bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short Time Tempering on 39MnCrB6-2 Steel to Find Best Compromise between Mechanical Properties and Use of Copper-Rich Scraps
Authors: Stocky C. , Acevedo D. Reyes , Clemang S. , Maurigh F. 
Published: September 2024

Abstract
Much more steel must be produced from scrap to meet emissions targets, and utilizing this growing resource is a sound economic strategy. However, the presence of contaminating elements restricts the applications in which end-of-life scrap can replace primary steel. The use of low alloyed quenching and tempering steel grade such as 39MnCrB6-2 to reach high mechanical characteristics (around 1000 MPa) obliges often to apply low tempering temperatures for which tempering embrittlement may be observed. In this paper, it is proposed to reduce the hold time and to increase the temperature during conventional tempering to (1) reduce the embrittlement because of segregation of elements like copper, (2) to change the fracture mechanism with finer martensite sub-grains and (3) to promote θ particles with smaller dimensions but higher density.
Sub-Zero Treatment of 17-4PH Stainless Steel Manufactured by Laser Powder Bed Fusion
Authors: Troyanosky Ellen K. , Liang Jianyu , Christiansen Thomas L. 
Published: September 2024

Abstract
Additively manufactured (AM) metals require a modified heat treatment to accommodate for slight differences in composition caused by powder atomization and cover gas used in the manufacturing process. 17-4PH stainless steel (17-4PH) is a precipitation hardening steel which hardens through the formation of Cu precipitates in a martensitic matrix during aging treatment. The powders used in Laser Powder Bed Fusion (LPBF) fabrication of 17-4PH are typically spray atomized using N2 cover gas, which is associated with a certain amount of nitrogen uptake. Nitrogen is a potent austenite stabilizer and will lower the martensite start temperature of the steel. To counteract the effect of nitrogen, a sub-zero heat treatment can be introduced to promote a more complete transformation into martensite. In this work, the effect of nitrogen on the heat treatment response of 17-4PH is investigated through comparing standard wrought, nitrogen loaded wrought, and LPBF 17-4PH. In particular, the effect of introducing a subzero treatment is addressed. After quenching from the solutionizing step (austenitization) LPBF fabricated 17-4PH was cold-treated in different combinations of dry ice (-78 °C) and boiling nitrogen (-196 °C). Subsequently, these conditions were aged in the conventional way. The sub-zero treatments were compared with the conventional heat treatment procedure, which does not entail a sub-zero step. In addition, phase transformations (above room temperature) were monitored in-situ using dilatometry. Finally, hardness tests and XRD analysis were performed to characterize the final microstructure. It is demonstrated that sub-zero treatment can be an effective route to address the problems associated with the additional nitrogen present in LPBF 17-4PH fabricated parts.
Coupled CFD and Part Distortion Modeling for Gas Quenching Applications
Authors: Zhang Lei , Petrus Greg , Miller James 
Published: September 2024

Abstract
Manufacturers regularly employ finite-element (FE) process modeling tools for the simulation of heat treatment applications, such as quenching. These tools may utilize thermal, mechanical and microstructural calculations in the analysis of part distortion and residual stresses. Heat treatment modeling workflows are challenged by the requirement for user-provided heat transfer boundary conditions, which vary based on part geometry and process parameters. Representative Heat Transfer Coefficients (HTCs) are typically reversed-engineered using experimental thermocouple data, thermal simulations and inverse optimization methods.
This paper will present ‘state of the art’ developments integrating computational fluid dynamics (CFD) capabilities into the heat treat modeling environment of the DEFORM system. It will describe how CFD and thermal modeling of a quench medium is being coupled with deformation and heat transfer modeling of a part through the use of CFD-calculated, local heat transfer boundary conditions. Studies verifying the implemented CFD methods against published literature will be summarized. Application examples will show how residual stress and distortion in parts, during single-part or batch gas quenching, is made possible by coupled CFD and thermo-mechanical process modeling tools.
Thermally Activated Martensite Formation: An Essential Revision of the Physical Metallurgy of Steel
Authors: Villa Matteo , Ali Basit , Somers Marcel A. J. 
Published: September 2024

