Tris(dipivalomethanato)holmium Induced NMR Shifts

Paramagnetic complexes of praseodymium and europium with 1,1,l,2,2,3,3- -heptafluoro-7, 7 ~dimethyl-4,6-octanedione [Pr(fod)3 and Eu(fod)3]1 and with 2,2,6,6-tetramethyl-3,5-heptanedione [Pr(DPM)3 and Eu(DPM)3] or sometimes ab:breviated as [Pr(tmhd)3 and Eu(tmhd)3]Z--5 have shown to !be very useful NMR shift reagents which can greatly s~mplify spectra of compounds having functional gro1ups with lone pair electrons. The only other lanthanide oormplex used for this :purpose was Yb(DPM)3 6>7 • However, Yb(DPM)3 exhibited a shift power between that of Pr(DPM)3 and Eu(DPM)3 and also strong line broadening8 and therefore did not offer any substantial advantage

Absorption characteristics of a quantum dot array induced intermediate band: implications for solar cell design

We present a theoretical study of the electronic and absorption properties of the intermediate band (IB) formed by a three dimensional structure of InAs/GaAs quantum dots (QDs) arranged in a periodic array. Analysis of the electronic and absorption structures suggests that the most promising design for an IB solar cell material, which will exhibit its own quasi-Fermi level, is to employ small QDs (~6–12 nm QD lateral size). The use of larger QDs leads to extension of the absorption spectra into a longer wavelength region but does not provide a separate IB in the forbidden energy gap

Continental Subduction Tectonics in the High Karst Dinarides of Western Croatia

The faults confining Palaeozoic inliers surrounded by Mesozoic rocks, show that their relation is not a consequence of folding but of neotectonic uplift causing a rather uneven relief of the Palaeozoic units underlying the carbonate Mesozoic. The predominance of tectonic contacts indicates that similar relations exist even between the Triassic and the confined Jurassic outcrops exhibiting inverse and, consequently, allochthonous relations. The allochthony is also confirmed by karst relief within some Triassic dolomites related to the unexpected ground water flow between the swallow holes (ponors) and karst springs. There are also indications of inverse relations between the Triassic volcanics and Palaeozoic clastics. However, in the surrounding area a normal superposition between the Triassic and Jurassic is also noticed. Consequently the Triassic and Jurassic of the Fuzine-Lokve area and of its environs may belong to two megatectonic units. Tectogenesis is explained by continental subduction of the Adriaticum under the Dinaricum

Functional and Environmental Advantage of Cleaning Ti5B1 Master Alloy

One of the greatest environmental goals for the aluminum alloys industry is generating higher quality products by introducing cleaner input materials while maintaining low production costs. A typical dilemma for the master alloy producers is the cleanness level of the master alloy since insoluble inclusions could serve as inoculants during the solidification process. In this work, commercial Ti5B1 master alloy is used for grain refinement of Al7Si4Cu aluminum alloy and compared with the cleaned master alloy that contained a lower amount of residual refractory oxides and salts. Metallography analysis was used for grain size measurement while Computer Aided Cooling Curve Analysis was used for assessment of the undercooling and heat release values. In all instances, specimens treated with the cleaned master alloy showed smaller grains in the final structure and lower undercooling values. The difference in released heat between liquidus and recalescence temperatures was about 25% in specimens where added 0.66 wt% of cleaned master alloys compared to specimens where the commercial master alloys were added. Using cleaner Ti5B1 master alloy with a higher number of TiAl3 and TiB2 particles improves its grain refinement efficiency and transmits fewer impurities in produced parts. Producing cleaner master alloy would be beneficial from economic and environmental aspects by increasing its value and service time of produced parts besides simplifying the recycling process at the end of parts life-cycle.This is the peer reviewed version of the paper: Mitrašinović, A., Tomić, M., 2021. Functional and Environmental Advantage of Cleaning Ti5B1 Master Alloy, International Journal of Precision Engineering and Manufacturing-Green Technology, [https://doi.org/10.1007/s40684-021-00339-2

