Surface Of Domain Research Articles

Novel generation method of tooth surface points for variable transmission ratio gears

Variable transmission ratio gears have shown considerable potential as key components of variable speed transmission steering boxes that balance steering portability and sensitivity. The objective of this study is to develop a novel method for designing variable transmission ratio tooth surfaces to circumvent the shortcomings of the meshing theory method. The involute rack of the variable transmission ratio pinion-and-rack pair is considered as a set of countless and infinitely close transverse sections, each of which is referred to as a gear element. Assuming evenly distributed circles in the physical domain of the variable transmission ratio tooth surfaces of the pinion, the problem of generating a tooth surface point is transformed into solving the specific geometric feature intersection point of each circle and corresponding gear element during variable transmission ratio meshing. Thereafter, a mathematical model and algorithm are developed to generate tooth surface points in an approximately even pattern. The normal deviations of the gear-element–generated tooth surface points and the corresponding tooth surface points calculated using meshing theory show that the proposed design method has a sufficiently high accuracy. Finite element models are employed analyzing the contact pattern, contact stress, bending stress, and transmission ratio error. The results indicate that the layout of approximately even tooth surface points using the gear element method is beneficial for improving the fitting precision of tooth surfaces and reducing the contact stress and transmission ratio error. Further, the same derived law of the flank and fillet tooth surfaces is conducive to the continuity of the tooth surfaces, which contributes toward reducing the bending stress. Finally, a prototype is manufactured via CNC end milling. The major contributions lie in a robust and efficient modeling method for variable transmission ratio tooth surfaces, which combined forms a solid foundation for their application.

Detection and computation of conservative kernels of models consisting of freeform curves and surfaces, using inequality constraints

We present an algorithm to compute a tight-as-needed conservative approximation of the kernel domain of freeform curves in R2 and freeform surfaces in R3. Inequality constraints to detect the interior of the kernel domain are formulated as multivariates, and solved with a subdivision-based approach to find the domains in R2 or R3 that satisfy the inequalities and are in the kernel. The convex hull of the computed domains is also included in the kernel, and adopted as the approximated kernel domain. We can apply the presented algorithm to detect the kernel domain of not only C1 continuous closed regular curves and surfaces, but also the kernel domains of multiple piecewise C1 continuous regular freeform curves and surfaces. Further, the presented algorithm can be applied to find the gamma-kernel as well as the kernel domain of open curves and surfaces, under some assumptions. We demonstrate our experimental result using various freeform curves and surfaces, and compare it with the kernel computation algorithm presented in Elber et al. (2006).

The Effect of Additives on Water Vapor Condensation on Bituminous Surfaces

Abstract Water condensation and freezing on asphalt roads can lead to slippery conditions, which are responsible for many winter accidents and have caused an overreliance on mostly environmentally damaging and pavement degrading deicing chemicals and salt, which requires active maintenance. Bitumen is a mechanically and chemically complex material mainly consisting of various hydrocarbon-based chemicals groups. Additionally, bitumen makes up approximately 5 wt.% of the asphalt concrete mixture because of its binder role and coating function of the aggregates, can control the bulk mechanical properties and surface properties of the asphalt mixture. Condensation as the first step and later freezing phenomena are investigated in this study and from ambient humidity toward understanding the fundamentals of icing on bituminous surfaces. Condensation experimental results show selective wettability of chemically and mechanically district bitumen surface domains. The effect of different bitumen modifiers of polyethylene terephthalate, polyamide (PA 66), polyacrylonitrile, and Sasobit wax at 1 wt.% were studied on condensation freezing and bitumen water affinity.

Enhanced dielectric energy storage performance of A-site Ca2+-doped Na0.5Bi0.5TiO3–BaTiO3–BiFeO3 Pb-free ceramics

(1-x) (0.98Na0.5Bi0.5TiO3–0.01BaTiO3–0.01BiFeO3)–xCaTiO3 (NBB-xCT) ceramics were produced using traditional solid-state synthesis methods. The surface morphology, domain structure, and electrical properties of the ceramic samples were systematically studied. In addition, the temperature and frequency stabilities of the NBB-15CT sample at 200 kV/cm were tested. Generally, NBB-xCT ceramics exhibit a typical single perovskite phase structure. The results indicate that the NBB-15CT ceramics showed a high energy density of 3.14 J/cm3 at 250 kV/cm. The piezoresponse force microscopy (PFM) results showed that the addition of CT broke the macrodomains of the 0.98Na0.5Bi0.5TiO3-0.01BaTiO3-0.01BiFeO3 ceramic and helped to form nanodomains, leading to an improved energy storage performance. The above performance indicates that the specimens possess very good temperature-and frequency-dependent energy storage performances at 30–150 °C and 1–100 Hz. Moreover, the electric energy storage and release in the NBB-15CT ceramic indicated that the power density could reach 55.30 MV/cm3 at 180 kV/cm. Therefore, the NBB-15CT ceramic is a promising material for electrical capacitors.

