Major Units Research Articles

Integrated geophysical methods and techniques for studying the perennial springs in Ikanje- Share, Kwara State, Nigeria

An integrated magnetic, self-potential (S.P.) and electrical resistivity survey involving magnetic profiling and 1D Vertical Electrical Sounding (VES) electrical imaging techniques were carried out in the transition environment between the Nupe Basin and Southwestern Nigeria Basement Complex at Ikanje-Share in Kwara State, Nigeria. The Ikanje-Share perennial springs started gaining a lot of attention after many travelers and tertiary institutions in Nigeria made it a good choice for their fieldwork exercise. The surveys were done in order to delineate the subsurface layers, determine the geoelectrical characteristics and identify geological structures (e.g., faults and fractures) that are responsible for the perennial spring formation. The magnetic profiling was used as reconnaissance technique to identify lineament features that are favourable to groundwater accumulation and transmission. Some magnetic lineaments were qualitatively inferred from some profiles in the study area. The fault locations coincide with inflection points in S.P. curves and occur as horizontal and consistent planes of discontinuities at depths of approximately 1.25, 4.25, 8.75, 13.15 and 21.25 m, respectively. The VES interpretation results indicated four to five major geologic units, which include: the topsoil/clay/lateritic layer, the lateritic layer, the weathered basement, the weathered/fractured basement and the fresh bedrock. The weathered and fractured basements constitute the main aquifer units and the overburden thickness varies from 5.0 to 16.8 m. The study has shown the usefulness of integrated geophysical methods and techniques in subsurface structural and groundwater development study over the perennial springs in the transition environment between the Nupe Basin and the Southwestern Nigeria Basement complex.

714 ‘Administration of Tranexamic Acid in Traumatic Brain Injury in a Major London Trauma Centre’

Abstract Aim Traumatic brain injury contributes to worldwide death and disability more than any other traumatic insult. CRASH-3 demonstrated tranexamic acid is safe in mild to moderate traumatic brain injury and head injury-related death was reduced when given within 3 hours of injury. This project aims to review adherence to the recommendations at a major trauma centre and implement changes with the view of improving outcomes. Method Patients presenting at St Mary's Hospital with a traumatic head injury over a 6-month period were identified. Data collection included: timings of injury and tranexamic acid administration, Glasgow Coma Scale at the scene and admission, and bolus vs. bolus and infusion. Results presented at the regional trauma network meeting with summary poster designed for display in the department. A second cycle of data collection was completed over 2 months following the interventions. Results There was an increase in the proportion of patients who received tranexamic acid from 29% in cycle 1 to 51% in cycle 2. The proportion of patients receiving both the initial bolus and infusion also increased from 25% in cycle 1 to 45% in cycle 2. The average time from injury to first dose of tranexamic acid was reduced from 2 hours 16 minutes to 1 hour 33 minutes. Conclusions The interventions implemented between cycles 1 and 2 led to an overall improvement in the major trauma unit's adherence to the CRASH-3 recommendations. Decisions where tranexamic acid is withheld are down to clinical judgement however it is recommended that the reasoning is also documented.

Geology of the Derain quadrangle (H10), Mercury

ABSTRACT We present the results of geological mapping of Mercury’s Derain (H10) quadrangle (0°-72°E and 22.5°N-22.5°S) using data from the MESSENGER spacecraft. The map is presented on a scale of 1:3,000,000, for which linework was drawn at 1:300,000. We distinguish three major morphological plains units: Smooth, Intermediate, and Intercrater Plains. We produced two versions of the map, with craters classified according to a 3- and 5-class degradation system. This allows compatibility with other MESSENGER-era maps and Mariner 10-era maps. This map will help provide science context for the ESA-JAXA BepiColombo mission to Mercury.