Abstract
Steel hardening is a long-standing practice that has accompanied human development over the last three millennia. For hardening, steel is heated to a high temperature to form austenite and subsequently cooled. During cooling, austenite transforms into various microstructural products, e.g. grain boundary ferrite, Widmanstätten ferrite, massive ferrite, pearlite, upper bainite, lower bainite,… and martensite. Martensite is the hardest of these products and is obtained when the applied cooling rate exceeds a critical value. This critical cooling rate for martensite formation is determined by the chemistry of the steel and is significantly reduced by increasing the content of alloying elements. Cooling from the austenite region by immersing the parts in water, generally provides this cooling condition.
The transformation that leads to martensite is called martensitic and, unlike all other transformations that occur in steel, it does not involve the diffusion of atoms. Martensitic transformations begin when a characteristic temperature, the martensite start temperature Ms is reached during cooling. Ms is essentially determined by the chemical composition of the steel. Subsequently, martensitic transformations continue during further cooling below Ms. In contrast, no transformation occurs when the steel is held isothermally below Ms, indicating that the transformation is time independent, i.e. athermal. Consistently, martensitic transformations would not be suppressible, not even by applying the most rapid cooling possible.
Tempering Behavior of Low Alloy Case Hardening Steels with Bainitic and Martensitic Microstructures
Authors: Steinbacher Matthias , Fechte-Heinen Rainer , Hellenbrandt Gerrit 
Published: September 2024

Abstract
Increasing power density and rotational speed pose significant challenges for transmission design, especially in the aerospace and electro mobility sectors. Due to increased energy input and reduced heat dissipation, higher operating temperatures occur in high performance gears. At higher temperatures, the hardness and microstructure of conventional bearing and gear materials are affected by annealing effects, which can reduce the load capacity of these components. Therefore, increased operating temperatures can only be considered if the components are made of special heat-resistant, high-performance material systems.
Heat treatment is essential to achieve the required performance. Today, high performance gears are typically case hardened to achieve the best performance in service. Due to the meta-stable properties of martensite and retained austenite, especially for low alloy case hardening steels, the microstructure can degrade in service if the temperature equals or exceeds the previous tempering. As a result, the hardness and performance of the components will decrease. Alternative steel grades with increased alloy content can mitigate but are in most cases more expensive. Therefore, an increase in temperature resistance through heat treatment of the low-alloy steels would be of increased interest. To achieve a more stable microstructure state, new heat treatments and alternative microstructures must be considered.
This presentation will address the tempering behavior of martensitic and bainitic microstructures under long-term thermal stress above typical tempering conditions at 210 °C for up to 200 hours. The microstructure degradation and hardness change are shown.
Developing Statistical Tools to Analyze Contributions to the Fatigue Performance of Additively Manufactured Materials
Authors: Wietecha-Reiman Ian J. , Palmer Todd A. 
Published: September 2024

Abstract
With the increasing amount of historical fatigue data for advanced manufacturing processes, such as additive manufacturing, it becomes increasingly feasible to use statistical and machine learning approaches to garner deeper insights into the contributions to fatigue performance in order to improve the design for fatigue failure or processing route parameters. Prior to model development, aggregated datasets, whether compiled through manual or automated processes, require extensive verification and profiling to eliminate systematic errors and identify insufficiently investigated parameter combinations. Without these steps, the veracity of any model, especially black-box models, is dubious. Once the structure and patterns of the dataset are established, proper implementation of random imputation can be used to expand the amount of usable data. This verified and augmented dataset can now be subjected to various statistical tools whose role in data exploration will be discussed, particularly regarding the role of distinguishing porosity- and microstructure-driven fatigue failure data.
Book Reviews
Authors: Vadi Priya , Finn Kirsty 
Published: September 2024