The Concept of Sense in Gilles Deleuze'sLogic of Sense

What is the concept of sense developed by Deleuze in his 1969 Logic of Sense? This paper attempts to answer this question analysing the three dimensions of language that Deleuze isolates: the primary order of noises and intensities (depth); the secondary order of sense (surface); and the tertiary organisation of propositions (height). What renders language possible is that which separates sounds from bodies (the primary order) and organises them into propositions (the tertiary organisation), freeing them for the expressive function. Deleuze argues that it is the dimension of sense that brings about this genesis of language, and he analyses in detail the three syntheses (connection, conjunction and disjunction) that bring about the production of this surface of sense. Yet Deleuze also distinguishes between two types of non-sense: the nonsense of Lewis Carroll's portmanteau words, which remain ensconced in the dimension of sense, and the more profound nonsense of Antonin Artaud's psychotic scream-breaths (‘Ratara ratara ratara Atara tatara rana Otara otara katara’), which penetrate the almost unbearable world of the primary order of noise and intensities. In the end, the focus of Logic of Sense is less the surface domain of sense than the primary depth of corporeal intensities. What Deleuze calls a ‘minor’ use of language is nothing other than an intensive use of language that constitutes a principle of metamorphosis.

Influence of La and Si promoters on the anaerobic heterogeneous catalytic decomposition of ammonium dinitramide (ADN) via alumina supported iridium active sites

Structural origins of the promotional effects of the La or Si doping of alumina supported Ir catalysts in anaerobic ammonium dinitramide decomposition were investigated. Our findings reveal that Ir/Al2O3 and Ir/La-Al2O3 favorably lower the onset temperature of the ADN decomposition reaction, whereas Si doping boosts the pressure generation during the reaction. Formation of mostly metallic Ir nanoparticles for Ir/Al2O3 and Ir/La-Al2O3 enables the lowering of the activation energy of the reaction. On the other hand, enhancement due to Si promotion is associated to the generation of small oxidic Irnx+ clusters which are strongly interacting with the SiOx-AlOx surface domains of the support material. Fundamental structure-functionality relationships unraveled in the current work may allow design of novel catalytic systems for aerospace monopropellant propulsion systems with higher performance by simultaneous exploitation of Ir active sites with different electronic properties.

Morphology Design and Fabrication of Bio-Inspired Nano-MgO-Mg(OH)2 via Vapor Steaming to Enable Bulk CO2 Diffusion and Capture.

The absorption of CO2 on MgO is being studied in depth in order to enhance carbon engineering. Production of carbonate on MgO surfaces, such as MgCO3, for example, has been shown to hinder further carbon lattice transit and lower CO2 collecting efficiency. To avoid the carbonate blocking effect, we mimic the water harvesting nano-surface systems of desert beetles, which use alternate hydrophobic and hydrophilic surface domains to collect liquid water and convey condensed droplets down to their mouths, respectively. We made CO2-philic MgO and CO2-phobic Mg(OH)2 nanocomposites from electrospun nano-MgO by vapor steaming for 2–20 min at 100 °C. The crystal structure, morphology, and surface properties of the produced samples were instrumentally characterized using XRD, SEM, XPS, BET, and TGA. We observed that (1) fiber morphology shifted from hierarchical particle and sheet-like structures to flower-like structures, and (2) CO2 capture capacity shifted by around 25%. As a result, the carbonate production and breakdown processes may be managed and improved using vapor steaming technology. These findings point to a new CO2 absorption technique and technology that might pave the way for more CO2 capture, mineralization, and fuel synthesis options.

