bluuebunny/crossref_metadata_2025_split huggingface dataset:
PENGEMBANGAN PERANGKAT PEMBELAJARAN BERBASIS PENDEKATAN REALISTIC MATHEMATICS EDUCATION (RME) KONTEKS ETNOMATEMATIKA PULAU-PULAU KECIL PERBATASAN (MALUKU BARAT DAYA)
Authors: Lekitoo John Nandito 
Published: February 2025

Data dari Programme for International Student Assessment (PISA) menunjukkan kemampuan literasi matematika siswa Indonesia yang berada pada peringkat ke 38 dengan skor 379 dari 41 Negara atau peringkat 4 dari bawah. Jika dibandingkan hasil PISA pada tahun 2015 maka kemampuan literasi matematika siswa Indonesia mengalami penurunan pada tahun 2018. Di sisi lain kenyataan terkait pembangunan yang tidak merata di daerah-daerah yang dikategorikan sebagai daerah terdepan, terpencil, dan tertinggal (3T) memperkelam kondisi pembelajaran matematika yang semestinya dapat mengembangkan kemampuan literasi matematika siswa yang seharusnya pembelajaran matematika di daerah tersebut semestinya berorientasi pada budaya-budaya lokal pada daerah tersebut. Penelitian ini bertujuan untuk mengembangkan perangkat pembelajaran berbasis pendekatan realistic mathematics education (RME) konteks etnomatematika pulau-pulau kecil perbatasan (maluku barat daya). Model pengembangan yang digunakan adalah model 4D dengan sampel uji coba adalah siswa kelas VII SMP Negeri 1 Lemola. Instrumen yang digunakan dalam penelitian ini adalah lembar validasi perangkat pembelajaran, lembar uji keterbacaan, lembar observasi, angket respons, dan soal tes awal dan akhir. Teknik analisis data menggunakan uji N-Gain untuk mengetahui keefektifan perangkat. Hasil penelitian menunjukkan bahwa perangkat pembelajaran dikembangkan valid, praktis, dan efektif meningkatkan hasil belajar siswa sebesar 71%.
Refurbishment of Aged PC Power Plants with Advanced USC Technology
Authors: Fukuda Masafumi , Sone Hideyuki , Saito Eiji , Tanaka Yoshinori , Takahashi Takeo , Shiibashi Akira , Iwasaki Jun , Takano Shinichi , Izumi Sakae 
Published: February 2025

Abstract
The capacity of PC power plants in Japan rose to 35GW in 2004. The most current plants have a 600 deg-C class steam temperature and a net thermal efficiency of approximately 42% (HHV). Older plants, which were built in the ‘70s and early ‘80s, will reach the point where they will need to be rebuilt or refurbished in the near future. The steam temperatures of the older plants are 538 deg-C or 566 deg-C. We have done a case study on the refurbishment of one of these plants with the advanced USC technology that uses a 700 deg-C class steam temperature in order to increase the thermal efficiency and to reduce CO2 emissions. The model plant studied for refurbishing has a 24.1MPa/538 deg-C /538 deg-C steam condition. We studied three possible systems for the refurbishing. The first was a double reheat system with 35MPa/700 deg-C /720 deg-C /720 deg-C steam conditions, the second one was a single reheat 25MPa/700 deg-C/720 deg-C system, the last one was a single reheat 24.1MPa/610 deg-C/720 deg-C system. In addition to these, the most current technology system with 600 deg-C main and reheat temperatures was studied for comparison. The study showed that the advanced USC Technology is suitable for refurbishing old plants. It is economical and environmentally-friendly because it can reuse many of the parts from the old plants and the thermal efficiency is much higher than the current 600 deg-C plants. Therefore, CO2 reduction is achieved economically through refurbishment.
UltraGen: a Proposed Initiative by EPRI to Advance Deployment of Ultra-Supercritical Pulverized Coal Power Plant Technology with Near-Zero Emissions and CO2 Capture and Storage
Authors: Wheeldon John , Parkes Jack , Dillon Des 
Published: February 2025

Abstract
UltraGen is an initiative proposed by EPRI to accelerate the deployment and commercialization of clean, efficient, ultra-supercritical pulverized coal (USC PC) power plants that are capable of meeting any future CO2 emissions regulations while still generating competitively-priced electricity. In addition to reducing CO2, these advanced systems will have to achieve near-zero emissions of criteria pollutants (SO2, NOX, and filterable and condensable particulate) and hazardous air pollutants such as mercury.
Creep Properties of Advanced Steels for High Efficiency Power Plants
Authors: Charit I. , Murty K.L. , Koch C.C. 
Published: February 2025

