External Shape Research Articles

The Dynamic Stability and Performance Implications of Piston-to-Turboprop Engine Modernization of a Light Aircraft for General Aviation

ABSTRACT This paper explores the influence of engine modernization on the dynamic stability and performance of a general aviation aircraft. Utilizing an integral mathematical model, the study conducts a comparative analysis of the I-23 Manager piston-engine aircraft and its modified I-31T turboprop version, examining changes in aircraft dynamics depending on the power plant type. The modernization necessitated a redesign of the nose section of the fuselage, resulting in alterations to the external shape and flight properties of the aircraft. The research evaluates various dynamic stability parameters, including phugoid, short period, Dutch roll, roll, and spiral modes, under different flight conditions. Results indicate minimal changes in aerodynamic characteristics due to the engine type, yet significant improvements are observed in efficiency, noise reduction, and operational costs. The impact of the propulsion unit on the dynamic stability of the light aircraft was assessed as insignificant, suggesting that the strategy of modernizing an existing piston-driven aircraft by switching to a turboprop drive is indeed promising. With appropriate initial design assumptions, a modern turbine aircraft with strong flight qualities can be efficiently modernized in this way, without compromising the good flying properties of the existing plane. The outcomes are validated against flight tests, reinforcing the viability of integrating more sustainable and efficient propulsion systems into light aircraft. This study may therefore inform future design and regulatory decisions, providing a perspective on the implications of engine upgrades in the general aviation sector.

Analysis of Library Building Design from the Concept of Green Building

Library is a symbol of urbanization in the present era. The external shape of the library is more elegant and solemn, and the interior also pays more attention to the convenience and comfort. In the design, we need to pay attention to the enjoyment of architectural art beauty, and at the same time, we need to make the layout of the library more scientific and applicable, and meet the needs of the public reading. As a public building with huge flow of people, the library needs to consume a lot of energy when it is open, which is not in line with the characteristics of green building advocated at present. Therefore, in order to implement the concept of environmental protection, it is necessary to integrate the design of library building with the concept of green building. At the same time, the library is also a cultural building, and it needs to reflect the scientific concept of humanistic care and people- oriented. Therefore, this paper mainly analyzes and discusses the library design under the concept of green building.

Navigating Cybersecurity: Environment’s Impact on Standards Adoption and Board Involvement

ABSTRACT This study investigates cybersecurity governance dynamics within organizations, investigating the influence of supply chains, environmental factors, and stakeholder engagement. Utilizing the UK’s Cyber Security Longitudinal Survey and employing artificial neural networks and k-means cluster analysis, we explore how organizational practices and external pressures shape cybersecurity strategies. Our findings show the managerial and political dimensions of improving organizational cybersecurity, highlighting the critical role of environmental influences alongside incident perception and self-efficacy. The research shows the necessity for organizations to remain receptive to external influences and identifies supply chains as critical factor in shaping cybersecurity practices, advocating for comprehensive security protocols. We demonstrate that guidance from governing bodies is essential for aligning with industry standards. The findings suggest a range of strategies, from implementing standards to encouraging board-level integration of cybersecurity, facilitated by a combination of coercive, normative, and mimetic pressures exerted by various agents, including governments, stakeholders, and the supply chain.

The Influence of Corporate Branding on Students' University Choice in Kenya

This article presents an exploratory study investigating the influence of corporate branding on the university choice of postgraduate students in selected universities in Kenya. The purpose of the research was to understand how internal, external, and service mix branding strategies shape students' perceptions and decisions. This study was significant as it sought to offer insights into the critical role of branding in the competitive higher education sector in Kenya. The study analyzed various branding strategies employed by universities, focusing on their effectiveness in shaping students’ perceptions of academic excellence, reputation, facilities, and overall value proposition. Data was collected through surveys with postgraduate students, providing a comprehensive view of the branding landscape. The findings highlighted that effective corporate branding significantly enhances the perceived academic strengths and unique programs of universities. The correlation between strong branding and perceptions of prestige was largely positive, as it required careful management to ensure that the emphasis on branding complements and enhances the actual quality and inclusiveness of the education provided. The promotion of state-of-the-art facilities and comprehensive branding that communicated the overall value and benefits of attending the university, including career prospects and alumni success, positively impacted students' choices. The study concluded that corporate branding substantially influences students' university choices in Kenya. It recommends that universities invest in robust and consistent branding strategies that clearly communicate their strengths and unique offerings. The study recommends that universities use both traditional and digital media to enhance their brand presence and engage with prospective students. It suggests that universities continuously assess and adapt their branding strategies to stay competitive in the dynamic educational environment in Kenya.

