There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Molecular self-assembly is the spontaneous association of molecules under equilibrium conditions into stable, structurally well-defined aggregates joined by noncovalent bonds. Molecular self-assembly is ubiquitous in biological systems and underlies the formation of a wide variety of complex biological structures. Understanding self-assembly and the associated noncovalent interactions that connect complementary interacting molecular surfaces in biological aggregates is a central concern in structural biochemistry. Self-assembly is also emerging as a new strategy in chemical synthesis, with the potential of generating nonbiological structures with dimensions of 1 to 10(2) nanometers (with molecular weights of 10(4) to 10(10) daltons). Structures in the upper part of this range of sizes are presently inaccessible through chemical synthesis, and the ability to prepare them would open a route to structures comparable in size (and perhaps complementary in function) to those that can be prepared by microlithography and other techniques of microfabrication.

Molecular self-assembly and nanochemistry: A chemical strategy for the synthesis of nanostructures

Zinc oxide can be called a multifunctional material thanks to its unique physical and chemical properties. The first part of this paper presents the most important methods of preparation of ZnO divided into metallurgical and chemical methods. The mechanochemical process, controlled precipitation, sol-gel method, solvothermal and hydrothermal method, method using emulsion and microemulsion enviroment and other methods of obtaining zinc oxide were classified as chemical methods. In the next part of this review, the modification methods of ZnO were characterized. The modification with organic (carboxylic acid, silanes) and inroganic (metal oxides) compounds, and polymer matrices were mainly described. Finally, we present possible applications in various branches of industry: rubber, pharmaceutical, cosmetics, textile, electronic and electrotechnology, photocatalysis were introduced. This review provides useful information for specialist dealings with zinc oxide.

Zinc Oxide-From Synthesis to Application: A Review.

Fiber-based structures are highly desirable for wearable electronics that are expected to be light-weight, long-lasting, flexible, and conformable Many fibrous structures have been manufactured by well-established lost-effective textile processing technologies, normally at ambient conditions The advancement of nanotechnology has made it feasible to build electronic devices directly on the surface or inside of single fibers, which have typical thickness of several to tens microns However, imparting electronic functions to porous, highly deformable and three-dimensional fiber assemblies and maintaining them during wear represent great challenges from both views of fundamental understanding and practical implementation This article attempts to critically review the current state-of-arts with respect to materials, fabrication techniques, and structural design of devices as well as applications of the fiber-based wearable electronic products In addition, this review elaborates the performance requirements of the fiber-based wearable electronic products, especially regarding the correlation among materials, fiber/textile structures and electronic as well as mechanical functionalities of fiber-based electronic devices Finally, discussions will be presented regarding to limitations of current materials, fabrication techniques, devices concerning manufacturability and performance as well as scientific understanding that must be improved prior to their wide adoption

Fiber‐Based Wearable Electronics: A Review of Materials, Fabrication, Devices, and Applications

We report white-light luminescence from ZnO-organic hybrid light emitting diodes grown on glass substrate by low temperature aqueous chemical growth. The configuration used for the hybrid white light emitting diodes (HWLEDs) consists of two-layers of polymers (PEDOT:PSS/PFO) on glass with top ZnO nanorods. Electroluminescence spectra of the HWLEDs demonstrate the combination of emission bands arising from the radiative recombination in polymer and ZnO nanorods. In order to distinguish emission bands we used a Gaussian function to simulate the experimental data. The emitted white light was found to be the superposition of a blue line at 454 nm, a green emission at 540 nm, orange line at 617 nm, and finally a red emission at 680 nm. The transitions causing these emissions are identified and discussed in terms of the energy band diagram of the hybrid junction. Color coordinates measurement of the WLED reveals that the emitted light has a white impression with 70 color rendering index and correlated color temperature 5500 K. Comparison between ITO and aluminum top contacts and its influence on the emitted intensity is also discussed.

Study of intrinsic white light emission and its components from ZnO-nanorods/p-polymer hybrid junctions grown on glass substrates

Annealing effect on the electrical and optical properties of Au/n-ZnO NWs Schottky diodes white LEDs

High-quality ZnO rods were grown by the vapour-liquid-solid (VLS) technique on 4H-p-SiC substrate. The current transport mechanisms of the diodes at room temperature (RT) have been explained in termof the space-charge-limited currentmodel based on the energy band diagram of ZnO rods/4H-p-SiC heterostructure. The tunneling mechanism via deep-level states was found to be the main conduction process at low-applied voltage but at trap-filled limit voltage VTFL all traps are filled and the space-chargelimited current conduction dominated the current transport. From the RT current voltage measurements, the energy of the deep level trap and the trap concentration were obtained as ∼ 0.24 ± 0.02 eV and 4.4 × 1018cm-3, respectively. The deep level states observed correspond to zinc interstitial (Zni), responsible for the violet emission.

/pdf/study-of-radiative-defects-using-current-voltage-44q6ldi28r.pdf

Study of radiative defects using current-voltage characteristics in ZnO rods catalytically grown on 4H-p-SiC

The variation of barrier height with the band gap in the metal/heterojunction systems is related to how the Fermi level position varies with respect to band edges If the Fermi level is pinned by the interface states its movement will also correspond to the movement of the neutrality level at the interface Metal/Si1−xGex/Si heterostructures (0⩽x⩽024) for both n- and p-type substrates were studied to understand the relation between Schottky barrier, Fermi level movement, and the band gap variations It was shown that a correlation exists between Schottky barrier height variation and band-offset values ΔEc and ΔEv For n-type substrate, measured barrier height differences are almost the same as the band offsets in the conduction band ΔEc For p-type substrates they were found to be slightly smaller than ΔEv This shows that Fermi level position relative to the conduction band edge does not change with band gap variation

Correlation between barrier height and band offsets in metal/Si1−xGex/Si heterostructures

https://liu.diva-portal.org/smash/get/diva2:730888/FULLTEXT01.pdf

Omer Nur

Papers

Study of intrinsic white light emission and its components from ZnO-nanorods/p-polymer hybrid junctions grown on glass substrates

Annealing effect on the electrical and optical properties of Au/n-ZnO NWs Schottky diodes white LEDs

Study of radiative defects using current-voltage characteristics in ZnO rods catalytically grown on 4H-p-SiC

Correlation between barrier height and band offsets in metal/Si1−xGex/Si heterostructures

The effect of oxygen-plasma treatment on the mechanical and piezoelectrical properties of ZnO nanorods