Search results for " Materials Science"
showing 10 items of 7414 documents
Angular Trapping of Anisometric Nano-Objects in a Fluid
2012
We demonstrate the ability to trap, levitate, and orient single anisometric nanoscale objects with high angular precision in a fluid. An electrostatic fluidic trap confines a spherical object at a spatial location defined by the minimum of the electrostatic system free energy. For an anisometric object and a potential well lacking angular symmetry, the system free energy can further strongly depend on the object's orientation in the trap. Engineering the morphology of the trap thus enables precise spatial and angular confinement of a single levitating nano-object, and the process can be massively parallelized. Since the physics of the trap depends strongly on the surface charge of the objec…
catena-Poly[[(18-crown-6-κ6O)potassium]-μ-chlorido-[(1H-benzotriazol-1-ol-κN3)chloridoplatinum(II)]-μ-(benzotriazol-1-olato-κ2N3:O)]
2010
In the structure of the title compound, [KPt(C6H4N3O)Cl2(C6H5N3O)(C12H24O6)], the PtII atom is in a distorted square-planar geometry. The crystal structure is consolidated by O—H⋯O hydrogen bonds. The measured crystal was a non-merohedral twin with four components.
Keggin heteropolyacid supported on BN and C3N4: Comparison between catalytic and photocatalytic alcohol dehydration
2020
The Keggin heteropolyacid (HPA), H3PW12O40 (PW12) has been supported on commercial boron nitride (BN) and two types of home prepared carbon nitride (C3N4). The supported PW12 was used in the gas-solid (photo)catalytic 2-propanol dehydration reaction to give propene at atmospheric pressure and temperatures in the range 70–120 °C and resulted more active than the pristine PW12. Reaction rate increased by increasing the temperature. Noticeably, the propene formation rate was higher by irradiating the catalytic system. The PW12/BN material resulted more active than PW12/C3N4. The acidity of the HPA cluster accounts for the catalytic role, whereas both the acidity and the redox properties of the…
Clinical utility of novel biosensing platform: Diagnosis of coronavirus SARS-CoV-2 at point of care
2021
Early detection is the first step in the fight against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, an efficient, rapid, selective, specific, and inexpensive SARS-CoV-2 diagnostic method is the need of the hour. The reverse transcription-polymerase chain reaction (RT-PCR) technology is massively utilized to detect infection with SARS-CoV-2. However, scientists continue to strive to create enhanced technology while continually developing nanomaterial-enabled biosensing methods that can provide new methodologies, potentially fulfilling the present demand for rapid and early identification of coronavirus disease 2019 (COVID-19) patients. Our review presents a summar…
Luminescent CdSe Quantum Dot Arrays for Rapid Sensing of Explosive Taggants
2022
Chemical sensors based on fluorescent quantum dots have attracted intense interest because of their excellent optical and electronic properties compared to the routinely employed fluorescent organic dyes. This study reports a CdSe QD-polymer-based luminescent chemosensor, which is based on an array containing either green-emitting or red-emitting CdSe QDs embedded in polycaprolactone as a polymer host matrix. We evaluate the sensing capability of the nanocomposites by exposing both sensors to vapors of explosive taggants, explosive-like molecules, and some common solvents. Both nanocomposites exhibit a very fast response time of <30 s. The limit of detection of the sensors for 3-nitrotoluen…
Nanodesign of new self-assembling core-shell gellan-transfersomes loading baicalin and in vivo evaluation of repair response in skin
2017
Gellan nanohydrogel and phospholipid vesicles were combined to incorporate baicalin in new self-assembling core-shell gellan-transfersomes obtained by an easy, scalable method. The vesicles were small in size (~107 nm) and monodispersed (P.I. ≤ 0.24), forming a viscous system (~24 mPa/s) as compared to transfersomes (~1.6 mPa/s), as confirmed by rheological studies. Gellan was anchored to the bilayer domains through cholesterol, and the polymer chains were distributed onto the outer surface of the bilayer, thus forming a core-shell structure, as suggested by SAXS analyses. The optimal carrier ability of core-shell gellan-transfersomes was established by the high deposition of baicalin in th…
Exploiting Low-Cost 3D Imagery for the Purposes of Detecting and Analyzing Pavement Distresses
2020
Road pavement conditions have significant impacts on safety, travel times, costs, and environmental effects. It is the responsibility of road agencies to ensure these conditions are kept in an acceptable state. To this end, agencies are tasked with implementing pavement management systems (PMSs) which effectively allocate resources towards maintenance and rehabilitation. These systems, however, require accurate data. Currently, most agencies rely on manual distress surveys and as a result, there is significant research into quick and low-cost pavement distress identification methods. Recent proposals have included the use of structure-from-motion techniques based on datasets from unmanned a…
Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy
2021
As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original …
Ionic liquid crystals based on viologen dimers: tuning the mesomorphism by varying the conformational freedom of the ionic layer
2016
ABSTRACTWe investigated the liquid crystal behaviour of newly synthesised bistriflimide salts of symmetric viologen dimers. A smectic A phase was observed for intermediate spacer lengths and for relatively long lateral alkyl chains. The systems were characterised by thermal analysis, polarised optical microscopy, X-ray scattering and solid-state NMR. An intermediate ordered smectic phase was also exhibited by the compounds (except for systems with very short lateral chains) consisting of molten layers of alkyl chains and partially ordered ionic layers. These results, relating to the mesomorphic behaviour of viologen salts, are qualitatively compared to those of the more common imidazolium s…
Effect of high temperature annealing (T > 1650 °C) on the morphological and electrical properties of p-type implanted 4H-SiC layers
2019
This work reports on the effect of high temperature annealing on the electrical properties of p-type implanted 4H-SiC. Ion implantations of Aluminum (Al) at different energies (30-200 keV) were carried out to achieve 300 nm thick acceptor box profiles with a concentration of about 10(20) at/cm(3). The implanted samples were annealed at high temperatures (1675-1825 degrees C). Morphological analyses of the annealed samples revealed only a slight increase of the surface roughness RMS up to 1775 degrees C, while this increase becomes more significant at 1825 degrees C (RMS = 1.2 nm). Room temperature Hall measurements resulted in a hole concentration in the range 0.65-1.34 x 10(18)/cm(3) and m…