A new species of bristletail of the genus <i>allopsontus</i> silv. (microcoryphia, machilidae) from western crimea

A new species of bristletail, Allopsontus tauricus sp. n., is described from western Crimea. In the external shape of the eyes, the structure of the mandibles, legs, abdominal sternites, ovipositor and male parameres, it seems to be especially similar to A. europeus (Kaplin 1983) from southern Crimea. Their main differences are the relative length of the cerci, the colour of the eyes and the shape of the paired ocelli. The structure of the distal part of the antennal flagellum, the chaetotaxy of the maxillary and lower labial palps in the male also differ significantly, as well as the ratio of the length of the styli to the length of the coxites of abdominal segments VIII and IX in both sexes.

Numerical study on the evaporation rate of an electronic cigarette atomizer

This work establishes an evaporation model for the electronic cigarette atomizer based on convective mass transfer theory, which is implemented through Fluent user-defined functions (UDFS). By adding the convection–diffusion equation and considering the energy loss caused by evaporation and the temperature variation over the atomizer body, the evaporation rate of the e-liquid from the atomizer is more accurately calculated, compared to the previous evaporation model based on the assumption of constant temperature over the atomizer body. The effects of external airflow velocity, atomizer porosity, heating power, atomizer shape, heating method, and groove width on the average surface temperature and evaporation rate of the atomizer are examined. The results show that compared with other factors, the external air flow velocity has relatively insignificant influence on the evaporation rate of the atomizer. Within a certain range, as the porosity of the atomizer decreases or the heating power increases, the evaporation rate of the atomizer increases. The cylindrical atomizer has better evaporation performance than the cuboid and grooved atomizer, if all atomizer surfaces are heated, however, when the heating area of the grooved atomizer is optimized, i.e., only the surfaces with large evaporation rates are heated, the evaporation rate of a grooved atomizer can be higher than that of a cylindrical atomizer. The evaporation rate increases with increasing groove width, in the parameter range studied.

A design method for continuous fiber-reinforced composite patches

The urgent need for lightweight and high-strength patches in the field of aircraft structural repair has propelled continuous fiber-reinforced thermoset composites into a research hotspot. However, constrained by manufacturing processes, the designs of composite repair structures primarily focus on external shape and ply layup. These approaches presently lack design methods for the internal fiber adaptability of patches driven by in-service loads. In this paper, we proposed a method for fiber distribution and orientation design based on maximum normal stress. The composite simulation model was established based on fracture toughness. The influence of tensile-shear coupling effects on the mechanical response of composites and the fiber orientation design were examined in the study. The orientation-density coupling effects on the enhancement of patch strength were also analyzed. Furthermore, additive manufacturing technology was employed to fabricate thermoset composite patches. The results show that the composite patches designed in this paper exhibit a 10.50 % improvement in strength compared to traditional unidirectional patches.

Exploring the link between blood pressure variability and atrial fibrillation: current insights and future directions.

Atrial fibrillation (AF) is the most common heart rhythm disorder, especially in people over the age of 50, which affects more than 40 million people worldwide. Many studies have highlighted the association between hypertension with the development of AF. Blood pressure variability (BPV) is a dynamic size obtained by recording blood pressure oscillations using specific readings and at specific time intervals. A multitude of internal and external factors shape BPV while at the same time constituting a common pathogenetic pathway with the development of AF. Until recently, BPV has been applied exclusively in preclinical and clinical studies, without significant implications in clinical practice. Indeed, even from the research side, the determination of BPV is limited to patients without AF due to doubts about the accuracy of its measurement methods in patients with AF. In this review, we present the current evidence on common pathogenic pathways between BPV and AF, the reliability of quantification of BPV in patients with AF, the prognostic role of BPV in these patients, and discuss the future clinical implications of BPV in patients with AF.

