| 1. |
|
|
| 2. |
- Liu, Zhiying, et al.
(författare)
-
Solution-Processable Nanotube/Polymer Composite for High-Performance TFTs
- 2011
-
Ingår i: IEEE Electron Device Letters. - 0741-3106 .- 1558-0563. ; 32:9, s. 1299-1301
-
Tidskriftsartikel (refereegranskat)abstract
- Thin-film field-effect transistors (TFTs) are readily fabricated using a semiconductor composite that is solution processed under ambient conditions for the conduction channel. The composite comprises single-walled carbon nanotubes (SWCNTs) embedded in poly-9,9' dioctyl-fluorene-co-bithiophene. Carrier mobility values approaching 10 cm(2)V(-1)s(-1) are obtained for the composite with relatively high SWCNT concentrations. When the SWCNT concentration is reduced for a large ON/OFF current ratio > 10(6), the mobility remains decent around 0.3 cm(2)V(-1)s(-1). The resultant TFTs display remarkable environmental and operational reliability. Nanotube-based composites are therefore of significance in printed electronics owing to their simplicity in device fabrication and competitiveness in device performance.
|
|
| 3. |
- Lopez Cabezas, Ana, 1980-, et al.
(författare)
-
Influence of Carbon Nanotubes on Thermal Stability of Water-Dispersible Nanofibrillar Polyaniline/Nanotube Composite
- 2012
-
Ingår i: Materials. - Basel, Switzerland : MDPI AG. - 1996-1944. ; 5:2, s. 327-335
-
Tidskriftsartikel (refereegranskat)abstract
- Significant influence on the thermal stability of polyaniline (PANI) in the presence of multi-walled carbon nanotubes (MWCNTs) is reported. By means of in-situ rapid mixing approach, water-dispersible nanofibrillar PANI and composites, consisting of MWCNTs uniformly coated with PANI in the state of emeraldine salt, with a well-defined core-shell heterogeneous structure, were prepared. The de-protonation process in PANI occurs at a lower temperature under the presence of MWCNTs on the polyaniline composite upon thermal treatment. However, it is found that the presence of MWCNTs significantly enhances the thermal stability of PANI's backbone upon exposure to laser irradiation, which can be ascribed to the core-shell heterogeneous structure of the composite of MWCNTs and PANI, and the high thermal conductivity of MWCNTs.
|
|
| 4. |
- Zhang, Zhi-qiang, et al.
(författare)
-
Effect of fault on tunnel stability with different distribution
- 2013
-
Ingår i: Global View of Engineering Geology and the Environment. - London : CRC Press, Taylor & Francis Group. - 9781138000780 ; , s. 279-285
-
Konferensbidrag (refereegranskat)abstract
- For tunnel engineering, the fault that locates near tunnel always plays an important role on the stability of the surrounding rock mass and the safety of the supporting system. To investigate the influence of the fault on the tunnel stability, systematic numerical experiments are carried out via the FINAL code. Through these numerical experiment results, the displacement and the distribution of the stress in surrounding rock mass are analyzed for these cases of the different locations and dips of fault around tunnel periphery, and the stress in the sprayed concrete layer are analyzed as well. To simulate the characteristics of the fault located in the rock mass, the COJO element, embedded in the FINAL code, is used in all numerical experiments. The quantized results reflecting the rules of the change for the displacement, stress, plastic region in the surrounding rock mass are obtained also in this paper.
|
|
| 5. |
- Feng, Yi, et al.
(författare)
-
Flexible UHF resistive humidity sensors based on carbon nanotubes
- 2012
-
Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 12:9, s. 2844-2850
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents the investigation of the resistive humidity-sensing properties of multi-walled carbon nanotubes (MWCNTs). MWCNTs functionalized by acid treatment (f-MWCNTs) exhibit rather high sensitivity in resistance toward humidity, owing to the presence of carboxylic groups on the nanotube surface. By integrating the f-MWCNTs resistor into a wireless sensor platform, flexible humidity sensors for ultra-high frequency applications are investigated. The operating frequency range of the sensor is dramatically increased from 600 MHz to 2 GHz by adjusting the resistor-electrodes' configuration. This enhancement is predominately attributed to the variation in parasitic capacitance between the resistor-electrodes.
|
|
| 6. |
- Jun, Chen, et al.
