This paper presents an optimized design approach using nonlinear dynamic analysis and finite element methods to ensure the structural integrity of square-shaped containers made from ductile cast iron for intermediate- and low-level radioactive waste packaging. Ductile cast iron, with its spherical graphite structure, effectively distributes stress throughout the material, leading to a storage capacity increase of approximately 18%. Considering the critical need for containers that maintain integrity under extreme conditions like earthquakes, the design focuses on mitigating stress concentrations at the corners of square structures.
View Article and Find Full Text PDFObjective: Two commonly used techniques for spinopelvic fixation in adult deformity surgery are iliac screw (IS) and sacral 2 alar-iliac screw (S2AI) fixations. In this article, we systematically meta-analyzed the complications of sacropelvic fixation for adult deformity surgery comparing IS and S2AI.
Methods: The PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched until March 29, 2023.
Adolescent idiopathic scoliosis (AIS) affects approximately 2% of adolescents across all ethnicities. The objectives of surgery for AIS are to halt curve progression, correct the deformity in 3 dimensions, and preserve as many mobile spinal segments as possible, avoiding junctional complications. Despite ongoing development in algorithms and classification systems for the surgical treatment of AIS, there is still considerable debate about selecting the appropriate fusion level.
View Article and Find Full Text PDFThis study examines the impacts of copper and boron in parts per million (ppm) on the microstructure and mechanical properties of spheroidal graphite cast iron (SCI). Boron's inclusion increases the ferrite content whereas copper augments the stability of pearlite. The interaction between the two significantly influences the ferrite content.
View Article and Find Full Text PDFThis paper describes a Stokes vector measurement method based on a snapshot polarization-sensitive spectral interferometry. We measure perpendicular linearly polarized complex wave information of an anisotropic object in the spectral domain from which an accurate Stokes vector can be extracted. The proposed Stokes vector measurement method is robust to the object plane 3-D pose variation and external noise, and it provides a reliable snapshot solution in numerous spectral polarization-related applications.
View Article and Find Full Text PDFSn-based nanostructures have emerged as promising alternative materials for commercial lithium-graphite anodes in lithium ion batteries (LIBs). However, there is limited information on their phase evolution during the discharge/charge cycles. In the present work, we comparatively investigated how the phases of Sn, tin sulfide (SnS), and tin oxide (SnO2) nanocrystals (NCs) changed during repeated lithiation/delithiation processes.
View Article and Find Full Text PDFThe infiltration of palladium nanoparticles (PdNPs) into the channels of SBA-15 was conveniently achieved via an incipient wetness procedure employing a tetraglyme solution. Electron tomography demonstrated that PdNPs were outgrown preferentially from the channels. The resultant Pd/SBA-15 showed high performance in the dehydrogenation kinetics of ammonia borane.
View Article and Find Full Text PDFVarious germanium-based nanostructures have recently demonstrated outstanding lithium ion storage ability and are being considered as the most promising candidates to substitute current carbonaceous anodes of lithium ion batteries. However, there is limited understanding of their structure and phase evolution during discharge/charge cycles. Furthermore, the theoretical model of lithium insertion still remains a challenging issue.
View Article and Find Full Text PDFGermanium-tin (Ge(1-x)Sn(x)) alloy nanocrystals were synthesized using a gas-phase laser photolysis reaction of tetramethyl germanium and tetramethyl tin. A composition tuning was achieved using the partial pressure of precursors in a closed reactor. For x < 0.
View Article and Find Full Text PDFGermanium sulfide (GeS and GeS2) nanoparticles were synthesized by novel gas-phase laser photolysis and subsequent thermal annealing. They showed excellent cycling performance for lithium ion batteries, with a maximum capacity of 1010 mA h g(-1) after 100 cycles. Metastable tetragonal phase Ge nanoparticles were suggested as active materials for a reversible lithium insertion-extraction process.
View Article and Find Full Text PDFNanodiamonds (ND) were found to generate hydrogen (H2) and carbon monoxide (CO) from water at a remarkable rate under pulsed laser (532 nm) irradiation. The transformation of diamond structure into graphitic layers takes place to form an onion-like carbon structure. The CO generation suggests the oxidative degradation reaction of graphitic layers, C + H2O → CO + 2H(+) + 2e(-), which produced a unique laser-induced reaction: C + H2O → CO + H2.
View Article and Find Full Text PDFScaling-down of phase change materials to a nanowire (NW) geometry is critical to a fast switching speed of nonvolatile memory devices. Herein, we report novel composition-phase-tuned GeSbTe NWs, synthesized by a chemical vapor transport method, which guarantees promising applications in the field of nanoscale electric devices. As the Sb content increased, they showed a distinctive rhombohedral-cubic-rhombohedral phase evolution.
View Article and Find Full Text PDFGermanium chalcogenide GeS(x)Se(1-x) nanocrystals (NC) were synthesized using a novel gas-phase laser photolysis reaction. The composition was simply controlled by the partial pressure of precursors in a closed reactor. Remarkably, these ligand-free NC undergo the photo-induced cation exchange reaction to produce a series of Cd, Zn, Pb, and Ag chalcogenide NC in aqueous solution, which is governed by the thermodynamic driving force based on solubility.
