Search results for "structures"
showing 10 items of 4815 documents
A large ameloblastic fibro-odontoma of the right mandible
2007
The ameloblastic fibro-odontoma is a rare mixed odontogenic tumor. It occurs predominantly in children and young adults with no sex predilection and locates most often in the posterior segment of the mandible. A painless swelling is the most common clinical sign. Radiologically, ameloblastic fibro-odontoma shows a circumscribed radiolucency, which contains radio-opaque foci of various sizes and shapes. Histological examination reveals a fibrous soft tissue, islands of odontogenic epithelium and a disordered mixture of dental tissues. The tumor produces enamel or enamel matrix, dentin and cementum. The treatment of ameloblastic fibro-odontomas usually consists of enucleation or surgical cure…
Crystal structure and Hirshfeld surface analysis of [N(CH3)4][2,2′-Fe(1,7-closo-C2B9H11)2]
2017
Abstract This work investigates the meta -ferrabis(dicarbollide) anion that was isolated as salt of tetramethylammonium. The structure of the obtained crystal consisted of discrete [2,2′-Fe(1,7- closo -C 2 B 9 H 11 ) 2 ] − anions and disordered [N(CH 3 ) 4 ] + cations. The anion had a considerable chemical stability ensured by ionic and Van der Waals interactions. Thus, Hirshfeld surfaces and fingerprint plot were used to visualize, explore, and quantify intermolecular interactions in the crystal lattice of the title compound. This investigation proved that close contacts were dominated by H⋯H interactions.
Ekskurs VIII. Powołania Ezechiela na stróża Izraela Ez 3,16-21 oraz Ez 33,1-20 w świetle retoryki hebrajskiej
2020
Kontekstem badań była konstatacja, że wielu komentatorów różnie określa strukturę opisywanych fragmentów Księgi Ezechiela. Czytelnik może odnieść wrażenie, że jest to zrobione na wyczucie, a wyczucie nie jest metodą naukową. Dlatego celem przeprowadzonych badań było opracowanie struktury tekstu przy pomocy naukowych metod. Wykorzystano metodę retoryki hebrajskiej, którą opracował Roland Meynet. Uzyskano wyniki: Ez 3,16-21: A, A’, B, B’ lub A, B, A’, B’; Ez 33,1-20: A, B, B’, A’; Ez 33,2-6: A, B, C, D, E, F, G, H, I, H’, G’, F’, E’, D’, C’, B’, A’; Ez 33,7-20: A, B, C, D, E, F, E’, D’, C’, B’, A’. Żeby można było sformułować naukowe, ogólne konstatacje na temat Księgi Ezechiela potrzebny jes…
Towards Automated Classification of Firmware Images and Identification of Embedded Devices
2017
Part 4: Operating System and Firmware Security; International audience; Embedded systems, as opposed to traditional computers, bring an incredible diversity. The number of devices manufactured is constantly increasing and each has a dedicated software, commonly known as firmware. Full firmware images are often delivered as multiple releases, correcting bugs and vulnerabilities, or adding new features. Unfortunately, there is no centralized or standardized firmware distribution mechanism. It is therefore difficult to track which vendor or device a firmware package belongs to, or to identify which firmware version is used in deployed embedded devices. At the same time, discovering devices tha…
Titanocene Selenide Sulfides Revisited: Formation, Stabilities, and NMR Spectroscopic Properties
2019
[TiCp2S5] (phase A), [TiCp2Se5] (phase F), and five solid solutions of mixed titanocene selenide sulfides [TiCp2SexS5−x] (Cp = C5H5−) with the initial Se:S ranging from 1:4 to 4:1 (phases B–E) were prepared by reduction of elemental sulfur or selenium or their mixtures by lithium triethylhydridoborate in thf followed by the treatment with titanocene dichloride [TiCp2Cl2]. Their 77Se and 13C NMR spectra were recorded from the CS2 solution. The definite assignment of the 77Se NMR spectra was based on the PBE0/def2-TZVPP calculations of the 77Se chemical shifts and is supported by 13C NMR spectra of the samples. The following complexes in varying ratios were identified in the CS2 solutions of …
