scholarly journals Conductance Tunable Suspended Graphene Nanomesh by Helium Ion Beam Milling

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 387 ◽  
Author(s):  
Fayong Liu ◽  
Zhongwang Wang ◽  
Soya Nakanao ◽  
Shinichi Ogawa ◽  
Yukinori Morita ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Ion Beam ◽  
Thermal Activation Energy ◽  
Exponential Relationship ◽  
New Approach ◽  
Suspended Graphene ◽  
Helium Ion ◽  
Defective Region ◽  
Graphene Nanomesh ◽  
The Individual

This paper demonstrates that the electrical properties of suspended graphene nanomesh (GNM) can be tuned by systematically changing the porosity with helium ion beam milling (HIBM). The porosity of the GNM is well-controlled by defining the pitch of the periodic nanopores. The defective region surrounding the individual nanopores after HIBM, which limits the minimum pitch achievable between nanopores for a certain dose, is investigated and reported. The exponential relationship between the thermal activation energy (EA) and the porosity is found in the GNM devices. Good EA tuneability observed from the GNMs provides a new approach to the transport gap engineering beyond the conventional nanoribbon method.

Quantum dot formation on suspended graphene nanomesh by helium ion beam milling technology

2021 ◽  
Author(s):  
Fayong Liu ◽  
Manoharan Muruganathan ◽  
Shinichi Ogawa ◽  
Yukinori Morita ◽  
Zhongwang Wang ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Ion Beam ◽  
Suspended Graphene ◽  
Helium Ion ◽  
Graphene Nanomesh

scholarly journals Thermal rectification on asymmetric suspended graphene nanomesh devices

Nano Futures ◽  
2021 ◽  
Author(s):  
Fayong Liu ◽  
Manoharan Muruganathan ◽  
Yu Feng ◽  
Shinichi Ogawa ◽  
Yukinori Morita ◽  
...  
Keyword(s):  
Thermal Transport ◽  
High Performance ◽  
Ion Beam ◽  
Phononic Crystal ◽  
Rectification Ratio ◽  
Suspended Graphene ◽  
Thermal Rectification ◽  
Helium Ion ◽  
Graphene Nanomesh ◽  
20 Nm

Abstract The graphene-based thermal rectification is investigated by measuring the thermal transport properties on asymmetric suspended graphene nanomesh devices. Sub-10 nm periodic nanopore phononic crystal structure is successfully patterned on the half area of the suspended graphene by the helium ion beam milling technology. The “differential thermal leakage” method is developed for thermal transport measurement without being disturbed by the electron current leakage through the suspended graphene bridge. Up to 60 % thermal rectification ratio is observed in a typical device with a nanopore pitch of 20 nm. By increasing the nanopore pitch in a particular range, the thermal rectification ratio shows an increment. However, this ratio is degraded by increasing the environmental temperature. This experiment preliminary shows a promising way to develop a high-performance thermal rectifier by using a phononic crystal to introduce the asymmetry on homogenous material.

Structurally Controlled Large-Area 10 nm Pitch Graphene Nanomesh by Focused Helium Ion Beam Milling

2018 ◽  
Vol 10 (12) ◽  
pp. 10362-10368 ◽  
Author(s):  
Marek Edward Schmidt ◽  
Takuya Iwasaki ◽  
Manoharan Muruganathan ◽  
Mayeesha Haque ◽  
Huynh Van Ngoc ◽  
...  
Keyword(s):  
Ion Beam ◽  
Large Area ◽  
Helium Ion ◽  
Graphene Nanomesh

X- ray diffraction and dielectric properties of PbSe thin films

2019 ◽  
Vol 15 (34) ◽  
pp. 1-14
Author(s):  
Bushra A. Hasan
Keyword(s):  
Thin Films ◽  
Thermal Activation ◽  
Thermal Evaporation ◽  
Thermal Activation Energy ◽  
Dielectric Constants ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Glass Substrates

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.

Automatic Determination of Optimal FIB Operations for Improved Circuit Probing and Fast Reconfiguration

2000 ◽  
Author(s):  
Romain Desplats ◽  
Timothee Dargnies ◽  
Jean-Christophe Courrege ◽  
Philippe Perdu ◽  
Jean-Louis Noullet
Keyword(s):  
Integrated Circuit ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Semiconductor Devices ◽  
Front Side ◽  
Automatic Determination ◽  
Metal Line ◽  
New Approach ◽  
Metal Layers

Abstract Focused Ion Beam (FIB) tools are widely used for Integrated Circuit (IC) debug and repair. With the increasing density of recent semiconductor devices, FIB operations are increasingly challenged, requiring access through 4 or more metal layers to reach a metal line of interest. In some cases, accessibility from the front side, through these metal layers, is so limited that backside FIB operations appear to be the most appropriate approach. The questions to be resolved before starting frontside or backside FIB operations on a device are: 1. Is it do-able, are the metal lines accessible? 2. What is the optimal positioning (e.g. accessing a metal 2 line is much faster and easier than digging down to a metal 6 line)? (for the backside) 3. What risk, time and cost are involved in FIB operations? In this paper, we will present a new approach, which allows the FIB user or designer to calculate the optimal FIB operation for debug and IC repair. It automatically selects the fastest and easiest milling and deposition FIB operations.