Controllable Tuning of the Uranium Photoreduction and Hydrogen Evolution Activity on Znln2s4 Surface Domain Heteroaromatic Junction Via Al/Cu Co-Doping

Controllable Tuning of the Uranium Photoreduction and Hydrogen Evolution Activity on Znln2s4 Surface Domain Heteroaromatic Junction Via Al/Cu Co-Doping

Controllable Tuning of Overall Water Splitting Activity on Znln2s4 Surface Domain Heteroaromatic Junction Via Al/Cu Co-Doping

Controllable Tuning of Overall Water Splitting Activity on Znln2s4 Surface Domain Heteroaromatic Junction Via Al/Cu Co-Doping

Extraction of Hidden Science from Nanoscale Images.

Scanning probe microscopies and spectroscopies enable investigation of surfaces and even buried interfaces down to the scale of chemical-bonding interactions, and this capability has been enhanced with the support of computational algorithms for data acquisition and image processing to explore physical, chemical, and biological phenomena. Here, we describe how scanning probe techniques have been enhanced by some of these recent algorithmic improvements. One improvement to the data acquisition algorithm is to advance beyond a simple rastering framework by using spirals at constant angular velocity then switching to constant linear velocity, which limits the piezo creep and hysteresis issues seen in traditional acquisition methods. One can also use image-processing techniques to model the distortions that appear from tip motion effects and to make corrections to these images. Another image-processing algorithm we discuss enables researchers to segment images by domains and subdomains, thereby highlighting reactive and interesting disordered sites at domain boundaries. Lastly, we discuss algorithms used to examine the dipole direction of individual molecules and surface domains, hydrogen bonding interactions, and molecular tilt. The computational algorithms used for scanning probe techniques are still improving rapidly and are incorporating machine learning at the next level of iteration. That said, the algorithms are not yet able to perform live adjustments during data recording that could enhance the microscopy and spectroscopic imaging methods significantly.

Surface domain potential difference-mediated efficient charge separation on a defective ZnIn2S4 microsphere photocatalyst

Low-efficiency charge separation in metal sulfides is a major obstacle to realizing high photocatalytic performance. Herein, we propose the concept of a similar surface domain potential difference between adjacent microdomains with and without surface S vacancies on ZnIn2S4 to mediate charge separation. Defective ZnIn2S4 microspheres (DZISNPs) are prepared through a solvothermal method combined with a low-temperature hydrogenation surface engineering strategy. The as-prepared DZISNPs with a narrowed bandgap of 2.38 eV possess a large specific surface area of 178.5 m2 g−1, a pore size of 6.89 nm, and a pore volume of 0.36 cm3 g−1, which further improves the visible light absorption. The resultant DZISNPs exhibit excellent visible light activity (2.15 mmol h−1 g−1), which is ∼two-fold higher than that of the original DZISNP. The experimental results and DFT calculations reveal that the enhanced property can be a result of the surface S vacancy-induced surface domain potential difference, promoting the spatial separation of electrons and holes. Furthermore, the long-term stability of the DZISNPs indicates that the formation of surface S vacancies can inhibit the photocorrosion of ZnIn2S4. This strategy provides new insights for fabricating highly efficient and stable sulfide photocatalysts.

Structure of Alloys for (Sm,Zr)(Co,Cu,Fe)z Permanent Magnets: III. Matrix and Phases of the High-Coercivity State.

Observations of the surface domain structure (Kerr-effect), optical metallography, scanning electron microscopy (SEM-SE), and electron microprobe analysis (EPMA-SEM), measurements of major and minor magnetic hysteretic loops were used to study pseudo-single-crystal samples of (Sm,Zr)(Co,Cu,Fe)z alloys subjected to heat treatments to the high-coercivity state, which are used in fabricating sintered permanent magnets. Correlations between the chemical composition, hysteretic properties, structural components, domain structure, and phase state were determined for the concentration ranges that ensure wide variations of 4f-/4d-/3d-element ratio in the studied samples. The phase state formed by collinear and coherent phase components determines the high coercive force and ultimate magnetic hysteresis loops of the pseudo-single crystals. It was found that the 1:5 phase with the hexagonal structure (P6/mmm) is the matrix of the alloys for (Sm,Zr)(Co,Cu,Fe)z permanent magnets; the matrix undergoes phase transformations in the course of all heat treatments for the high-coercivity state. The heterogeneity observed with optical magnifications, namely, the observation of main structural components A and B, is due to the alternation, within the common matrix, of regions with modulated quasi-spherical precipitates and regions with hexagonal bipyramids (cellular phase) although, traditionally, many investigators consider the cellular phase as the matrix. It is shown that the relationship of volume fractions of structural components A and B that account for more than 0.9 volume fraction of the total, which is due to the integral chemical composition of the alloys, determines the main hysteretic performances of the samples. The Zr-rich phases, such as 5:19, 2:7, and 6:23, and a structural component with the variable stoichiometry (Sm(Co,Cu,Fe)3.5–5) that is almost free of Zr and contains up to 33 at% Cu, were found only within structural component A in quantities sufficient for EPMA analysis.

