bluuebunny/crossref_metadata_2025 huggingface dataset:
Limestone in cement compositions with additives to increase frost resistance
Authors: Корчунов И.В. , Потапова Е.Н. , Сивков С.П. , Волошин Е.А. , Лукошкин С.А.
Published: December 2023

Исследование проведено с целью определить влияние известняка как минеральной добавки в составе цемента на морозостойкость цементного камня. Структура и свойства материалов были изучены с применением методов рентгенофазового и дифференциально-термического анализов, сканирующей электронной микроскопии, пикнометрического определения плотности, а также путем физико-механических испытаний стандартных образцов. Установлено, что замещение части клинкера в цементе известняком в количестве до 15 % масс. может привести к некоторому снижению прочности, однако этот недостаток компенсируется большей экологичностью и повышенной морозостойкостью такого добавочного цемента. Показано, что цементы с добавкой известняка успешнее, чем бездобавочный цемент, противостоят коррозии при попеременном замораживании—оттаивании в водном растворе NaCl. Причина — образование в цементном камне в присутствии СаСО3 плотной, химически более инертной по отношению к NaCl структуры на основе кристаллов фаз AFm- CO3. В отсутствие известняка структура формируется фазами AFm-SO4, склонными к многократному цикличному взаимодействию с ионами порового раствора с образованием хлорсодержащих фаз AFt. Это приводит к перекристаллизации кристаллогидратов, возникновению внутренних напряжений  и, в конечном счете, к снижению прочности цементного камня. Таким образом, при прочих равных условиях выше морозостойкость цементного камня, в котором благодаря введению в состав цемента добавки известняка содержится минимальное количество моногидросульфоалюминатов кальция и повышенное количество гидрокарбоалюминатов кальция.

The purpose of the research was to determine the effect of limestone as a mineral additive in cement on frost resistance of hardened cement. The structure and properties of materials have been studied us-ing methods of X-ray phase and differential thermal analysis, scanning electron microscopy, pycnometer density tests, as well as by physical and mechanical tests of standard samples. It was found that the replacement of the clinker in cement with limestone in an amount up to 15 wt. % can lead to some reduction in strength, but this drawback is compensated by a greater environmental friendli-ness and increased frost resistance of such cement.
Modelling of aspiration modes of ball tube mills
Authors:  Богданов В.С. ,  Анциферов С.И. ,  Богданов Д.В. ,  Бажанова О.И. ,  Сычев Е.А.
Published: December 2023

Рассмотрено моделирование аспирационных режимов шаровой барабанной мельницы с учетом термовлажностных условий измельчения многокомпонентной шихты, в составе которой содержатся клинкер, гипс и шлак. Получены уравнения для расчета следующих показателей: размера частиц готового продукта; давления водяного пара в аспирационном воздухе в зависимости от влагосодержания шихты при различных значениях разряжения аспирационного воздуха; коэффициента динамической вязкости аспирационного воздуха в зависимости от влагосодержания шихты при различных температурах. Приведен пример численного расчета поля скоростей аспирационного воздуха в барабане мельницы.

Modelling of the aspiration modes of a ball tube mill taking into account the thermal and moisture conditions of grinding a multicomponent charge containing clinker, gypsum and slag is discussed. Equations for calculating the following indicators are obtained: the particle size of the finished product, water vapor pressure in the aspiration air depending on the moisture content of the charge at different values of underpressure of the aspiration air; the coefficient of dynamic viscosity of the aspiration air depending on the moisture content of the charge at different temperatures. An example of numerical calculation of the velocity field of aspiration air in the mill shell is given.
Synthesis of ultrafine additive produced by hydrolysis of Portland cement for cement matrix modification
Authors: Урханова Л.А. , Лхасаранов С.А. , Данзанов Д.В. , Макаров В.Р.
Published: December 2023

В статье представлены результаты исследований использования коллоидной добавки, полученной путем гидролиза портландцемента, для модификации цементного камня. Разработан способ получения такой добавки, установлены ее оптимальные дозировки, предложен механизм гидратации цемента в ее присутствии. Установлено, что исследованная добавка в интервале дозировки 0,2—1 % массы цемента (в расчете  на 2 %-ный раствор) является ускорителем твердения цемента и модификатором, повышающим его прочность. Предел прочности при сжатии цементного камня с исследованными добавками во все сроки твердения выше, чем у контрольных образцов. Максимальные значения прочности показали образцы цементного камня в возрасте 28 сут —  98—100 МПа.

The paper presents the results of studies of the use of colloidal additive produced by hydrolysis of Portland cement to modify the cement matrix. The method for obtaining this additive has been developed, its optimum dosages established, the mechanism of cement hydration in its presence suggested. It was found that the examined additive in the dosage interval of 0.2—1% of cement mass (in relation to 2% mortar) is a cement hardening agent and a cement modifier increasing its strength. The compressive strength of cement matrix with the tested additives in all periods of hardening was higher than that of the control samples. The maximum strength values were shown by the samples of cement matrix at the age of 28 days — 98—100 MPa.
Best Available Technologies as a driving force of ecological and technological modernization of cement production
Authors: Потапова Е.Н. , Гусева Т.В. , Тихонова И.О. , Аверочкин Е.М.
Published: December 2023

Описаны особенности перехода к технологическому нор­мированию в сфере охраны окружающей среды в Российской Федерации, основанному на концепции наилучших доступных технологий. Обсуждены требования и технологические показа­тели наилучших доступных технологий в сфере производства цемента, а также подходы к применению альтернативного топ­лива, повышению ресурсной эффективности и установлению индикативных показателей выбросов парниковых газов.

