scholarly journals Germanium Nanowires as Sensing Devices: Modelization of Electrical Properties

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 507
Author(s):  
Luca Seravalli ◽  
Claudio Ferrari ◽  
Matteo Bosi
Keyword(s):  
Charge Transfer ◽  
Electrical Properties ◽  
Surface Charges ◽  
Molecular Sensing ◽  
Germanium Nanowires ◽  
Physical Mechanisms ◽  
Additional Doping ◽  
Different Types ◽  
N Doping ◽  
Very High

In this paper, we model the electrical properties of germanium nanowires with a particular focus on physical mechanisms of electrical molecular sensing. We use the Tibercad software to solve the drift-diffusion equations in 3D and we validate the model against experimental data, considering a p-doped nanowire with surface traps. We simulate three different types of interactions: (1) Passivation of surface traps; (2) Additional surface charges; (3) Charge transfer from molecules to nanowires. By analyzing simulated I–V characteristics, we observe that: (i) the largest change in current occurs with negative charges on the surfaces; (ii) charge transfer provides relevant current changes only for very high values of additional doping; (iii) for certain values of additional n-doping ambipolar currents could be obtained. The results of these simulations highlight the complexity of the molecular sensing mechanism in nanowires, that depends not only on the NW parameters but also on the properties of the molecules. We expect that these findings will be valuable to extend the knowledge of molecular sensing by germanium nanowires, a fundamental step to develop novel sensors based on these nanostructures.

Measurement and Analysis of Triboelectric Surface Charge

2021 ◽  
Vol 30 (1/2) ◽  
pp. 7-11
Author(s):  
Jinhong PARK ◽  
Jinhyeok CHOI ◽  
Sang Hyeok PARK ◽  
Minbaek LEE
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Surface Properties ◽  
Elastic Moduli ◽  
Surface Charges ◽  
Contact Electrification ◽  
Measurement And Analysis ◽  
Different Types ◽  
Triboelectric Charging ◽  
Method Of Measurement

Contact electrification occurs when two isolated objects come into contact. Such a phenomenon led humans to first realization of the existence of electricity. Until now, the main causes of the triboelectric charging phenomenon have generally been thought to be the transfer of electrons, ions, and materials. This article, however, is limited to electron transfer on the surface, which is regarded as a general case not limited to specific situations. The contact between two objects occurs between the two surfaces; therefore, the surface properties of the material under examination are the most important properties in triboelectric charge transfer. The surface properties may include the types of materials in contact, their energy states, the roughnesses of their surfaces, and their elastic moduli. In this regard, we introduce here the current understanding of the energy band structures involved in the different types of materials, the method of measurement, an analysis of surface charges, and related applications.

Unsymmetrical phthalocyanines with cyclopalladated azo functions

2012 ◽  
Vol 16 (02) ◽  
pp. 192-199 ◽  
Author(s):  
H. Yasemin Yenilmez Akkurt ◽  
Ali ihsan Okur ◽  
Ahmet Gül
Keyword(s):  
Organic Solvents ◽  
Column Chromatography ◽  
Spectroscopic Analysis ◽  
Palladium Complex ◽  
Palladium Complexes ◽  
High Solubility ◽  
Synthetic Procedure ◽  
Different Types ◽  
New Compounds ◽  
Very High

In this study, a synthetic procedure for unsymmetrical metallophthalocyanines of the form M[Pc(AB3)], where A and B refer to two different types of peripheral functionality, has been developed and the new compounds have been converted to monomeric and dimeric palladium complexes. Asymmetrically substituted phthalocyanines were synthesized with the well-known statistical condensation method, by using two differently substituted precursors, namely 4-(2-ethoxyethoxy)-1-2-dicyanobenzene (1) and 4-{4-[Z/E]-phenylazo]-1-naphthyl}oxy-1,2-dicyanobenzene (2). Consequently, electron-donating 2-ethoxyethoxy groups and electron-withdrawing palladium complex are present in the same structure. Cyclopalladation was performed with [Pd(PhCN)2Cl2] to yield the bis-μ-chloro-bridged dimers and subsequently, the corresponding monomers were obtained by refluxing with three equivalents of potassium acetylacetonate. The resulting products were purified by column chromatography and characterized by several chemical and spectroscopic analysis methods. All compounds have very high solubility in organic solvents due to the presence of 2-ethoxyethoxy moiety.

scholarly journals Microgels and Nanoparticles: Where Micro and Nano Go Hand in Hand

2015 ◽  
Vol 229 (1-2) ◽  
Author(s):  
Beatriz H. Juarez ◽  
Luis M. Liz-Marzán
Keyword(s):  
Magnetic Nanoparticles ◽  
Optical Tweezers ◽  
Hybrid System ◽  
Inorganic Nanoparticles ◽  
Stimuli Responsive ◽  
Single Particles ◽  
Nanoscale Systems ◽  
Different Types ◽  
Potential Applications ◽  
Very High

AbstractThe integration of different types of materials in a single hybrid system allows the combination of multiple functionalities, which can even be used in conjunction with each other. This strategy has been exploited in nanoscale systems for the creation of so-called smart nanomaterials. Within this category, the combination of inorganic nanoparticles with stimuli-responsive microgels is of very high interest because of the wide variety of potential applications. We present here a short overview of this type of materials in which the nano- and micro-scales get nicely integrated, with a great potential to expand the range of technological applications. We focus mainly on the integration of metal nanoparticles, either by themselves or in combination with semiconductor and magnetic nanoparticles. Various examples of the synergic properties that can be obtained are described, as well as the possibility to extract useful information when optical tweezers are used to manipulate single particles. We expect that this review will stimulate additional research in this field.