Improving trophic niche and diet resolution of the salmonid community of Lake Ontario using three stable isotopes and multiple tissues

Salmonids are ecologically and economically important fishes in Lake Ontario but declines in Alewife (Alosa pseudoharengus), recently the primary prey item, may cause shifts in salmonid diets. Improving our understanding of salmonid trophic niches and diets and whether these have changed over time will provide insight into salmonid foraging patterns, ecology, and management. Using three stable isotopes (δ13C, δ15N and δ34S) and Bayesian models, we estimated core trophic niches, niche overlaps among species, and diets for six salmonid species from Lake Ontario sampled during 2018. We used fin and muscle tissue with different temporal assimilation periods to assess seasonal variability in diet, and investigated salmonid trophic niches and diets among three major spatial units (East, Central, West). Overall, core trophic niches overlapped across all species, except Lake Trout (Salvelinus namaycush). Consistent with previous lake-wide analyses of Lake Ontario salmonid diets, Alewife were the preferred prey fish, although Lake Trout and Atlantic Salmon (Salmo salar) had more varied diets, particularly based on white muscle. Fin-based isotope mixing models predicted greater consumption of shallow (< 30 m depth) Round Goby (Neogobius melanostomus) for Lake Trout, Brown Trout (Salmo trutta), and Rainbow Trout (Oncorhynchus mykiss) than other salmonids, indicating seasonal variation in diets. Lake Trout and Brown Trout also varied across spatial units with greater Round Goby consumption in western Lake Ontario. Spatially distinct diets suggest that Brown Trout and Lake Trout populations should be monitored regionally. Understanding prey consumption trends are important to effectively manage fish populations, especially considering on-going ecological changes in the Great Lakes.

Three-dimensional architecture and evolution of Quaternary contourite drifts on the Vøring Plateau, Norwegian Sea

We use newly available, extensive two- and three-dimensional seismic datasets in the Vøring Plateau sector of the mid-Norwegan continental margin to investigate the architecture and evolution of Quaternary contourite drifts in the Norwegian Sea. The drifts typically comprise tens of cubic kilometres of sediment, often intercalated between lenses of glacigenic debris flows, and demonstrate migrating depositional centres along the upper and middle slope sectors of the mid-Norwegian margin through the last ~2.7 M.yr. By contrast, the contourite deposited in the southern Vøring Plateau area is anomalously large covering an area of ~17,000 km2 and comprising over 720 km3 of sediment. Correlation of internal drift surfaces with well-dated sediment cores shows that the massive, up to 280 m thick drift contains two major units that were deposited over the last two glacial-interglacial cycles, yielding extremely high sedimentation rates, comparable to those sourced directly from erosive meltwater-rich glaciers and fast-flowing ice streams. A revised evolutionary drift model provides an end-member example of how a combination of rapid glacially-derived sediment delivery and its subsequent transport and deposition by along-slope processes may exert considerable influence on continental margin morphology over geologically short timescales.

Geochemistry of Volcano-sedimentary and Plutonic Formations of the Agbaou Gold Deposit, Ivory Coast

Located in the south-west part of the Fettekro greenstone belt, Agbaou gold deposit is marked by three major lithological units: (i) a volcano-plutonic unit composed of basaltic to andesitic lavas, amphibolites, chlorite-schists and sills of microdiorite and microgabbro; (ii) a volcano-sedimentary unit containing pyroclastic lavas (basaltic and dacitic) and sediments (shale and grauwacke); (iii) the late felsic dikes (rhyolite and rhyodacite) probably contemporary with the formation of granitoids form the third unit. These host rocks are mostly intensely deformed and altered. Alteration phenomena were revealed by the high values in fire loss, the decreasing of silica contents, the sometimes high values of alkaline for rocks also basic, the constant depletion in LREE and LILE. The Eu and Nb negative anomalies reveal a crustal contamination of magmatic series. Basaltic lavas are volcanic arc tholeiites nearing N-MORB type; they are associated to a magmatogenesis of ocean floor. Their magmatic source would probably be spinel lherzolitic type. Andesites have a calc-alkaline composition and seem far link to active subduction margin. Geodynamics context would be that of an area where transcurrent faults of lithospheric extension generate heat corridors able of generating by fusion the andesitic calc-alkaline magma. This context would probably be the one that prevailed during the establishment of the gold mineralization. Pyroclastic rocks of dacitic composition as acid lavas (rhyolite and rhyodacite) have also evolved in this same geotectonic context. Plutonic rocks are located in arc-volcanic granites field, while metasediment are linked to active continental margin field.

