Thermal Stability and Degradation of NCA in Solid-polymer Batteries

Festkörperbatterien mit Polymerelektrolyt in Kombination mit Ni-reichen Kathodenmaterialien, wie zum Beispiel LiNi$_{0.8}$Co$_{0.15}$Al$_{0.05}$O$_{2}$ (NCA), sind vielversprechende Kandidaten für die nächste Generation von Energiespeichern. Angesichts der Vorteile hinsichtlich Sicherheit und der potentiellen Ermöglichung von hohen Energiedichten, haben sich zahlreiche (Start-up-) Unternehmen mit der Kommerzialisierung dieser Technologie auseinandergesetzt. Dennoch verbleiben einige technologische Herausforderungen, die auf die eingeschränkte Batterieleistung aufgrund des (thermisch) anfälligen Kathodenmaterials, die engen elektrochemischen Stabilitätsfenster nutzbarer Polymerelektrolyte, und andere, noch aufzuklärende, Degradationsprozesse zurückzuführen sind. Diese Arbeit ist daher auf die Analyse möglicher Degradationsphenomäne fokussiert, die auf unterschiedlichen Ebenen der Polymer-Festkörperbatterien in Kombination mit NCA vorkommen. Durch die Nutzung moderner Synchrotrontechniken, wird hierbei ein besonderer Schwerpunkt auf das chemische, thermische und mechanische Zusammenspiel der hierarchisch strukturierten Polymer-Festkörperbatterie gelegt. Die systematische Herangehensweise bestrebt hierbei die komplexe thermo-mechanische, chemo-thermische, und chemo-mechanische Stabilität von NCA im delithiierten Zustand, auf der Ebene eines einzelnen Partikels, aufzuklären. Dabei wird dargestellt, wie sich die durch thermische Belastungen ausgelöste Zersetzung in Form von freigesetztem Sauerstoff, Phasenumwandlung und gleichzeitiger Reduktion von Ni sowie durch die Entstehung von Mesoporen zeigt. Zudem wird die hohe Bedeutung des chemo-thermischen Zusammenspiels des Aktivmaterials, Polymerelektrolyten und Lithiumsalzes in der Kathode demonstriert. Letztendlich wird illustriert, dass die Entstehung von intergranularen Frakturen die Deaktivierung von Subpartikel-Domänen verursacht und folglich einen Verlust der Ionen- und Elektronenleitfähigkeit innerhalb von Partikeln, die wiederum eine lokale Impedanzerhöhung so wie Änderung der Transportwege von Ladungsträgern mit sich bringt

Eksistensi Perusahaan Sub Sektor Restoran, Hotel dan Pariwisata Dalam Masa Pandemi Covid-19

Penelitian ini bertujuan untuk membuat prediksi kebangkrutan perusahaan sub sektor hotel, restoran dan pariwisata yang go public pada tahun 2019-2022. Jenis penelitian yang digunakan adalah deskriptif kuantitatif dengan menjelaskan angka hasil perhitungan. Prediksi kebangkrutan dihitung menggunakan Altman Z” Score. Hasil penelitian menunjukkan bahwa selama masa pandemi Covid-19 mayoritas perusahaan berada pada zona kebangkrutan. Perusahaan yang diprediksi bangkrut mengalami masalah pada pembayaran kewajiban dan tren kerugian. Kebijakan pemerintah dalam mengatasi pandemi berkontribusi terhadap kinerja buruk yang dialami perusahaan. Penelitian ini dapat menjadi sistem peringatan dini terkait kemungkinan kebangkrutan perusahaan

Image and Texture Independent Deep Learning Noise Estimation using Multiple Frames

In this study, a novel multiple-frame based image and texture independent convolutional Neural Network (CNN) noise estimator is introduced. The estimator works