Photo-crosslinked hydrogel as injectable intraocular lens for cataract surgery implantation

Cataract is the leading cause of the blindness worldwide. Natural lens removal followed with intraocular lens (IOL) implantation is the main clinical treatment for cataract. However, the shape and the optical power of current IOLs were fixed, which were not favorable for patients, especially for children with congenital cataracts. An injectable IOL is an immerging replacement for a regular IOL due to the accommodation of external packing shapes. In this study, we developed a rapid, in situ gelation of an injectable photo-crosslinked hydrogel as an injectable IOL material. In this investigation, injectable hydrogel (G/D hydrogel) was fabricated from Gelatin methacrylate (GelMA) and N- (3, 4-dihydroxyphenylidene ethyl) methacrylamide (DMA) via photo-crosslinking for injectable IOL applications. Different preparation parameters such as the concentration, proportion, light intensity, and curing time were optimized based on the gelation time, swelling ratio, and mechanical properties of the produced G/D hydrogels. The results of in vitro cellular experiments showed that the G/D hydrogel had good and stable clearance of lens epithelial cells. The hydrogel was implanted into the eyes of the young rabbits for 1 month, and the results also showed that injectable G/D hydrogel can obtain good intraocular implants and have inhibitory effects on posterior capsular opacification. Thus such photo-crosslinked G/D hydrogel can serve as an injectable IOL application in cataract surgery.

Converging on Institutional Logics: The Expansion of Syringe Service Programs in a Midwest State

ABSTRACT Institutional logics are theoretical constructs that describe how organizations and other actors make sense of, and organize their everyday practices. This paper describes how syringe service programs (SSPs) have incorporated disparate institutional logics in efforts to meet the needs of a stigmatized population. SSPs are a type of human service organization that allows intravenous drug users (IDUs) to obtain unused needles, stemming the spread of bloodborne infections. Using qualitative interviews with 26 SSP employees at 22 SSP programs in a Midwestern US state, we reveal how these individuals understand how their organizations adapt to different logics (community, state, and professional) during changes in the field. We use Skelcher and Smith’s types of organizational hybridity to describe how SSPs incorporate different institutional logics into their work. Implications for understanding what happens at the organizational and field level as external pressures shape organizational activity and logic adoption are discussed.

Homogeneous B0 coil design method for open-access ultra-low field magnetic resonance imaging: A simulation study

A multimodal brain function measurement system integrating functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) is expected to be a tool that will provide new insights into neuroscience. To integrate fMRI and MEG, an ultra-low-field MRI (ULF-MRI) scanner that can generate a static magnetic field (B0) with an electromagnetic coil and turn off the B0 during MEG measurements is desirable. While electromagnetic B0 coil has the above advantages, it also has a trade-off between size and the broadness of the magnetic field homogeneity. In this study, we proposed a method for designing a B0 multi-stage circular coil arrangement that determines the number of coils required to maximize magnetic field homogeneity and minimize the total wiring length of the coils. The optimized multi-stage coil arrangement had an external shape of 600 mm in diameter and a maximum height of 600 mm, with an aperture of 600 mm in diameter and 300 mm in height. The magnetic field homogeneity was <100 ppm over a 210 mm diameter spherical volume (DSV). Compared to a previous two coil pairs arrangement with the same magnetic field homogeneity, the diameter was 1/1.9 times smaller, indicating that the newly designed B0 coil arrangement realized a smaller size and wider magnetic field homogeneity.

Study of physical and mechanical properties of plant fruits on the example of walnut

Perennial plantations that are zoned in Ukraine allow to obtain high-quality fruits (nuts), which are widely used in the perfumery, pharmaceutical, oil, confectionery and other industries, as well as in the production of feed and feed additives. The known technologies of mass processing of walnut kernels mostly work well with crops that have a spherical or close to spherical external shape. The simplest, but least productive, are primitive manual devices for peeling walnut shells. Despite the simplicity of their design, these devices are inefficient and unsuitable for adjusting their operation to different varieties and physical and mechanical properties of biological fruits. The analysis of the known designs of walnut shell destruction machines and mechanisms showed the need to study the physical and mechanical properties of biological fruits (walnuts), to develop technical recommendations for the design of impact mechanisms to improve the quality of shell destruction and the possibility of their application in mass production technologies. A research methodology was developed, a laboratory setup was manufactured, and experiments were conducted. To determine the strength characteristics, the author designed and manufactured a device. It consists of a lever mechanism and a deforming device. The dimensions and load measurements were carried out according to well-known methods of physical mechanics. The statistical analysis of the results showed the need for in-depth scientific research of the geometric parameters of the design of the working bodies of machines for destroying the walnut shell in the mechanisms of fruit peeling machines, taking into account the quality indicators performance of works with certain conditions of their implementation. We conclude that according to the results of the experiments, there is a fairly high dependence between the geometric dimensions of the walnut fruit at the level of 0.72, 0.57 and 0.49, respectively. The weight of the fruit also depends on its dimensional characteristics, which is logical at the level of 0.6–0.75. The force of critical static fracture has a weak correlation with the dimensional characteristics at the level of 0.3. And it depends little on the plane of its application.