Geology, Geochemistry, and Geochronology of the Giant Rio Tinto VMS Deposit, Iberian Pyrite Belt, Spain

Abstract The Rio Tinto deposit is a giant volcanogenic massive sulfide deposit (VMS) that contains more than 500 Mt of pyrite-rich massive sulfides and more than 2 Gt of mineralized stockwork. Three broad lithostratigraphic groups occur in the regional stratigraphy: the phyllite-quartzite group, the volcano-sedimentary complex, and the Baixo Alentejo Flysch Group. These three major packages reflect the evolution of a depositional environment from a stable platform to deposition in pull-apart continental basins during oblique subduction and collision and coeval synorogenic flysch sequence. The volcano-sedimentary complex, which hosts massive sulfide mineralization at Rio Tinto, can be divided into four major units: (1) the Mafic Siliciclastic Unit, (2) the Lower Sedimentary Unit, (3) the Felsic Unit, and (4) the Upper Sedimentary Unit. The Felsic Unit is further subdivided based on new U-Pb zircon geochronology into three distinct subunits. Felsic Unit I (ca. 356 Ma) includes dome complexes dominated by rhyodacite and reflects the onset of felsic magmatism in the region. Felsic Unit II (ca. 352–348 Ma) represents the main interval of volcanic activity, also dominated by rhyodacite domes and related aprons, and is associated with widespread VMS mineralization. Felsic Unit III (ca. 340 Ma) reflects a late pulse of rhyolitic volcanism. Massive sulfides occur as two different styles of mineralization: (1) replacive ores as discordant pipes hosted by glass-rich felsic rocks and enclosed by a large zone of stockwork-like mineralization and (2) overlying shale-hosted exhalative mineralization in small anoxic basins, probably formed during the collapse of the volcanic domes of Felsic Unit II in the Middle-Late Tournaisian. New lithogeochemical data illustrate two types of mafic rocks in the Mafic Siliciclastic Unit: a basaltic andesite and a high–Ti-Zr basalt, both of tholeiitic affinity. Using immobile element ratios (heavy rare earth elements [HREEs], Al, Y, Zr, and Ti) of the Felsic Unit, fundamental differences have been recognized between the subunits. The unmineralized Felsic Unit I is characterized by high Zr content (225–300 ppm) and a pronounced Eu negative anomaly, and probably represents the most fractionated rocks. Felsic Unit II is characterized by Zr values between 50 and 200 ppm. The low Zr values of the mineralized unit contrast with the typically high Zr values of the felsic rocks related to volcanogenic massive sulfides elsewhere and, at a regional scale, can help to discriminate potentially fertile domes from barren volcanism.

Beach Placer Deposit Modelling using Geospatial Methods: A Case Study from Brahmagiri Mineral Sand Deposit, Puri District, Odisha

Abstract An integrated approach has been attempted for 3D representation of various geo-exploration data pertaining to Brahmagiri Mineral Sand Deposit (BMSD). GIS platforms are utilized to represent the prime depositional environments of sediments under which Total Heavy Minerals (THM) concentrated. In recent times, deeper exploration by sonic drilling has been carried out in the main sand bar of the deposit and retrieved huge lithological data. Different 3D visualization of exploration data using various geological Softwares (ArcGIS, Rockworks and Datamine) carried out.Understanding the morphology of the deposit is carried out using the topographic representation on GIS platform. Discontinuous linear dune ridges are present across the deposit. Sand column explored at an average depth of 40m represents the variety of depositional environment (lagoonal, barrier and beach) within basin. Lithological correlation for the entire (20km) stretch of BMSD carried out and major sand units have been summarized for the area. Heavy mineral (HM) concentrations in each sand column and their correlation using geospatial methods classify the trend and extent of mineralization into two potential zones (Zone 1 and Zone 2) depth wise. This study emphasizes the relationship between surface and subsurface manifestation of exploration data which reveals that BMSD could be part of Barrier bar system having different sub-depositional environments as back-barrier, barrier beach and inlet channel which are controlling the total heavy mineral concentration at various depths. Upper zone of ore body is confined to beach regime whereas lower zone is controlled by combination of beach, back-barrier and inlet channel sediments.