Juncture between Complex Theory and History & Philosophy of Science

Complexity research shows certain trends, that include: interdisciplinarity, unexpected fields and humanities. At current stage of the theory of complex systems certain historically and philosophically recognizable situations and philosophic-scientifically re-examination which refers to the history of science, appear. As a presentation of that, we introduce two examples: the first concerns the interpretation of a well known situation from the history of science in the context of determining the origin of complexity, and the second reflects the current state in research of light and photonics

The Ultimate Paradoxes of Black and White

U cilju rasvetljavanja paradoksalnosti antinomičnog para crno i belo do sada je ispitivano njihovo pojavljivanje u ikonopisu, nauci, mitologiji, simvolici, što je učinjeno razmatranjem ključnih činjenica, saznanja i paradigmatičnih epizoda. Sada su istraživanja dovedena do erminevtičkih limita, uzimajuću u obzir antičku mitologiju, istoriju nauke, biblistiku i ikonografiju. Izdvojeni su tehnološko-koloristički paradoks, kosmološki i astrofizički paradoks, paradoks iz epistemologije, te onirički paradoks. Kao vrhunjenje uzete su u razmatranje ikone Preobraženja, Raspeća i Vaskrsenja, starozavetni motiv izlaska iz Egipta i biblistički motiv Božanskog primraka. Da se zaključiti da istraživanja crnog i belog kao otvorena tema, u svakom vremenu nude integrativne i ultimativne mogućnosti i izazove.In order to uncover the paradoxical nature of antinomic pair of black and white, so far their appearance in icon painting, science, mythology and symbolism has been examined, which has been done by considering key facts, findings, and paradigmatic episodes. Now, the examination has been brought to hermeneutical limits, taking into account the ancient mythology, history of science, biblical studies and iconography. Technological-coloristic paradox, cosmological and astrophysical paradox, paradox from epistemology, and oneiric paradox have been singled out. As the culmination, the icons of Transfiguration, Crucifixion and Resurrection have been considered, along with the Old Testament motif of the exodus from Egypt and the biblical motif of the cloud of unknowing. It has been concluded that research on black and white as an open topic, gives integrative and ultimate possibilities and challenges at all times

General Classification of "Cosmic Energy" by Đorđe Stanojević

U radu su izložena teorijska i praktična otkrića na koja se oslanjao Đorđe Stanojević prilikom klasifikovanja „vasionske energije“. Predstavljena je njegova sistematizacija oblika u kojima se javlja materija. To su: telo, molekul, atom i ćelija. Na osnovu oblika javljanja materije izvršena je podela „vasionske energije“ na energiju tela, „molekilarnu“ energiju, atomsku energiju i „ćelijčnu“ energiju. Podelu energije prati i podela prirodnih nauka čime Stanojević zaokružuje ne samo opštu klasifikaciju koja mu je cilj već i predmetno određenje prirodnih nauka.Theoretical and practical findings on which Đorđe Stanojević relied upon when classifying “cosmic energy”, are displayed. His systematization of forms in which matter occurs is presented. These are: body, molecule, atom, and cell. Based on the form of matter, the division of the “cosmic energy” into an energy of a body, a molecular energy, an atomic energy and a cell energy, was made. The division of energy is followed by the division of natural sciences, by which Stanojević encompasses not only the general classification which was his goal but also the subject matter of natural sciences

Effects of Lifshitz Transition on Charge Transport in Magnetic Phases of Fe-Based Superconductors

The unusual temperature dependence of the resistivity and its in-plane anisotropy observed in the Fe-based superconducting materials, particularly Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$, has been a longstanding puzzle. Here we consider the effect of impurity scattering on the temperature dependence of the average resistivity within a simple two-band model of a dirty spin density wave metal. The sharp drop in resistivity below the N\'eel temperature $T_N$ in the parent compound can only be understood in terms of a Lifshitz transition following Fermi surface reconstruction upon magnetic ordering. We show that the observed resistivity anisotropy in this phase, arising from nematic defect structures, is affected by the Lifshitz transition as well.Comment: 8 pages, 5 figure