Gradual Evolution Research Articles

Gradual evolution of a homo-l-peptide world on homo-d-configured RNA and DNA.

Modern life requires the translation of genetic information - encoded by nucleic acids - into proteins, which establishes the essential link between genotype and phenotype. During translation, exclusively l-amino acids are loaded onto transfer RNA molecules (tRNA), which are then connected at the ribosome to give homo-l-proteins. In contrast to the homo-l-configuration of amino acids and proteins, the oligonucleotides involved are all d-configured (deoxy)ribosides. Previously, others and us have shown that if peptide synthesis occurs at homo d-configured oligonucleotides, a pronounced l-amino acid selectivity is observed, which reflects the d-sugar/l-amino acid world that evolved in nature. Here we further explore this astonishing selectivity. We show a peptide-synthesis/recapture-cycle that can lead to a gradual enrichment and hence selection of a homo-l-peptide world. We show that even if peptides with a mixed l/d-stereochemistry are formed, they are not competitive against the homo-l-counterparts. We also demonstrate that this selectivity is not limited to RNA but that peptide synthesis on DNA features the same l-amino acid preference. In total, the data bring us a step closer to an understanding of how homochirality on Earth once evolved.

Additive manufacturing of functionally graded stellite6/17-4 PH fabricated via direct laser deposition

Multi-material structures with variable functionalities can lead to unique solutions for engineering problems compared to single-material structures. Additive manufacturing of Functionally Graded Materials (FGMs) using Direct Laser Deposition for the multi-material deposition of Stellite6 and 17–4 PH stainless steel has been investigated in this study. Process parameter design was successfully applied to achieve FGM structures with expected composition ratio and defect free. Results revealed that clads with insufficient laser power had unmelted 17-4 PH powders, while those with excessive power resulted in micro-cracks and disrupting the expected composition for the previous layer. Energy Dispersive Spectroscopy analysis results showed that the composition was almost as expected, with less than 10% deviation. The Stellite6 composition in FGM exhibits a minimum ratio near the substrate due to the penetration of 17-4 PH elements. Meanwhile, in multi-track clads, the Stellite6% decreases along the transverse direction due to increased heat input, multiple cladding tracks, higher dilution, and slower solidification rate. The results of the micro-hardness tests illustrated the gradual evolution of micro-hardness along the build direction starting from the base metal, which had a hardness of approximately 300 HV for 17-4 PH and for the compositions of 25%, 50%, 75%, and 100% Stellite6 showed increases of 10%, 39%, 43%, and 63% respectively, reaching up to 490 HV for fully Stellite6 at the top of the specimen.

Étude pilote transversale descriptive des profils et représentations d’étudiants infirmiers concernant la profession et la recherche en début de formation en France

Introduction: In 2009, the Nursing Diploma evolved with the awarding of a Bachelor's degree, placing the profession in the Bachelor's-Master's-Doctorate curriculum. The creation of the Nursing Sciences section of the National Council of Universities and the gradual evolution towards the complete universitarization of training, raises questions about the evolution of news students’ profiles.Objective: To identify the profiles of students, to question their representations of the profession and research as well as their expectations.Method: Pilot cross-sectional descriptive study carried out via questionnaire on all nursing students starting their training.Results: 30 students with various profiles were included. The choice of nursing was based on: a family identification model, orientation aids, parcoursup, the desire to be useful, and to pursue a university curriculum. The latter was found to be 53.3%. In terms of representation, 76.7% thought that nurses were subordinate to doctors.Discussion: The visibility of the profession in the media and a better knowledge of nurses' missions are major areas of work for the trainers. The desire to pursue studies is to be considered at the governmental level in the impact on the renewal of nursing professionals.

