Suboptimal Structure Research Articles

Effect of electric arc surfacing on the structure and properties of coatings

Surfacing, like welding, is associated with heating metals in a wide range of temperatures and subsequent cooling of heated zones at different rates. This leads to complex structural and phase changes that are crucial for operational properties of the “protected material – coating” joint. The structure and properties of the alloyage zone of these two materials depend on the degree of penetration, nature of the intermediate layers that arise, and carbon diffusion in the boundary areas. When surfacing on low-carbon steel, depending on the composition of the deposited metal, the structures with a predominant amount of martensite or austenite can be obtained in the alloyage zone, depending on carbon content. The structure and mechanical properties of the bimetallic joint between carbon steel and stainless steel were studied depending on the modes of electric arc surfacing (submerged arc surfacing in one pass, in argon for one and two passes). It was established that the structural and phase composition of the deposited metal is austenite, finely dispersed carbides and a needle component. The structure of the layer deposited in argon in one pass is more homogeneous and does not contain defects. The microhardness increases smoothly along the depth of the deposited layer. As a result of surfacing in argon in two passes, the joint has a homogeneous microstructure, but a large number of microdefects are formed in the layer, which can further lead to the formation of a crack near the alloyage boundary. In submerged surfacing, the heating rate and specific heat input are insufficient, therefore, the surfacing bath is poorly mixed, which leads to a suboptimal structure and the formation of thermal stresses at the alloyage boundary and to the formation of a coating that is heterogeneous in structure and microhardness.

The Relationship Between Maternal Nutrition During Pregnancy and Primary Tooth Caries in Stunted Toddlers: A Study at Umbulsari

Particularly during the 5th week of gestation when primary tooth enamel begins forming. Disruptions during this crucial period can lead to suboptimal enamel structure, increasing susceptibility to cavities in toddlers. A study conducted observed dental examinations of 10 stunted toddlers, all of whom exhibited dental caries. This prompted an investigation into whether maternal nutrition during pregnancy correlates with primary tooth caries in stunted toddlers. The research, a retrospective case-control study using purposive sampling of 90 respondents, utilized maternal BMI data and assessed primary tooth caries incidence. Analysis using Spearman's non-parametric correlation test indicated a significant relationship (p=0.001, r=0.351) between maternal nutritional status and primary tooth caries. Findings from the Umbulsari Community Health Center revealed that most mothers had below-normal nutritional status during pregnancy, and stunted toddlers averaged 7.3 dental caries. It was concluded that there was a relationship between maternal nutritional status during pregnancy and primary tooth caries in stunted toddlers at the Umbulsari Community Health Center with a weak correlation coefficient and the direction of correlation between variables was negative or inversely proportional.

Design and test of a novel converging groove-guided seed tube for precision seeding of maize

In precision seeding operations, the irregular shapes of maize seed particles and the suboptimal geometric structure of the seed tube contribute to the rolling and bouncing of seeds upon falling into the furrow, ultimately compromising seeding uniformity. To address this issue, a convergent groove-guided (CGG) seed tube was proposed based on the principle of brachistochrone curve considering friction (BCCF). The discrete element method (DEM) was employed to conduct a comprehensive phenomenological analysis and numerical investigation of particle guide characteristics. Bench tests and field experiments were designed to verify the simulation results. Through response surface analysis, the optimal seeding performance was achieved at a groove angle of 111.34°, tube incline angle of 1.56°, and ground speed of 7.2 km h−1, resulting in a lateral dispersion landing range of 11.10 mm, angular velocity of 17.38 rad s−1, seed landing speed variation coefficient of 2.29%, and plant spacing variation coefficient of 6.04%. Bench test results unveiled that, under a ground speed of 7.2 km h−1, the variation coefficient of plant spacing for CGG seed tubes was measured at 7.63%, with a deviation of 1.59% from the simulation results. At high ground speeds of 9.0–14.4 km h−1, the seed guiding performance was also better than traditional seed tubes. Consistent results were also verified through field experiments. Therefore, the CGG seed tube manifested superior seed guidance efficacy when juxtaposed with its conventional counterpart, and this design can provide technical support for the realization of seed-to-ground positioning technology.

Towards a dependable data set of structures for L-asparaginase research.

