Large Dimensions Research Articles

Optimization of the Second Target Station cold source moderators using an automated workflow

The Second Target Station (STS) at the US Department of Energy’s Oak Ridge National Laboratory is designed to become the world’s highest peak-brightness spallation source of cold neutrons. Successful completion of the STS, which is currently in the preliminary design phase, will provide transformative new capabilities to examine novel materials for future technologies. At STS, neutrons will be generated by spallation reactions in a solid tungsten target. They will be moderated and thermalized in two cold (20 K) para-hydrogen moderators. Careful optimization of these moderators is essential to the project’s success. To find optimal moderator designs, an advanced optimization workflow integrates high-fidelity neutronics calculations using the Monte Carlo N-Particle (MCNP) transport code MCNP6.2 with state-of-the-art optimization algorithms in the Dakota optimization toolkit. For each design iteration, a parametrized solid CAD geometry is generated in Creo and automatically converted into an unstructured mesh geometry by Attila 4MC for the neutronics calculation with MCNP. Iterations repeat until optimal designs are found. This paper presents the results of a sensitivity and optimization study for the cylindrical and tube moderators. Both moderators can be optimized for maximum peak brightness, maximum time-integrated brightness, or any combination between these extremes. Maximum peak brightness is achieved by using smaller optimal dimensions of the moderators, whereas maximum time-integrated brightness is achieved by using larger dimensions. A Pareto front details the designs that optimally balance both brightness metrics. The Pareto front can be found in only 40–110 iterations with 4–5 design parameters when using the efficient global and Pareto-set optimization algorithms in Dakota. Additionally, important engineering constraints can be taken into account, such as the coupling between the cylindrical moderator radius and aluminum vessel wall thicknesses required to ensure structural integrity of the vessels. This interaction has a significant impact on the resulting optimal designs. Our new, highly efficient, fully automated optimization workflow will be used to optimize additional STS components in the future and can be adopted for design and optimization studies at other experimental neutron and accelerator facilities.

Growth and Temperature Properties of the Phase-Matching Angle of 23% Deuterated ADP Crystal.

Theoretical analysis indicated that partially deuterated ammonium dihydrogen phosphate (DADP) crystal with a deuterium content of 23% could realize spectral noncritical phase-matching (S-NCPM) for type-I frequency doubling of an Nd:glass laser. To explore the temperature dependence of the phase matching (PM) angle of the second harmonic generation (SHG) process and the output SHG bandwidth of DADP crystal at 1.053 μm, we used the point-seed rapid-growth method to grow targeted DADP crystal with 23% deuterium content. Experimental results indicated that the grown DADP crystal had high quality and large dimensions (7 × 6 × 6 cm3). Using a femtosecond OPO laser as a tunable light source, the temperature dependence of the PM angle of the SHG process in DADP crystal at 1.053 μm was investigated. The PM angle changed linearly with temperature, as predicted by the theoretical calculation. In addition, under the condition of higher temperature, broad bandwidths of the second harmonic of DADP crystal were still observed. These results provide excellent guidance and reference value for the application of wavelength insensitive phase-matched second harmonic generation in partially deuterated DADP.

Generalized bent functions with large dimension

By a fundamental result by Mesnager et al. in 2018, a generalized bent function (originally defined as a class of functions from an $ n $-dimensional vector space $ \mathbb{V}_n^{(p)} $ into a cyclic group), is a bent function $ g: \mathbb{V}_n^{(p)}\rightarrow \mathbb{F}_p $ with a partition $ \mathcal{P} $ of $ \mathbb{V}_n^{(p)} $, such that for every function $ C $ which is constant on the sets of $ \mathcal{P} $, the function $ g + C $ is bent. The set of these bent functions forms then an affine space of dimension $ |\mathcal{P}| \le p^{n/2} $. This characterization of generalized bent functions is much more comprehensive than any earlier description.In this article, we analyse some classes of bent functions under this perspective. As shown earlier, Maiorana-McFarland bent functions permit the largest possible partitions, giving rise to $ p^{n/2} $-dimensional affine bent function spaces. The reason behind is their characterization as the bent functions, which are affine restricted to the $ n/2 $-dimensional affine subspaces of a trivial cover of $ \mathbb{V}_n^{(p)} $. We will show that maximal possible partitions can also be obtained for other classes of (regular) bent functions. Most notably, these classes are described as bent functions which are affine restricted to non-trivial covers of $ \mathbb{V}_n^{(p)} $. We investigate (largest) partitions for other types of bent functions, including weakly regular and non-weakly respectively non-dual bent functions. We round off the article giving partitions for bent functions obtained from bent partitions, which includes the partial spread class, and partitions for Carlet's class $ \mathcal{C} $ and $ \mathcal{D} $.