Features of the transition to technological standardization in the field of environmental protection in the Russian Federation based on the concept of the best available technologies are described. Requirements and technological parameters of the best available technologies in the field of cement production, as well as approaches to the use of alternative fuels, increasing the resource efficiency and the establishment of indicative values of greenhouse gas emissions are discussed.
Role of material selection in mix optimization of 3D printable concrete
Authors: Триведи А.  ,  Мандре М.К. , Сингх Б.  ,  Оджха П.Н.
Published: December 2023

3D-печать представляет собой инновационный метод аддитивного производства с цифровым управлением, который позволяет создавать архитектурные и структурные компоненты без опалубки, в отличие от традиционных методов строительства с использованием бетона. Наиболее важные свойства свежеприготовленного бетона —  экструдируемость и сохраняемость формы уложенного материала, которые тесно связаны с удобо укладываемостью и допустимым временем работы со смесью*. На эти характеристики существенно влияют пропорции между содержанием компонентов смеси и наличие в ее составе химических добавок. Настоящее исследование посвящено оптимизации дозировки материалов при изготовлении смеси для 3D-печати. При разработке рецептуры смеси использовались цемент, зола-унос, микрокремнезем, мелкий заполнитель и вода, а также химические добавки. Результаты настоящего исследования показывают, что как оптимизация смеси с использованием различных комбинаций цементных вяжущих, так и выбор оптимальной дозировки химических добавок очень важны для получения бетона, пригодного для 3D-печати.

The printing process is a novel digitally-controlled additive manufacturing method which can build architectural and structural components without formwork, unlike conventional concrete construction methods. The most important fresh properties are extrudability and buildability, which have mutual relationships with workability and open time. These properties are greatly influenced by the mix proportions and the presence of superplasticiser, retarder, accelerator and polypropylene fibres. The present study is about optimisation of material quantity to obtain a 3D printable mix with 3D printer. Cement, fly ash, silica fume, fine aggregate, water and chemical admixture are used for developing a 3D printable mix and optimum dose of chemical admixture such as PC base chemical admixture and Viscosity Modifying Admixture (VMA) is used to optimise the 3D printable mix. The study indicated that the dosage of superplasticizer needed to achieve the similar flow value increases as a/b increases. The plastic viscosity increased by about 35 % when a/b increased from 0.75 to 0.9. The flow was ranging from 160 to 225 mm which indicates dependency on the material type and packing density. Study also highlighted that yield stress of mix is important to achieve buildability and low yield stress value can lead to collapse of layers and will also prevent layer wise buildability. The optimum dose of polypropylene fibre was found to be 0.1 % to achieve 3D printable mix without clogging or shrinkage crack. The open time is found to be about 12—15 minutes for the materials. Studies reported in this paper highlights that both mix optimisation with different combination of cementitious binders and selection of optimum dosage of superplasticizer and VMA are very critical in achieving a 3D printable concrete.
Mechanics of crushing media in ball tube mills with transverse-longitudinal motion of grinding bodies
Authors:  Богданов В.С. ,  Анциферов С.И. ,  Богданов Д.В. ,  Сычев Е.А.
Published: December 2023

В статье рассматривается методика расчета кинематических параметров движения мелющих тел в шаровой барабанной мельнице с их поперечно-продольным перемещением. Получены математические зависимости, позволяющие рассчитать углы отрыва шара от внутренней поверхности барабана мельницы и наклонной межкамерной перегородки. Приведен анализ расчетов траектории движения и углов отрыва шара в течение цикла. Подтверждена интенсификация движения мелющих тел за счет их дополнительного продольного перемещения наклонной межкамерной перегородкой.

The paper considers the method of calculation of kinematic parameters of the transverse-longitudinal motion of grinding bodies in a ball tube mill. The mathematical dependences allowing to calculate the angles of ball bounce from the inner surface of the mill tube and the inclined inter-chamber partition were obtained. The analysis of calculations of the ball movement trajectory and breakaway angles during the cycle is given. The intensification of grinding bodies’ motion due to their additional longitudinal displacement by the inclined inter-chamber partition is confirmed.
The Language of Eco-feminism and Early 20th century Feminist writers Buck and Cather
Authors: Yogmaya Kandel
Published: December 2023

This paper explores the language of eco-feminism and its intersection with the works of early 20th-century feminist writers Buck and Cather. Ecofeminism is a branch of feminism that examines the connections between women and nature, emphasizing the ways both nature and women are treated by patriarchal society. The paper examines the historical evolution of ecofeminist thought and its key tenets, including the revaluing of nonpatriarchal structures and a view of the world that respects organic processes and holistic connections. It also discusses the early critiques of ecofeminism and its relationship with environmentalism. The works of early 20th-century feminist writers Buck and Cather are analyzed in the context of ecofeminist philosophy, exploring how their language and themes intersect with the principles of ecofeminism. Keywords: Ecofeminism, Feminism, Environmentalism, Early 20th-century, Writers, Buck,Cather
The Employment Dynamics and Economic Contributions of Community College Graduates in Rupandehi District, Nepal
Authors: Rana Ashok , Gautam Jagannath , Kuwar Dhan , Chaudhary Homan , Kharal Hemchandra
Published: December 2023