The Protein Data Bank (PDB) includes a carefully curated treasury of experimentally derived structural data on biological macromolecules and their various complexes. Such information is fundamental for a multitude of projects that involve large-scale data mining and/or detailed evaluation of individual structures of importance to chemistry, biology and, most of all, to medicine, where it provides the foundation for structure-based drug discovery. However, despite extensive validation mechanisms, it is almost inevitable that among the ∼215 000 entries there will occasionally be suboptimal or incorrect structure models. It is thus vital to apply careful verification procedures to those segments of the PDB that are of direct medicinal interest. Here, such an analysis was carried out for crystallographic models of L-asparaginases, enzymes that include approved drugs for the treatment of certain types of leukemia. The focus was on the adherence of the atomic coordinates to the rules of stereochemistry and their agreement with the experimental electron-density maps. Whereas the current clinical application of L-asparaginases is limited to two bacterial proteins and their chemical modifications, the field of investigations of such enzymes has expanded tremendously in recent years with the discovery of three entirely different structural classes and with numerous reports, not always quite reliable, of the anticancer properties of L-asparaginases of different origins.

In Situ Fabricated Poly(1,8‐naphthalenediamine)/Active Carbon Composite Cathodes for Aqueous Zinc‐Ion Batteries with High Active Sites Utilization and Ultralong Life Span of 50 000 Cycles

AbstractPolymers with redox activity are one type of promising candidates of cathode materials for aqueous Zn‐ion batteries due to their potential low‐cost, high safe, and renewable features. Unfortunately, suboptimal polymer electrode structure often results in unsatisfactory electrochemical performance. Herein, poly(1,8‐diaminonaphthalene)/active carbon composite electrodes are prepared via nanoconfined in situ electropolymerization within porous active carbon, which have ultrahigh specific surface area (1035.0 m2 g−1) and unique nano‐porous structure, thereby highly enhancing the utilization of the active site up to 91.6%. The as‐prepared cathodes deliver ultrahigh reversible capacity of 479.5 mAh g−1, ultrafast rate capability of up to 60 A g−1 and an ultralong life span of 50,000 cycles. Storage mechanism investigation indicates that the cathode material involves a bipolar‐type behavior. These encouraging results demonstrate that nanoconfined in situ electropolymerization in active carbon is a brand‐new strategy for the design of advanced polymer electrodes for high‐performance aqueous Zn‐organic batteries.

Microbial etch: A novel construction method of functionalized biochar for enhanced uranium extraction in radioactive wastewater

Nuclear energy is playing an increasingly important role on the earth, but the nuclear plants leaves a legacy of radioactive waste pollution, especially uranium-containing pollution. Straw biochar with wide sources, large output, low cost, and easy availability, has emerged as a promising material for uranium extraction from radioactive wastewater, but the natural biomass with suboptimal structure and low content of functional groups limits the efficiency. In this work, microbial etch was first came up to regulate the biochar's structure and function. The surface of the biochar becomes rougher and more microporous, and the mineral contents (Ca, P) indirectly increased by microbial etch. The biochar was modified by calcium phosphate and exhibited a remarkable uranium extraction capacity of 590.8 mg g−1 (fitted value). This work provides a cost-effective and sustainable method for preparing functionalized biochar via microbial etch, which has potential for application to uranium extraction from radioactive wastewater.

Preemptive patenting, secondary patents, and the persistence of monopoly

AbstractWe develop a theoretical economic model that establishes the link between fragmented patenting systems in an industry already characterized as a monopoly resulting in continuous/steady monopolistic market structure. We demonstrated that preemptive patenting strategy, by using secondary patenting scheme, may lead to an increase in the number of patents without changing actual number of products on the market. Moreover, when such a strategy is employed by a monopoly, it only serves to sustain and further monopolistic and therefore socially suboptimal market structure. Institutional/legal framework must exist to promote this kind of socially suboptimal behavior and resulting outcomes.