Radioiodination of extravesicular surface constituents to study the biocorona, cell trafficking and storage stability of extracellular vesicles

BackgroundExtracellular vesicles (EVs) are produced by all cell types and serve as biological packets delivering a wide variety of molecules for cell-to-cell communication. However, the biology of the EV extravesicular surface domain that we have termed EV ‘biocorona’ remains underexplored. Upon cell secretion, EVs possess an innate biocorona containing membrane integral and peripheral constituents that is modified by acquired constituents post secretion. This distinguishes EVs from synthetic nanoparticulate biomaterials that are limited to an adsorption-based, acquired biocorona. MethodsThe EV biocorona molecular constituents were radiolabeled with 125I to study biocorona constituents and its surface dynamics. As example toolset applications, 125I-EVs were utilized to study EV cell trafficking and the stability of the EV biocorona during storage. ResultsThe biocorona of EVs consisted of proteins, lipids, DNA and RNA. The cellular uptake of 125I-EVs was temperature dependent and internalized 125I-EVs were rapidly recycled by cells. When 125I-EVs were stored in a purified state, they exhibited time and temperature dependent biocorona shedding and proteolytic degradation that was partially inhibited in the presence of serum. ConclusionThe EV biocorona is complex and dynamic. Radiolabeling of the EV biocorona enables a unique platform methodology to study the biocorona and will facilitate unlocking EV's full clinical translation potential. General significanceThe EV biocorona affects EV mediated biological processes in health and disease. Acquiring knowledge of the EV biocorona composition, dynamics, stability and structure not only informs the diagnostic and therapeutic translation of EVs but also aids in designing biomimetic nanomaterials for drug delivery.

(Invited) Ion Implantation and Polarity Control: Paths Toward a III-Nitride Superjunction

III-nitrides wide bandgap semiconductors currently offer a future alternative to maintain the growing demand for high power electronic devices. Current III-nitride device architectures already show promising results, offering higher breakdown voltages and reduced on resistances compared to traditional semiconductor alternatives. However, these devices are still limited by the classical Baliga figure of merit (BFOM) that consider the main properties of a power device, breakdown voltages and on- series resistance. In order to surpass the BFOM, novel device geometries have been introduced such as the superjunction (SJ). The concept of the SJ has been demonstrated in silicon, with devices such as CoolMOS and attempted in SiC. These have demonstrated capabilities which have surpassed the BFOM. Nevertheless, there are no demonstrations of III-nitride SJs in the literature based on one major limitation, the difficulty in obtaining selective area doping.In order to achieve III-nitride SJs, there are several research barriers to address concerning selective area doping. A SJ device basically requires alternating, lateral n- and p-type doping regions with zero net charge. Two approaches can be considered to address this challenge: ion implantation and polarity control. The first approach, ion implantation, is one of the basic tools for semiconductor device fabrication and as such any maturing semiconductor system should be capable of being processed in this form. Currently, III-nitrides dot not possess a robust ion implantation toolbox that allows for reliable implantation control and activation. Recent advances in ion implantation for the realization n-type AlN and p-type GaN will be discussed. For the case of n-type AlN, Si implantation was realized and with implementation of defect quasi Fermi level control, self-compensation via DX and vacancy complex formation was inhibited. Thus, the highest reported n-type conductivity in AlN was achieved. For the case of p-type GaN, we demonstrate the ability to successfully achieve p-type conductivity in GaN films via room temperature Mg implantation and a post-implantation annealing procedure at high pressure (1 GPa). The highest recorded p-type conductivity (~0.1 Ω-1·cm-1) was measured on the Mg implanted GaN and annealed at 1300 °C and 1 GPa.The second approach to realize the lateral doped regions is by polarity control. The inherent polar doping selectivity of GaN can be used to achieve the doping scheme for a lateral GaN p/n junction. Oxygen, which unintentionally incorporates into N-polar GaN at levels >1019 cm-3, acts as the n-type dopant, whereas Ga-polar GaN does not readily incorporate oxygen. Accordingly, lateral polarity junctions (LPJs) with alternating domains of O doped N-polar and Mg doped Ga-polar GaN have been fabricated to realize lateral p/n junctions. In addition to this lateral patterning, the proper doping profiles must be attained in the N- and Ga-polar domains for SJ operation. For drift regions, the n-type doping in the N-polar domain (and p-type doping in Ga-polar domain) must be reduced to ~1017 cm-3 for typical micron wide domains. By implementing the chemical potential control (CPC) framework, MOCVD process conditions were designed in order to decrease the oxygen concentration by increasing the growth supersaturation. This led to a reduction in oxygen from >1019 cm-3 to low 1017 cm-3.Due to the difficulty of making reliable Schottky rectifying contacts to the N-polar surface, the alternating Schottky/ohmic contacts on a typical superjunction are replaced with alternating p+/n- junction (N-polar) and p+/p-junctions (Ga-polar). In this direction, a N-polar p/n junction with rectifying behavior comparable to a Ga-polar p/n junction was achieved. Finally, the growth of a GaN LPJs must exhibit N-/Ga-polar domains with a smooth surface and equal growth rates. To achieve these requirements, we demonstrate a supersaturation modulated growth (SMG) where the V/III ratio, and thus supersaturation, was modulated between low and high values. A GaN LPJ with a smooth surface and equal domain heights, with the necessary doping profile is hence demonstrated.All these results show the pathway for realizing superjunction device structures in III-nitrides and the possibility of such device architecture.