This study investigates the role of human resources graduating from Rupandehi district's community colleges in Nepal's economic development. The research emphasizes the need to reduce income and social security disparities across industries, regions, and labor markets for balanced employment opportunities, especially for higher education institution (HEI) graduates. Data from 162 community college graduates in Rupandehi district, spanning 17 colleges, are meticulously collected while adhering to ethical and safety measures. This research provides valuable insights into the status and role of human resources produced by community colleges, benefiting various stakeholders. In the context of Nepal, the study addresses the shift in labor outmigration trends to developed countries for employment opportunities. It explores how graduates effectively convert their skills and knowledge into sustainable income within diverse economic sectors. Higher education institutions (HEIs) are integral to Nepal's economy, producing a dynamic workforce. The study highlights the importance of ensuring that investments in education lead to productive employment outcomes, with many graduates contributing to self-employment and job creation. Employing a mixed-method approach, combining field surveys and HEI data, this research sheds light on the complex interplay between education and employment in Nepal. Keywords: Community College Graduates, Employment Dynamics, Economic Contributions, Unemployment Challenges, Income Disparities and Higher Education Institutions
უცხოური ენების სწავლების ძირითადი ეტაპები ჩინეთში
Authors: ბერიშვილი ლეილა , მუშკუდიანი ზურაბ , ოსტრიანსკა მარინა
Published: December 2023

მიუხედავად ჩინური ცივილიზაციის ხანგრძლივი ისტორიისა, ჩინეთში, ინგლისური ენის ფორმალური სწავლების სათავედ ინგლისურენოვანი მისიონერების მიერ დაარსებული სკოლები ითვლება და ჩვენც ამ მიდგომას უნდა დავეთანხმოთ. ჩინეთ-იაპონიის ომის (1894-1895 წწ.) შედეგად, მთავრობის წარმომადგენლებმა სულ უფრო დაიწყეს იმის გაცნობიერება, რომ დასავლური საზოგადოებიდან სწავლა და გამოცდილების გაზიარება, მჭიდრო კონტაქტები ერთადერთი გზა იყო განვითარებისა და თუნდაც, უცხოური აგრესიის წინააღმდეგ საბრძოლველად. ამგვარად წახალისდა ინგლისურენოვანი განათლება ამ მოთხოვნის დასაკმაყოფილებლად. 1903 წელს ინგლისური შეტანილ იქნა ეროვნული საშუალო სკოლის სასწავლო გეგმებში. ქვეყნის ისტორიაში იყო პერიოდები, როცა უცხოური ენის სწავლება განიხილებოდა ქვეყნის ეროვნული ინტერესების საწინააღმდეგოდ, თუმცა გონივრული პოლიტიკის შედეგად, ჩინეთმა სძლია ცალმხრივობას და დღეს ის გვევლინება ნოვატორად, რომელსაც საინტერესო მიდგომები აქვს ინგლისურის ენის, როგორც სასწავლო საგნის მიმართ.
LEGAL ASPECTS OF HEALING THERAPY PROGRAM METHADON (PTRM) TO HEALTH PERSONNEL AND PATIENTS AT THE REGIONAL HOSPITAL DR. DJASAMEN SARAGIH PEMATANG SIANTAR CITY
Authors: Mulyadi Mulyadi , Fitriyani Pakpahan Elvira , Duan Ferry
Published: December 2023

Drugs (narcotics, psychotropics, and dangerous drugs) have basically been used by mankind for a long time. Many types of narcotics and psychotropics provide great benefits when used properly and correctly. In the field of medicine, narcotics and psychotropic substances can cure various diseases and end suffering. This indicates, drugs do not always have a bad impact. The problem arises when drugs are abused and used excessively. The problem of drug use disorders (narcotics, psychotropics and other addictive substances) is a complex problem whose management involves many scientific fields, both medical and non-medical. Drug use disorders are very complex bio-psycho-socio-cultural problems that need to be addressed in a multidisciplinary and cross-sectoral manner in a comprehensive and consistent program. This is in accordance with the provisions of Law Number 35 of 2009 concerning narcotics in article 54. Djasamen Saragih Regional General Hospital Pematang Siantar City is one of the hospitals that participate in carrying out medical rehabilitation and social rehabilitation through the Methadon Maintenance Therapy Program (PTRM).In this case, from the applicable law, the MMT program is adequate although it needs improvements both in the ability of health workers, both patient non-compliance in undergoing the program and the participation of local governments in supporting the improvement of the ability of health workers in the MMT program and the need for implementing this program with spiritual therapy.
LEGAL STATUS OF LAND RIGHTS CONTROLLED BY BUDDHIST RELIGIOUS FOUNDATIONS IN MEDAN CITY
Authors: Amanda Esitria Sumampow Michelle , Fitriyani Pakpahan Elvira , Pakpahan Kartina , Nafrial Ramon , Adhiguna Samvara Made
Published: December 2023

The purpose of this study is to analyze the mechanism in the process of ownership of the property rights on the foundation land, as well as the factors that obstruct the process of ownership of the property rights on the foundation land, and to analyze the legal remedies available to a foundation so that land owned by the foundation but certified in the name of an individual can be changed to the foundation's name. The approach used was the juridical-empirical method, which is legal research carried out by combining a juridical legal approach with empirical elements. Literature review and interviews were employed as data collecting or processing techniques in this study. The research results obtained are based on Law 28 of 2004 concerning Amendments to Law 16 of 2001 on Foundations at ensuring greater legal certainty and order. Therefore, the Management of the Buddhist Religious Foundation in Medan City is required to continue the process of transferring for rights or applying for rights at the National Land Office in an orderly manner. Based on Government Regulation No. 18 of 2021 on Right to Manage, Land Rights, Multi-story Housing Units, and Land Registration in Article 87 Paragraph 1, "Systematic Land Registration". As a result, Buddhist Religious Foundations can conduct Land Registration in line with the applicable legislation. Based on the Decree of the Directorate General of Buddhist Community Guidance No. 323 of 2017 on Registration of Buddhist Religious Institutions so that Buddhist Religious Foundations can be independently registered to the Ministry of Religious Affairs through the Organization and Houses of Worship Information System (SIORI) on the website: https://sioribuddha.kemenag. go.id/.
Legal Certainty on Fiduciary Guarantee Deed Based on Power of Attention Under The Leasing Agreement
Authors: Rizkiryanto Permana Recky
Published: December 2023