Effect of Non-Uniform Concentration Field on TiN Growth in Two-Phase Region with Electropulsing

Ti microalloyed steel has the advantages of high toughness and high strength, but it is easy to form TiN particles with large dimensions at high temperatures, which is harmful to the metal and seriously affects the quality of cast billets. In this paper, by analyzing the kinetic characteristics of Ti element diffusion in the two-phase region with electropulsing, the influence mechanism of pulsed current on the growth of TiN particles in the two-phase region is investigated. The results show that the pulsed current improves the flow rate of Ti and N elements in the molten steel, reduces the concentration of Ti in the liquidoid along the solid-liquid interface, and the more the current intensity, the more obvious the impact; in addition, with the increase of the flow rate, the diffusion flux of Ti elements is also gradually improved. Therefore, the pulsed current promotes the diffusion of Ti elements by improving the concentration field of Ti and other solute elements in the two-phase region, thus inhibiting the growth of TiN.

TO THE ISSUE OF EQUIPPING A CATEGORY O2 TRAILER TRAIN

Summary. In recent years, enterprises and private manufacturers of Ukraine have mastered the production of a wide range of trailers. Today, trailer manufacturers offer a wide range of various designs, including those with large dimensions and strong sides. Thanks to this, the devices can transport not only bulky goods, but also those that are not recommended for transportation in the car cabin. The trailer, in particular a multifunctional one, will become indispensable for the transportation of construction materials, the removal of garbage and other waste after repairs, the transportation of heavy equipment, office and household furniture, etc. In the production of multi-functional trailers of the PVBF type, the main component products (running and braking systems, coupling devices, parking risers, winches, element base for fixing sides and doors, etc.) manufactured by the companies "Knott", "AI-Ko Kober", " Reynolds transport systems (Europe)", "Aluvan", etc., which meet modern certification requirements. For these trailers, the general characteristics of the mass and dimensional parameters of the five main groups of the standard size series, which differ in gross weight (1500, 2000,……3500 kg) and trailer base (2500...5000 mm), are defined. Taking into account that the weight of the trailer should not exceed the weight of the towing vehicle, you can choose your own towing vehicle for each group of the size series. When choosing a traction vehicle, you should proceed from the condition of ensuring the movement of the road train at maximum speed. Under this condition, the maximum engine power of the traction vehicle for a road train with a trailer weight of 1,500 to 3,500 kg is determined. The obtained power of the motor train engine for the entire standard-sized series of trailers is significantly less than the real power of the traction vehicle engine. Therefore, the traction vehicle must be selected based on mass indicators from the vehicles that are operated in Ukraine. Keywords: car, multi-functional trailer, road train, standard size range, mass, speed, power

Self-similar ring element array develop for Fano response as mid-infrared: Liver cancer study

the mid-infrared metasurfaces play an important in optical applications including sensing and having Fano response is a benefit in this field for many goals including biosensing. So, these points are considered in this study and self-similar Plasmonic metasurface is suggested for sensing application. The suggested structure has a symmetrical formation but non-similar elements are considered to raise the Fano response. The structure contains five rings while the central one has a larger dimension than the four elements surrounding the central ring as an array of rings. The interaction of bright modes for both elements of the central ring and the array elements makes the Fano response at 1850 and 1910 nm while the single central ring has resonance at 1910 nm and the array rings have resonance at 1850 nm. The interaction of the element enhances the Q-factor of both resonances. The Full-wave method finite integrated technique (FIT) is used for modeling as a time domain method and the couple mother theory (CMT) is used for the analytical model. This metasurface is implemented as a sensor for detecting material under test and the sensitivity of the sensor is obtained 282 nm/RIU (Refractive Index Unit). Finally, the tissue of the liver as healthy and cancer cells are considered for examining the quality of the sensor.