Constrained optimized dynamic mode decomposition with control for physically stable systems with exogeneous inputs

Reduced order models (ROMs) generated by the dynamic mode decomposition (DMD) are sensitive to the selection of DMD hyperparameters and suffer from spurious eigenvalue issues. To address these challenges, this paper presents a novel method named constrained optimized DMD with Control (cOptDMDc) that extends optimized DMD to systems with exogenous inputs and can optionally enforce the stability of the resulting ROM. The variable projection and the exponential data fitting approaches are reformulated to consider temporal effects of exogenous inputs on state evolution. A new process combining iterative exponential data fitting and a linear inequality constraint is proposed to optimally place eigenvalues within the stable region, yielding a sub-optimal spectral structure, which is more robust and effective to mitigate spurious eigenvalue issues and alleviate the brittleness of DMDc. Three case studies are conducted to compare the proposed cOptDMDc with the native Dynamic Mode Decomposition with Control (DMDc) and Sparsity-Promoting DMDc (SPDMDc). The results prove that the cOptDMDc method is accurate with maximum relative error < 0.5% and more robust to the choice of ROM subspace dimensions, thus eliminating the need for a trial-and-error process and additional validation data for ROM construction.

Dark network resilience in a hostile environment: optimizing centralization and density

Objective: to analyze the legal nature, structure, and features of violent extremism and to develop measures to prevent this illegal behavior.Methods: dialectical approach to cognition of social phenomena, allowing to analyze them in historical development and functioning in the context of the totality of objective and subjective factors, which predetermined the following research methods: formal-logical and sociological.Results: in recent years, the world has witnessed the emergence of violent extremists (VEs), and they have become an ongoing concern for countries around the globe. A great deal of effort has been expended examining their nature and structure in order to aid in the development of interventions to prevent further violence. Analysts and scholars have been particularly interested in identifying structural features that enhance (or diminish) VE resilience to exogenous and endogenous shocks. As many have noted, VEs typically seek to balance operational security and capacity/efficiency. Some argue that their desire for secrecy outweighs their desire for efficiency, which leads them to be less centralized with few internal connections. Others argue that centralization is necessary because security is more easily compromised and that internal density promotes solidarity and limits countervailing influences. Unsurprisingly, scholars have found evidence for both positions. In this paper, we analyze the Noordin Top terrorist network over time to examine the security-efficiency tradeoff from a new perspective. We find that the process by which they adopt various network structures is far more complex than much of the current literature suggests.Scientific novelty: the research showed that a dark network’s adoption of a network structure is far more complex than what current literature suggests, namely that a network structure at either side of the cohesion and centralization continuums offers potential advantages and disadvantages in terms of network resilience. In the case of Noordin Top, it appears that his network’s focus on establishing external ties after its operations provided it possible access to resources but likely became a factor contributing to its exposure and eventual disruption. The network, much like its Bali I predecessors who also focused on establishing external ties after their operation, faced significant losses and needed to reconstitute itself immediately following each operation. This tendency, along with the general adoption of a centralized structure, suggests that Noordin’s network adopted a suboptimal structure that ultimately contributed to his demise.Practical significance:the main provisions and conclusions of the article can be used in scientific, pedagogical and law enforcement activities when considering the issues related to fighting extremism and terrorism. The article was first published in English language by Criminology, Criminal Justice, Law &amp; Society and The Western Society ofCriminology Hosting by Scholastica. For more information please contact:CCJLS@WesternCriminology.orgThe submitted material is published in full, as interpreted by the author.For original publication: Everton, S. F., &amp; Cunningham, D. (2015). Dark network resilience in a hostile environment: optimizing centralization and density. Criminology, Criminal Justice, Law &amp; Society, 16(1), 1–20.PublicationURL:https://ccjls.scholasticahq.com/article/341-dark-network-resilience-in-a-hostile-environment-optimizingcentralization-and-density

High‐Efficiency All‐Small‐Molecule Organic Solar Cells Based on New Molecule Donors with Conjugated Symmetric/Asymmetric Hybrid Cyclopentyl‐Hexyl Side Chains