A Modeling-Based Design to Engineering Protein Hydrogels with Random Copolymers.

Protein enzymes have shown great potential in numerous technological applications. However, the design of supporting materials is needed to preserve protein functionality outside their native environment. Direct enzyme-polymer self-assembly offers a promising alternative to immobilize proteins in an aqueous solution, achieving higher control of their stability and enzymatic activity in industrial applications. Herein, we propose a modeling-based design to engineering hydrogels of cytochrome P450 and of PETase with styrene/2-vinylpyridine (2VP) random copolymers. By tuning the copolymer fraction of polar groups and of charged groups via quaternization of 2VP for coassembly with cytochrome P450 and via sulfonation of styrene for coassembly with PETase, we provide quantitative guidelines to select either a protein-polymer hydrogel structure or a single-protein encapsulation. The results highlight that, regardless of the protein surface domains, the presence of polar interactions and hydration effects promote the formation of a more elongated enzyme-polymer complex, suggesting a membrane-like coassembly. On the other hand, the effectiveness of a single-protein encapsulation is reached by decreasing the fraction of polar groups and by increasing the charge fraction up to 15%. Our computational analysis demonstrates that the enzyme-polymer assemblies are first promoted by the hydrophobic interactions which lead the protein nonpolar residues to achieve the maximum coverage and to play the role of the most robust contact points. The mechanisms of coassembly are unveiled in the light of both protein and polymer physical-chemistry, providing bioconjugate phase diagrams for the optimal material design.

Controllable band offset in monolayer MoSe2 driven by surface termination and ferroelectric field of BiFeO3(0001) substrate

Integration of 2D van der Waals crystals into ferroelectric materials is a reliable way for the technological leap toward next-generation (opto)electronic applications. In present work, first-principles density functional theory calculations were performed to describe nonvolatile carrier modulation and ferroelectric field effect caused by interface coupling of MoSe2 monolayer with ferroelectric BiFeO3(0001) substrate. The Fermi level of MoSe2 monolayer on BiFeO3(0001) surface showed strong dependence on surface termination and polarization direction. Furthermore, polarization switching made MoSe2/BiFeO3(0001) heterointerface evolve into energetically metastable state and remarkable ferroelectric field effect on band offset in MoSe2 monolayer was observed due to distinct interface charge transfer. Therefore, the results of this work open up new prospects for surface chemistry and domain structure engineering of MoSe2 homojunctions for MoSe2/BiFeO3(0001)-based ferroelectric field effect devices.