Transitioning from Communicative Competence to Multimodal and Intercultural Competencies: A Systematic Review

The formulation of the construct of communicative competence (CC) was the consequence of the perceived “inappropriateness” of the theory of linguistic competence and performance. To obtain a comprehensive understanding of second language (L2) CC, a systematic review of 85 studies was conducted to assess how empirical studies have defined and operationalized the construct in the context of L2 learning and assessment. Four main themes emerged from the papers: (1) beliefs and perceptions about CC, (2) expansion of CC, (3) mixed specifications of CC, and (4) tests and measures of CC and communicative language ability (CLA). The analysis of these themes foregrounded several significant findings. First, the construct of L2 CC was significantly more prevalent in the body of research compared to L2 CLA. Second, CC has been perceived as a multifarious construct that has been researched from varied perspectives. It was found that older studies were more consistent with traditional approaches to defining CC and CLA, while the construct shifted focus to technology and self-appraisals in more recent studies. Third, there is no consensus amongst the reviewed studies about tests and methods of operationalization of CC, suggesting that the evidence provided is sample-specific and non-replicable. Importantly, it was found that over the years, CC has undergone a gradual evolution. With the multimodal and intercultural turn, CC has branched into new concepts namely intercultural and multimodal communicative competencies. Pertaining to these concepts, new notions such as telecollaboration, digital literacies, and multiliteracies have emerged. CC has also been, for long, analogous to performance, proficiency, social rules of language use, rules of appropriateness, willingness to communicate, self-perceptions of CC, and the goal of being a native speaker, which can add to the confusion surrounding the construct. The implications of the present research synthesis are two-fold. It becomes imperative to adapt world language classrooms to the rising trend in intercultural and multimodal communicative competencies. In addition, further replicable investigations should focus on developing optimal methods of operationalization that are in line with the new contemporary theoretical frameworks of language in the age of digital technologies and artificial intelligence.

The CAVITY project: The spatially resolved stellar population properties of galaxies in voids

The Universe is shaped as a web-like structure, formed by clusters, filaments, and walls that leave large low number-density volumes in between named voids. Galaxies in voids have been found to be of a later type, bluer, less massive, and to have a slower evolution than galaxies in denser environments (filaments and walls). However, the effect of the void environment on their stellar population properties is still unclear. We aim to address this question using 118 optical integral field unit datacubes from the Calar Alto Void Integral-field Treasury surveY (CAVITY), observed with the PMAS/PPaK spectrograph at the 3.5 m telescope at the Calar Alto Observatory (Almería, Spain). We fitted their spectra from 3750 Å to 7000 Å with the non-parametric full spectral fitting code STARLIGHT to estimate their stellar population properties: stellar mass, stellar mass surface density, age, star formation rate (SFR), and specific star formation rate (sSFR). We analysed the results through the global properties, assessing the behaviour of the whole galaxy, and the spatially resolved information, by obtaining the radial profiles from the 2D maps up to the 2 half-light radius of each stellar population property. The results were examined with respect to their morphological type and stellar mass. Then, we compared them with a control sample of galaxies in filaments and walls, selected from the CALIFA survey and analysed following the same procedure. To make a fair comparison between the samples, we selected a twin filament galaxy for each void galaxy of the same morphological type and closest stellar mass, to match the void galaxy sample as much as possible in morphology and mass. Key findings from our global and spatially resolved analysis include void galaxies having a slightly higher half-light radius (HLR), lower stellar mass surface density, and younger ages across all morphological types, and slightly elevated SFR and sSFR (only significant enough for Sas). Many of these differences appear in the outer parts of spiral galaxies (HLR > 1), where discs are younger and exhibit a higher sSFR compared to galaxies in filaments and walls, indicative of less evolved discs. This trend is also found for early-type spirals, suggesting a slower transition from star-forming to quiescent states in voids. Our analysis indicates that void galaxies, influenced by their surroundings, undergo a more gradual evolution, especially in their outer regions, with a more pronounced effect for low-mass galaxies. We find that below a certain mass threshold, environmental processes play a more influential role in galactic evolution.