The Fiduciary Guarantee Law requires legal certainty over the implementation of fiduciary guarantee object activities so that special rights can arise from the issuance of a fiduciary guarantee certificate. guarantee binding agreement between creditor and debtor. The power of attorney under the hand used in imposing fiduciary guarantees on credit objects does not contain the actual will of the debtor, this can lead to unilateral arbitrariness by creditors to take credit objects against the will of the debtor so as to eliminate the debtor's rights as the party who controls the object of the fiduciary guarantee. The method used is descriptive-analysis with a normative juridical approach. The research phase uses library research with secondary data and field studies with primary data. This data collection was obtained by means of library research and also interviews obtained by means of field studies. Furthermore, the data were analyzed using the juridical-qualitative method. The use of a power of attorney under the hand as the basis for loading/making a fiduciary deed is "illegitimate". Legal certainty on the Fiduciary Deed based on a Power of Attorney under the hand in a leasing agreement, is not achieved by using a power of attorney as the basis for loading/making a fiduciary deed, then based on the teaching of causality the validity of the fiduciary deed will depend on the validity of the power of attorney that.
REVIEW JURIDICAL REDISTRIBUTION OF LAND TO THE OBJECT OF LAND IN THE DISTRICT DELI SERDANG
Authors: Tanjaya Willy , Yusriando Yusriando , Liesaputra Djevin Septry
Published: December 2023

For the State of Indonesia  the land is a gift from God Almighty  as well as national wealth Land in an agrarian society has a very important  positions   so it  is  very  necessary  for  the   state   and   society    to    mak e  the  best  use    of    th e  land    for    the welfare of the people for their survival Therefore  this discussion is very interesting to study This    research    is: analyzing the    laws    and    regulations concerning    the redistribution of land objects in Indonesia  analyzing the implementation of redistribution land object in Deli Serdang Regency  analyzing the obstacles experienced in land redistribution for land objects in Deli Serdang Regency Can provide benefits for the development of legal science  especially regarding Land Redistribution in Indonesia  Practical Benefits  is expected to provide useful information useful for the community/readers and Notaries in carrying out their duties related to Land Redistribution of Land Objects in Indonesia Indonesia The theoretical framework used is legal certainty  namely providing legal certainty to individuals with the aim of protecting individuals from the arbitrariness of the government or other legal entities.
The Legal Status Of Land Tenure Of Foreign Nationals Obtained Through Public Auction On The Object Of Mortgage Rights
Authors: Purwa Patriana , Prasetyo Geta Ilham Adi , Farizy Budi Salman , Pratama Mariam , Noor Aslan
Published: December 2023

The concept of citizenship stipulates that non-citizens are prohibited from acquiring land ownership in Indonesia, meaning that "only Indonesian citizens are eligible for land ownership rights in Indonesia." This regulation is outlined in Article 21 and Article 26, paragraph (2) of the UUPA. If a foreign national is unable to own land, they are granted land tenure status through auctions, entailing rights of usage or other entitlements. This situation can potentially lead to issues of legal ambiguity and inconsistencies in the regulations governing property rights for foreign nationals who acquire land through auctioned mortgage rights. The primary concern addressed by the author is to determine the status of the auction minutes document as proof of land rights transfer to foreign nationals and the legal status of land rights control held by foreign nationals who obtain property through mortgage rights auctions. The objective of this study is to investigate and analyze the validity of the auction minutes document as evidence of land rights transfer to foreigners and to analyze the legal status of land rights held by foreign nationals who acquire property through mortgage rights auctions. The research employs a normative juridical research method, specifically a normative legal research approach. This approach encompasses both a statutory analysis and a conceptual analysis. Based on the findings of this research: 1. The auction minutes' position as evidence of the transfer of land ownership rights to foreign nationals indicates that these minutes, prepared by the auctioneer, can serve as a valid basis for documenting the transfer of rights to foreign nationals. 2. Regarding the legal status of land ownership obtained by foreign nationals through mortgage rights auctions, it is established that such land ownership is legally valid. Foreign nationals can manage this land under usage rights status, with the utilization rights in the name of foreign nationals being subject to the prescribed rights transfer procedures.
[Cost-Effectiveness Analysis of Maribavir in Patients with Post-Transplant Cytomegalovirus Infection or Disease that are Refractory or Resistant to Conventional Therapy]
Authors: Marcellusi Andrea , Bini Chiara , Corinti Simone , Fioravanti Laura , Dalla Vedova Laura , Amorosi Stacey L. , De Lacey Tam , Chowdhury Emtiyaz , Mennini Francesco Saverio
Published: December 2023