Eski Uygur Türkçesinde Geçen baça- Fiilinin Kökeni Üzerine

Köken bilim dil bilimin önemli çalışma alanlarından biridir ve günümüzde de gelişimini sürdüren kendine özgü yöntemleri vardır. Söz konusu yöntemler ile ses, kelime ve anlam bilim yasalarının gerekleri yerine getirildiğinde bir kelimenin köken bilim açısından analizi ve sentezi yapılabilir. Türk dilinin kelime varlığı üzerine yapılan köken bilim araştırmaları 19. yüzyılda başlayıp günümüze kadar devam etmiştir. Bu çalışmamızın sonucunda incelediğimiz baça- fiilinin köken bilgisi ve sahip olduğu anlamsal gelişim süreci için yeni bir açıklama önerdik. Bu araştırmada kullandığımız yöntem şu şekilde özetlenebilir: Eski ve Orta Türkçe kelimelerin köken bilgisi ve bu konu üzerine yapılmış sözlüklerin oluşturduğu sahanın temel eserleri “Rusça, İngilizce ve Almanca” dillerinde yazılmıştır. “Leksika, “Versuch Eines Etymologischen Wörterbuchs der Türksprachen”, “Drevnetyurskiy Slovar’”, “Etymological Dictionary of preThirteenth-Century Turkish” ve “Old Turkish Word Formation” adlı eserler sahaya birçok malzeme kazandırmıştır. Türkiye’de yapılmış iki değerli saha sözlüğü de güncel bazı malzemeyi sahaya kazandırmıştır: “Köken Bilim Sözlüğü” ve “Türk Dilinin Etimolojik Sözlüğü”. Eski Uygur Türkçesinde baça- ‘oruç tutmak’ fiili geçmektedir. Bu fiilden türemiş bir isim olan baçaḳ ‘hristiyanların orucu, perhizi’ Eski Uygur Türkçesinde ve Divanü Lugati’t-Türk’te yer alır. Bu makalede baça- fiilinin kökeni, fonetik, morfolojik ve semantik bakımından geçirdiği değişiklikler analiz edilecektir

Pengendalian Intern Piutang pada PT Astragraphia Medan

Proses penagihan piutang dagang menjadi kas perusahaan memerlukan sistem yang memadai, sehingga diharapkan semua piutang dagang dapat ditagih. Penting bagi perusahaan untuk menetapkan suatu pengelolaan dan pengendalian yang efeftif dalam hal piutang dagang yang memadai seperti kebijaksanaan kredit yang efektif dan prosedur penagihan untuk menjamin penagihan yang tepat waktu dan mengurangi kerugian akibat piutang yang tak tertagih, disertai dengan aktivitas pengendalian lainnya. Karena bila piutang tak tertagih terus meningkat, maka bukan laba yang diperoleh perusabaan tetapi perusahaan akan mengalami kerugian. Pengendalian internal yang sehat dan layak atas piutang dagang dapat berpengaruh penting pada kemampuan operasi perusahaan untuk mencapai laba

Effect of Liquid Electrolyte Soaking on the Interfacial Resistance of Li7La3Zr2O12 for All-Solid-State Lithium Batteries.

The impact of liquid electrolyte soaking on the interfacial resistance between the garnet-structured Li7La3Zr2O12 (LLZO) solid electrolyte and metallic lithium has been studied. Lithium carbonate (Li2CO3) formed by inadvertent exposure of LLZO to ambient conditions is generally known to increase interfacial impedance and decrease lithium wettability. Soaking LLZO powders and pellets in the electrolyte containing lithium tetrafluoroborate (LiBF4) shows a significantly reduced interfacial resistance and improved contact between lithium and LLZO. Raman spectroscopy, X-ray diffraction, and soft X-ray absorption spectroscopy reveal how Li2CO3 is continuously removed with increasing soaking time. On-line mass spectrometry and free energy calculations show how LiBF4 reacts with surface carbonate to form carbon dioxide. Using a very simple and scalable process that does not involve heat-treatment and expensive coating techniques, we show that the Li-LLZO interfacial resistance can be reduced by an order of magnitude

THE FACTORS WHICH INFLUENCE EARNINGS MANAGEMENT WITH GOOD CORPORATE GOVERNANCE AS MODERATING VARIABLE IN MANUFACTURE COMPANIES LISTED IN BEI

