for the annular blockage behavior observed, but the mounting body of evidence indicates that the predominant mechanism is indeed creep (i.e., the viscoplastic behavior of argillaceous rocks). In the laboratory and field work published to date, stimulation of shale barriers through accelerated creep by pressure and temperature manipulation has received the most attention. The authors investigate barrier activation not only by temperature and pressure activation but also by chemical activation, because it offers practical advantages and reduces risks associated with temperature and pressure activation. Temperature has a significant effect on the viscoplastic behavior of shale, but heating a long shale section (with a minimum barrier length of 50 m) through casing with an effective downhole heater presents considerable practical challenges. Pressure reduction in the annulus through reduction of the hydrostatic head in the wellbore brings with it well-control concerns, particularly when no functional annular barrier is in place. By contrast, circulating a chemical solution in place in an annular space through casing perforations with a workstring and packer arrangement is relatively straightforward and is routine when practicing the perforate, wash, and cement technique in the field.

The northern Gulf of Mexico offshore super basin: Reservoirs, source rocks, seals, traps, and successes

The northern Gulf of Mexico federal offshore area easily qualifies as a super basin based upon estimated petroleum endowment of more than 100 BOE and cumulative production of 60 BOE. Like other super basins, it has multiple petroleum systems and stacked reservoirs. Examination of four key elements of these petroleum systems (reservoirs, source rocks, seals, and traps) yields important insights to the geologic processes that result in such an exceptional habitat for conventional hydrocarbons. The bulk of hydrocarbon resources in federal offshore waters is in Cenozoic sandstone reservoirs such as the Paleogene Wilcox reservoir of deep-water subsalt areas. Overall, Cenozoic sandstone reservoirs in both suprasalt and subsalt fields yield the highest flow rates and cumulative production volumes. Notable is the recent addition of the deep-water Jurassic Norphlet sandstone play, the newest and second largest by ultimately technically recoverable resources. Overall, Gulf of Mexico reservoirs are diverse, formed in paleoenvironments ranging from aeolian to deep water. Powering this super basin are three primary marine source rocks centered in the Oxfordian, Tithonian, and Cenomanian–Turonian Stages. These source rock intervals commonly act as top seals, but other Neogene and Mesozoic shales and even carbonate mudstones are also important trap-sealing elements, as proven by analytical work and downhole pressure measurements. The extensive salt distribution and relatively late Cenozoic burial delayed source rock maturation and migration until the culmination of trap formation in many areas. High rates of Cenozoic deposition on a mobile salt substrate also generated a myriad of salt tectonic structures, ranging from simple diapiric closures and extensional fault traps to complex subsalt configurations such as salt-cored compressional anticlines, salt-cutoff traps, and bucket weld traps. Exploration success in the past 20 yr is a direct result of improved seismic imaging around and below salt, as well as advances in drilling, completing, and producing wells and fields.

Innovative Application of Managed Pressure Drilling to Stabilize Creeping Salt Formation at 0.2159 m (8 ½”) section

La Perforación con Presión Controlada(MPD)ha sido utilizada para resolver problemas de estabilidad de hoyo durante la construcción de pozos petroleros. Sin embargo, no fue aplicada en la perforación desales móviles hasta finales del año 2017. Durante este año el primer pozo fue completado utilizando esta tecnología, por lo cual, se requirió de un análisis riguroso para determinar su aplicabilidad en la perforación de nuevos pozos. El presente artículo presenta algunas de las características más importantes de la hidráulica de la MPD y un análisis exhaustivo de un caso de estudio de Pakistán. El estudio de la hidráulica de este pozo demostró que las correlaciones de Herschel-Bulkley aproximan las pérdidas de presión por fricción con un error menor a 1% comparado con la información de campo, por lo tanto, estas pueden ser utilizadas en el proceso de planificación de la perforación. Además, se determinó que la MPD puede manejar ventanas de perforación muy pequeñas (entre 2.346 SG y 2.388 SG) evitando simultáneamente pérdidas de fluido y fractura de las formaciones. Finalmente, se propuso un nuevo escenario con una densidad reducida (desde2.2SG hasta2.15 SG)y un incremento en la contra presión en superficie (desde1 033 928,57Pa hasta1 585 357,14Pa)para la perforación de nuevos pozos.