OBJECTIVES: Cytomegalovirus (CMV) infection represents a serious post-transplantation complication, particularly among transplant recipients with resistant or refractory (R/R) infection. Despite the improvement made in CMV prevention and treatment, remains a need for new therapies that are better tolerated and safer for patients, especially for refractory or resistant (R/R) infections. This analysis investigates the cost-effectiveness of maribavir versus investigator-assigned therapy (IAT) for treatment of post-transplant R/R CMV in the Italian context.METHODS: The analysis was conducted from the National Health Service (NHS) perspective using a Markov model previously developed in Excel® to evaluate the cost-effectiveness of maribavir versus IAT for the treatment of post-transplant R/R CMV. Health event rates and transition probabilities were informed by data from observational studies and from SOLSTICE clinical trial, which compared maribavir to conventional antiviral treatments for transplant patients with R/R CMV infections. Utilities were from SOLSTICE and a utility vignette study. Costs inputs were derived from published literature and Italian national tariffs for outpatient and hospital services. Costs and outcomes were discounted by 3%.RESULTS: Maribavir compared to the IAT used for the treatment of post-transplant R/R CMV achieved an incremental cost of € 11,455 for an incremental quality adjusted life year (QALY) gain of 0.313. This resulted in an incremental cost-effectiveness ratio of € 36,626/QALY, for maribavir compared to IAT, which is below the generally accepted, national willingness-to-pay threshold for orphan drugs (€ 37,000/QALY).CONCLUSIONS: This analysis showed that maribavir, an orphan drug treatment, is cost-effective compared to the current antiviral treatments used for treatment of post-transplant R/R CMV.
BILL S-231: The Ethics of Familial and Genetic Genealogical Searching in Criminal Investigations
Authors: Clausius Katharina , Kenny Erin , Crawford Michael J
Published: December 2023

Recent breakthroughs in criminal investigations, especially of high-profile cold cases, have helped to consolidate the role of DNA analysis in investigative contexts. Consequently, some jurisdictions are looking to expand DNA collection and analysis methods. In Canada, legislation has been proposed to expand the National DNA Databank (NDDB) and to allow familial searching in criminal and forensic investigations. This article outlines the ethical implications of the proposed legislation and, more broadly, of genealogical methods already in use that operate outside the NDDB and rely heavily on for-profit and consumer DNA services. Current DNA analysis within the criminal justice system is heavily regulated and provides important protections not only for individuals but also for genetic relatives whose biometric data is indirectly implicated. In contrast, familial searching poses risks for offender privacy as well as for their relatives. Additionally, the expanding practice of genetic genealogical searching relies on unregulated commercial products that use different technology to expose highly detailed genetic information. This technology falls short of rigorous investigational standards and poses significant problems for informed consent. We conclude that expanding DNA collection within the NDDB to include familial searching risks exacerbating existing systemic bias and that genetic genealogical searching outside of the NDDB is incompatible with existing Canadian legislation that safeguards privacy, genetic non-discrimination, and fundamental rights and freedoms.
Evidence-Based Practice and Power Struggles Over Pedagogic Practices in “High-” and “Low-Stakes Accountability” Contexts
Authors: Haugen Cecilie
Published: December 2023

The Norwegian Knowledge Promotion Reform has followed international trends by combining centralised control over results with increasing autonomy in the curriculum and choice of methods. Local and professional autonomy is challenged through the combination of result-based and evidence-based accountability. However, whether the stakes related to results are “high” or “low” could impact the role of “evidence-based practices” in schools. This paper investigates how evidence-based practices have formed part of the power struggles in the forming of pedagogic practice in a high- versus low-stakes accountability context in Norway. In the two municipalities, evidence-based practices have been used to legitimise and exercise authority, increase external control and create hierarchies between different stakeholders. The influence of teachers and parents has been limited, as has been the possibility to adapt the teaching to students’ diverse needs. However, local gatekeepers have been important for relieving external pressure, and for ensuring local and professional autonomy.
Okul Öncesi Öğretmenlerinin Teknolojik Araç Gereç Kullanımı
Authors: ÖZDEMİR Güzide , KANAK Mehmet , BİLBAY Asuman
Published: December 2023

Teknoloji günden güne kendini yenileyerek gelişimini hızlı bir şekilde sürdürmektedir. Bu yeniliklerin eğitim alanında da kullanımı kaçınılmaz olmuştur. Bu araştırmanın temel amacı, okul öncesi öğretmenlerinin eğitimde teknolojik araç gereçlerin kullanımına ilişkin tutumlarının ve bu araç gereçleri kullanım yeterliklerine ilişkin görüşlerinin belirlenmesidir. Çalışmanın nicel boyutu tarama modelinde yapılmıştır. Araştırmanın evrenini Türkiye’de çeşitli illerinde görev yapan okul öncesi öğretmenler oluşturmaktadır. Çalışmada amaçlı örneklem türlerinden ölçüt (kriter) örnekleme yöntemi kullanılmış ve 200 okul öncesi öğretmenden nicel veriler toplanmıştır. Nitel veriler ise araştırmanın nicel boyutunda yer alan ve görüşmeyi gönüllü olarak kabul eden 17 okul öncesi öğretmeninden elde edilmiştir. Nicel verilerin analizi sonucunda; öğretmenlerin cinsiyetlerinin, mesleki kıdemlerinin ve çalıştıkları kurumda teknolojiye erişim durumunun teknolojik araç gereç kullanımları üzerinde etkisinin olmadığı ancak görev yaptıkları yerin ve teknoloji kullanımı konusunda eğitim almalarının etkisinin olduğu bulgusuna ulaşılmıştır. Araştırmanın nitel sonuçlarına göre, öğretmenlerin teknolojiyi kullanım amaçlarında, etkinlik uygulamalarında kullanım ilk sırada yer almaktadır. Teknolojinin öğretmenlere sağladığı yararlara ilişkin görüşlerde, öğretimi zenginleştirme, zaman tasarrufu sağlama, öğrenmeyi kolaylaştırma eşit oranda dile getirilmiştir. Teknolojinin çocuklara sağladığı yararlar konusunda kalıcı öğrenmeyi sağladığı görüşü ilk sırada yer almıştır. Öğretmenlerin çoğunluğu teknoloji kullanımında problem yaşamadığını ifade ederken, problem yaşayanlar bunun sebebinin teknolojinin hızlı gelişimi, hizmet öncesi ve hizmet içi eğitimin yetersizliği olduğunu ifade etmişlerdir
Balancing Investments in Health Care and Social Determinants—The Need for Benefit-Cost Analysis
Authors: Glied Sherry , Robinson Lisa A.
Published: December 2023