The giant panda is cryptic
2021
The giant panda (Ailuropoda melanoleuca) is an iconic mammal, but the function of its black-and-white coloration is mysterious. Using photographs of giant pandas taken in the wild and state-of-the-art image analysis, we confirm the counterintuitive hypothesis that their coloration provides camouflage in their natural environment. The black fur blends into dark shades and tree trunks, whereas white fur matches foliage and snow when present, and intermediate pelage tones match rocks and ground. At longer viewing distances giant pandas show high edge disruption that breaks up their outline, and up close they rely more on background matching. The results are consistent across acuity-corrected c…
Image formation with plasmonic nanostructures
2015
En 1873, Ernst Abbe concluyó que debido a la difracción de la luz el límite de resolución de un sistema óptico es aproximadamente la mitad de la longitud de onda de trabajo. Este límite, llamado el límite de difracción produce porque las ondas evanescentes no contribuyen a la formación de la imagen. En cualquier sistema óptico formado por materiales presentes en la naturaleza los detalles espaciales del objeto que sean más pequeños que el límite de resolución son transportados por ondas evanescentes. Normalmente estas ondas se pierden debido a la fuerte atenuación que experimentan viajando del objeto a la imagen. // En 1968, Veselago mostró que un material con permitividad y permeabilidad n…
Phonons in MoSe2/WSe2 van der Waals heterobilayer
2021
We report first-principles calculations of the structural and vibrational properties of the synthesized two-dimensional van der Waals heterostructures formed by single-layers dichalcogenides MoSe2 and WSe2. We show that, when combining these systems in a periodic two-dimensional heterostructures, the intrinsic phonon characteristics of the free-standing constituents are to a large extent preserved but, furthermore, exhibit shear and breathing phonon modes that are not present in the individual building blocks. These peculiar modes depend strongly on the weak vdW forces and has a great contibution to the thermal properties of the layered materials. Besides these features, the departure of fl…
Thiophene based imino-pyridyl palladium(II) complexes : Synthesis, molecular structures and Heck coupling reactions
2017
The new compounds (5-methyl-2-thiophene-2-pyridyl(R))imine [R = methyl (L1); R = ethyl (L2)] and (5-bromo-2-thiophene-2-pyridyl(R)imine [R = methyl (L3); R = ethyl (L4)] were successfully synthesized via Schiff base condensation reaction and obtained in good yields. These potential ligands were reacted with [PdCl2(COD)] and [PdClMe(COD)] to give the corresponding complexes [PdCl2(L)] (L = L1-L4; 1–4) and [PdClMe(L)] (L = L1-L4; 5–8). All compounds were characterized by IR, 1H and 13C NMR spectroscopy, elemental analysis and mass spectrometry. The molecular structures of 1, 2, 6 and 8 were confirmed by X-ray crystallography. The complexes were evaluated as catalyst precursors for standard He…
Trzy poziomy struktur i kompozycja w wyroczniach przeciw Egiptowi Księga Ezechiela rozdziały 29–32 w świetle retoryki hebrajskiej
2022
Kontekstem badań było to, że różni komentatorzy Księgi Ezechiela proponują różniące się między sobą struktury badanych tekstów. Większość z nich pracowała (nadal pracuje) metodami diachronicznymi. Zazwyczaj ci autorzy układają wersy w grupy i tym grupom nadają tytuły. Dlatego celem badań stało się odkrycie struktur opartych o wersy tekstu biblijnego. Można wtedy wskazać konkretne wersy (lub ich części, człony), których użył starożytny autor natchniony. Dlatego zastosowano metodę biblijnej retoryki hebrajskiej, która ma 3 etapy: analizę oddolną, analizę odgórną oraz interpretację teologiczną. W wyniku przeprowadzonych badań na pierwszych dwóch etapach odkryto, że teksty wyroczni przeciw Egip…