Abstract
Driven mainly by the environmental and economic concerns, there is an urgent need for increasing the thermal efficiency of fossil fuel power generation plants, which still languishes at around 32% under current practices. Several programs have been undertaken worldwide to address this issue. One of the immediate options is to increase the steam temperature and pressure (to the supercritical range). However, the current power plant materials appear to have inadequate creep resistance under these demanding conditions along with corrosion/oxidation problems. Hence, to meet these challenges a variety of new steels and stainless steels have been developed in the United States, Japan, and Europe. Alloy design and microstructural design approaches in developing these alloys (ferritic/martensitic, austenitic and oxide-dispersion- strengthened steels) will be briefly reviewed. Further, this paper presents creep data of these steels found in the literature in terms of Larson-Miller parameters (LMP). A detailed account of plausible creep micromechanisms in these advanced steels is also be summarized.
Life Management of Creep Strength Enhanced Ferritic Steels—Solutions for the Performance of Grade 91 Steel
Authors: Coleman Kent 
Published: February 2025

Abstract
Recent in-service experiences have revealed critical vulnerabilities in creep-strength enhanced ferritic (CSEF) steels, with cracking potentially occurring surprisingly early in a component's operational life. Fabrication irregularities have been found to introduce substantial property deficiencies compared to average material performance, raising serious concerns among industry users regarding personnel safety and equipment reliability. In response, a collaborative research program between the Electric Power Research Institute and Structural Integrity Associates, Inc. has been initiated to comprehensively address these critical material challenges. The program's extensive scope encompasses a holistic approach to material management, including rigorous investigations spanning material procurement, shop fabrication, field erection, and appropriate quality assurance procedures for each implementation phase. The research will systematically examine the behavior of both base and weld metals, with a strategic focus on developing a comprehensive life prediction methodology and optimizing maintenance protocols. Beyond its core technical objectives, the program is designed to facilitate knowledge exchange through regular participant workshops, where both program-generated findings and global utility experiences will be critically reviewed and discussed to ensure the research maintains optimal direction and relevance. This collaborative effort aims to establish a robust framework for understanding, mitigating, and managing the complex challenges associated with CSEF steel materials in high-performance industrial applications.
Creep Behavior and Microstructural Analysis of FB2 Trial Rotor Steel
Authors: Di Gianfrancesco A. , Cipolla L. , Venditti D. , Neri S. , Calderini M. 
Published: February 2025

Abstract
The development of new ferritic-martensitic steels for rotor applications was a primary focus of the joint research projects COST 501 and COST 522. During COST 501, multiple trial compositions of 9-10% chromium steels underwent comprehensive testing, with the COST 522 project ultimately selecting the most promising candidate, FB2, a 10% Cr steel containing cobalt and boron additions, notably without tungsten. Società delle Fucine (SdF) successfully produced an FB2 prototype rotor using a conventional manufacturing process involving ladle furnace and vacuum degassing techniques. A comprehensive creep test program was initiated to characterize the full-size component's properties, with results demonstrating consistency with laboratory material performance in both creep resistance and ductility. The extensive testing, which exceeded 30,000 hours, aimed to achieve a 15-20 MPa improvement over Grade 92, targeting 100,000 creep hours at 600°C. Complementing the mechanical testing, a parallel microstructural investigation program was launched to evaluate structural evolution and gain deeper insights into boron's role as a creep-strengthening element in advanced ferritic-martensitic steels.
Manufacturing Experiences and Investigation of Properties of 12% Cr Steel Forgings for Steam Turbines
Authors: Mikami M. , Wakeshima Y. , Miyata T. , Kawano K. 
Published: February 2025