IBAQ: Frequency-Domain Backdoor Attack Threatening Autonomous Driving via Quadratic Phase

The rapid evolution of backdoor attacks has emerged as a significant threat to the security of autonomous driving models. An attacker injects a backdoor into the model by adding triggers to the samples, which can be activated to manipulate the model’s inference. Backdoor attacks can lead to severe consequences, such as misidentifying traffic signs during autonomous driving, posing a risk of causing traffic accidents. Recently, there has been a gradual evolution of frequency-domain backdoor attacks. However, since the change of both amplitude and its corresponding phase will significantly affect image appearance, most of the existing frequency-domain backdoor attacks change only the amplitude, which results in a suboptimal efficacy of the attack. In this work, we propose an attack called IBAQ, to solve this problem by blurring semantic information of the trigger image through the quadratic phase. Initially, we convert the trigger and benign sample to YCrCb space. Then, we perform the fast Fourier transform on the Y channel, blending the trigger image’s amplitude and quadratic phase linearly with the benign sample’s amplitude and phase. IBAQ achieves covert injection of trigger information within amplitude and phase, enhancing the attack effect. We validate the effectiveness and stealthiness of IBAQ through comprehensive experiments.

Beynəlxalq münasibətlər diskursunda postkolonializm

Turning to history has always been an important tool for understanding international relations, and this trend remains relevant today. However, if earlier researchers mainly focused on individual events and their possible interpretations, now the main attention is focused on determining the historical characteristics of systems and reflecting this legacy in modern international relations. That is why the postcolonial approach, focused on the gradual evolution of colonial relations into the modern system of international relations, has become especially important; postmodernism is used to explain the concept of postcolonialism. In these concepts, an important place is occupied by the terms colonialism and postcolonialism, which seem to be a continuation of each other, despite the fact that they oppose each other. This article explains some of these concepts. Looking at the development and theoretical history of the concept of postcolonialism, it can be concluded that the concept was first used by Edward Said in his work entitled “Orientalism”. In Edward Said's “Orientalism” (1978) [Said, 1978], although many derivative terms from the concepts of colonialism and imperialism are used, the word postcolonialism does not appear even once in this work. No less important than Edward Said's research into the consolidation of postcolonialism as a concept is Subaltern Studies, first developed by Indian Marxist historians in 1982. Thus, although postcolonialism has not yet reached its final form in terms of naming, thanks to the book "The Empire Writes Back" [Ashcroft, Griffiths, & Tiffin, 1989] published in 1989, today both the term and the theoretical concept are used in modern scientific circles.

Ландшафт меняющихся идентичностей на фоне военного вторжения: роман Тамары Дуды Доця сквозь призму перевода

In the environment of Russia’s ongoing war against Ukraine, literary translation acquires critical significance as a way to get Ukraine’s narratives of destruction and urbicide across cultural and political borders. This article will focus on Daisy Gibbons’s 2021 translation of Tamara Duda’s 2019 novel Daughter, set in the Eastern Ukrainian city of Donetsk, to examine the translator’s project of reconstructing the complex interplay of Eastern and Western Ukrainian identities embroiled in the narrative of crawling occupation. Daughter tells the story of Russia’s 2014 invasion of Donetsk, dissecting the city’s fragmented identity along cultural and linguistic divides and exploring internal tensions and propaganda-fueled conflicts leading to its eventual downfall. The storyline adopts the female protagonist’s insider/outsider perspective, tracing her gradual evolution from an invisible observer to a fearless insurgent fighting for the survival of her unravelling home. The analysis will centre on the translator’s approach, which combines textual and paratextual techniques to highlight the processes of division and destruction – with their transformative impact on the urban space – and to enter into a visible dialogue with the narrator/protagonist’s voice to amplify and reinforce its distinctly pro-Ukrainian perspective.

Incorporating Interaction into Teaching Writing Essays in the EFL/ESL (L2) Setting