Anisotropy of the Runaway Electron Generation Process in Strongly Inhomogeneous Electric Fields

An investigation of runaway electron (RE) kinetics under the influence of a strongly inhomogeneous electric field was carried out by means of 2-D analytical and 2-D numerical Monte–Carlo approaches. Several shapes of cathodes generating an inhomogeneous electric field were studied. Within the developed 2-D analytical model, blade-shaped and cone-shaped cathodes were considered. The voltage values which allow electrons to scatter at large angles close to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pi $ </tex-math></inline-formula> /2 near a blade-shaped cathode were determined. Also, it was shown that the RE scatter angles are larger for the blade (in comparison with the ones for the cone) due to the electric field defocusing effect. Within the framework of the numerical 2-D Monte–Carlo model, a cathode was assumed to have a parabolic shape. Inapplicability of the classical runaway criterion in strongly inhomogeneous electric fields was demonstrated. Also, it was shown that the cathode surface domain of electron emission and an initial direction of electron motion have a strong influence on their energy balance and, hence, on the probability for electrons to transit into the continuous accelerating regime. Energy losses of REs were estimated. A correlation between the full-width at half-maximum of the RE energy spectrum and an inelastic energy loss value was proposed.

Obligate movements of an active site–linked surface domain control RNA polymerase elongation and pausing via a Phe pocket anchor

The catalytic trigger loop (TL) in RNA polymerase (RNAP) alternates between unstructured and helical hairpin conformations to admit and then contact the NTP substrate during transcription. In many bacterial lineages, the TL is interrupted by insertions of two to five surface-exposed, sandwich-barrel hybrid motifs (SBHMs) of poorly understood function. The 188-amino acid, two-SBHM insertion in Escherichia coli RNAP, called SI3, occupies different locations in elongating, NTP-bound, and paused transcription complexes, but its dynamics during active transcription and pausing are undefined. Here, we report the design, optimization, and use of a Cys-triplet reporter to measure the positional bias of SI3 in different transcription complexes and to determine the effect of restricting SI3 movement on nucleotide addition and pausing. We describe the use of H2O2 as a superior oxidant for RNAP disulfide reporters. NTP binding biases SI3 toward the closed conformation, whereas transcriptional pausing biases SI3 toward a swiveled position that inhibits TL folding. We find that SI3 must change location in every round of nucleotide addition and that restricting its movements inhibits both transcript elongation and pausing. These dynamics are modulated by a crucial Phe pocket formed by the junction of the two SBHM domains. This SI3 Phe pocket captures a Phe residue in the RNAP jaw when the TL unfolds, explaining the similar phenotypes of alterations in the jaw and SI3. Our findings establish that SI3 functions by modulating TL folding to aid transcriptional regulation and to reset secondary channel trafficking in every round of nucleotide addition.

Stereoselective Growth of Small Molecule Patches on Nanoparticles.

Patchy nanoparticles featuring tunable surface domains with spatial and chemical specificity are of fundamental interest, especially for creating three-dimensional (3D) colloidal structures. Guided assembly and regioselective conjugation of polymers have been widely used to manipulate such topography on nanoparticles; however, the processes require presynthesized specialized polymer chains and elaborate assembly conditions. Here, we show how small molecules can form 3D patches in aqueous environments in a single step. The patch features (e.g., size, number, conformation, and stereoselectivity) are modulated by a self-polymerizable aromatic dithiol and comixed ligands, which indicates an autonomous assembly mechanism involving covalent polymerization and supramolecular assembly. Moreover, this method is independent of the underlying nanoparticle material and dimension, offering a streamlined and powerful toolset to design heterogeneous patches on the nanoscale.

LNG supplies' security with autonomous maritime systems at terminals' areas

The transportation of liquefied natural gas by sea has a strategic function for ensuring the energy security of Poland and, in a broader perspective, also of the countries in the Central and Eastern Europe region (primarily the Visegrad Group - V4 and others). The article points out the importance of Polish LNG/FSRU terminals in diversification and building the region's energy independence. It analyzes the security environment of the Baltic coastal waters, which is the arena for the activity of many countries with different multidimensional interests. A package of threats to maritime critical infrastructure facilities (LNG/FSRU terminals) and cryogenic tankers in the air, surface, and underwater domains is identified, noting the dynamic nature of many of them. The author analyzes the capabilities (strengths and weaknesses) of autonomous maritime systems (USV, UUV-ROV, UAV) in terms of their use to increase the effectiveness of LNG/FSRU terminal security systems. Possibilities of cooperation and achieving a synergy effect within the combined architecture of USV/UUV-ROV/UAV platforms are also indicated. The article presents a package of missions that autonomous systems can perform to increase the safety of operators and reduce the response time to threats, thus increasing the level of protection. The article presents a vision of a modular USV base platform model as a base element for an autonomous system dedicated to protecting LNG terminal/FSRU infrastructure and cryogenic tankers.