Possible application of non-invasive tools to characterise European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) from two different farming systems

Rearing conditions can affect fish morphology, physiology, and welfare in several manners, for instance given the different hydrodynamic conditions or stocking densities. This preliminary study aimed to evaluate non-invasive tools to understand if and how the farming system can influence external shape, skin pigmentation, and freshness evolution during refrigerated storage of European sea bass and gilthead sea bream. A total of 100 individuals (50 sea bass and 50 sea bream) were obtained from a fish farm (located in Piombino, Italy) equipped with floating cages and inland tanks. Fishes were photographed in lateral aspect to analyse shape, while skin colour was analysed with a colorimeter. Freshness and Rigor Index were observed during 7 days of refrigerated storage. Results showed that shape and colour analyses can be useful tools to discriminate fish farmed under different conditions, i.e., marine sea cages and inland tanks. Moreover, farming conditions significantly affected rigor resolution and fish freshness, especially in European sea bass.

Academic Support, Peer Pressure, and Emotional Intelligence: A Mixed-Methods Investigation in Shanghai's Higher Education Landscape

This study explores the dynamics of emotional intelligence among higher education students in Shanghai, China, by examining the impact of external influences on EI development. Employing a mixed-methods approach, quantitative surveys and qualitative interviews are utilized to gather comprehensive data. The quantitative component employs standardized measures and custom-designed questionnaires to assess EI and external influences, while qualitative interviews provide rich narratives. Analysis of quantitative data includes correlation, mediation, and regression analyses, while qualitative data undergoes thematic analysis. This study aims to contribute to the understanding of EI in the context of Shanghai's diverse and dynamic higher education environment, shedding light on how external factors shape students' emotional intelligence development.

P‐76: The Influence of Bending FFC Transmission Line on High‐Speed Signal Channels

Generally, display devices interconnect FFC transmission lines with circuits to form a transmission line network system to achieve data communication between Tcon and Driver. Due to the limitations of the external shape and internal space structure of the display device, the FFC transmission cable presents a curved shape from 0 to 180 degrees during the wiring process. Under the action of spatial electromagnetic fields, the display device will involve the field‐circuit hybrid problem of electromagnetic coupling of the FFC transmission line's bent line and circuit conduction interference, which will cause severe electromagnetic interference(EMI), resulting in deterioration of the high‐speed channel signal at the receiving end and even inability to correctly restore and decode the signal, thus causing signal distortion, which in turn leads to display image distortion or pixel loss.

Turbulent System Dynamics: An Introduction to Spectral Decomposition and External Forcing in Sobolev Spaces

Turbulent systems represent a complex and ubiquitous phenomenon in various natural and engineered environments. This study investigates the dynamics of turbulent systems through the lens of four fundamental theorems. The first theorem establishes a spectral decomposition of the velocity correlation function, shedding light on the coherent and incoherent structures within turbulent flows. The second theorem delves into the energy distribution in Sobolev spaces, providing insights into the regularity and properties of turbulent solutions. Expanding on these findings, the third theorem explores the influence of external forcing on energy distribution, elucidating how external factors shape turbulent behavior. Building upon these insights, the fourth theorem integrates the concepts from the previous theorems, describing the interplay between spectral decomposition, energy distribution, and external forcing effects in turbulent systems. This comprehensive analysis offers a deeper understanding of turbulent dynamics, with implications for fields such as fluid mechanics, atmospheric science, and engineering. By elucidating the underlying mechanisms governing turbulent behavior, this study paves the way for improved modeling, prediction, and control of turbulent systems in various practical applications.

Visualizing the Internal Nanocrystallinity of Calcite Due to Nonclassical Crystallization by 3D Coherent X-Ray Diffraction Imaging.