AbstractAll small molecule organic solar cells (ASM‐OSCs) have numerous advantages but lower power conversion efficiencies (PCEs) than their polymer equivalents, which is largely due to the suboptimal nanoscale network structure in a bulk heterojunction (BHJ). Herein, new small molecule donors with symmetric/asymmetric hybrid cyclopentyl‐hexyl side chains are designed, accounting for manipulated intermolecular interactions and BHJ morphology. Theoretical and experimental results reveal that the asymmetric cyclopentyl‐hexyl side chains modification has a significant influence on potential energy surface and intermolecular interaction that can ensure preferable molecular assembly and regulate the D/A interfacial energetics, thus boosting the exciton dissociation and charge transport when pairing with a wide‐used acceptor L8‐BO. Concurrently, a nanoscale bicontinuous interpenetrating network with optimal domain size can be fully evolved in the BHJ layer. As a consequence, the As‐TCp‐based binary device achieves a superior PCE of 16.46% in comparison to that of the controlled symmetric counterparts S‐BF (14.92%) and A‐TCp (15.77%), and ranks one of best performance among ASM‐OSCs. This study demonstrates that precise manipulation of the cyclo‐alkyl chain in combination with the asymmetric 2D side chain strategy is an effective synergistic approach to control intermolecular interaction and nanoscale bicontinuous phase separation for achieving high‐performance ASM‐OSCs.

Ligand-assisted structure tailoring of highly luminescent Cu-In-Zn-S/ZnS//ZnS quantum dots for bright and stable light-emitting diodes.

Harnessing environment-friendly and low-cost multinary Cu-In-Zn-S quantum dots (QDs) as emitters for light-emitting diodes (LEDs) has attracted great attention for display and lighting application. However, suboptimal QD structure is a huge obstacle, which results in serious non-radiative recombination and efficiency roll-off. Herein, we synthesized structure-tailored Cu-In-Zn-S/ZnS//ZnS QDs by improving the reactivity of shell growth by 2-ethylhexanoic acid (EHA) ligands. The EHA-assisted shell growth can boost an extended alloyed layer at the core-shell interface and a smoothed confinement barrier, which effectively passivate the interface defects and suppress Förster resonance energy transfer (FRET) process. These synthesized QDs display a bright photoluminescence emission (quantum yield of 83%) and a larger size of 8.4nm. Moreover, the resulting LEDs based on the EHA-assisted QDs exhibit a maximum luminance of 8074cd/m2, and a current efficiency of 7.3cd/A with a low efficiency roll-off. Our results highlight a remarkable ligand strategy to tailor the QD structure for high performance QD-based LEDs.

Implementation of the Tourism Park Development Program in Unamendaa Village

This research aims to explore and describe the implementation of the tourism park development program in Unamendaa Village. This research uses an inductive qualitative analysis. Inductive analysis is an approach that begins with field facts, analyzes them based on relevant theories and arguments, and ultimately yields a conclusion. The results show that implementing the Tourism Park development program in Unamendaa Village faces several significant obstacles related to communication, resources, disposition, and bureaucratic structure. Regarding communication, the Village Tourism Park program’s socialization needs to be implemented optimally. Regarding resources, there needs to be more BUMDes Organizers in managing the Village Tourism Park. Concerning disposition, although the Village Government has entrusted development responsibility to BUMDes, there still needs to be clarity in the tax payment mechanism. Additionally, the suboptimal bureaucratic structure adds complexity to the obstacles, including issues of supervision, coordination, facility provision, and communication between the Village Government and the community, which collectively hinder the achievement of the Village Tourism Park development goals. Therefore, it is recommended that the Village Government improve communication effectiveness with the community through increased frequency and more innovative socialization methods to ensure that information about the Village Tourism Park development is evenly distributed to all community members. For BUMDes, it is suggested that resource deficiencies be addressed by training organizers in tourism park management and operations and clarifying the division of responsibilities between organizers and traders to prevent role overlaps. Traders are expected to cooperate more closely with BUMDes Organizers, especially regarding compliance with the established tax payment mechanism. The community is encouraged to actively participate in every process of the Village Tourism Park development, in aspects of planning, execution, and supervision, to create good collaboration between the Village Government, BUMDes, traders, and the community, aiming for the sustainable and beneficial development of the Village Tourism Park for all parties in the future.

Manufacturing and Characterization of Wide-Bundle Bamboo Scrimber: A Comparison with Other Engineered Bamboo Composites.