СТРУКТУРНИЙ СТАН КОМПОЗИТІВ, СПЕЧЕНИХ ІЗ ПОРОШКІВ сBN З ПОКРИТТЯМ ЗІ СПОЛУК Ті

The paper presents the results of experimental studies of the structural state of composites obtained at high temperatures and pressures from cBN powders with coatings deposited by CVD from Ti compounds using a gas transport reaction. The features and quantitative parameters of the structure of the composites depending on the presence of Ti in the coating were determined. It has been experimentally established that the matrices of the obtained composites are formed by submicron grains of TiN and TiB2, the quantitative differences of which correspond to the concentration of Ti in the coating - from 3 to 8 %. The structure of the obtained composites is characterized by a uniform distribution of the ceramic matrix between the cBN grains, which is achieved due to the high-quality encapsulation of individual grains of the superhard phase in the coating. The ceramic layers have the largest dimensions (up to 10-12 μm) in the area of triple joints, the width of the zone between two adjacent cBN particles is < 1 μm. When moving from a coated powder to a composite, the shape of the diffraction peaks changes, which is associated with the stresses of the first and/or second kind inherent in the studied samples. Sintering of the powder leads to a decrease in the size of the blocks from 56 nm to 27 nm, an increase in the lattice strain from 0.11 to 0.24 %, in TiN - to an increase in the lattice parameter in the composite by 10% (from 0.4244 nm to 0.4253 nm), a decrease in the size of crystallites within individual grains from 100 nm to 20 nm, and an increase in the lattice strain by 0.47 %. At the same time, TiN nitride is supersaturated with nitrogen, which is a significant increase in its lattice parameter, and the coating formed in this case is exclusively oriented in the (022) direction.

Influence of oxygen content on selective laser melting leading to the formation of spheroidization in additive manufacturing technology.

Selective laser melting (SLM) additive manufacturing technology with different oxygen contents leads to the appearance of spherical solids of different sizes on the surface of the part, which affects the mechanical properties of the part, surface roughness, etc. In this study, the SLM molding technique was applied using three different 316L metal powders with different oxygen contents. The spheroidization properties and morphology of the samples were observed using a Quanta 200 environmental scanning electron microscope (ESEM), and the samples were observed microscopically and subjected to EDX spectroscopy using metallographic microscopy, and the mechanical properties were investigated. The results of the study showed that when using gas atomized powders, no spheroidization occurred when the oxygen content of the powders was 5.44 ± 0.01% in all cases, whereas using water atomized powders produced spherical structures with larger dimensions. This observation was closely related to the shape and particle size of the powder. When 316L metal powder with an oxygen content of 4.52 ± 0.01% was used for molding, small spherical structures appeared on the surface of the samples. When metal powder with an oxygen content of 5.44 ± 0.01% was used for the molding, larger spherical structures appeared on the surface of the samples. When the powder with an oxygen content of 5.90 ± 0.01% was used for the molding, more small spherical structures and some large spherical structures appeared on the surface of the samples. This suggests that higher oxygen levels may inhibit the occurrence of spheroidization. EDX spectroscopic analysis revealed that the white matter on the surface of the samples without spheroidization was mainly composed of Fe and Cr, whereas the white matter on the surface of the large-sized spherical structures was mainly composed of Si and Mn, which may be related to the oxygenophilicity of the various substances.

Design and experimental research of UHV flanges for the Hefei Advanced Light Facility

The Hefei Advanced Light Facility (HALF) is a diffrac-tion-limited storage ring (DLSR) light source based on the compact multi-bend achromat (MBA) lattice. There-fore, the gaps between those focusing magnets are small. The commonly used ConFlat® flange, with a large axis dimension, is not suitable for the compact lattice in HALF. In this work, a stainless steel tapered flange fas-tened by a chain clamp has been designed for its smaller axis dimension. Two types of sealing structures are used, which are knife-edge and spring-energized metal C-ring structures, respectively. The copper gaskets with and without silver coating are used for knife-edge flange, respectively. Besides, the spring-energized metal C-ring is manufactured by SUS 304 with a tin layer of 50 μm. These flanges and chain clamps were made of SUS 304, and their vacuum properties were tested. The results indi-cate that these UHV flanges can meet the demands for the vacuum system of HALF.

Vapor-phase methods for synthesizing metal-organic framework thin films

<p>Due to their unique structures and exceptional physical and chemical properties, metal-organic framework (MOF) materials have garnered extensive attention in various fields, including catalysis, separations, sensing, and optics. Compared with powders or bulk MOF materials, MOF thin films exhibit large vertical and horizontal dimensions, higher specific surface areas, and abundant active sites and undergo facile combination with other functional centers for adsorption/separation, catalysis, and photoelectronic device applications. Among the methods used in preparing MOF thin films, the vapor phase approach enables more effective growth of MOF films with controllable thicknesses, uniformity, and compatibility; thus, it has attracted significant interest. This extensive review presents four vapor-phase approaches for preparing MOF thin films: the steam-assisted conversion method, vapor-phase transformations of metal oxide templates, vapor-phase linker exchange, and the atomic layer deposition/molecular layer deposition method. We summarize the advantages and disadvantages of these different vapor-phase-based methods for thin-film preparation, aiming to promote their use in precise and controllable surface syntheses.</p>