Abstract
Demand of 9-12% chromium steel rotor forgings becomes higher from point of view of environmental protection in coal fired fossil power generations. Japan Casting & Forging Corporation (JCFC) has manufactured 9-12% Cr steel rotor forgings with JCFC's original techniques since 1991. Recently, type E steel developed by European COST program has been trial melted to meet the demand of such high Cr steel forgings in the world. Full size two forgings have been manufactured from approximately 70 ton ingot applying Electro Slag Hot Topping by JCFC (ESHT-J) process. One of the trial forgings has been austenitized at higher temperature in the quality heat treatment to improve long term creep strength. Their productivities and sufficient qualities have been ascertained.
Development of Ni-Based Superalloy for Advanced 700°C-Class Steam Turbines
Authors: Yamamoto Ryuichi , Kadoya Yoshikuni , Nakano Takashi , Tanaka Yoshinori , Magoshi Ryotaro , Kurata Seiji , Ueta Shigeki , Noda Toshiharu 
Published: February 2025

Abstract
Advanced 700°C-class steam turbines require the use of austenitic alloys instead of conventional ferritic 12Cr steels, which are inadequate in creep strength and oxidation resistance above 650°C. While austenitic alloys offer improved performance, they traditionally possess a significantly higher coefficient of thermal expansion (CTE) compared to 12% Cr steels. Through extensive research, the authors systematically investigated the effects of various alloying elements on thermal expansion and high-temperature strength. As a result of these investigations, they developed "LTES700," an innovative nickel-based superalloy specifically designed for steam turbine bolts and blades. This novel alloy uniquely combines a coefficient of thermal expansion comparable to 12Cr steels with high-temperature strength equivalent to conventional superalloys like Refractaloy 26, effectively addressing the critical limitations of previous materials.
Nano-Structured Erosion Resistant Coatings for Gas and Steam Turbines
Authors: “Swami” Swaminathan V.P. , Wei Ronghua , Gandy David W. 
Published: February 2025

Abstract
Erosion from solid and liquid particles in gas turbine and steam turbine compressors degrades efficiency, increasing downtime and operating costs. Conventional erosion-resistant coatings have temperature and durability limitations. Under an Electric Power Research Institute (EPRI) project, ultra-hard nano-coatings (~40 microns thick) were developed using Plasma Enhanced Magnetron Sputtering (PEMS). In Phase I, various coatings—including TiSiCN nanocomposites, stellite variants, TiN monolayers, and multi-layered Ti-TiN and Ti-TiSiCN—were deposited on turbine alloys (Ti-6Al-4V, 17-4 PH, Custom-450, and Type 403 stainless steel) for screening. Unlike conventional deposition methods (APS, LPPS, CVD, PVD), PEMS employs high-current-density plasma and heavy ion bombardment for superior adhesion and microstructure density. A novel approach using trimethylsilane gas successfully produced TiSiCN nanocomposites. Stellite coatings showed no erosion improvement and were discontinued, but other hard coatings demonstrated exceptional erosion resistance—up to 25 times better than uncoated substrates and 20 times better than traditional nitride coatings. This paper details the deposition process, coating properties, adhesion tests, and characterization via SEM-EDS, XRD, nanoindentation, and sand erosion tests.
Ferritic and Austenitic Grades for the New Generation of Steam Power Plants
Authors: Caminada S. , Cipolla L. , Cumino G. , Di Gianfrancesco A. , Minami Y. , Ono T. 
Published: February 2025

Abstract
The increasing steam parameters in modern high-efficiency fossil fuel power plants demand advanced materials with enhanced creep strength for operation under extreme temperature and pressure conditions. Tenaris has focused on developing ferritic-martensitic and austenitic grades for tube and pipe applications. At TenarisDalmine, efforts on ferritic-martensitic steels include ASTM Grade 23, a low-alloyed alternative to Grade 22 with 1.5% W, offering good weldability, creep resistance up to 580°C, and cost competitiveness. Additionally, ASTM Grade 92, an improved version of Grade 91, provides high creep strength and long-term stability for components like superheaters and headers operating up to 620°C. At TenarisNKKT R&D, austenitic steel development includes TEMPALOY AA-1, an improved 18Cr-8NiNbTi alloy with 3% Cu for enhanced creep and corrosion resistance, and TEMPALOY A-3, a 20Cr-15Ni-Nb-N alloy with superior creep and corrosion properties due to its higher chromium content. This paper details the Tenaris product lineup, manufacturing processes, and key material properties, including the impact of shot blasting on the steam oxidation resistance of austenitic grades. It also covers ongoing R&D efforts in alloy design, creep testing, data assessment, microstructural analysis, and damage modeling, conducted in collaboration with Centro Sviluppo Materiali.
The Use of Advanced Materials on Large Steam Turbines in Supercritical Steam Cycles in the Czech Republic
Authors: Prchlik L. , Polivka V. , Kapic M. , Duchek K. 
Published: February 2025