Pre-salt clastic systems in the Herodotus Basin, SE Mediterranean Sea

This study is focused on the architectural characteristics of the offshore extension of a late Messinian deep-sea fan system through the analysis of a large set of multichannel seismic-reflection profiles. A 2 km thick Messinian Salinity Crisis sequence occurs on top of a clastic system, indicating that even during the maximum sea-level drop, this part of the basin was still a marine setting. The top of the clastic system is characterized by a sharp surface on which several shear surfaces within the overlying Messinian salt terminate. This is attributed to the northward gliding of the Messinian mobile salt layer from the Nile cone to the deep Herodotus basin. Mapping the base of the clastic system, it is concluded that the bathymetry on which it evolved was complex, forming valley-like structures in the southern half of the study area. The sediment source of this clastic system is interpreted to have originated from the Nile River through gravity flows during the early stages of the Messinian Salinity Crisis that resulted in thick deposits at the deepest parts of the Herodotus basin. Medium to high amplitude discontinuous reflections with multiple sudden terminations representing local (channel-like) to broader-scale erosional surfaces characterize the late Messinian clastic system. Such a seismic character, in combination with its confined nature, indicates the development of a submarine channel complex set. On the other hand, towards the north, the convex top surface of the clastic system and discontinuous internal reflections, exhibit in multiple occasions, bidirectional downlap geometries that point to the basinward evolution of the channel complex set into a lobe complex set at the most unconfined parts of the basin. This clastic system is time equivalent to the fluvio-deltaic deposits of the Abu Madi Formation of the Nile Delta region.

Desalination of Seawater Using Cationic Poly(acrylamide) Hydrogels and Mechanical Forces for Separation

AbstractIn this study, the ability of cationic poly(acrylamide‐co‐(3‐acrylamidopropyl)trimethylammonium chloride) hydrogels to desalinate seawater is explored, where the salt separation is based on the partial rejection of mobile salt ions by the fixed charges along the polymer backbone. Water absorbency measurements reveal that artificial seawater‐containing divalent ions (Mg2+, Ca2+, and SO42−) drastically decrease the swelling capacity of previously employed anionic poly(acrylic acid‐co‐sodium acrylate) hydrogels, whereas no influence on the swelling behavior of the synthesized cationic hydrogels is found. The swelling behavior and mechanical properties are studied by varying the degree of crosslinking and degree of ionization systematically in the range of 1–5 and 25–75 mol%, respectively. Finally, artificial seawater (csea = 0.171 mol L−1) is desalinated in a custom‐built press setup with an estimated efficiency of Em³ = 17.6 kWh m−³ by applying an external pressure on the swollen hydrogels.

Salt tectonics in a double salt‐source layer setting (Eastern Persian Gulf, Iran): Insights from interpretation of seismic profiles and sequential cross‐section restoration

