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Recycling of NdFeB magnets employing oxidation, selective leaching, and iron precipitation in an autoclave
No full textThe increasing production of neodymium-iron-boron (NdFeB) magnets for technological applications results in disposal problems. NdFeB magnets contain a significant quantity of rare earth elements (REEs). China is the largest REEs producer, but it applies quotas and increases the export prices of REEs. To address this issue, this study aims at investigating the recovery process of REEs from scrap NdFeB magnets. After oxidation of NdFeB magnet powders, selective leaching with nitric acid was carried out to achieve high-purity REE-rich leaching liquor. First, the oxidation kinetics of NdFeB powders was studied in detail to determine the oxidation temperature and duration. Afterwards, the effects of selective leaching parameters, including acid concentration, leaching temperature, stirring speed and solid/liquid ratio, were examined by analysis of variance (ANOVA) analysis based on Taguchi method. The most substantial parameters were assigned to be the temperature and solid/liquid ratio. Eventually, the dissolution kinetics were studied to propose a model for REEs. Several universal equations for dissolution kinetics were tested, and (1 - (1 - x) = k x tn) gives the best results for REEs. The findings show that the leaching process follows the shrinking core model. Activation energy was calculated to be 40.375 kJ mol(-1) for REEs. As the last step, the iron dissolved during leaching was precipitated as hematite in the autoclave. The hematite precipitation experiments were performed based on the Box-Behnken design. The effect of precipitation parameters was investigated by ANOVA analysis, and the precipitation process was optimized using response surface methodology (RSM), which resulted in the minimum iron and maximum REEs content in the leach liquor.Federal Ministry for Economic Affairs and Climate Action [273 EN]; Scientific and Technological Research Council of Turkey [120N331]; project Sustainable recovery of rare earth elements (Nd, Pr, Dy) from spent magnetsThis research was funded by the Federal Ministry for Economic Affairs and Climate Action, grant number 273 EN, and The Scientific and Technological Research Council of Turkey under grant agreement 120N331. The APC was funded by the project Sustainable recovery of rare earth elements (Nd, Pr, Dy) from spent magnets. Elif Emil-Kaya would like to thank TUBITAK 2214-A - International Research Fellowship Programme for PhD Students
Effects of the Jokela type of spinal muscular atrophy-relatedG66V mutation on the structural ensemble characteristics ofCHCHD10
No full textThe G66V pathological variant of the coiled-coil-helix-coiled-coil-helix domain-containing protein 10 (CHCHD10), mitochondrial, plays a role in Jokela type spinalmuscular atrophy. The wild-type and G66V mutant-type CHCHD10 proteins containintrinsically disordered regions, and therefore, their structural ensemble studies havebeen experiencing difficulties using conventional tools. Here, we show our resultsregarding the first characterization of the structural ensemble characteristics of theG66V mutant form of CHCHD10 and the first comparison of these characteristicswith the structural ensemble properties of wild-type CHCHD10. We find that thestructural properties, potential of mean force surfaces, and principal component anal-ysis show stark differences between these two proteins. These results are importantfor a better pathology, biochemistry and structural biology understanding ofCHCHD10 and its G66V genetic variant and it is likely that these reported structuralproperties are important for designing more efficient treatments for the Jokela typeof spinal muscular atrophy disease
The place of vat in the legal order in terms of constitutional taxation principles from the perspectives of Turkish and German tax law
No full textVergiler genel olarak gelir, servet ve harcamalar üzerinden alınmaktadır. KDV harcamalar üzerinden her safhada net olarak alınan ve dünyada yaygın olarak tercih edilen tipik bir muamele vergisidir. Dolaylı bir vergi olması ve nihai tüketiciler tarafından ödenmesi, nihai tüketicilerin ise vergilendirme ilişkisinin tarafı olmaması gibi özellikleri olan KDV’nin, anayasamızda yer alan vergilendirme ilkelerinin alanına girmediğini söylemek mümkün değildir. Bu çalışmada KDV’nin anayasal vergilendirme ilkeleri bakımından incelenmesi amaç edinilmektedir.Taxes are generally levied on income, wealth and expenditure. VAT is a typical transaction tax that is levied on expenditures at every stage and is widely preferred in the world. It is not possible to say that VAT, which is an indirect tax and is paid by final consumers and final consumers are not parties to the taxation relationship, does not fall within the scope of the taxation principles in our constitution. This study aims to analyse VAT in terms of constitutional taxation principles