Abstract
The paper summarizes several years of research on the application of modern materials in the design of large steam turbines operating at high temperatures. The use of 9-12% chromium steels on main steam turbine components, the application of abradable coatings in seals and the seize/corrosion protection of selected components by modern surfacing techniques are presented. Results of materials long-term testing supported by the field application at elevated steam temperatures were used to verify the new material solutions and manufacturing techniques. The second section of the paper presents the design of a new 660 MW supercritical power plant to be built in the Czech Republic between 2008 and 2010. The unit parameters and steam cycle characteristics are presented together with the visualization of the new block. The steam turbine design is discussed with respect to the application of advanced materials.
Novel Hafnium-Containing Steels for Power Generation
Authors: Grice R.J. , Faulkner R.G. , Yin Y. 
Published: February 2025

Abstract
Research has demonstrated that creep damage in power plant steels is directly linked to grain boundary precipitates, which serve as nucleation sites for cavities and micro-cracks. The formation of M23C6 carbides along grain boundaries creates chromium-depleted zones vulnerable to corrosion and significantly reduces creep life due to rapid coarsening. Through combined Monte Carlo grain boundary precipitation kinetics and continuum creep damage modeling, researchers have predicted that increasing the proportion of MX-type particles could enhance creep performance. This hypothesis was tested using hafnium-containing steel, which showed improved creep and corrosion properties in 9% Cr steels. Ion implantation of Hafnium into thin foils of 9 wt% Cr ferritic steel resulted in two new types of precipitates: hafnium carbide (MX-type) and a Cr-V rich nitride (M2N). The hafnium carbide particles, identified through convergent beam diffraction and microanalysis, appeared in significantly higher volume fractions compared to VN in conventional ferritic steels. Additionally, Hafnium was found to eliminate M23C6 grain boundary precipitates, resulting in increased matrix chromium concentration, reduced grain boundary chromium depletion, and enhanced resistance to intergranular corrosion cracking.
Long-Term Crack Behavior under Creep and Creep-Fatigue Conditions of Heat Resistant Steels
Authors: Scholz A. , Berger C. , Mueller F. , Klenk A. 
Published: February 2025

Abstract
High temperature components with notches, defects and flaws may be subject to crack initiation and crack propagation under long-term service conditions. To study these problems and to support an advanced remnant life evaluation, fracture mechanics procedures are required. Since a more flexible service mode of power plants causes more start up and shut down events as well as variable loading conditions, creep-fatigue crack behavior becomes more and more decisive for life assessment and integrity of such components. For steam power plant forged and cast components, the crack initiation time and crack growth rate of heat resistant steels were determined in long-term regime up to 600 °C. Component-like double edge notched tension specimens have been examined. The results are compared to those obtained using the standard compact tension specimen. Crack initiation time and crack growth rate have been correlated using the fracture mechanics parameter C*. The applicability of the stress intensity factor KI to describe the creep crack behavior is also being assessed. A modified Two-Criteria-Diagram was applied and adapted in order to recalculate crack initiation times under creep-fatigue conditions. Recommendations are given to support the use of different fracture mechanics parameters in order to describe the long-term crack behavior under creep and/or creep-fatigue conditions.
Failure Behavior of High Chromium Steel Welded Joints Under Creep and Creep-Fatigue Conditions
Authors: Takahashi Y. , Tabuchi M. 
Published: February 2025

Abstract
The strength of welded joints in high-chromium steels is a critical concern for operators of ultra-supercritical thermal power plants. To investigate this, a series of creep-fatigue tests with tensile strain holds were conducted on welded joints of two widely used high-chromium steels: Grade 91 and Grade 122. The tests revealed that failure consistently occurred in the fine-grain heat-affected zone, even at relatively low temperatures and short durations, whereas in simple creep tests, failure occurred in the plain base metal region. Four different procedures were used to predict failure life, and their results were compared with experimental data. Among them, a newly proposed energy-based approach provided the most accurate failure life estimations, independent of material type and temperature.
Alternative Filler Materials for Dissimilar Metal Welds Involving P91 Materials
Authors: Coleman K. , Gandy D. 
Published: February 2025