In silico modeling of cellular probabilistic nanoparticle radiosensitization in head and neck cancers

Nanomedicine ◽  
2020 ◽  
Vol 15 (29) ◽  
pp. 2837-2850
Author(s):  
Myxuan Huynh ◽  
Ivan Kempson ◽  
Eva Bezak ◽  
Wendy Phillips
Keyword(s):  
Head And Neck ◽  
Patient Outcomes ◽  
Head And Neck Cancers ◽  
New Approach ◽  
Treatment Regimens ◽  
Therapeutic Benefits ◽  
In Silico Modeling ◽  
The Individual ◽  
Dose Deposition ◽  
Therapy Treatment

Background: The use of gold nanoparticles (AuNPs) as radiosensitizers may offer a new approach in the treatment of head and neck cancers; minimizing treatment-associated toxicities and improving patient outcomes. AuNPs promote localized dose deposition; permitting improved local control and/or dose reduction. Aim: This work aimed to address the theoretical optimization of radiation doses, fractionation and nanoparticle injection schedules to maximize therapeutic benefits. Materials & methods: Probabilistic nanoparticle sensitization factors were incorporated into the individual cell-based HYP-RT computer model of tumor growth and radiotherapy. Results: Total dose outcomes across all radiation therapy treatment regimens were found to be significantly reduced with the presence of AuNPs, with bi-weekly injections showing the most decrease. Conclusion: Outcomes suggest the need for regular AuNP administration to permit effective radiosensitization.

Large-Scale Focused Helium Ion Beam Lithography

2021 ◽  
Vol 31 (5) ◽  
pp. 1-4
Author(s):  
Jay C. LeFebvre ◽  
Shane A. Cybart
Keyword(s):  
Large Scale ◽  
Ion Beam ◽  
Ion Beam Lithography ◽  
Helium Ion

scholarly journals Sustainable Geographical Changes in Rural Areas: Key Paths, Orientations and Limits

2021 ◽  
Vol 13 (4) ◽  
pp. 2059
Author(s):  
Angel Paniagua
Keyword(s):  
Rural Areas ◽  
Anglo Saxon ◽  
Rural Studies ◽  
New Approach ◽  
Rural Restructuring ◽  
Theoretical Approaches ◽  
Methodological Approaches ◽  
Social Environmental ◽  
The Individual ◽  
New Rurality

Rural differentiation processes have formed the backbone of rural studies. Owing to the strength of rural–urban and local–global relationships, the theoretical approaches to rural restructuring in the Anglo-Saxon world and new rurality in Latin America only have a limited capacity to explain contemporary global phenomena of rural spaces. Due to this, transverse theoretical and methodological approaches have emerged to explain social, environmental and spatial (rural) processes. Here, a new approach is proposed called the individual–global field, based on the individual–global binary category to substitute the traditional relevance of the locality–community–globality association This new approach tries to reinvigorate rural geography in a more flexible way, based on minor theory, to adapt to all the phenomena that can occur globally. In any case, various spatial planes are proposed, dominated by specific socioeconomic processes on which the rural individual would move.

scholarly journals Individualized Hemodynamic Management in Sepsis

2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Marcell Virág ◽  
Tamas Leiner ◽  
Mate Rottler ◽  
Klementina Ocskay ◽  
Zsolt Molnar
Keyword(s):  
Fluid Overload ◽  
Fluid Management ◽  
Multiple Organ ◽  
Treatment Protocols ◽  
Hemodynamic Management ◽  
New Approach ◽  
Hemodynamic Optimization ◽  
The Individual ◽  
Sepsis And Septic Shock ◽  
Insight Into

Hemodynamic optimization remains the cornerstone of resuscitation in the treatment of sepsis and septic shock. Delay or inadequate management will inevitably lead to hypoperfusion, tissue hypoxia or edema, and fluid overload, leading eventually to multiple organ failure, seriously affecting outcomes. According to a large international survey (FENICE study), physicians frequently use inadequate indices to guide fluid management in intensive care units. Goal-directed and “restrictive” infusion strategies have been recommended by guidelines over “liberal” approaches for several years. Unfortunately, these “fixed regimen” treatment protocols neglect the patient’s individual needs, and what is shown to be beneficial for a given population may not be so for the individual patient. However, applying multimodal, contextualized, and personalized management could potentially overcome this problem. The aim of this review was to give an insight into the pathophysiological rationale and clinical application of this relatively new approach in the hemodynamic management of septic patients.

Sign in / Sign up

Export Citation Format

Share Document