A comparison of the effects of incremental and snowplow techniques on the mechanical properties of composite restorations
No full textBackground:Glass fibre-reinforced composite (GFRC) has the potential to enhance the mechanical properties of resin-based restorations. Nevertheless, the application technique can influence the cervical margin porosity, potentially reduc-ing the mechanical strength of restorations.Methods:In anin vitrosetup, mould specimens underwent six different treatments to assess the effects of snowplow andincremental curing techniques on the properties of GFRC (EverX) and universal resin composite (Filtek). Mechanicalproperties, namely flexural strength (FS), compressive strength (CS) and Vickers hardness (VH), were evaluated followingISO 4049 standards. Data interpretation utilized the Kruskal–Wallis tests.Results:No significant difference emerged across groups for FS. CS in the snowplow method with lesser EverX thickness(SnPl_1) was comparable with only EverX and Filtek (P>0.05). The CS was reduced in the snowplow technique withgreater EverX thickness (SnPl_2) (P<0.05) and further decreased with the incremental method (P<0.001). VH resultsshowed that EverX Posterior was consistently softer than Filtek, with specific patterns of hardness variations among dif-ferent application methods.Conclusions:Applying EverX and Filtek using the snowplow technique delivers superior CS and VH for restorations incontrast to the incremental method. Utilizing the snowplow approach in high-stress areas can make restorations morefracture-resistant
Gücün aynası yahut Taklidi: Prusya Kralı Büyük Friedrich’in Osmanlı İmparatorluğu’na gönderdiği mektuplarda vurguladığı nüfuz alanları
No full textOne of the practices of international diplomacy in the early modern period was enumerating the localities ruled and/or claimed by the rulers in the letters sent to other states in order to point out that the exercise of power relies on God’s grace (divine right). ?is practice, which finds its reflex in many languages, was widely used from the 15th century until the 19th century by both Christian and Muslim states. ?is article examines the question of whether the Ottoman-Prussian diplomatic relations, which became tenser in the second half of the 18th century, reflected this practice in relevant diplomatic documents. To consider this, five letters of Frederick the Great, who made the Prussian state one of the great powers of Europe, addressed to the Sublime Porte between 1758 and 1762 in Latin, which included the above practice as a continuation of its historical course have been analyzed. Moreover, the localities enumerated in the letters are compared in terms of area and population using the demographic data of the Ottoman Empire and contemporary German sources on historical geography
Kaldıraçlı alım satım (foreks) işlemlerinin hukukî niteliği ve bu işlemlerden doğan uyuşmazlıklara ilişkin bazı değerlendirmeler
Get PDF6502 sayılı Tüketicinin Korunması Hakkında Kanun’la tüketici işlemlerinin kapsamı genişletilmiştir. Bu durum ticarî iş ile adî işin sınırlarının belirlenmesini zorlaştırmaktadır.Ticarî iş ile adî iş ayırımının isabetli biçimde yapılabilmesi, ancak bir işlemin niteliğinin tam anlamıyla anlaşılmasıyla mümkündür. Bu bağlamda finansal piyasalarda yatırımcının daha fazla yer almasında etkin rol oynayan daha az sermayeyle daha büyük hacimli işlemler yapılmasına imkân sağlayan kaldıraç sistemi ile bu sistem kapsamında yapılan “kaldıraçlı işlemlerin” (forex) niteliğinin ortaya konulması; bu işlemlerden doğacak uyuşmazlıklarda görevli ve yetkili mahkemenin doğru şekilde belirlenmesini de sağlayacaktır. Sermaye Piyasası Kurulu’nun konuyla ilgili Tebliğ’lerindeki düzenlemesine göre, kaldıraçlı işlem, yatırılan teminat tutarı karşılığında, döviz ve kıymetli madenler ile Sermaye Piyasası Kurulu’nca belirlenecek diğer varlıkların kaldıraçlı olarak elektronik bir platformda alım-satım işlemlerini ifade etmektedir. Böylece kaldıraç sistemi, yatırılan belli bir teminat karşılığında bu teminatın belli bir misli miktarında, Tebliğ kapsamındaki varlıkların alım satımına imkân tanır. Kaldıraçlı alım satım işlemleri bir tür bankacılık sözleşmesidir. Yargıtay’ın nispeten daha eski tarihli kararlarında kaldıraçlı alım satım işlemi yapan kişi bakımından Tüketicinin Korunması Hakkında Kanun’un 3/k, 3/l ve 49. maddelerinin şartları mevcutsa, bu kişi tüketici sayılmıştır. Bu sebeple, tüketici işlemi söz konusu olduğundan, tüketici sıfatına sahip olan kişilerin yapmış oldukları kaldıraçlı alım satım işlemlerinden doğan uyuşmazlıklarda tüketici mahkemelerinin görevli olduğu sonucuna ulaşılmıştır. Oysa Yargıtay’ın güncel kararanlarında kaldıraçlı alım satım işlemi ticarî iştir. Bu nedenle kaldıraçlı alım satım işlemlerinden doğan uyuşmazlıklarda asliye ticaret mahkemesi görevlidir. Kanaatimizce kaldıraçlı alım satım işlemlerinde nihaî amaç tüketim olmadığı, için bu tür işlemler tüketici işlemi olarak nitelendirilemez. Kaldıraçlı alım satım işlemi yapan kişi de tüketici sayılamaz. Çünkü bir işlemin tüketici işlemi sayılması