Geologic and Petrologic Characteristics of the Lahar Deposits at the Western Foot of Zao Volcano

The lahars are one of the most hazardous volcanic phenomena causing the third greatest causalities among the volcanic hazards since the 16th century worldwide. Lahars can flow down a long distance and cause tremendous disaster at the foot of volcanoes often beyond the areas of primary volcanic impacts of pyroclastic fall and pyroclastic density currents. Therefore, the research on lahar history of active volcanoes approaching from an analysis of a geological record in distal volcanic regions is significant for lahar hazard risk evaluation. Zao volcano has high risks of future eruptions, because volcanic tremors have been detected since 2013. The presence of a crater lake at the summit area, and steep slopes at the high altitude of Zao indicates high potential energy for future lahars, if triggered by an eruption starting underneath the crater lake. This study firstly reports the existence of lahar deposits at the western foot of Zao and discusses the depositional features and the origin of these as well as the lahar hazard risk at this volcano. The lahar deposits were exposed during the archaeological excavation of the Fujiki ruin, western foot of the Zao volcano. Two major lahar units, L1 and L2, were recognized. Based on the 14C dating and stratigraphic relationships, the ages of units L1 and L2 were estimated to be &lt;ca. 4.0 and ca. 4.6 cal ka, respectively. The lithology, granulometry, and componentry features of the lahar deposits revealed the depositional features and the source materials. The upper part of L1 (L1-1) unit and lower part of L2 (L2-2) unit were deposited from a hyperconcentrated flow, whereas, the lower part of L1 (L1-2) unit and upper part of L2 (L2-1) unit were formed by a debris flow. The sources of both units were phreatomagmatic eruption products that may have erupted shortly before the lahar events. This implies that these eruptions were the most plausible trigger for the lahars. These results suggest that lahar risk will increase especially after the phreatomagmatic eruptions as well as phreatic eruptions, even in the western foot of this volcano.

Students’ perceptions on the difficulty of biochemistry concepts covered in Rwandan secondary school biology curriculum

This study explored the Rwandan secondary students’ opinions on learning biochemistry concepts covered in the Rwandan advanced level of secondary school biology curriculum, and the reasons behind the difficulty of the concepts. In this research, sequential exploratory mixed-method designs were adopted. The sample comprised 195 secondary school students, who were purposively selected from the schools in Rwamagana and Kayonza districts of Rwandan Eastern Province. Data were collected using self-administered questionnaires and focus group semi-structured interview guides. Data analysis was carried out using both quantitative and qualitative approaches. Results from this research showed that photosynthesis and respiration are the major units that are challenging to study with the respective percentages of 62.5 and 75.1. On the other hand, the concept of enzymes is the most difficult according to students’ views. The lack of adequate laboratory and learning resources and teachers’ teaching styles were reportedly the reasons behind the difficulty of these units. Therefore, the provision of continuous professional development training on advances in teaching and learning biochemistry to in-service teachers would be one of the strategies to enhance students’ understanding of these concepts.&#x0D; &#x0D; Keywords: Biochemistry, photosynthesis, enzymes, respiration, secondary school students.

Development of an English Writing Model: A Guide to Self-Directed Learning for Local Food Product Entrepreneur

This study aimed to analyse local food product labelling and information and to develop a writing model focusing on local food product labelling and information. Ten entrepreneurs in one province in the south of Thailand selling local food products were selected. The research employed the quantitative research approach which involved three phases of data collection. In phase one, a questionnaire was employed to gain data necessary for the development of a writing model and to study local food products and labelling of 10 local food products in the selected province. Phase two involved the development of a writing model in which document analysis was employed to strengthen the content included in the writing model. In phase three, a satisfaction questionnaire was utilized as an additional data to adjust the writing model and confirm its usage. The study revealed that the participating entrepreneurs placed an importance on English food labelling. Consequently, the writing model was developed to meet the needs of the participants. The components of the writing model included four major units of information which were product safety, product value, product advertising, and product reliability and warranty. In each unit, crucial information was provided to allow users to study relevant information and related food vocabularies by following the step-by-step information in a form of Thai-English translation. Along with the information provided, the writing model presented a process of writing which can enable the users to develop their product labelling in English.