Comparative Study on Electrical Properties of Three Different Types of Graphene-Based Thin Films

2013 ◽  
Vol 53 (14) ◽  
pp. 1-9
Author(s):  
X. Wang ◽  
J. Yu ◽  
H. Dong ◽  
F. Jiang ◽  
Q. Zhu ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Comparative Study ◽  
Different Types

scholarly journals CNN BASED DETECTION OF BUILDING ROOFS FROM HIGH RESOLUTION SATELLITE IMAGES

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 187-192
Author(s):  
L. Hang ◽  
G. Y. Cai
Keyword(s):  
High Resolution ◽  
Residential Building ◽  
Training Image ◽  
Training Dataset ◽  
Classification Approach ◽  
Object Based ◽  
High Resolution Satellite Images ◽  
Different Types ◽  
Model Training ◽  
Very High

Abstract. The detection and reconstruction of building have attracted more attention in the community of remote sensing and computer vision. Light detection and ranging (LiDAR) has been proved to be a good way to extract building roofs, while we have to face the problem of data shortage for most of the time. In this paper, we tried to extract the building roofs from very high resolution (VHR) images of Chinese satellite Gaofen-2 by employing convolutional neural network (CNN). It has been proved that the CNN is of a higher capability of recognizing detailed features which may not be classified out by object-based classification approach. Several major steps are concerned in this study, such as generation of training dataset, model training, image segmentation and building roofs recognition. First, urban objects such as trees, roads, squares and buildings were classified based on random forest algorithm by an object-oriented classification approach, the building regions were separated from other classes at the aid of visually interpretation and correction; Next, different types of building roofs mainly categorized by color and size information were trained using the trained CNN. Finally, the industrial and residential building roofs have been recognized individually and the results have been validated individually. The assessment results prove effectiveness of the proposed method with approximately 91% and 88% of quality rates in detection industrial and residential building roofs, respectively. Which means that the CNN approach is prospecting in detecting buildings with a very higher accuracy.

scholarly journals State of the art olfactometers. Different types

2021 ◽  
Keyword(s):  
Human Beings ◽  
Pathological Conditions ◽  
New Concepts ◽  
Different Types ◽  
Clinical Diagnoses ◽  
Human Use ◽  
The Brain ◽  
Very High ◽  
Human Olfaction

The complexity of human olfaction is very high and the importance of being able to measure it directly, objectively and qualitatively has led experts to search for mechanisms that can be applied. Human beings use this sense, which is one of the oldest, to recognize danger and distinguish between pleasant and unpleasant odors. Smells are mixtures of molecules that, at different concentrations in the inhaled air, stimulate the olfactory area and are recognized at the brain level. Therefore, there is a coding and decoding system. Human olfactometer techniques use equipment designed to be able to measure its intensity and quality of volatile substances. If we are able to measure this sense, we will be able to know its variations and be able to make clinical diagnoses in normal and pathological conditions and diagnose the losses that occur in certain infectious, degenerative diseases, traumatic processes and other variants. For many years, systems have been developed that can measure subjective olfaction in humans, as well as objective forms, but it is also true that there is no equipment available that is fast, simple handling and that can be applied in daily clinical services. Aim of the Study Present the recent achievements in olfactometer technology; Elaborate the scientific articles about olfactometry published mainly in the last 10 years; To gather the information published in the last years in relation to the usefulness, existence in the market and purposes of equipment that can measure the odors, what we will call the Smell-o-meter or olfactometer for human use. Material and Methods: In the first part of this research we will gather most of the information existing so far in international bibliography, as well as the achievements and utilities obtained to date. Following, we will analyze all the new concepts related to smell-o-meters devices that exist on the market and assess the possibility, based on what has been done so far, to seek new practical systems for application in the medical field.

scholarly journals Geoelectric method applied in correlation between physical characteristics and electrical properties of the soil

2017 ◽  
Vol 2 (2) ◽  
pp. 37 ◽  
Author(s):  
Antonio Marcelino Silva Filho ◽  
Carlos Leandro Borges Silva ◽  
Marco Antonio Assfalk Oliveira ◽  
Thyago Gumeratto Pires ◽  
Aylton José Alves ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Soil Moisture ◽  
Electrical Properties ◽  
Moisture Content ◽  
Soil Compaction ◽  
Clay Content ◽  
Physical Characteristics ◽  
Soil Dynamics ◽  
Different Types ◽  
The Relationship