Carlnita P. Greene (Ed.), Foodscapes: Food, Space, and Place in a Global Society (New York Peter Lang, 2019), 325 pages, £33.60 (paperback)
Suzanne Beech, The Geographies of International Student Mobility: Spaces Places and Decision-Making (Singapore: Palgrave Macmillan, 2019), 271 pp., 5 b/w illustrations, €59,49 (paperback)
Effects of Thinning on the Diversity, Composition, and Spatial Structure in a Mixed Temperate Forest
Authors: Rubio-Camacho Ernesto A. , Xelhuantzi-Carmona Jaqueline , Chávez-Durán Álvaro A. , Monárrez-González José C. 
Published: September 2024

structure in a temperate mixed forest.
Design/methodology/approach: Data were collected in a 1 ha research plot. Five scenarios were evaluated through computer simulations: no thinning (T1), thinning with removal of 25% of basal area (Gha-1), (T2), thinning with removal of 25% of Gha-1 (T3), thinning with removal of 45% of Gha-1 (T4), and thinning with removal of 70% of Gha-1 (T5). The importance value index, alpha diversity, Pretzsch's A index and structural complexity index were estimated. A spatial distribution analysis was performed using the pair-correlation function g(r).
Results: Pinus douglasiana and Quercus resinosa were the species of highest ecological value. Due to the removal effect, no significant changes in tree diversity were observed in the applied thinning scenarios. However, as thinning became more intense, at least one species (Quercus candicans) was lost. Thinning from below affected the oaks and thinning from above affected the pine species, which is also reflected in the spatial distribution of the remaining trees.
Limitations on study/implications: The analysis is static; therefore, it is recommended that a long-term study be conducted under varying ecological conditions.
Findings/conclusions: The effect of thinning on forest diversity, composition and structure depends on the type of thinning, condition of the structure, initial composition and intensity of removal. Thinning of less than 25% of the basal area, in the immediacy, allows timber harvesting without generating changes in the diversity, structure and composition of the temperate mixed forest under study.
Intellectual Capital Efficiency and Cost of Capital among Listed Manufacturing Companies In Nigeria
Authors: Ukpong Mmaeyen Ofonime , Ukpong Eno Gregory , Ibok Nkanikpo 
Published: September 2024

Despite the shift from industrial-based economy to knowledge-based economy, traditional accounting has continued to focus more on the physical assets in their financial statements to the exclusion of intangible asset. The main objective of this study therefore was to examine the effect of intellectual capital efficiency on cost of capital of manufacturing companies listed on the floor of the Nigerian Exchange Group from the period of 2014-2023. The research design adopted for the study was ex post facto, secondary data were used and the population of the study consisted of 62 listed manufacturing companies out of which a sample size of 27 was purposively selected. The data used in this study were analyzed using the Generalized Method of Moment (GMM) regression analysis. The findings of this study revealed that human capital efficiency (HCE), has a significant positive effect on the cost of equity; relational capital efficiency (RCE) has no significant effect on cost of equity; while structural capital efficiency (SCE) has no significant effect on cost of equity of listed manufacturing companies in Nigeria. Based on the above findings, it was concluded that intellectual capital efficiency can significantly impact on the cost of capital of listed manufacturing companies in Nigeria. It was therefore recommended among others that management of listed industrial goods companies should utilize advanced customer relationship management (CRM) systems to efficiently manage their interactions with customers and create competitive advantage.
تأثير منهج تعليمي باستخدام انموذج (درايفر) في تعلم مهارة قفز فتحا على حصان القفز في الجمناستك
Authors: Lec. Dr. Muhammad Yassin Al-Zahawi  
Published: September 2024