Abstract
In the late 1980s, the domestic utility industry experienced failures in dissimilar metal welds (DMWs) between low-alloy ferritic tubing and austenitic tubing in superheaters and reheaters. Extensive research by EPRI identified that nickel-based filler metals significantly improved service life compared to 309 SS filler metals. Additionally, optimized joint geometries and increased weld metal reinforcement were found to further enhance durability. A new nickel-based filler metal was developed with thermal expansion properties similar to the low-alloy base metal, along with a low chromium content designed to minimize the carbon-denuded zone. However, this filler metal was never commercialized due to its tendency to microfissure, which resulted in a shorter-than-expected service life. This paper explores further investigations into the microfissuring of this filler metal and examines long-term testing to assess its suitability for high-temperature applications.
Design Considerations for Advanced Materials in Oxygen-Fired Supercritical and Ultra-Supercritical Pulverized Coal Boilers
Authors: Hack Horst , Seltzer Andrew , Stanko Greg 
Published: February 2025

Abstract
As the demand for worldwide electricity generation grows, pulverized coal steam generator technology is expected to be a key element in meeting the needs of the utility power generation market. The reduction of greenhouse gas emissions, especially CO2 emissions, is vital to the continued success of coal-fired power generation in a marketplace that is expected to demand near-zero emissions in the near future. Oxycombustion is a technology option that uses pure oxygen, and recycled flue gas, to fire the coal. As a result, this system eliminates the introduction of nitrogen, which enters the combustion process in the air, and produces a highly-concentrated stream of CO2 that can readily be captured and sequestered at a lower cost than competing post-combustion capture technologies. Oxycombustion can be applied to a variety of coal-fired technologies, including supercritical and ultra-supercritical pulverized coal boilers. The incorporation of oxycombustion technology in these systems raises some new technical challenges, especially in the area of advanced boiler materials. Local microclimates generated near and at the metal interface will influence and ultimately govern corrosion. In addition, the fireside corrosion rates of the boiler tube materials may be increased under high concentration oxygen firing, due to hotter burning coal particles and higher concentrations of SO2, H2S, HCl and ash alkali, etc. There is also potential to experience new fouling characteristics in the superheater and heat recovery sections of the steam generator. The continuous recirculation of the flue gases in the boiler, may lead to increasing concentrations of deleterious elements such as sulfur, chlorine, and moisture. This paper identifies the materials considerations of oxycombustion supercritical and ultrasupercritical pulverized coal plants that must be addressed for an oxycombustion power plant design.
Egymásrautaltság : Gondolatokaz alárendeltségről és a kiszolgáltatottságról
Authors: Jakab Nóra 
Published: February 2025

A munkaerőpiacon a más részére történő önálló vagy önállótlan munkavégzés során az egymásrautaltság értelemszerűen benne foglaltatik a jogviszonyban. A pacta sunt servanda, a jog és felelősség vállalása mindkét szerződő felet a szerződés betartására készteti. Ugyanakkor, amikor eltűnik a partnerség az egymásrautaltság állapotából, szükség van átláthatóságra, kiszámíthatóságra, biztonságra: védelemre. Az utóbbi években eltűnt a stabil foglalkoztatás, a munkavállaló helyett munkavégzőről beszélünk, és a függő viszonyok egyenlőtlenségét elemezzük. Mi történt valójában? Ebben a tanulmányban ezekre a változásokra mutatok rá, gondolkodom a szerződési elvről és az egymásrautaltság árnyalatiról.
IoT-Based Smart Lockers: A Validation for the Saudi Arabian Market
Authors: Khan Waseem Ullah 
Published: February 2025

The adoption of IoT technology has revolutionized logistics and e-commerce worldwide. IoT smart lockers enable efficient last-mile delivery through secure, automated storing and retrieval. In this article, the viability of smart lockers in Saudi Arabia, in terms of Vision 2030 aspirations, is examined through a qualitative case study, with lessons drawn from international implementations such as Amazon Hub, Hive Box, and InPost Lockers. Economic savings, efficiency in logistics, and ease of use for consumers rank high, but face-to-face preference and compliance with laws and legislation hinder them. There is a critical necessity for localized adaptations for driving adoption, and collaboration with logistics providers and governments is paramount. Integration with Saudi smart city development is a critical opportunity for rollout. Consumer willingness and pilot studies in key urban locations must be considered in future studies. Actionable information for stakeholders for the rollout of IoT-powered smart lockers in Saudi Arabia’s modernization of its logistics infrastructure is presented through this paper.