Research on the Load Characteristics of Squeezed Film Gas Bearings

In this paper, a gas microbody is proposed to address the issues related to the limited load‐carrying capacity of squeezed film gas bearings, complex mechanical structures, large overall dimensions, high manufacturing costs, and complicated installation. Initially, the gas continuity equation of squeezed film was established for modal analysis, without regard to the gas inertial force and the gas volume force which are all far less than the gas viscous force. Then the load‐carrying characteristics of squeezed film gas bearing were studied and analyzed with the fluid‐structure coupling method. The load‐carrying capacity of the squeezed film gas bearing is determined by factors such as bearing amplitude, rotor‐axial clearance, and rotor‐axial tile contact area. In conclusion, the load‐carrying capacity can be enhanced by increasing the amplitude value, reducing the clearance, and increasing the contact area. Among them, when adjusting the amplitude and clearance to improve the bearing’s load‐carrying capacity, the stability of bearing operation should be considered. When the clearance is too small, the pressure distribution of the air film will be uneven, and when the contact area is too large, the development of the air film in all directions will be asymmetrical.

Multiband Convolutional Riemannian Network with Band-wise Riemannian Triplet Loss for Motor Imagery Classification.

This paper presents a novel motor imagery classification algorithm that uses an overlapping multiscale multiband convolutional Riemannian network with band-wise Riemannian triplet loss to improve classification performance. Despite the superior performance of the Riemannian approach over the common spatial pattern filter approach, deep learning methods that generalize the Riemannian approach have received less attention. The proposed algorithm develops a state-of-the-art multiband Riemannian network that reduces the potential overfitting problem of Riemannian networks, a drawback of Riemannian networks due to their inherent large feature dimension from covariance matrix, by using fewer subbands with discriminative frequency diversity, by inserting convolutional layers before computing the subband covariance matrix, and by regularizing subband networks with Riemannian triplet loss. The proposed method is evaluated using the publicly available datasets, the BCI Competition IV dataset 2a and the OpenBMI dataset. The experimental results confirm that the proposed method improves performance, in particular achieving state-of-the-art classification accuracy among the currently studied Riemannian networks.

Vplyv tvaru telesa na deformáciu čelného ozubenia

The article is devoted to the analysis of the influence of the basic parameters of the body of the spur gear on the deformation of the teeth in meshing. The problem is solved for spur gears of large dimensions, the semi finished product of which can be a weldment, casting or forging. Gear deformations are determined by the finite element method. Examples of simulation and subsequent processing of the results demonstrate the extent of the influence of individual parameters of the gear body on the deformation of the gearing. At the same time, the results point to suitable designs of shape and dimensions to achieve the desired deformation of the teeth but with the smallest possible weight of the gears.

Enhancing sustainability in the production of cruise-ship modules through quality monitoring

Constructing cruise-ship hull is long, complex and requires relatively precise metal carpentry, welding and assembly operations. Timely detection and correction of anomalies is vital to the sustainability of the process, in terms of reducing production time and costs. This paper presents a novel statistical quality control (SQC) methodology for monitoring the workshop for the production of so-called “modules” within shipyards, i.e., roughly parallelepiped sub-assemblies of large dimensions (on the order of several tens of meters on each side), obtained through manual carpentry and welding operations. The proposed methodology adopts a standardized p control chart with samples of variable size, incorporating two elements: (i) it accounts for the high level of customization of modules, and (ii) it takes into consideration the measurement uncertainty associated with the large-volume metrology instrument employed for conformity verification (such as a state-of-the-art Leica RTC360 laser scanner), following the ISO 14253-1:2017 standard. A real-world case study at an Italian Fincantieri S.p.A. shipyard demonstrates its practical application.

Collective Protective Equipment Using Netting Materials in Construction of Industrial Buildings

The article presents conditions for ensuring the safe performance of construction and installation works during construction/reconstruction of industrial buildings and facilities of various purposes, based on the use of fall arrest nets, which are collective protective equipment for preventing work-related injuries in case of a person’s or an object’s potential fall from height. The article specifies the basic elements of these devices where synthetic netting materials are suggested as the most pacing factor of the required protection degree. Consideration is given to governing parameters of fall arrest safety nets that make it possible to ensure the safety of works at heights. This produced net deflection values that are acceptable for conditions under which construction is carried out, with required contour-rope tension values. The value of the maximum negative acceleration that acts on a body falling from height to the net was assessed. Herewith, the performed calculations showed, based on relatively large dimensions of the fall arrest device’s net fabric, that overloads that occur when catching fallen objects are insignificant and do not require that additional equipment be used to reduce dynamic loads.