هدف البحث الى التعرف على الفروقات بين الاختبارات القبلية والبعدية لتأثير منهج تعليمي باستخدام انموذج (درايفر) في مهارة قفز فتحا على جهاز حصان القفز، واستخدم الباحث المنهج التجريبي لملائمته لطبيعة ومشكلة البحث واشتمل مجتمع وعينة البحث على طلاب كلية التربية البدنية وعلوم الرياضة المرحلة الثالثة والبالغ عددهم (14) طالب وتم تقسيمهم الى مجموعتين (تجريبية وضابطة)، وتم استبعاد (2) طالب لغرض التجربة الاستطلاعية، وتم إجراء التجربة الاستطلاعية للمنهج التعليمي وفق اسلوب درايفر على مجتمع البحث، لمعرفة مدى ملائمة وصلاحية لتعلم مهارة قفزة فتحا على حصان القفز. وقد تم اجراء الاختبارين القبلي والبعدي على عينة البحث، حيث استغرقت مدة البرنامج (5) اسابيع وبواقع وحدتين تعليميتين في الاسبوع. وتم معالجة البيانات الاحصائية عن طريق الحقيبة الاحصائية (spss).
Small molecular weight alginate gel porogen for the 3D bioprinting of microvasculature
Authors: Vanlauwe Florian , Dermaux Charlotte , Shamieva Sabina , Vermeiren Stef , Van Vlierberghe Sandra , Blondeel Phillip 
Published: September 2024

In order to recreate the complexity of human organs, the field of tissue engineering and regenerative medicine has been focusing on methods to build organs from the bottom up by assembling distinct small functional units consisting of a biomaterial and cells. This bottom-up engineering requires bioinks that can be assembled by 3D bioprinting and that permit fast vascularization of the construct to ensure survival of embedded cells. To this end, a small molecular weight alginate (SMWA) gel porogen is presented herein. Alginate is a biocompatible biomaterial, which can be easily converted into small porogen gels with the procedure reported in this article. The SMWA porogen is mixed with photo-crosslinkable hydrogels and leached from the hydrogel post-crosslinking to increase porosity and facilitate vascularization. As a proof of concept, this system is tested with the commonly used biomaterial Gelatin Methacryloyl (GelMA). The SMWA porogen-GelMA blend is proven to be bioprintable. Incubating the blend for 20 min in a low concentration phosphate buffered saline and sodium citrate solution significantly reduces the remaining porogen in the hydrogel . The intent to completely leach the porogen from the hydrogel was abandoned, as longer incubation times and higher concentrations of phosphate and citrate were detrimental to endothelial proliferation. Nonetheless, even with remnants of the porogen left in the hydrogel, the created porosity significantly improves viability, growth factor signaling, vasculogenesis, and angiogenesis in 3D bioprinted structures. This article concludes that the usage of the SMWA porogen can improve the assembly of microvasculature in 3D bioprinted structures. This technology can benefit the bottom-up assembly of large scaffolds with high cell density through 3D bioprinting by improving cell viability and allowing faster vascularization.
Structure-based virtual screening towards the discovery of novel thrombin inhibitors with Anti-HCC activities
Authors: Zhang Xiaoxi , Zheng Xumei , Han Chun , Wu Lintao 
Published: September 2024