Controlling the variability in mat structure and properties in bamboo scrimber (BS) is key to producing the product for structural applications, and wide strip scrimber (WBS) is an effective approach. In this study, the effects of scrimmed bamboo bundle morphology and product density on the properties of WBS were investigated. WBS panels were manufactured and tested using wide (200 to 250 mm) bamboo strips with different fiberization intensity. Maximum strength properties (flexural, compressive, and shear strength), and lowest thickness swelling and water absorption were achieved with three or four passes due to the higher resin absorption by strips. For balanced product cost and performance, we recommend 1-2 fiberization passes and a panel density of 0.9-1.0 g/cm3. Panel mechanical properties were compared with other common bamboo composites. Bamboo scrimber products were highly variable in properties due to differing manufacturing processes, element treatments, and suboptimal mat structure. Products including laminated bamboo lumber and flattened bamboo made from nonfiberized elements show markedly different relationships between strength and elastic properties mostly due to inadequate bonding between the laminae, which causes premature bond-line failure. This study helped improve the understanding of the structure-property relationship of engineered bamboo products while providing insights into process optimization.

Elucidating the Sectioning Fragmentation Mechanism in Silica‐Supported Olefin Polymerization Catalysts with Laboratory‐Based X‐Ray and Electron Microscopy

AbstractStrict morphological control over growing polymer particles is an indispensable requirement in many catalytic olefin polymerization processes. In catalysts with mechanically stronger supports, e. g., polymerization‐grade silicas, the emergence of extensive cracks via the sectioning fragmentation mechanism requires severe stress build‐up in the polymerizing catalyst particle. Here, we report on three factors that influence the degree of sectioning in silica‐supported olefin polymerization catalysts. Laboratory‐based X‐ray nano‐computed tomography (nanoCT) and focused ion beam‐scanning electron microscopy (FIB‐SEM) were employed to study catalyst particle morphology and crack propagation in two showcase catalyst systems, i.e., a zirconocene‐based catalyst (i.e., Zr/MAO/SiO2, with Zr=2,2’‐biphenylene‐bis‐2‐indenyl zirconium dichloride and MAO=methylaluminoxane) and a Ziegler‐Natta catalyst (i.e., TiCl4/MgCl2/SiO2), during slurry‐phase ethylene polymerization. The absence of extensive macropores in some of the catalysts’ larger constituent silica granulates, a sufficient accessibility of the catalyst particle interior at reaction onset, and a high initial polymerization rate were found to favor the occurrence of the sectioning pathway at different length scales. While sectioning is beneficial for reducing diffusion limitations, its appearance in mechanically stronger catalyst supports can indicate a suboptimal support structure or unfavourable reaction conditions.

An Introduction to the Orthopaedic Diversity Leadership Consortium: Advancement of Our Orthopaedic Leaders of Diversity, Equity, and Inclusion Through Networking, Strategy, and Innovation.

Achievement of diversity, equity, and inclusion (DEI) is an ongoing discussion that has evolved over time in the field of orthopaedic surgery. To enhance and highlight commitments to diversity, many academic department and health organizations have designated individuals to serve as their DEI leader. However, suboptimal structure and support of this specific leadership position have limited its potential and have led to increased position turnover and stagnation in progress. To mitigate these challenges, the Orthopaedic Diversity Leadership Consortium (ODLC) was formed as a growing network of orthopaedic diversity leaders from around the United States as well as international members and industry affiliates. The mission of ODLC is to optimize the sustainability of DEI efforts by providing professional development support and best-practice solutions to leaders serving in this capacity. The efforts of the organization are guided by 3 key objectives: leadership development, design of strategic plan models for diversity, and interprofessional education for perioperative care teams on inclusion. Through this powerful network and its educational offerings, ODLC works to increase role efficacy and to encourage sustainable creation of diverse, equitable, and inclusive environments for our patients, colleagues, and team members.

THEORETICAL PRINCIPLES OF THE DEVELOPMENT OF MECHANISMS FOR IMPLEMENTING PARTNERSHIP RELATIONS OF THE STATE AND THE BANKING SECTOR

The current military-political situation poses new challenges to the Ukrainian economy. The destruction and losses for the national economy are fully in line with the most intense military conflict of recent times. However, it would be a mistake to explain the current economic problems only by war. One of the most painful issues is the suboptimal structure of the national economy and the lack of successful attempts by the state to carry out structural reforms that could correct the negative inertial scenario of its development. With regard to the regulation of structural change, it is important to emphasize the importance of integrated use of the criteria set out in the article for effective analysis of the structure of the national economy. Applied comprehensively, they will provide a sufficient understanding of the processes taking place in the national economy, and will give a picture of the imbalances that need to be corrected through structural policies.