AbstractSalt tectonics in the Eastern Persian Gulf (Iran) is linked to a unique salt‐bearing system involving two overlapping ‘autochthonous’ mobile source layers, the Ediacaran–Early Cambrian Hormuz Salt and the Late Oligocene–Early Miocene Fars Salt. Interpretations of reflection seismic profiles and sequential cross‐section restorations are presented to decipher the evolution of salt structures from the two source layers and their kinematic interaction on the style of salt flow. Seismic interpretations illustrate that the Hormuz and Fars salts started flowing in the Early Palaeozoic (likely Cambrian) and Early Miocene, respectively, shortly after their deposition. Differential sedimentary loading (downbuilding) and subsalt basement faults initiated and localized the flow of the Hormuz Salt and the related salt structures. The resultant diapirs grew by passive diapirism until Late Cretaceous, whereas the pillows became inactive during the Mesozoic after a progressive decline of growth in the Late Palaeozoic. The diapirs and pillows were then subjected to a Palaeocene–Eocene contractional deformation event, which squeezed the diapirs. The consequence was significant salt extrusion, leading to the development of allochthonous salt sheets and wings. Subsequent rise of the Hormuz Salt occurred in wider salt stocks and secondary salt walls by coeval passive diapirism and tectonic shortening since Late Oligocene. Evacuation and diapirism of the Fars Salt was driven mainly by differential sedimentary loading in annular and elongate minibasins overlying the salt and locally by downslope gliding around pre‐existing stocks of the Hormuz Salt. At earlier stages, the Fars Salt flowed not only towards the pre‐existing Hormuz stocks but also away from them to initiate ring‐like salt walls and anticlines around some of the stocks. Subsequently, once primary welds developed around these stocks, the Fars Salt flowed outwards to source the peripheral salt walls. Our results reveal that evolving pre‐existing salt structures from an older source layer have triggered the flow of a younger salt layer and controlled the resulting salt structures. This interaction complicates the flow direction of the younger salt layer, the geometry and spatial distribution of its structures, as well as minibasin depocentre migration through time. Even though dealing with a unique case of two ‘autochthonous’ mobile salt layers, this work may also provide constraints on our understanding of the kinematics of salt flow and diapirism in other salt basins having significant ‘allochthonous’ salt that is coevally affected by deformation of the deeper autochthonous salt layer and related structures.

Tectonic controls on sedimentary system along the continental slope of the central and southeastern Tyrrhenian Sea

Continental margins are often characterised by wide slope sectors with complex topography due to seafloor deformation linked with mobile shale or salt, or local tectonics. Within the resulting slope environments, sedimentary systems can be complex and often structured in variously connected, separate intraslope basins. In this paper, we investigate how the diverse arrangement of sedimentary systems on topographically complex slopes relate to regional differences in extensional tectonic setting. Our study is carried out through the analysis of bathymetric data in the central and southeastern portion of the Tyrrhenian Sea, a back-arc basin that displays wide slope sectors, surrounding the deep Marsili and Vavilov basin plains. A “connected tortuous corridor” forms in the Latium-Campanian slope, where extensional faults are parallel to the margin. Here, tectonic structures are important in controlling the relative extent of dip and strike sectors as well as depositional and erosional segments of submarine drainage networks. Confined, margin-parallel troughs, such as the Capo d’Orlando and the Paola Basins, form respectively landward from volcanic edifices and mud remobilisation ridges. Their depositional setting is mainly the result of the relationships between the basin dip and the site of major sediment input. An unconfined trough parallel to the margin forms when its edge coincides with down-to the basin extensional faults, such as in the case of the Gioia Basin. Its axis is the site of a longitudinal slope valley that shows morphologic variations controlled by tectonic structures. Transverse troughs cutting the entire slope form when tectonic structures are perpendicular to the margin, such as in the Cilento slope. Here, the pattern of extensional faulting is the major control on the degree of connection of successive basins and the eventual development of a drainage system. Throughgoing slope valleys form in graded slope, where sedimentary packages are thick enough to heal the relief associated with tectonic structures. They have planforms, relief and erosional or depositional attitude that is controlled by slope steps connected with faults. As a general outcome, our research provide a valid framework that illustrates the range of possible architectures of sedimentary systems and of their constituents in extensional continental margins.

Microstructure Determines Water and Salt Permeation in Commercial Ion-Exchange Membranes.

