Effect of ZnO/K2O ratio on the crystallization sequence and microstructure of lithium disilicate glass-ceramics

The effect of ZnO/K₂O (Z/K) ratio on the crystallization sequence and microstructure of lithium disilicate (Li₂Si₂O₅: LS2) glass-ceramics was carefully investigated for the SiO₂-Li₂O-K₂O-ZnO-P₂O₅ system. The Z/K ratios of precursor glasses were varied from 0 to 3.5 while the nucleating agent of P₂O₅ and glass modifiers of ZnO plus K₂O were fixed to have 1.5 and 4.5 mol% relative to LS2, respectively. For the samples prepared by two-stage heat treatments of 500 °C for 1 h and 800 °C for 2 h in air, the LS2 nucleation rate was increased with increasing the Z/K ratio due to the variation in crystallization sequence from type II (Li₂SiO₃: LS) to type I (LS + LS2) in addition to an amorphous phase separation in base glass. Consequently, with increasing the Z/K ratio, the LS2 crystalline phase within the glass matrix continuously changed from larger acicular ones to smaller equiaxed ones.     

Scanning Probe Lithography Patterning of Monolayer Semiconductors and Application in Quantifying Edge Recombination

Scanning probe lithography is used to directly pattern monolayer transition metal dichalcogenides (TMDs) without the use of a sacrificial resist. Using an atomic‐force microscope, a negatively biased tip is brought close to the TMD surface. By inducing a water bridge between the tip and the TMD surface, controllable oxidation is achieved at the sub‐100 nm resolution. The oxidized flake is then submerged into water for selective oxide removal which leads to controllable patterning. In addition, by changing the oxidation time, thickness tunable patterning of multilayer TMDs is demonstrated. This resist‐less process results in exposed edges, overcoming a barrier in traditional resist‐based lithography and dry etch where polymeric byproduct layers are often formed at the edges. By patterning monolayers into geometric patterns of different dimensions and measuring the effective carrier lifetime, the non‐radiative recombination velocity due to edge defects is extracted. Using this patterning technique, it is shown that selenide TMDs exhibit lower edge recombination velocity as compared to sulfide TMDs. The utility of scanning probe lithography towards understanding material‐dependent edge recombination losses without significantly normalizing edge behaviors due to heavy defect generation, while allowing for eventual exploration of edge passivation schemes is highlighted, which is of profound interest for nanoscale electronics and optoelectronics.     

A dynamic control technique to enhance the flexibility of software artifact reuse in large-scale repository

The Journal of Supercomputing - Reuse is the activity of developing new software systems using software components (or artifacts) that are already proven and reliable. However, traditional...     

A simple explicit single step time integration algorithm for structural dynamics

In this article, a new single-step explicit time integration method is developed based on the Newmark approximations for the analysis of various dynamic problems. The newly proposed method is second-order accurate and able to control numerical dissipation through the parameters of the Newmark approximations. Explicitness and order of accuracy of the proposed method are not affected in velocity-dependent problems. Illustrative linear and nonlinear examples are used to verify performances of the proposed method.     

Advanced Functional Structure‐Based Sensing and Imaging Strategies for Cancer Detection: Possibilities,Opportunities, Challenges,and Prospects

Cancer is the second most common cause of death in the world. The principal limitations thus far encountered in the clinical practice of probing cancer are diverse and include low sensitivity, time consumption, bulkiness, and cost. In this respect, nanomaterial (NM)‐based sensing techniques are recognized as a superior alternative to efficiently resolve such limitations. A better understanding of NM‐based sensing platforms is thus important so that these novel avenues can easily be explored for clinical applications. These platforms have the merits of high sensitivity, high specificity, rapid response, and easy‐to‐read signals. This review offers a comprehensive survey of NM‐based advanced cancer‐sensing techniques and will help the scientific community establish optimum sensing strategies based on an accurate assessment of the interactions between cancer biomarkers and NM‐based platforms.     

Correlations between histopathologic and dermoscopic findings in Korean actinic keratosis

Skin biopsy for AK diagnosis is usually performed on only a limited part of the whole lesion. Therefore, a clinical diagnosis is important. According to a study, there is no significant correlation between histopathological and clinical classification system. We examined the correlation between microscopic information and dermoscopic findings to deduce if dermoscopic information reflects histopathologic grade severity. Forty seven patients with histologically confirmed AK were enrolled and positive ratio of red pseudonetwork, rosette, red background and targetoid signs, white‐to‐yellow scale, white structureless area, and pigmentation from dermoscopic findings were investigated. Furthermore, viable epidermal thickness, vessel lumen dimensions, existence and thickness of ortho‐ and parakeratosis, degree of sola elastosis, flag sign existence, and Roewert‐Huber classification were measured as histologic findings. Red background did not show a significant correlation with vascular dimension or viable epidermal thickness. When targetoid sign was present, vascular dimension was significantly larger but showed no correlation with viable epidermal thickness, parakeratosis or orthokeratosis. Solar elastosis level was significantly higher when white‐to‐yellow scale was present. According to Spearman's correlation analysis, ortho/parakeratotic thickness showed correlations with each other. The negative correlation between viable epidermal thickness and vascular dimension was also shown. Roewert‐Huber histologic AK classification showed no correlation with any factors we checked. Factors considered to be characteristic features of AK in dermoscopy seemed unassociated with histologic AK classification and additional research is needed to determine degree of dysplasia of AK lesions using dermoscopy.     

Cost analysis of erasure coding for exa-scale storage

The Journal of Supercomputing - With the increasing demand for mass storage, research on exa-scale storage is actively underway. When the scale of storage grows to the exa-scale, the space...