Оценка вклада МСП в выпуск продукции городов республиканского значения Казахстана

Small and medium-sized enterprises (SME) development in the regions of Kazakhstan is characterised by substantial imbalances. The cities of republican significance — Nur-Sultan and Almaty — are leading in terms of SME performance indicators. However, the quantitative development of such enterprises in these cities does not always lead to a corresponding increase in their contribution to output. Meanwhile, literature lacks studies on this relationship and its causal analysis necessary to provide scientific substantiation of the state policy to support SME development in regions. The present article aims to assess the contribution of SMEs to the output of the cities of republican significance and find solutions to the problems hindering business development. It is hypothesised that there is a weak linear correlation between the number of operating SMEs and output in Nur-Sultan and Almaty. The study utilised the Pearson correlation method, comparative and causal analysis. The presence of a positive correlation between the number of operating SMEs and the production output in the studied regions was confirmed, although, according to the correlation coefficient value, this relationship is weak. The suboptimal structure of the SME sector, as well as the low labour productivity in small enterprises are the key reasons for the weak correlation. Recommendations to stimulate the activities of SMEs were formulated based on the analysis of hindering factors (including inefficient government support). It is concluded that the reduction of the SME sector due to the COVID-19 pandemic in some way positively affected the market, since ineffectively functioning entities were eliminated. Thus, the state should focus on the targeted support and directly stimulate strong players capable of self-renewal. The research results can be useful to the state and local authorities to create measures to support SMEs and regional business regulation policy.

STRUCTURING THE NATIONAL ECONOMY: THEORETICAL ASPECT

The current military-political situation poses new challenges to the Ukrainian economy. The destruction and losses for the national economy are fully in line with the most intense military conflict of recent times. However, it would be a mistake to explain the current economic problems only by war. One of the most painful issues is the suboptimal structure of the national economy and the lack of successful attempts by the state to carry out structural reforms that could correct the negative inertial scenario of its development. With regard to the regulation of structural change, it is important to emphasize the importance of integrated use of the criteria set out in the article for effective analysis of the structure of the national economy. Applied comprehensively, they will provide a sufficient understanding of the processes taking place in the national economy, and will give a picture of the imbalances that need to be corrected through structural policies.

Highly Efficient Photothermal Conversion and Water Transport during Solar Evaporation Enabled by Amorphous Hollow Multishelled Nanocomposites.

Solar evaporation, which enables water purification without consuming fossil fuels, has been considered the most promising strategy to address global scarcity of drinkable water. However, the suboptimal structure and composition designs still result in a trade-off between photothermal conversion, water transport, and tolerance to harsh environments. Here, an ultrastable amorphous Ta2 O5 /C nanocomposite is designed with a hollow multishelled structure (HoMS) for solar evaporation. This HoMS results in highly efficient photoabsorption and photothermal conversion, as well as a decrease of the actual water evaporation enthalpy. A superfast evaporation speed of 4.02kg m-2 h-1 is achieved. More importantly, a World Health Organization standard drinkable water can be achieved from seawater, heavy-metal- and bacteria-containing water, and even from extremely acidic/alkaline or radioactive water sources. Notably, the concentration of pseudovirus SC2-P can be decreased by 6 orders of magnitude after evaporation.

Efficient Compound Barge Design

During the twentieth century, naval architects worked to improve the performance of pusher tugs. The ropes used to secure the pusher to a barge were prone to tearing; this problem was remedied by the development of several coupling devices, including one that was highly advanced. Previous researchers have identified three major issues regarding this matter: the vessel's seaworthiness when not coupled, safety, and suboptimal structure. The purpose of this paper is to propose solutions to the aforementioned problems by introducing an efficient compound vessel design. Comparative advantages of compound vessels are analysed. Designs of a compound barge and effective coupling mechanism are introduced. Prospective weight reduction and economic advantages of coupled barges are calculated and analysed.