This paper presents the study of the relationship between electrical properties and physical characteristics of the soil. Measures of apparent electrical resistivity of the soil were made for different types of soil, varying moisture content gradually while maintaining a constant compaction, and then varying the compaction and relating it to a constant humidity. Development of a correlation surface is proposed in order to identify granulometry of the soil from moisture and compaction measurements. For the study of spatial variability, two areas were chosen to allow the change of moisture content and compaction in order to verify the measurement capacity of apparent electrical resistivity of the soil as methodology to identify change in soil dynamics. Results obtained show correlations among apparent electrical resistivity of the soil, moisture, soil compaction and clay content.

scholarly journals Glucose status in cerebrospinal fluid (CSF) in different meningitic children in a hospital in Chittagong, Bangladesh

2013 ◽  
Vol 6 (1-2) ◽  
pp. 41-49
Author(s):  
Sharmistha Mitra ◽  
Robiul Hasan Bhuiyan ◽  
Md Arifuzzaman ◽  
Mohammad Sayedul Islam ◽  
Mahmood A Chowdhury ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Glucose Level ◽  
Viral Meningitis ◽  
Pyogenic Meningitis ◽  
Detailed Medical History ◽  
Different Types ◽  
The Brain ◽  
Very High ◽  
Potential Tool ◽  
Glucose Status

Meningitis is referred to as an inflammatory process of the leptomeninges and cerebrospinal fluid (CSF) within the sub-arachnoid space of the brain. We have investigated glucose status in CSF in different types of meningitis together with detailed medical history in children. In addition, we have also carried out the detailed cytological and microbiological examinations. A total of 40 subjects were investigated. We observed that the glucose level was significantly decreased (<20 mg/dl) in 65%, moderately decreased (20-40 mg/dl) in 20% and mildly decreased (40-50mg/dl) in 15% of the patients in our study. Patients with Pyogenic meningitis had tremendously reduced glucose level (9.0 mg/dl) in their CSF whereas in viral meningitis the CSF glucose level is highly variable (10 to 65 mg/dl). Furthermore, 5 (12.5%) patients showed high lymphocyte counts and 34 (85%) patients showed high neutrophil counts. Interestingly, in Pyogenic meningitis, the neutrophil count was very high compared to that in viral meningitis. The present study clearly demonstrates that biochemical parameters such as glucose level in CSF might be a potential tool for detecting meningitis and as well as differentiation of the different types of meningitis. DOI: http://dx.doi.org/10.3329/cujbs.v6i1-2.17080 The Chittagong Univ. J. B. Sci.,Vol. 6(1&2):41-49, 2011

Encapsulating third donors into D-A hybrid heterostructures to form three-component charge-transfer complexes for enhanced electrical properties

2021 ◽  
Author(s):  
Meng-Hua Li ◽  
Ming-Hua You ◽  
Mei-Jin Lin
Keyword(s):  
Charge Transfer ◽  
Electrical Properties ◽  
Organic Molecules ◽  
Steric Effects ◽  
Charge Transfer Complexes ◽  
Coordination Sites ◽  
Component Charge

inorganic donors and organic acceptors. However, due to the steric effects of inorganic coordination sites, it is difficult for the large organic molecules to form compact packing at the molecule...

Electroreception in Gymnotus carapo: pre-receptor processing and the distribution of electroreceptor types

2000 ◽  
Vol 203 (21) ◽  
pp. 3279-3287 ◽  
Author(s):  
M.E. Castello ◽  
P.A. Aguilera ◽  
O. Trujillo-Cenoz ◽  
A.A. Caputi
Keyword(s):  
Electric Fields ◽  
Electric Fish ◽  
Fish Tissue ◽  
Field Vector ◽  
The Body ◽  
Type I ◽  
Type Ii ◽  
Field Patterns ◽  
Different Types ◽  
Very High

This paper describes the peripheral mechanisms involved in signal processing of self- and conspecific-generated electric fields by the electric fish Gymnotus carapo. The distribution of the different types of tuberous electroreceptor and the occurrence of particular electric field patterns close to the body of the fish were studied. The density of tuberous electroreceptors was found to be maximal on the jaw (foveal region) and very high on the dorsal region of the snout (parafoveal region), decaying caudally. Tuberous type II electroreceptors were much more abundant than type I electroreceptors. Type I electroreceptors occurred exclusively on the head and rostral trunk regions, while type II electroreceptors were found along as much as 90 % of the fish. Electrophysiological data indicated that conspecific- and self-generated electric currents are ‘funnelled’ by the high conductivity and geometry of the body of the fish. These currents are concentrated at the peri-oral zone, where most electroreceptors are located. Moreover, within this region, field vector directions were collimated, constituting the most efficient stimulus for electroreceptors. It can be concluded that the passive properties of the fish tissue represent a pre-receptor device that enhances exafferent and reafferent electrical signals at the fovea-parafoveal region.

Sign in / Sign up

Export Citation Format

Share Document