This JAMA Forum discusses how to balance investments in health care and social determinants of health, using benefit-cost analysis and other methods to rationally balance investments across sectors.
Global Burden of Chronic Obstructive Pulmonary Disease Through 2050
Authors: Boers Elroy , Barrett Meredith , Su Jason G. , Benjafield Adam V. , Sinha Sanjeev , Kaye Leanne , Zar Heather J. , Vuong Vy , Tellez Daniela , Gondalia Rahul , Rice Mary B. , Nunez Carlos M. , Wedzicha Jadwiga A. , Malhotra Atul
Published: December 2023

Importance

Chronic obstructive pulmonary disease (COPD) is a respiratory condition that is associated with significant health and economic burden worldwide. Previous studies assessed the global current-day prevalence of COPD, but to better facilitate resource planning and intervention development, long-term projections are needed.

Objective

To assess the global burden of COPD through 2050, considering COPD risk factors.

Design, Setting, and Participants

In this modeling study, historical data on COPD prevalence was extracted from a recent meta-analysis on 2019 global COPD prevalence, and 2010 to 2018 historical prevalence was estimated using random-effects meta-analytical models. COPD risk factor data were obtained from the Global Burden of Disease database.

Main Outcomes and Measures

To project global COPD prevalence to 2050, generalized additive models were developed, including smoking prevalence, indoor and outdoor air pollution, and development indices as predictors, and stratified by age, sex, and World Bank region.

Results

The models estimated that the number of COPD cases globally among those aged 25 years and older will increase by 23% from 2020 to 2050, approaching 600 million patients with COPD globally by 2050. Growth in the burden of COPD was projected to be the largest among women and in low- and middle-income regions. The number of female cases was projected to increase by 47.1% (vs a 9.4% increase for males), and the number of cases in low- and middle-income regions was expected to be more than double that of high-income regions by 2050.

Conclusions and Relevance

In this modeling study of future COPD burden, projections indicated that COPD would continue to affect hundreds of millions of people globally, with disproportionate growth among females and in low-middle income regions through 2050. Further research, prevention, and advocacy are needed to address these issues so that adequate preparation and resource allocation can take place.
Intrinsic disorder of a nucleoplasmin‐like histone chaperone specifies its discrete nuclear and nucleolar functions
Authors: Gauthier Courtney M. , LeGallais Josey , Savic Neda , Moradi‐Fard Sarah , Grew Arden , Loe Martin , Kirlikaya Baran , Cobb Jennifer , Nelson Christopher J.
Published: December 2023

Nucleoplasmin (NPM) histone chaperones regulate distinct processes in the nucleus and nucleolus. While intrinsically disordered regions (IDRs) are hallmarks of NPMs, it is not clear whether all NPM functions require these unstructured features. We assessed the importance of IDRs in a yeast NPM‐like protein and found that regulation of rDNA copy number and genetic interactions with the nucleolar RNA surveillance machinery require the highly conserved FKBP prolyl isomerase domain, but not the NPM domain or IDRs. By contrast, transcriptional repression in the nucleus requires IDRs. Furthermore, multiple lysines in polyacidic serine/lysine motifs of IDRs are required for both lysine polyphosphorylation and NPM‐mediated transcriptional repression. These results demonstrate that this NPM‐like protein relies on IDRs only for some of its chromatin‐related functions.
Nickel‐Catalyzed Cycloisomerization of 1,5‐Allenynes
Authors: Nieto‐Carmona Juan C. , Manjón‐Mata Inés , Quirós M. Teresa , Caballero‐Santiago Gema , Pérez‐Maseda Fernando , Cárdenas Diego J.
Published: December 2023

We report the Ni‐catalyzed cycloisomerization of 1,5‐allenynes. Substrates containing terminal alkynes afford cyclopentene derivatives, whereas internal alkynes lead to the formation of two consecutive C−C bonds to give fused 5–5 bicyclic compounds. The reaction shows a wide scope. Experimental and computational mechanistic studies suggest a Ni(0)−Ni(II) catalytic cycle. The reaction starts with an oxidative cyclometallation followed by a β‐hydrogen elimination. The trans arrangement of alkenyl and hydride ligands is key to allow formation of the second carbocycle.
Lamellar Crystal Structure and Haldane Magnetism in NH4VPO4OH
Authors: Samarin Aleksandr Sh. , Trussov Ivan A. , Pchelkina Zlata V. , Fedotov Stanislav S. , Ovchenkov Yevgeniy A. , Zhurenko Sergei V. , Tkachev Alexei V. , Gippius Andrei A. , Shvanskaya Larisa V. , Vasiliev Alexander N.
Published: December 2023