Identification of two major direct repeat unit clusters, 8i and 11ce, among methicillin resistant Staphylococcus aureus strains: the emergence of novel dru types and repeats

The changing epidemiology and decreasing susceptibility to first-line antibiotics, such as vancomycin and linezolid, leave clinicians with few therapeutic options for MRSA infections. This study aimed to conduct an epidemiology study and characterize MRSA isolates. A total of 150 MRSA isolates were collected from clinical specimens. Antimicrobial susceptibility was determined using the disk diffusion method. Resistance and major virulence genes were screened using the polymerase chain reaction. The SCCmec and dru typing were used to conduct molecular epidemiology. The BioNumerics tandem-repeat sequence typing plug-in tool was utilized for dru type cluster analysis. We constructed a minimum spanning tree using the similarity matrix of the DSI model. We discovered 24 dru types among the 55 dru sequenced MRSA isolates. Additionally, eight new dru types were discovered and added to the dru typing database. Two dru clusters (8i, 11ce) and nine single dru types were identified in 55 dru sequenced MRSA isolates. The two dru clusters, 8i and 11ce, accounted for 46 MRSA isolates (83.63%). The most common one of the nine singles dru types in this study was dt9bd, which belonged to the SCCmec types of IX. Given that two clusters account for the majority of strains in our study, we can conclude that the genetic origin of these strains is the same. Therefore, the spread of these strains can be prevented with effective MRSA monitoring in hospitals and communities.

Clonality and genetic structure of an endangered aquatic plant, Typha minima, in the French Alps: consequences for conservation

The dwarf bulrush (Typha minima Hoppe) is a perennial aquatic plant that has been rapidly disappearing in Northern Europe following flood control methods (dikes, dams, embankments). Floods, by erasing and creating new banks, maintain a metapopulation system (extinction/recolonization of populations). The largest and most diverse populations are located in France. To identify the size of the metapopulations, we studied clonality, genetic diversity and genetic structure of an extensive sample of the French populations using AFLP markers. Clonality was high (on average, each genotype was found in three copies) but variable across sites: some genotypes had a high number of copies (> 20) and were distributed over several river catchments while 239 genotypes were unique. Genetic diversity was high but did not accumulate downstream indicating both up- and downstream long-distance gene flow through pollen and seeds. Genetic diversity is structured in three major clusters. One (cluster N) is restricted to sites north of 44°4 N. The other two (clusters S and E), coexist in river catchments or even in the same site. However, the highest Fst were found between cluster E and clusters N or S, indicating a recolonization from different refugia, one possibly located east of the Alps (cluster E) and one or two on the Western side. Therefore conservation actions should take into account these three major conservation units (CU) in France. These CU cover large areas. It is thus important to maintain a natural river dynamics with frequent extinction/recolonization events over whole drainage basins.

Intrusion detection using optimized ensemble classification in fog computing paradigm

Fog computing is a framework, which expands services of the cloud to network for addressing inherent issues of the cloud. Intrusion Detection Systems (IDSs) represent a major unit of the security model for fog networks for facilitating service quality. This paper devises a hybrid optimization-driven ensemble classifier in a fog computing platform. In fog computing, the complete processing is done utilizing trio layers that include the cloud layer, end point layer, and fog layer. In the cloud layer, three procedures, like data transformation, selection of features, and classification processes were carried out. A data transformation is conducted with log transformation. A feature is chosen using Kolmogorov–Smirnov correlation-based filter. Then, the classification is done utilizing ensemble classifiers, named RideNN, Deep Neuro-Fuzzy Network (DNFN), and Shepard convolutional neural network (ShCNN). The tuning of the ensemble classifier is conducted utilizing the developed Rider Sea Lion Optimization (RSLO) algorithm. RSLO algorithm is conceived by amalgamating the Rider optimization algorithm (ROA) and Sea Lion Optimization Algorithm (SLnOA). At an end point layer, a physical process is done. In the fog layer, intrusion detection is done based on a trained ensemble classifier. The proposed RSLO-based ensemble approach provides enhanced performance with higher precision of 88%, recall of 88.4%, F-measure of 88.2%, and accuracy of 97.2%.

Seismic-stratigraphic analysis and depositional architecture of the Cenozoic Kribi-Campo sub-basin offshore deposits (Cameroon): Seismic attributes approach and implication for the hydrocarbon prospectivity

