National Taiwan University of Science and Technology

About: National Taiwan University of Science and Technology is a education organization based out in Taipei, Taipei, Taiwan. It is known for research contribution in the topics: Fuzzy logic & Control theory. The organization has 16288 authors who have published 21577 publications receiving 426294 citations. The organization is also known as: Taiwan Tech & Taiwantech.

Intercalation-assisted longitudinal unzipping of carbon nanotubes for green and scalable synthesis of graphene nanoribbons

Abstract: We have demonstrated an effective intercalation of multi-walled carbon nanotubes (MWCNTs) for the green and scalable synthesis of graphene nanoribbons (GNRs) using an intercalation-assisted longitudinal unzipping of MWCNTs. The key step is to introduce an intercalation treatment of raw MWCNTs with KNO3 and H2SO4, making it promising to decrease the strong van der Waals attractions in the MWCNTs bundles and between the coaxial graphene walls of CNTs. Systematic micro Raman, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) characterizations suggest that potassium, nitrate and sulfate ions play an important role in the CNT intertube and intratube intercalations during the pretreatment. Detailed scanning electron microscopy (SEM), transmission electron microscopy, XRD and micro Raman characterizations indicate that the developed methodology possesses the ability to synthesis GNRs effectively with an improved CNT concentration in H2SO4 of 10 mg/ml at 70 °C, which is amenable to industrial-scale production because of the decreased amount of strong acid. Our work provides a scientific understanding how to enhance the GNR formation by accelerating the CNT longitudinal unzipping via suitable molecular intercalation.

Automatic generation of NC cutter path from massive data points

Abstract: This paper proposes methodologies and algorithms through which a three-axis NC cutter path can be directly generated from massive data points obtained with contact or non-contact measuring devices. At the beginning, a Z-map model is employed to set up mesh points in order to economize on the use of computer memory. Rough-cut paths are produced by machining volumes of material in a slice-by-slice manner: firstly cutting the raw material into several slices on the basis of depth of cut, next judging from intersection information the cut and non-cut areas, and then generating roughcut paths of slices. Fine-cut paths are achieved by the height correction method, which by degrees examines mesh points within the cutters' projection areas. Any interference between the cutting tool and the data points is taken into account during the correction of the cutter height. Aside from a theoretical discussion, this research develops a computer-aided engraving system to prove the applicability of the proposed methods. In contrast to traditional copy milling, computer-aided engraving provides users with much more flexibility, reduces machining time, and adapts the workpiece forms to different circumstances so as to manufacture male or female dies.

Site Activity and Population Engineering of NiRu-Layered Double Hydroxide Nanosheets Decorated with Silver Nanoparticles for Oxygen Evolution and Reduction Reactions

Abstract: Developing efficient and durable bifunctional electrocatalysts for oxygen reduction and evolution reaction (ORR/OER) is highly desirable in energy conversion and storage systems. This study prepares nickel–ruthenium layered double hydroxide (NiRu-LDHs) nanosheets subjected to decoration with conductive silver nanoparticles (Ag NP/NiRu-LDHs), which interestingly induce their multivacancies associated with catalytic site activity and populations. The as-prepared Ag NP/NiRu-LDH shows excellent catalytic activity toward both OER and ORR features with low onset overpotentials of 0.21 V and −0.27 V, respectively, with a 0.76 V potential gap between OER potential at 10 mA cm–2 and ORR potential at −3 mA cm–2, demonstrating that it is the preeminent bifunctional electrocatalyst reported to date. Compared with pristine NiRu-LDHs, the resulting Ag NP/NiRu-LDHs nanosheets require only an overpotential of 0.31 V to deliver 10 mA cm–2 with excellent durability. The superb bifunctional performance of Ag NP/NiRu-LDH is ...