Objective: The paper highlights the challenges of writing essays and emphasizes the importance of a systematic approach to essay writing. The author aims to convey that good writing is a gradual process that requires interaction, rigorous thinking and meticulous planning, contrasting the notion that essays are spontaneously produced in one draft. Method: Applying a mixed-methods research approach, the author undertakes the study. The research involves the use of questionnaires to gather data from 38 undergraduate students in a reputed college in Nepal. The use of mixed methods suggests a comprehensive investigation that combines quantitative and qualitative data to provide a more holistic understanding of the student’s experiences with essay writing. Result: The findings of the research reflect a strong need for step-by-step guidance, fun, and interaction in writing classes, particularly when teaching essay writing. The result suggests that students benefit from a systematic and interactive approach to learning how to write essays. It implies that a more engaging and structured method of teaching can be effective in addressing the challenges students face in essay writing. Conclusion: The conclusion drawn from the study is that the production of a quality essay is rather a gradual evolution resulting from rigorous thinking and meticulous planning. It recommends a methodical division of the essay-writing process into steps to achieve coherence and effectiveness. Additionally, it proposes incorporating hands-on activities in conjunction with writing theories to enhance the teaching of essay writing. Overall, the conclusion emphasizes the importance of a systematic and interactive approach to teaching writing essays.

Formation mechanism and structural evolution of recumbent fold nappes: New insights from the bizerte area, northern Tunisia

The structural analysis of the Bizerte area in northern Tunisia, utilizing well data and field observations, reveals a complex arrangement of fold structures characterized by recumbent fold nappes to local sheath-like fold structures, indicative of a deep detachment phenomenon. The genesis and present geometry of these fold structures unravel a multifaceted structural history: (i) In the Tortonian folding phase, a detachment mechanism may have initiated the formation of a horizontal shearing plane at the base of the Paleocene marls. The gradual evolution of syn-shear recumbent fold nappes into sheath folds within sedimentary to pseudo-metamorphic rocks is attributed to a flow perturbation process analogue to “layer-parallel shearing,” dictating the geometric configuration of folds subsequent to a simple shear inducing perturbations in pre-existing layer disturbances. (ii) During the Late Quaternary shortening phase, a NW-trending right lateral shear zone emerged, delineated by the reactivation of pre-existing faults under compression. The reorientation of the anterior fold axes is attributed to the counterclockwise rotation of rigid blocks within the framework of P-type conjugate fractures. (iii) The transition to thin-skinned tectonics, characterized by the uplift of previously buried material, was characterized by a significant increase in shortening during Neogene events, encompassed in the broader regional geodynamic context of continental collision. From the Lower Quaternary onward, the structural model exhibits a combination of layer-parallel and layer-normal shear processes.

Slow Dynamics of Hydrate Systems Revealed by a Double BSR

AbstractDetermining how gas hydrate distribution evolved along continental margins in the past is essential to understanding its evolution in the future. Moreover, hydrate decomposition has been linked to several catastrophic events, including some of the largest submarine landslides on Earth and the massive release of greenhouse gases into the ocean. Offshore Romania, the presence of a second bottom‐simulating reflector (BSR) provides an opportunity to gain valuable insights into hydrate dynamics since the Last Glacial Period (LGP). We conducted transient modeling of hydrate thermodynamic stability by merging in‐situ observations with indirect assessments of sea‐bottom temperature, thermal conductivity, salinity, sedimentation rate, and sea‐level variations. We reveal a strong correlation between the BSRs and the base of the Gas Hydrate Stability Zone (GHSZ) during both the present and LGP periods. The gradual evolution of the GHSZ over the past 34 ka presented here supports a conceptual model that excludes catastrophic environmental scenarios.

The Darwinian Theory of Evolution and Creation Account of Genesis: Contradiction or Complementary?

The question of the origin of humans has been fiercely contested for a long period. One perspective is the creation model, which asserts that the Universe and all its components emerged through the deliberate actions of God, driven by design and purpose. Conversely, the evolution model posits that the Universe’s formation occurred solely through mechanistic processes, devoid of any supernatural intervention. Narrowing the scope to humanity, the evolution model contends for the gradual evolution of the human species through a process of descent with modification from an ancestor shared with apes, while the creation model proposes the direct creation of humankind by God in his image. Certainly, the implications either model has on human dignity are very important for human existence. Whether God created humankind directly or through evolution from an ape-like ancestor has a bearing on human dignity. It raises, for example, the question as to whose image humanity bears: God’s or apes’? The way one answers this question will definitely affect his or her human-divine and human-human relationships. A literary research approach was used to gather data from books, articles, and dissertations. The data were critically examined to consider the arguments for either side of the debate. It was found out that both biblical and scientific data may allow for variations within a particular species (microevolution) but not the production of one species from another (macroevolution). The findings suggest that the creation model must be accepted with its attendant implications for human dignity. Keywords: Evolution, Creation, Human Dignity, Origin