(författare)
-
A Novel Acceleration Data Compression Scheme for Wireless Sensor Network Application in Fresh Food Tracking System
- 2009
-
Ingår i: The Ninth International Conference on Electronic Measurement & Instruments ICEMI’2009. - : IEEE Press. - 9781424438631 ; , s. 3-1-3-5
-
Konferensbidrag (refereegranskat)abstract
- An enhanced dual-layer wide area wireless sensor network (WSN) system was developed and applied in fresh food tracking application. The sensor nodes of WSN provide a set of useful measurements about the environmental conditions during the fresh food transportation. Since the 3-axis acceleration data in such application account for more than 99% out of all collected source data, we propose a novel acceleration data compression scheme for this specific application, to overcome the resource and cost limitation imposed on embedded sensing nodes and wireless communication links in WSN. According to general fresh food transport behavior pattern, the acceleration data can be extracted into three components (D waveform, A waveform and P waveform). Each component could be compressed separately according to its distinct characteristic and then packetized as an encoded frame. In this paper we examine the experimental acceleration dataset from a field test (fresh melon fruit transport from Brazil to Sweden in 20 days) as a test case. Experimental results show that a high compression ratio (around 10:1) with the acceptable distortion could be achieved, confirming the effectiveness of the compression scheme proposed in this work.
|
|
| 7. |
- Pang, Zhibo, et al.
(författare)
-
Global Fresh Food Tracking Service Enabled by Wide Area Wireless Sensor Network
- 2010
-
Ingår i: 2010 IEEE Sensors Applications Symposium, SAS 2010. - : IEEE Sensors Council. ; , s. 6-9
-
Konferensbidrag (refereegranskat)abstract
- A global fresh food tracking service is presented, in which a set of primary environmental conditions for transport of fresh fruits and vegetables, including global position, temperature, relative humidity, concentrations of CO2, O2 and ethylene gases and 3-axis acceleration, is collected through mobile and remotely controllable wireless sensor nodes. Real time monitoring, tracking, alarming, close-loop controlling and information sharing could therefore be provided as WEB services with service oriented architecture. Fully functioned hardware modules, protocols and system software have been developed. A 50-day field test has been successfully carried out, proving the system concept and the robustness of hardware and software designed. Due to its worldwide deploy-ability and added-values to fresh food supply chain, it is feasible to establish a practical fresh food tracking service business.
|
|
| 8. |
- Pang, Zhibo, et al.
(författare)
-
Mobile and Wide Area Deployable Sensor System for Networked Services
- 2009
-
Ingår i: 2009 IEEE SENSORS. - NEW YORK : IEEE. - 9781424445486 ; , s. 1329-1332
-
Konferensbidrag (refereegranskat)abstract
- A mobile and wide area deployable wireless sensor system, including hardware and software, is developed to enhance the mobility, deployment and capability of wireless sensors for networked services. Due to the dual-layer dual-directional wireless communication capability of a novel WAN-SAN coherent architecture and the removal of fix-installed gateway, all sensor nodes are remotely controllable and seamlessly integrated to internet services. Hardware modules are optimized for ultra low power and compact size. Abstract and extendable application interface is developed, based on SMS and TCP/UDP protocol, to be integrated easily into existing service systems. Hierarchical CPS-LPS Adaptive Localization, is supported based on CPS, wireless cellular ID, RFID, IR-UWB and inertial prediction. Specific data compression technique is adopted for high density data source. Finally, Fresh Food Tracking service is presented as an application example, including some field test data.
|
|
| 9. |
|
|
| 10. |
- Zhang, Zhi, et al.
(författare)
-
A low delay multiple reader passive RFID system using orthogonal TH-PPM IR-UWB
- 2010
-
Ingår i: Proceedings - International Conference on Computer Communications and Networks, ICCCN. - Zurich.
-
Konferensbidrag (refereegranskat)abstract
- Current passive RFID systems face the challenges to locate mobile objects in real time in indoor environments, including the realization of low delay as well as effective cooperation among readers and accurate ranging ability in the physical layer. In order to overcome these challenges, this paper presents a low delay multi-reader passive RFID system using ultra high frequency (UHF) radio as the forward link from readers to tags and orthogonal time hopping pulse-position modulation (TH-PPM) impulse ultra-wideband radio (IR-UWB) over the dynamic framed slotted ALOHA algorithm as the backward link from tags to readers. The asymmetric radio links overlap parts of the forward and backward transmission and avoid reader-tag collisions. Readers cooperate via network synchronization by a server and a contention-based update strategy to acknowledge tags. An optimal system configured with 4 readers using 16 orthogonal TH sequences is suggested and operates 3 times faster than the theoretical potential of EPC Class-1 Generation-2 protocol with the listen-before-talk scheme.
|
|