The offshore deposits were formed the main part of the Kribi-Campo sub-basin, which is one of the three Cameroonian coastal margin basins formed during the progressive opening of the South Atlantic margin. Determination of the seismic facies and their architecture in seismic units are lacking in the Kribi-Campo sub-basin and calibration of the stratigraphic unit and the hydrocarbon prospectivity of Cenozoic offshore deposits remains unclear. Therefore, the seismic stratigraphic unit, data from five boreholes, and seismic attributes of 2D seismic data were analysed to determine the seismic stratigraphic distribution, the paleoenvironment evolution, and to assess the hydrocarbon prospectivity of the Cenozoic offshore deposits of the Kribi-Campo sub-basin. Five main seismic facies include parallel to subparallel, hummocky, chaotic, sigmoidal, and oblique, and four major seismic stratigraphic units SSU1, SSU2, SSU3, and SSU4 have been identified. The seismic stratigraphic unit has been divided into five major unconformities dated Upper Paleocene, Lower Eocene, Middle Miocene, Upper Miocene, and Pliocene to Pleistocene. The depositional environments evolve from delta to prograding continental shelves, both influenced by high and low energy processes, controlled by relative sea-level change. The offlap-breaks in the SSU4 seismic unit show the presence of both the Low Stand Systems Tract (LST) or Shelf Margin Systems Tract, and retrograding Transgressive Systems Tract (TST). The presence of potential source rocks, reservoirs, seals, and structural and stratigraphic traps throughout the studied seismic intervals highlight the prospective nature for oil and gas exploration within the offshore Cenozoic of the Kribi-Campo sub-basin.

Multi-stage construction of the Little Cotton wood stock, Utah, USA: Origin, intrusion, venting, mineralization, and mass movement

AbstractMany porphyry molybdenum deposits are hosted in multi-phase plutons, but it is unclear in some deposits how these magmas originated and whether the pluton intruded as it fractionated or was intruded by new batches of magma. New mapping has clarified field relationships between units in the White Pine porphyry Mo system hosted in the Little Cottonwood stock, Utah (western United States), including the White Pine intrusion, the Red Pine porphyry, rhyolite dikes, and phreatomagmatic pebble dikes. Geologic relations and geochemistry show the system formed in a continental arc setting during rollback of the subducting Farallon slab rather than during extension related to orogenic collapse. Whole-rock geochemistry shows distinct fractionation trends for each of the major intrusive units in the composite pluton, suggesting they formed separately, which is supported by new U-Pb zircon laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) ages of ca. 30 Ma for the Little Cottonwood stock, 27 Ma for the White Pine intrusion, and 26 Ma for the previously undated Red Pine porphyry. Mineral textures, cross-cutting relationships, and alteration mineralogy indicate that intrusion of the youngest phase led to a fluid-saturated magmatic system and triggered venting, including emplacement of pebble dikes. In the adjacent east Traverse Mountains, pebble dikes contain clasts that have similar mineral assemblages, textures, and ages as the major igneous units in the White Pine deposit. This indicates that the pebble dikes in east Traverse Mountains and in the pluton are the upper and lower parts of the same magmatic-hydrothermal system, which was decapitated by a mega-landslide that was likely facilitated by alteration in the Oligocene hydrothermal system and by later Basin and Range faulting.

Cambrian/Ordovician boundary as a milestone in the sedimentation history of the southern Siberian craton: Evidence from U-Pb dating of detrital zircons

The paper presents petrographic, geochemical, and new U-Pb zircon (LA-ICP-MS) geochronological data on the Upper Lena Fm. sediments which make part of the Cambrian sedimentary cover of the Siberian craton. The composition of lithic fragments in these clastic sediments, including mafic and felsic volcanics and granitoids, along with the correlation of major element ratios and the values of trace-element ratios point to predominant igneous (mainly felsic) rocks in the provenance. The U-Pb ages of detrital zircons from the sampled Upper Lena Fm. sandstones are mostly Early Paleozoic (∼500 Ma), with very few Archean-Paleoproterozoic determinations and quite many Neoproterozoic zircons. Ediacaran and Earliest Cambrian clastic sediments bearing Early Precambrian and Neoproterozoic detrital zircons, as well as Neoproterozoic and Early Paleozoic complexes of the Central Asian Orogenic Belt, could provide material for the Upper Lena clastic deposition. The geochronological evidence shows that the Upper Lena Fm. sandstones were deposited over vast territories of the southern Siberian craton in the Late Cambrian, in a single sedimentary basin, and originated from the same provenance. The Upper Lena deposition event in the Late Cambrian, immediately before the Ordovician period, makes a key milestone in the geological history of Siberia: the end of a large-scale Early Cambrian transgression and the beginning of gradual uplift of the southern craton margin, at least till the Carboniferous, which was associated with the formation of the Central Asian Orogenic Belt, a major tectonic unit of Asia.