A thorough assessment of various forest management planning initiatives and development of improvement strategies towards an ecosystem-based planning

Management planning for forests in Turkey has undergone gradual evolution over the last century. Developing and implementing a comprehensive management planning framework present significant challenges. This paper evaluates the effectiveness of various forest management planning approaches implemented across the country over different time periods, with overarching planning principles. It formulates a robust planning framework and proposes improvements grounded in scientific advancements and international standards. The assessment indicated that the management plans were developed using reputable scientific methods and principles aimed at ensuring the sustainable management of forest resources with certain strengths and opportunities presented by SWOT analysis. All management plans shared a common planning concept primarily focused on maximizing wood production through the area-control harvest scheduling method (except for continuous cover forest, which employed the single tree selection method). Each management plan established its unique vision, targets, policies, objectives, and planning guidelines. Forest inventory data were gathered through a combination of ground surveys and remotely sensed data to characterize and stratify the landscape. A robust in-house management authority and governance system with appropriate technical capacity and guidelines were developed and implemented, fostering a sound common working culture and tools. However, some notable drawbacks were identified, including political pressure, biomass/carbon accounting, growth-yield modelling, economic analysis, limited characterization of the full range of ecosystem services, risk and uncertainty analysis, food security and, particularly, long-term sustainability and scenario analysis with the appropriate decision-making tools and methods. Despite a few strengths, these limitations may raise concerns about the far-sighted design and application, potentially jeopardizing the sustainable management of forest ecosystems. Proposed improvement strategies for an efficient forest ecosystem management planning system include characterization of ecosystem services, modelling their productivity, scenario analysis with a decision support system, stakeholder involvement, balancing utilization and conservation targets, conducting risk and uncertainty analysis and economic analysis of management actions.

Ferritinophagy mediates adaptive resistance to EGFR tyrosine kinase inhibitors in non-small cell lung cancer

Osimertinib (Osi) is a widely used epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). However, the emergence of resistance is inevitable, partly due to the gradual evolution of adaptive resistant cells during initial treatment. Here, we find that Osi treatment rapidly triggers adaptive resistance in tumor cells. Metabolomics analysis reveals a significant enhancement of oxidative phosphorylation (OXPHOS) in Osi adaptive-resistant cells. Mechanically, Osi treatment induces an elevation of NCOA4, a key protein of ferritinophagy, which maintains the synthesis of iron-sulfur cluster (ISC) proteins of electron transport chain and OXPHOS. Additionally, active ISC protein synthesis in adaptive-resistant cells significantly increases the sensitivity to copper ions. Combining Osi with elesclomol, a copper ion ionophore, significantly increases the efficacy of Osi, with no additional toxicity. Altogether, this study reveals the mechanisms of NCOA4-mediated ferritinophagy in Osi adaptive resistance and introduces a promising new therapy of combining copper ionophores to improve its initial efficacy.

Developing an Optimal Model for Water Distribution System Design

Future difficulties related to water utilization in sustainable cities will be influenced by factors such as urban development, climate change, and resource scarcity. Distribution accounts for 80–85% of the entire cost of a water supply system, making it a crucial part of all urban water systems. To increase system reliability, water distribution systems (WDS) are typically designed with the "worst scenario" or "robustness" in mind. Because deterministic assumptions are historically incorrect, a new design methodology that acknowledges uncertainty and provides greater flexibility is needed. To design WDS that are more adaptive, a Genetic Algorithm Flexibility Optimization (GAFO) model is created in Visual C++ and connected to EPANET. In contrast to classical GA optimization, GAFO uses a dynamic decision-making method to maximize a WDS's versatility at the lowest possible cost while taking into account a variety of potential future scenarios. The result is a WDS that may develop a staged implementation strategy that enables a gradual evolution of the WDS over time and follows various future trajectories (changing conditions). The convergence and flexibility of the GAFO model were determined to be good after it was tested on several fictitious scenarios. In comparison to traditional, non-flexible designs, cost reductions of 35% to 72% were achieved. DOI: https://doi.org/10.52783/pst.386

Transcriptional Control of Seed Life: New Insights into the Role of the NAC Family.