Ion-exchange membrane (IEM) performance in electrochemical processes such as fuel cells, redox flow batteries, or reverse electrodialysis (RED) is typically quantified through membrane selectivity and conductivity, which together determine the energy efficiency. However, water and co-ion transport (i.e., osmosis and salt diffusion/fuel crossover) also impact energy efficiency by allowing uncontrolled mixing of the electrolyte solutions to occur. For example, in RED with hypersaline water sources, uncontrolled mixing consumes 20-50% of the available mixing energy. Thus, in addition to high selectivity and high conductivity, it is desirable for IEMs to have low permeability to water and salt to minimize energy losses. Unfortunately, there is very little quantitative water and salt permeability information available for commercial IEMs, making it difficult to select the best membrane for a particular application. Accordingly, we measured the water and salt transport properties of 20 commercial IEMs and analyzed the relationships between permeability, diffusion, and partitioning according to the solution-diffusion model. We found that water and salt permeance vary over several orders of magnitude among commercial IEMs, making some membranes better suited than others to electrochemical processes that involve high salt concentrations and/or concentration gradients. Water and salt diffusion coefficients were found to be the principal factors contributing to the differences in permeance among commercial IEMs. We also observed that water and salt permeability were highly correlated to one another for all IEMs studied, regardless of polymer type or reinforcement. This finding suggests that transport of mobile salt in IEMs is governed by the microstructure of the membrane and provides clear evidence that mobile salt does not interact strongly with polymer chains in highly swollen IEMs.

Molar Mass Analysis of Hydrophobically Modified Hyaluronic Acid by SEC‐MALLS: Facing the Challenges of Amphiphilic Biomacromolecules

AbstractA size exclusion chromatography–multiangle laser light scattering (SEC‐MALLS) method is developed for determining the molar masses of amphiphilic hyaluronan (HA), consisting of a hydrophilic polymer backbone modified to varying extents with hydrophobic, polymerizable acrylate groups. The polymers are prepared via the base‐catalyzed esterification of HA with acrylic anhydride. Various parameters are investigated including mobile phase composition, temperature, pH, salt type, and concentration in order to find the most suitable conditions for completely dissolving the modified polymers irrespective of the degree of substitution (DS), and for suppressing secondary polymer interactions. The hydrolytic and the thermal stability of the different materials at various experimental conditions are also extensively investigated. HAs with DS varying from 0 to 3.4 are subsequently analyzed at the optimized experimental conditions for the mobile phase being DMSO/H2O 60/40(v/v) with 0.05 M LiBr and an operating temperature of 40 °C. The refractive index increments (dn/dc) of the HAs are determined and the results show a dependence of dn/dc on DS.

Using salt tectonic structures as proxies to reveal post-rift crustal tectonics: The example of the Eastern Sardinian margin (Western Tyrrhenian Sea)

Abstract The METYSS project (Messinian Event in the Tyrrhenian from Seismic Study) is based on high-resolution seismic data acquired along the Eastern Sardinian margin, Western Tyrrhenian Sea. The main aim is to study the Messinian Salinity Crisis (MSC) in the Western Tyrrhenian Basin, but we also investigated the thinning processes of the continental crust and the timing of crustal vertical movements across this backarc domain. Our first results shown that rifting ended before the MSC, but that crustal activity persisted long after the end of the rifting. This has been particularly observed on the proximal margin, the East-Sardinia Basin, where the Mobile Unit (MU, mobile Messinian salt) is thin or absent. In this study, we examined the distal margin, the Cornaglia Terrace, where the MU accumulated during the MSC and acted as a decollement, thus potentially decoupling the basement from the sedimentary cover. Our observations provide evidence for lateral flow and gravity gliding of the salt and its brittle sedimentary overburden along local basement slopes generated by the post-MSC tilting of some basement blocks formerly generated during the rifting. We also investigated an intriguing wedge-shaped body of MU located in a narrow N-S half graben bounded to the west by a major, east-dipping, crustal normal fault. Classically, one could think that this salt wedge is related to the syn-tectonics deposition of the MU, but we propose an original scenario, in which the post-rift vertical motion of the major fault has been cushioned by lateral flow of an initially tabular salt layer, leaving the supra-salt series apparently unaffected by the crustal motions of the basement. We tested this scenario by comparing natural data and physical (analogue) modelling data. Our results reveal that salt tectonics provides a powerful tool to understand the deep crustal tectonics of the margin and to constrain the timing of vertical motions in the Western Tyrrhenian Basin, results that can be applied to rifted salt-bearing margins worldwide.