View Article and Find Full Text PDFThe deposition of silver (Ag) or gold (Au) nanoparticles (NPs) on vertically aligned silicon-carbon (Si-C) core-shell nanowires (NWs) produces sensitive substrates for surface-enhanced Raman spectroscopy (SERS). The undoped and 30% nitrogen (N)-doped graphitic layers of the C shell (avg thickness of 20 nm) induce a higher sensitivity toward negatively (-) and positively (+) charged dye molecules, respectively, showing remarkable charge selectivity. The Ag NPs exhibit higher charge selectivity than the Au NPs.
View Article and Find Full Text PDFChem Commun (Camb)
January 2012
Detonated nanodiamonds (NDs) exhibit remarkable photocatalytic activity towards the hydrogen gas generation upon 532 nm laser pulse irradiation. Hydrogenation dramatically increases the quantum yield, suggesting that hydrogen-terminated sites work as electron reservoirs. NDs can also be used as effective photocatalysts to reduce graphene oxide.
View Article and Find Full Text PDFWe experienced rare combination of multiple irregular shaped aneurysms along the course of the feeding artery and arteriovenous malformation (AVM) in the posterior circulation. We could not explain which aneurysm was a cause of bleeding because all the aneurysms showed irregular in shape like pseudoaneurysms and location of the aneurysms was very close each other. We report two cases in which multiple irregular shaped aneurysms were related with AVMs and first episode of hemorrhage.
View Article and Find Full Text PDFJ Korean Neurosurg Soc
September 2011
Spinal subdural hematoma (SSDH) is an extremely uncommon condition. Causative factors include trauma, anticoagulant drug administration, hemostatic disorders, and vascular disorders such as arteriovenous malformations and lumbar punctures. Of SSDH cases, those that do not have any traumatic event can be considered cases of nontraumatic acute spinal subdural hematoma, which is known to have diverse clinical progress.
View Article and Find Full Text PDFTHz emission was observed from the vertically aligned silicon nanowire (Si NW) arrays, upon the excitation using a fs Ti-sapphire laser pulse (800 nm). The Si NWs (length = 0.3 approximately 9 microm) were synthesized by the chemical etching of n-type silicon substrates.
View Article and Find Full Text PDFVertically aligned ZnO--CdSSe core-shell nanocable arrays were synthesized with a controlled composition and shell thickness (10-50 nm) by the chemical vapor deposition on the pregrown ZnO nanowire arrays. They consisted of a composition-tuned single-crystalline wurtzite structure CdS1-xSex (x=0, 0.5, and 1) shell whose [0001] direction was aligned along the [0001] wire axis of the wurtzite ZnO core.
View Article and Find Full Text PDFElectron tomography and high-resolution transmission electron microscopy were used to characterize the unique three-dimensional (3D) structures of twinned Zn(3)P(2) (tetragonal) and InAs (zinc blende) nanowires synthesized by the vapor transport method. The Zn(3)P(2) nanowires adopt a unique superlattice structure that consists of twinned octahedral slice segments having alternating orientations along the axial [111] direction of a pseudo cubic unit cell. The apexes of the octahedral slice segment are indexed as six equivalent <112> directions at the [111] zone axis.
View Article and Find Full Text PDFSingle-crystalline rock-salt PbS nanowires (NWs) were synthesized using three different routes; the solvothermal, chemical vapor transport, and gas-phase substitution reaction of pregrown CdS NWs. They were uniformly grown with the [100] or [110], [112] direction in a controlled manner. In the solvothermal growth, the oriented attachment of the octylamine (OA) ligands enables the NWs to be produced with a controlled morphology and growth direction.
View Article and Find Full Text PDFPurpose: Since there has been little reporting on the prevalence or morphologic characteristics of ponticulus posticus in Asians, we retrospectively reviewed cervical 3-dimensional CT scan images and plain radiographs which had been ordered by neurosurgeons or orthopaedic surgeons for evaluation of cervical spine problems to investigate the prevalence and morphologic features of the ponticulus posticus in Koreans.
Patients And Methods: The presence and types of ponticulus posticus were investigated on 200 consecutive cervical 3-D CT scans.
Results: Thirty-one patients, 48 ponticulus posticus, complete or partial, bilateral or unilateral, were identified on the 200 cervical 3-D CT scans; therefore, the prevalence was 15.
J Korean Neurosurg Soc
October 2008
We report a rare case of symptomatic Rathke's cleft cyst with thick calcified wall. Brain CT scans revealed a large cystic mass with round thick calcified wall. In this case, we selected the pterional approach instead of transsphenoidal approach due to the possibility of cystic craniopharyngioma.
View Article and Find Full Text PDFObjective: Aneurysms are very rarely encountered in the distal posterior inferior cerebellar artery (PICA). The authors experienced 5 cases with a distal PICA aneurysm among 368 cases of intracranial aneurysms during the period from January 2003 to January 2008. Here, the authors describe their clinical and surgical experiences and include a review of the relevant literature.
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