Transcription factors (TFs) regulate gene expression by binding to specific sequences on DNA through their DNA-binding domain (DBD), a universal process. This update conveys information about the diverse roles of TFs, focusing on the NACs (NAM-ATAF-CUC), in regulating target-gene expression and influencing various aspects of plant biology. NAC TFs appeared before the emergence of land plants. The NAC family constitutes a diverse group of plant-specific TFs found in mosses, conifers, monocots, and eudicots. This update discusses the evolutionary origins of plant NAC genes/proteins from green algae to their crucial roles in plant development and stress response across various plant species. From mosses and lycophytes to various angiosperms, the number of NAC proteins increases significantly, suggesting a gradual evolution from basal streptophytic green algae. NAC TFs play a critical role in enhancing abiotic stress tolerance, with their function conserved in angiosperms. Furthermore, the modular organization of NACs, their dimeric function, and their localization within cellular compartments contribute to their functional versatility and complexity. While most NAC TFs are nuclear-localized and active, a subset is found in other cellular compartments, indicating inactive forms until specific cues trigger their translocation to the nucleus. Additionally, it highlights their involvement in endoplasmic reticulum (ER) stress-induced programmed cell death (PCD) by activating the vacuolar processing enzyme (VPE) gene. Moreover, this update provides a comprehensive overview of the diverse roles of NAC TFs in plants, including their participation in ER stress responses, leaf senescence (LS), and growth and development. Notably, NACs exhibit correlations with various phytohormones (i.e., ABA, GAs, CK, IAA, JA, and SA), and several NAC genes are inducible by them, influencing a broad spectrum of biological processes. The study of the spatiotemporal expression patterns provides insights into when and where specific NAC genes are active, shedding light on their metabolic contributions. Likewise, this review emphasizes the significance of NAC TFs in transcriptional modules, seed reserve accumulation, and regulation of seed dormancy and germination. Overall, it effectively communicates the intricate and essential functions of NAC TFs in plant biology. Finally, from an evolutionary standpoint, a phylogenetic analysis suggests that it is highly probable that the WRKY family is evolutionarily older than the NAC family.

The evolution of femoral morphology in giant non-avian theropod dinosaurs.

Theropods are obligate bipedal dinosaurs that appeared 230 million years ago and are still extant as birds. Their history is characterized by extreme variations in body mass, with gigantism evolving convergently between many lineages. However, no quantification of hindlimb functional morphology has shown if these body mass increases led to similar specializations between distinct lineages. Here we studied femoral shape variation across 41 species of theropods (n= 68 specimens) using a high-density 3D geometric morphometric approach. We demonstrated that the heaviest theropods evolved wider epiphyses and a more distally located fourth trochanter, as previously demonstrated in early archosaurs, along with an upturned femoral head and a mediodistal crest that extended proximally along the shaft. Phylogenetically informed analyses highlighted that these traits evolved convergently within six major theropod lineages, regardless of their maximum body mass. Conversely, the most gracile femora were distinct from the rest of the dataset, which we interpret as a femoral specialization to "miniaturization" evolving close to Avialae (bird lineage). Our results support a gradual evolution of known "avian" features, such as the fusion between lesser and greater trochanters and a reduction of the epiphyses' offset, independently from body mass variations, which may relate to a more "avian" type of locomotion (more knee-than hip-driven). The distinction between body mass variations and a more "avian" locomotion is represented by a decoupling in the mediodistal crest morphology, whose biomechanical nature should be studied to better understand the importance of its functional role in gigantism, miniaturization and higher parasagittal abilities.