IntroductionHepatic carcinoma (HCC) is one of the most lethal malignant tumors in the world, and new treatment regimens for this disease are urgently needed. Studies have shown that thrombin stimulates tumor progression by forming fibrin and activating platelets. Dabigatran etexilate, a thrombin inhibitor, can inhibit the activity of thrombin and prevent the proliferation and metastasis of HCC in cells and nude mice.MethodsThe present study was designed to find thrombin inhibitors with novel skeletons, and further confirm the correlation between thrombin inhibition and HCC prevention to identify potential anti-HCC drug leads.Results and DiscussionThe potential thrombin inhibitors were firstly screened in the Topscience Database, and 20 potential active molecules were found by molecular docking. The effect of these molecules on thrombin inhibition, coagulation and tumor proliferation were evaluated, and the definite activity of ZXX-4 was identified. Further in vivo assays in nude mice showed that ZXX-4 inhibited tumor proliferation in nude mice, reduced tumor metastasis, and enhanced the clinical efficacy of first-line drug sorafenib for the treatment of HCC. ZXX-4 can be further explored as an anti-tumor lead compound with a novel skeleton, and inhibition of thrombin can serve as a potential treatment strategy for HCC.
Cathepsin D elevates the fibrocalcific activity in human aortic valve cells through the ERK1/2-Sox9 pathway
Authors: Yao Qingzhou , The Erlinda , Nedumaran Balachandar , Zhai Yufeng , Ao Lihua , Fullerton David A. , Meng Xianzhong 
Published: September 2024

BackgroundHuman Aortic valve interstitial cells (AVICs) from calcific aortic valve disease (CAVD)-affected valves exhibit elevated fibrocalcific activity although the underlying mechanism remains incompletely understood. This study aimed to identify endogenous factors that promote aortic valve fibrocalcification.Methods and resultsProteomic analysis found increased cathepsin D levels in AVICs from CAVD-affected valves compared to AVICs from normal valves, and this finding was validated by immunoblotting. ELISA assay identified exacerbated release of cathepsin D by AVICs of diseased valves. Recombinant human cathepsin D upregulated the expression of runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), collagen I and collagen IV in human AVICs, resulting in the deposition of calcium and collagen. Blocking of the ERK1/2-Sox9 signaling pathway markedly reduced the pro-fibrocalcific effect of cathepsin D. Moreover, normal AVICs express and release greater levels of cathepsin D when exposed to soluble matrilin 2. Knockdown of cathepsin D attenuated the fibrocalcific response induced by soluble matrilin 2.ConclusionAVICs of diseased aortic valves produce and release greater levels of cathepsin D that exerts a pro-fibrocalcific effect on AVICs through the ERK1/2-Sox9 pathway. Soluble matrilin 2 up-regulates cathepsin D to elevate AVIC fibrocalcific activity. Over-expression of cathepsin D in the aortic valve may enhance the pathobiological activities in AVICs.
Association of triglyceride-glucose index with sarcopenia: NHANES 2011–2014
Authors: Wei Xue , Liu Dandan 
Published: September 2024

BackgroundA newly developed technique, the Triglyceride-glucose (TyG) index, supplies a more straightforward method to identify IR than the HOMA-IR (Homeostasis Model Assessment of Insulin Resistance). Yet no methodical analysis has looked into the link involving the TyG index and low muscle mass (LMM), low muscle strength (LMS), and sarcopenia within the US. Thus, this study intended to find any connection concerning the TyG index and LMM, LMS, and sarcopenia.MethodsBetween 2011 to 2014, data from the NHANES were used to conduct a nationally representative study involving 2,504 participants. LMM, LMS, and sarcopenia were the outcome variables. Moreover, this positive correlation persists irrespective of age and gender.ResultsThe TyG index revealed a significant correlation with the prevalence of developing LMM (OR = 1.63(1.26–2.11), p=0.001), LMS (OR = 1.61(1.36–1.91), p&lt;0.001) and sarcopenia (OR = 1.59 (1.23–2.07), p&lt;0.001), after correcting for all variables. Utilizing smooth curve fitting alongside two-piecewise linear regression models, an inverted U-shaped correlation between the TyG index and the prevalence of LMM, LMS, and sarcopenia. Finally, subgroup analysis revealed that the association between the TyG index and LMM, LMS, and sarcopenia was particularly evident in all gender, age subgroups, and individuals with a normal BMI of 25.ConclusionSarcopenia and the TyG index reveal an essential positive link. It highlights the potential utility of the TyG index as a screening tool for identifying individuals at risk of sarcopenia earlier.