Surgical and Prosthetic Management of a Juvenile Ossifying Fibroma In a 5-Year-Old Child: A Clinical Report

Juvenile ossifying fibroma (JOF) is a rare and benign fibro-osseous lesion of the craniofacial skeleton commonly seen in children under 15 years of age. Despite being classified as benign, JOF lesions are aggressive in nature and reach large dimensions in a short period of time. Thus, their resections may cause large orofacial defects which have serious detrimental effects on the functional and nutritional requirements of pediatric patients being in the pe-riod of growth. Therefore, its early diagnosis and proper surgical and prost-hetic management are of vital importance for the survival of patients. However, no detailed reports in the literature describe the prosthetic mana-gement of large intraoral defects in pediatric patients under 10 years old.

Characterizations of the minimum weights of LCD codes of large dimensions

Characterizations of the minimum weights of LCD codes of large dimensions

Characterization of the Infinite State Representation of the Fractional Order Chaotic Lü System

In this paper, the Infinite State Representation is applied to the fractional Lü chaotic system. Thanks to a finite dimension approximation, the original fractional order system is converted into a large dimension set of integer-order nonlinear equations whose initial conditions allow to test the butterfly effect of the equivalent chaotic system. This sensitivity to initial conditions is quantified thanks to Lyapunov exponents computed with an experimental technique. Then, the largest Lyapunov exponent is used as a fractional index to characterize the Infinite State Representation.

Dimensiones tomográficas para la instalación de miniimplantes de expansión rápida maxilar en diferentes grupos de edad

Objective: The purpose of the research was to com-pare the dimensions of the upper jaw between different age groups for the installation of mini-implants for rapid maxillary expansion. Materials and Methods: The study was descriptive, retroprospective and observational. Cone beam computed tomography was used for the evaluation of 30 patients between 7 and 56 years of age, divided into three groups, ten up to 14 years, ten from 15 to 30 years, and ten from 31 years and older. The premolar and molar regions were selected for the measurement of the maxilla in the coronal plane, both bone and soft tissue. To compare the measurements, the Kruskal Wallis and Mann-Whitney U tests were used. Results: No statistically significant differences were found between the groups. The thicknesses of the bone tissue decreased from the first premolar to the second molar from 9.48 +/-3.71 mm to 5.40 +/-2.80 mm respectively, while the soft tissue thicknesses were more homogeneous with measurements of 0.56 +/-0.74 mm to 2.76 +/- 2.42 mm. Conclusions: The dimensions of the bone and soft tis-sue of the upper jaw, evaluated vertically for the installa-tion of mini-implants, were similar in all the age groups studied, with larger dimensions in men than in women at the premolar level. The dimensions of the maxilla for the palatal miniimplants were close to 9 mm in bone tissue and 3 mm of soft tissue at the level of premolars and 5 mm in hard tissue with 1 mm of soft tissue at the level of molars. Keywords: Palatal expansion technique; Dental im-plants; Mini implants; Maxilla; Cone-beam computed to-mography; Age groups

Rancang Bangun Alat Sortir Jeruk Medan Berdasarkan Luas Lingkar Berbasis Mikrokontroler ATMega2560

The increasing demand in the agricultural sector demands efficient fruit sorting solutions. This study considered the design and implementation of a orange fruit sorter combining ultrasonic sensor technology, servo motor, and infrared proximity. This tool aims to measure small to large dimensions of orange fruits. The use of infrared proximity aims to counter the fruit in each path where the orange runs to its container, and then the calculated information is displayed on the LCD screen to provide clear information for farmers. The main advantage of this tool is its ability to automatically classify orange fruits by size and amount. The integration of ultrasonic sensors and infrared proximity provides accuracy in distance measurement and fruit counting. This tool innovation provides unprecedented solutions and potential in orange fruit sorting, and can increase productivity in the agricultural industry. This research uses a technology design and implementation approach by integrating ultrasonic sensors, servo motors, IR proximity, on microcontrollers. The designed tool is able to classify orange fruits automatically by size and number. The design of this orange sorter promises to increase efficiency in the agricultural industry. The implementation of sensor technology and automation systems has the potential to provide the right solution for fruit sorting needs.