The internal crystallinity of calcite is investigated for samples synthesized using two approaches: precipitation from solution and the ammonium carbonate diffusion method. Scanning electron microscopy (SEM) analyses reveal that the calcite products precipitated using both approaches have a well-defined rhombohedron shape, consistent with the euhedral crystal habit of the mineral. The internal structure of these calcite crystals is characterized using Bragg coherent diffraction imaging (BCDI) to determine the 3D electron density and the atomic displacement field. BCDI reconstructions for crystals synthesized using the ammonium carbonate diffusion approach have the expected euhedral shape, with internal strain fields and few internal defects. In contrast, the crystals synthesized by precipitation from solution have very complex external shapes and defective internal structures, presenting null electron density regions and pronounced displacement field distributions. These heterogeneities are interpreted as multiple crystalline domains, created by a nonclassical crystallization mechanism, where smaller nanoparticles coalescence into the final euhedral particles. The combined use of SEM, X-ray diffraction (XRD), and BCDI allows for structurally differentiating calcite crystals grown with different approaches, opening new opportunities to understand how grain boundaries and internal defects alter calcite reactivity.

СОВРЕМЕННЫЕ НАУЧНЫЕ ПРЕДСТАВЛЕНИЯ О ФАКТОРАХ, ВЛИЯЮЩИХ НА УСПЕХ ДЕНТАЛЬНОЙ ИМПЛАНТАЦИИ

For the full-fledged work of a dentist-implantologist working in the field of replenishment of dentition with the help of dental implants and prostheses based on them in the modern realities of excessive variability of implant systems and suprastructures for them, the clinician needs to understand the criteria that various structural elements must meet, regardless of whether the structure is a single tooth, a bridge, or a full dentition restored with the above structure. In accordance with modern scientific concepts, the long-term survival of implants and teeth restored with their help is influenced by various mechanical and biological factors, such as: switching platforms, the type of connection of the abutment to the implant body, including the cone, its angle, internal or external polyhedron, the type and shape of the thread, the coating of the screw fixing the superstructure to the shaft of the dental implant (DI), the condition of the soft tissues and other factors disclosed in this article. The article will be useful for dentists involved in the restoration of dentition using various types of prostheses based on DI to become familiar with modern trends and scientifically proven facts about various elements of the implant-prosthesis complex. The article will also be useful for the clinician to select an implantological system that meets modern criteria of reliability and efficiency among the many variations presented on the medical device market. The team of authors recommends that the article be read by senior students and residents studying at the dental faculties of medical universities for a deeper understanding of the conditions that in the near future they will have to take into account when following the path of an orthopedic dentist or dental surgeon.

EFFECT OF THE STRANDS FIXITY PROFILE SHAPE ON THE FLEXURAL BEHAVIOR OF STEEL BEAMS

This study concerns the effect of the external prestressing strand shape profile on the flexural behavior of steel beams. Seven steel beams that have the same cross-section are strengthened by external strands fixed by using Saddle Points of Deviation (Deviators). Based on two criteria, beams tested are divided into two categories whether external prestressing with fixity strands is present. The first group includes only one beam as a reference, while the second group deals with beams strengthened by two external strands. Six samples have been separated according to the eccentricity for external prestressing at a jacking stress of 815 MPa. During testing, it was discovered that the moment-curvature responses at the bottom and top flange region were stiffer than those in the reference, and the degree of hardening increases with eccentricity increasing. However, failure occurs with a slight warning as a result of insufficient ductility. Due to the presence of external prestressing, the ultimate moment capacity is enhanced by approximately 6.1%, 31.7%, 38.5%, 57.6%, 29.4%, and 80.2% as compared to the reference. Finally, the radius of curvature at the top flange region for strengthening samples has grown by approximately -16.7%, 8.0%, -26.9%, 21.5%, 17.5%, and 17.4% as compared to the reference case. In contrast, the percentage of the radius of curvature at the bottom flange region for strengthened samples dropped to 24,9%, 73.9%, 83.2%, 83.6%, 69.2%, and 89.0%, respectively, with an increase in the eccentricity position as compared to the reference.

Study on deformation-induced martensitic transformation behavior of 304 and 316 stainless steels

In this paper, the deformation-induced martensitic transformation behavior of 304 and 316 stainless steels is studied. The results show that martensitic transformation occurs in both 304 stainless steel and 316 stainless steel. With the increase of the strain, the martensitic transformation of the stainless steel samples increases, but the 304 stainless steel increases more significantly. The external shape of stainless steel has a certain influence on martensitic transformation behavior, and the martensite content of bar-shaped stainless steel is lower than that of plate-shaped samples under the same strain. The study results can provide technical guidance for the selection of stainless steel materials in the power grid.