Robust simulation-optimization framework for synthesis and design of natural gas downstream Incorporating renewable hydrogen network under uncertainty

Many intrinsic uncertainties are part of natural gas downstream synthesis, design, and operation. This work extends the earlier developed deterministic model to account for new decision variables, unit operations, and uncertainty in the network. The uncertainty includes the feedstock composition and flowrate, utility requirements, by-products, and final product market price. The proposed two-stage stochastic model includes new major processing units (helium recovery units), hydrogen production via renewable technologies (biomass gasification, water electrolysis), and operating modes. The stochastic formulation simultaneously considers uncertainty in 12 different model parameters. The model's first stage aims to find the optimal network's design variables, such as processing units, technologies, and operating modes common to all scenarios. The second stage is concerned with deriving operational variables, for example, the network's overall inlet feedstock flowrates, individual units' inlet flowrates, and units' capacity. Outcomes obtained for a range of uncertain material/energy feedstock and products/by-products market prices result in higher expected operating profits than the equivalent deterministic model. The analysis's key takeaways show that the most prevailing network consists of two syngas technologies: (1) auto-thermal reforming to feed a low-temperature Fischer Tropsch synthesis unit and (2) steam methane reforming for hydrogen production. Additionally, renewable hydrogen is produced via electrolysis and biomass gasification. There is an improvement of 2.22% in the objective function value using the stochastic approach instead of the deterministic.

Technological Options for Direct Air Capture: A Comparative Process Engineering Review.

The direct capture of CO2 from ambient air presents a means of decelerating the growth of global atmospheric CO2 concentrations. Considerations relating to process engineering are the focus of this review and have received significantly less attention than those relating to the design of materials for direct air capture (DAC). We summarize minimum thermodynamic energy requirements, second law efficiencies, major unit operations and associated energy requirements, capital and operating expenses, and potential alternative process designs. We also highlight process designs applied toward more concentrated sources of CO2 that, if extended to lower concentrations, could help move DAC units closer to more economical continuous operation. Addressing shortcomings highlighted here could aid in the design of improved DAC processes that overcome trade-offs between capture performance and DAC cost.

Resolved and Redeemed: A New Fleck to the Evolutionary Divergence in the Genus Scomberomorus Lacepède, 1801 (Scombridae) With Cryptic Speciation

The genus Scomberomorus, with 18 nominal species, sustains a significant heterogeneous fishery throughout its range. The sole molecular systematic study of this genus concerned the species group S. regalis, which contains the new world taxa. The species diversity of Scomberomorus in the northern Indian Ocean has not been studied at the molecular level, often leading to misidentifications. Here, novel genetic data are provided that reconfigure species boundaries from the region. We used single and multilocus data (eight mitochondrial and three nuclear genes) to infer phylogenetic relationships, species delimitation, and the resurrection of a time-calibrated phylogenetic tree. Our aim was also to verify the hypothesis of geographical races in S. guttatus predicated on variable vertebral counts. Interestingly, all species delimitation analyses have recovered another highly cryptic species in the nominal S. guttatus previously believed to have an Indo-Pacific distribution. Scomberomorus guttatus (Bloch and Schneider, 1801) in the sensu stricto, is redeemed from its type locality based on genetic data and preliminary morphomeristic investigations and has a restricted distribution in the Bay of Bengal. The cryptic species Scomberomorus aff. guttatus which exhibits &amp;gt;10% genetic divergence from S. guttatus is resurrected here from the synonymy of the latter as Scomberomorus leopardus (Shaw, 1803). Widespread in the Indo-Pacific, this species contains two major molecular operational taxonomic units (MOTUs) with a divergence threshold of over 2% between them. Our analysis suggests that vertebral counts must be coupled with other features to identify the species/lineages in the nominal S. guttatus. The heterogeneity in the S. guttatus species group is discussed in relation to the ecological diversity of the region which facilitates larval recruitment and niche specialization. The results also revealed two allopatric putative species in S. commerson, found primarily in the Pacific and Indian Oceans. This study added genetic data from S. lineolatus and S. koreanus, not previously represented in the sequence repositories. Estimation of divergence time indicated that the Indo-West Pacific species group undergoes multiple diversification events besides the recent splits detected within S. leopardus.