Study of the phase change processes of encapsulated phase change material for solar thermal energy storage in domestic hot water production

This study aims to examine the melting processes of encapsulated PCM in a cylindrical-shaped capsule, made of stainless steel. It has a diameter of 60 mm and a height of 20 mm. The chosen PCM is the paraffin RT35HC, which has a melting point around 35 ºC. Experiments are conducted in a water-filled thermal bath, placing the capsule vertically and heating the water using a thermostat. Temperature field analysis of the PCM is performed using thermocouples, and simultaneously, the inside of the encapsulated material is observed through a transparent wall. It has been proven that the sensors are capable of detecting the gradual evolution of the liquid phase of the PCM and its accumulation at the top of the capsule due to its lower density.

Onboard pre-combustion carbon capture with combined-cycle gas turbine power plant architectures for LNG-fuelled ship propulsion

This paper investigates the concept of pre-combustion carbon capture (Pre-CCS) with a combined cycle gas turbine (CCGT) propulsion system to achieve energy efficient carbon capture onboard a Liquid Natural Gas fuelled vessel. A basic CCGT model with energy efficiency of 51.6 % when using LNG as fuel was integrated with a Pre-CCS system composed of a steam methane reformer, water–gas shift reactors, pressure swing adsorption (SMR-PSA), and liquid CO2 storage. Various waste heat utilisation schemes integrated with the CCGT-reformer were modelled in Aspen HYSYS. The modelling of the waste heat recovery networks as energy streams integrating between various processes and unit of operations has facilitated a closed-loop simulation of various systems. It was concluded that a proper utilisation of the high-grade heat from the gas turbine (GT) exhaust and from the reformer is crucial to improve the overall energy efficiency and carbon capture rate, exemplified by a scheme where the heating needs for the SMR and the cooling needs from the water–gas-shift reactors are fully integrated. When optimised, the integrated system had an overall energy efficiency of 41.5 % and 43.2 % (i.e. an efficiency loss of 10.2–10.5 percentage points from the base CCGT system) accompanied with specific GHG emission reduction of 51.2 % and 52.3 % for operation of the GT at a turbine entry temperature of 1700 K and 1850 K, respectively. Intermediate levels of reforming, where the GT uses a mix of LNG and reformate gases, were also simulated, showing an almost linear evolution from the 100 % LNG feed to the GT to the 100 % reformate case. Such a strategy could be used for gradual evolution to meet the required CO2 reduction timeline. It was determined that the 100 % reformate case provides the highest CO2 capture rate. Estimates of other emissions from the GT assuming typical combustor residence times for the whole range of fuel blends were also carried out, showing that the overall greenhouse gas emission is dominated by CO2, given that the GT emits negligible N2O and unburnt methane. Some capital cost estimates were also made to determine the unit price of hydrogen fuel produced onboard, suggesting that the CAPEX was not prohibitive. These findings support the pre-combustion CCS − CCGT integrated system as a promising long-term decarbonisation and propulsion strategy to comply with emissions regulations, displaying good performance in terms of cost, energy consumption, and CO2 reduction. The scalability and adaptability of the proposed system for existing and new-built ships across the decarbonisation timeline is also discussed.

How Does the Structure of Rarefaction Regions Develop?

A rarefaction region (RR) occurs at the trailing edge of the fast solar wind stream. It comes from an area of small longitudinal extent on the solar surface and exhibits a fine and complex structure. In our study, we did a superposed epoch analysis of the proton and α parameters across the RR and observed their gradual evolution. We did not find any clear boundary between the fast and slow solar winds inside the RR because a majority of our observations show that most of the RR plasma corresponds to the fast solar wind; only the α–proton drift velocity decreases from the beginning of the RR. We investigate different ways of its reduction in interplanetary space and show that this feature is likely associated with the mirroring of the multicomponent solar wind. Nevertheless, considering the observed solar wind characteristics and taking into account the mutual relations between the proton and α parameters, we define the composition boundary where the α relative abundance and α–proton temperature ratio change abruptly from the values typical for the fast wind toward slow wind values. This boundary is the most probable candidate for the stream interface. Based on these findings, we speculate that the RR formation starts already near the Sun and formulate two possible scenarios.