A novel vanadium hydroxide‐phosphate, NH4VPO4OH, was synthesized hydrothermally in V2O5−NH4H2PO4‐citric acid system at 230 °C. It was characterized by XRD, TG‐DSC, SEM‐EDX, FTIR and NMR spectroscopy. NH4VPO4OH is isostructural with NH4GaPO4OH and features edge‐sharing chains of VO6 octahedra. These chains running along [010] direction of the unit cell are connected by phosphate tetrahedra to form infinite layers parallel to the (100) plane. Ammonium cations are embedded between the heteropolyhedral layers. According to the thermodynamic and NMR measurements supported by the first‐principles calculations, NH4VPO4OH presents a rare case of Haldane spin system with spin S=1 based on V3+ ions.
Calcitonin gene‐related peptide and persistent corneal pain: A trigeminal nerve sensitization perspective
Authors: Hong Xiaoping , Ding Fadian , Xiong Jie , Wu Yuyu , Chen Wanzhu
Published: December 2023

Persistent corneal pain (PCP) has excellent research prospects, especially the central sensitization mechanism of the trigeminal nerve, which is involved in migraine, corneal pain, and trigeminal neuralgia. The cornea has dense sensory innervation, and repeated corneal neuropathic pain has been associated with trigeminal nerve central sensitization, which is induced in PCP. The calcitonin gene‐related peptide (CGRP) is involved in corneal pain conduction, injury protection, and immune homeostasis. A high CGRP level maintains corneal pain perception and protects corneal epithelial cells. However, a persistently high CGRP level causes hypersensitivity of the corneal and trigeminal nerves, resulting in PCP. CGRP‐related drugs can effectively improve trigeminal nerve sensitization and relieve central sensitization‐related pain (PCP, migraine, and trigeminal neuralgia). Exploring the role of CGRP in PCP's pain sensitization mechanism is vital in the pain perception field, with the potential to improve the quality of life of patients with PCP and strengthen the understanding of CGRP's dual role in corneal pain.
Einflussfaktoren hinsichtlich der Reaktivität von calcinierten Tonen – Eine Literaturrecherche
Authors: Overmann Steffen , Vollpracht Anya , Matschei Thomas
Published: December 2023

Kurzfassung

Calcinierte Tone gehören auf Grund der weltweiten Verfügbarkeit der Rohtone zu den vielversprechendsten alternativen Zementersatz‐/Betonzusatzstoffen. Ton ist ein inhomogenes Gemisch verschiedener Tonminerale und weiteren Mineralphasen und kann in seiner Zusammensetzung und Eigenschaften erheblich variieren. Die reaktivitätsbestimmenden Faktoren sind bisher nicht im Detail verstanden, so dass die optimalen Calcinierungsparameter sowie die resultierenden Eigenschaften für den Einsatz als Zementersatz‐/Betonzusatzstoff nicht zuverlässig durch Charakterisierung der Rohtone vorhergesagt werden können. Daher gibt es zahlreiche Studien, in denen das Potential der jeweiligen Tone im Einzelfall mit umfangreichen Untersuchungen evaluiert wird. In dieser Literaturstudie wird der Wissensstand bezüglich der reaktivitätsbestimmenden Faktoren qualitativ herausgearbeitet. Zudem werden Literaturdaten hinsichtlich der Materialcharakterisierung und Reaktivität zusammengetragen und quantitativ ausgewertet. Es zeigt sich, dass die meisten Literaturstudien nur schwer miteinander vergleichbar sind, da sich die Methodenauswahl jeweils stark unterscheidet und wichtige Eigenschaften oft nicht untersucht werden. Jedoch konnten die maßgeblichen Trends aus der qualitativen Literaturauswertung größtenteils studienübergreifend mit der quantitativen Auswertung bestätigt werden.
Early age and long‐term properties of mortars containing metakaolin and limestone powder as SCMs
Authors: Metallari Alban , Bier Thomas A.
Published: December 2023

In this study we focus on the development of plastic shrinkage and capillary pore pressure on mortars containing metakaolin and limestone powder as cement replacement. Isothermal calorimetry was also used to compliment the early age properties of the investigated mortars. Strength development and phase assemblage using thermal analysis were also investigated. Five different replacement levels of metakaolin and LSP and two different amounts of SP were used. Our data show that the shrinkage strain values increased as the amount of SCMs increased, while capillary pressure showed a mixed trend. The hydration kinetics did not appear to be influenced much from the SCMs used. Strength development improved in general when metakaolin was used while decreasing when LSP was added, as already expected. The TGA data show an increase in the consumption of portlandite as the amount of SCMs was increased.
PCE Superplasticizers for Calcined Clay Blended Cements – Challenges and Solutions
Authors: Chen Jiaxin , Li Ran , Thienel Karl‐Christian , Plank Johann
Published: December 2023

A high content of metakaolin in calcined clay blended cement has a positive effect on the early strength development, however, it also leads to a poor workability. Moreover, slump retention is more difficult to achieve in this system than in OPC or other composite cements. In this study, several approaches were investigated to achieve fluidizing ability of mortars prepared from composite cements holding 30 wt. % of calcined clay with varying amounts of metakaolin (∼ 23 wt.%, ∼ 51 wt.%). First, it was found that the slump retaining performance of a common industrial ready‐mix type HPEG PCE rapidly decreases when the content of metakaolin increases. Furthermore, a combination of the ready‐mix HPEG PCE and a retarder (sodium gluconate) which is commonly applied in ready‐mix concrete, also fails to improve fluidity retention in calcined clay blended cement with a high level of metakaolin, hence highlighting the difficulty of slump retention for such cements. To mitigate this problem, a unique admixture based on the combination of a precast type HPEG PCE and a novel PCE‐LDH nanocomposite is introduced. Mortar tests reveal that the high water‐reducing (precast) type HPEG PCE and the PCE‐LDH nanocomposite enables to achieve a remarkable improvement in fluidity retention of such calcined clay blended cements.
Influence of calcined clay on micromechanical properties and creep of hardened cement paste
Authors: Deiters Macielle , Rozanski Corinna , Schack Tobias , Haist Michael
Published: December 2023