için nihaî kullanım amacıyla edinilmiş olması gerekir. Kaldıraçlı alım satım işlemlerinde ise belli bir teminat karşılığında bu teminatın kaldıraç oranı mislince bir sözleşme akdedilir, satın alınan yabancı para değer kazanırsa, buradaki değer artışından doğan kâr miktarı müşteriye ödenir. Dolayısıyla kaldıraçlı alım satım işlemi, döviz bürosundan yabancı para veya kuyumcudan altın alıp, bu varlıkların değer artışından yarar elde etmekten farklıdır. Buradaki malvarlığı artışı, yapılan tüketimin tesadüfî bir neticesi olmayıp, yapılan tüketimin doğrudan amacıdır. Kaldıraçlı alım satım işlemi aslında, alımı yapılan varlığın tüketimi için değil, onun değer artışı sonucu tekrar satılarak kazanç elde etmek amacıyla yapılır. Bu sebeple kaldıraçlı alım satım işlemi kesinlikle tüketici işlemi olarak nitelendirilemez. Kaldıraçlı alım satım işleminden doğan uyuşmazlıklara ilişkin davalar Türk Ticaret Kanunu’nun dördüncü maddesine göre, mutlak ticarî dava olarak kabul edilmelidir.With the Law No. 6502 on the Protection of the Consumer, the scope of consumer transactions has been expanded. This makes it difficult to determine the boundaries of commercial transactions and ordinary transactions.Accurately distinguishing between commercial and ordinary transaction is only possible if the nature of the transaction is fully understood. The leveraged trading system plays an active role in an investor's involvement in financial markets and enables larger transactions with less capital. Determining the legal characteristic of leveraged trading transactions plays a key role in ensure the correct determination of the competent and authorized court in disputes arising from these transactions. According to the regulation of the Capital Markets Board in the relevant Communiqués, leveraged transaction refers to the leveraged trading of foreign currency and precious metals and other assets to be determined by the Capital Markets Board on an electronic platform in return for the deposited collateral. Thus, the leverage system allows the trading of assets covered by the Communiqué, in return for a certain collateral deposited. Leveraged trading is a type of banking contract. In the relatively older decisions of the Court of Cassation, if the conditions of Articles 3/k, 3/l and 49 of the Law on the Protection of the Consumer exist, this person is deemed to be a consumer. For this reason, since consumer transactions are in question, it has been concluded that consumer courts are responsible for disputes arising from leveraged buying and selling transactions made by people who have the title of consumer. However, in the current decisions of the Court of Cassation, leveraged trading is a commercial transaction. For this reason, the commercial court of first instance is the competent court for disputes arising from leveraged trading transactions. In our opinion, since the ultimate purpose of leveraged buying and selling transactions is not consumption, such transactions cannot be qualified as consumer transactions. For a transaction to be considered a consumer transaction, it must be acquired for end-use purposes. Leveraged trading is actually done not for the consumption of the purchased asset but for the purpose of earning a profit by reselling it as a result of its increase in value. For this reason, leveraged trading cannot be considered as a consumer transaction. Lawsuits regarding disputes arising from leveraged trading should be considered as absolute commercial transaction according to the fourth article of the Turkish Commercial Code
Code Index Modulation-Aided Spatial Media-Based Modulation System for Future Wireless Networks
No full textFuture wireless networks, increment in mobile users, and Internet-connected devices have brought many needs, such as high data rate, low transmission energy, high error performance, and low latency. Index modulation-based systems have been considered as one of the strong candidates for meeting these demands and needs. In this article, a novel wireless communication system that combines code index modulation (CIM)-aided spatial modulation (SM) and media-based modulation (MBM) techniques, briefly called CIM-SMBM, is proposed for future wireless networks. In the CIM-SMBM system, source information bits are carried in transmitted symbols in addition to three indices: active antenna index selected by SM, indices of different channel states that vary depending on the propagation pattern with MBM, and selected spreading code indices determined by CIM. In order to further reduce the complexity of optimal maximum-likelihood (ML) and despreading-based ML detectors for the CIM-SMBM scheme, an enhanced low-complexity detector that can achieve near-ML error performance is proposed. The average bit error rate (ABER), throughput, energy efficiency, and complexity analyses of the CIM-SMBM system are derived over Rayleigh fading channels for the -quadrature amplitude modulation technique. It has been observed that the ABER and simulation results are quite close to each other