The objective of the research was to find out some factors which influenced earnings management consisted of Information asymmetry, firm size, leverage, institutional ownership, and profitability with good corporate governance proxied   with independent board of commissioners and audit committee as moderating variable in manufacture companies listed in BEI in the period of 2013-2015. The research used hypothetical test or explanatory research method. The population was 144 manufacture companies listed in BEI, and 106 of them were used as the samples, taken by using proportional random sampling technique. The result of the research showed that, simultaneously, Information asymmetry, firm size, leverage, institutional ownership, and profitability influenced earnings management. Partially, Information asymmetry and profitability influenced earnings management, while firm size, leverage, and institutional ownership did not have any influence on earnings management. Good corporate governance which proxied with independent board of commissioners and audit committee was moderating variable in this research in which independent board of commissioners and audit committee were not the variables which could moderate the influence of Information asymmetry, firm size, leverage, institutional ownership, and profitability on earnings management

A new approach for measuring viscoelastic properties of soft materials using the dynamic response of a spherical object placed at the sample interface

Background: There are several techniques to characterize the mechanical properties of soft materials, such as the indentation method and the method based on the application of a spherical object placed inside the sample. The indentation systems usually yield the elastic properties of materials and their mathematical models do not consider the inertia of the sample involved in motion and radiation damping, while placing an object inside the sample is not practical and this procedure can alter the mechanical properties of the sample for the method based on the application of a bubble/sphere placed inside the sample. Objective: A new approach for the identification of the viscoelastic properties of soft materials using the dynamic response of a spherical object placed at the sample interface was proposed. Methods: The spherical object placed at the sample interface was pressed using an electromagnet and the dynamic response of the spherical object was tracked using a high-speed camera, while the dynamic response of the spherical object placed at the sample interface was estimated using a comprehensive analytical model. The effects of the shear modulus, viscosity, Poisson’s ratio and density of the soft sample, the radius and density of the spherical object and the damping due to radiation were considered in this mathematical model. The shear modulus and viscosity of the soft sample were determined by matching the experimentally identified and theoretically estimated responses of the spherical object. Results: The shear moduli and viscosities of the three phantoms with the gelatin mass ratios of 0.20, 0.25 and 0.29 were measured to be 3450, 4300 and 4950 Pa and 12.5, 14.0 and 15.0 Pa⋅s, respectively. The shear modulus and viscosity of the phantom increases as the gelatin mass ratio increases. The frequency of oscillations of the hemisphere placed at the phantom interface increases as the gelatin mass ratio increases due to stiffness increase. Conclusions: After matching the experimental and theoretical steady-state displacements and amplitudes of oscillations of the hemisphere at the sample interface, the comparison of the experimentally identified and theoretically predicted frequency of oscillations further confirmed the identified material properties of the samples. The approach presented here is expected to provide valuable information on material properties in biomedical and industrial applications.WOS:0010826474000032-s2.0-85174051012ArticleUluslararası işbirliği ile yapılan - EVET2023YÖK - 2022-23Eki

Evaluation of Response to Therapy in Thyroid Carcinoma Patients after Radioactive Iodine Therapy

Radioactive iodine therapy is an important treatment modality for differentiated thyroid carcinoma patients. Radioactive iodine, similar to elementary iodine, is concentrated in the thyroid follicular cells after oral application, and it can damage the remnant or malignant thyroid cells. Unlike many antineoplastic drugs, radioactive iodine can easily be applied without causing serious side effects. Radioactive iodine was first used for the treatment of a differentiated thyroid carcinoma patient in 1949. In Turkey, it has been used in many nuclear medicine centers for treatment of both differentiated thyroid carcinoma and hyperthyroid patients since 1954. For evaluation of response to therapy with radioactive iodine, different clinical, biochemical, scintigraphic, and radiological imaging modalities are available. Today, many international guidelines aid the clinicians in the assessment of therapy response after radioiodine application. This review aims to discuss the methods recommended in current guidelines for therapy response assessment in differentiated thyroid carcinoma patients after radioactive iodine therapy