A highly interesting approach to lower CO2 emissions in cement and concrete industry is to reduce the cement clinker content while using supplementary cementitious materials (SCMs) such as calcined clays. Whereas for classical Portland cement clinker, comprehensive studies are already available on the microstructural development during hydration as well as on the resulting macromechanical properties such as compressive strength or long‐term deformation behavior, such understanding is missing for calcined clays. In this paper, systematic micromechanical investigations using microindentation of hardened cement pastes with various amounts of calcined clay at ages up to 28 days are presented. The micromechanical results indicate a faster strength development as well as a lower overall porosity of the classical clinker system compared to mixtures containing calcined clay. Looking to creep, the indentation creep modulus is higher for pure OPC mixtures compared to calcined clay systems up to seven days, indicating less pronounced creep. Beyond this age, however, the differences in creep behaviour became less pronounced. The outcomes suggest that the reactivity of the calcined clay seems to be decisive when it comes to mechanical properties and creep behaviour rather than the rate of substitution.
Materialkorrosion und Alterung von zementgebundenen Beschichtungen in der Trinkwasserspeicherung
Authors: Kämpfer Wolfram , Berndt Michael
Published: December 2023

In order to ensure durability, mineral coatings in drinking water storage must be sufficiently resistant to chemical and physical influences. The effects are described in the DVGW W 300 worksheets. This results in requirements for the composition, the mechanical properties, the bond strength, the minimum layer thickness, the surface quality and the impermeability of the mineral coatings.

Durability is currently ensured descriptively based on the applicable set of standards. This verification concept reaches its limits when the normatively secured area of experience is left behind using new binding agents. A number of performance‐oriented test concepts have been developed in recent years for the durability assessment, with which a quantitative assessment of the durability is made possible, taking into account the damage processes and the effects to be expected.

The course of the leaching kinetics can be described with a diffusion‐erosion model and corresponds to a diffusion‐controlled process with a √t course and a linear course with an unchanged top layer. Once the linear damage process has been reached, an estimate of the remaining service life is possible. A model for durability assessment based on diffusion‐erosion processes is presented.
Modified Periclase‐Spinel Refractories for Cement Rotary Kilns
Authors: Borysenko Oksana , Logvinkov Sergii , Shabanova Halyna
Published: December 2023

This research paper gives the development data obtained for modern modified periclase‐spinel materials that have an increased adaptive ability to preserve the material integrity and the operational reliability of the refractories exposed to the effect of the sign‐alternating high‐gradient and thermal loads. Based on the research done, a concept was developed to improve the heat resistance of the periclase‐spinel materials and it includes both the known mechanisms of absorbing excess energy by cracks that are developed under the action of thermal shocks (in particular, the effect of heterophasicity and creation of a microcracked structure due to the difference in thermal efficiency coefficients (TEC) for different phases) and new mechanisms of the structure‐&‐phase adaptations preserving simultaneously the integrity of modified periclase‐spinel refractories. The use of the developed modified periclase‐spinel refractories results in the energy saving of up to 15 %, reduction of material costs due to the extension of the service life of the lining elements of rotary kilns; reduction of the resources required for the maintenance and an increase in the amount of overhaul sessions.
Einfluss der Kristallinität auf die Festigkeit und die Mikrostruktur alkalisch aktivierter Metakaoline
Authors: Lohmann Jessica , Schmidt‐Döhl Frank
Published: December 2023

Kurzfassung

Bei der Reaktion von Metakaolin mit alkalischen Anregern entstehen eine röntgenamorphe, alumosilikatische Gelmatrix sowie kristalline Natrium‐ bzw. Calcium‐Aluminat‐Silikat‐Hydratphasen zu unterschiedlichen Anteilen. In dieser Arbeit wurden grundlegende Zusammenhänge zwischen dem Kristallinitätsgrad der alkalisch aktivierten Metakaoline sowie deren mechanischen Eigenschaften untersucht. Dabei wurde insbesondere auf die Porosität, die Druckfestigkeit und thermoanalytische Eigenschaften eingegangen. Die Kristallinität wurde mittels Röntgendiffraktometrie bestimmt. Voraussetzungen für die Ausbildung eines amorphen Gefüges ist die Lösung der reaktiven Ausgangsmaterialien. Nicht vollständige Lösung führt zu inhomogenem Gefüge, in dem sowohl amorphe Matrix als auch kristalline Bereiche vorliegen. Kristalline Reste im Metakaolin dienen als Kristallisationskeim und begünstigen die Bildung weniger stabiler kristalliner Hydratphasen. Es zeigte sich, dass ein höherer Kristallinitätsgrad mit größeren Poren und einem höheren Porenvolumen einherging, das die Druckfestigkeit der erhärteten Bindemittel herabsenkte. Zusätzlich zeigten die thermogravimetrischen Untersuchungen, dass ein dichteres Gefüge gleichzeitig durch den vermehrten Einbau von Kristallwasser gekennzeichnet war.