Adjustable-free and movable Nd:YVO_(4) thin disk laser based on the telecentric cat's eye cavity

In this paper, we propose and demonstrate an adjustable-free and movable Nd:YVO_(4)thin disk laser based on the telecentric cat’s eye cavity. We design a V-shaped laser cavity containing two reflectors with Nd:YVO_(4)thin disks as the gain medium.The experimental results from the traditional plane-plane cavity, plane-telecentric cat’s eye cavity, and double telecentric cat’s eye cavity are compared. They show that plane-telecentric cat’s eye cavity laser can keep operating at the adjustablefree range of -6° to +6°, which is up to 60 times better than that of traditional plane-plane cavity. In the double telecentric cat’s eye case, the adjustable-free range is improved to-13° to +13°. Additionally, in the case of the double telecentric cat’s eye cavity, the output telecentric cat’s eye can achieve free movement within the horizontal range of ±20 mm.

Development of an upgraded motional Stark effect diagnostic system on EAST tokamak

A new multi-channel motional Stark effect(MSE)diagnostic system has been developed on the upgraded EAST tokamak,which was installed on the port C to observe a tangential neutral beam.A telecentric imaging lens was deployed to ensure uniform illumination from the core to the boundary.A square fiber head which contained 23 fiber bundles was mounted to this imaging lens;each fiber bundle contained 19 fibers and two of them were assigned to CXRS and BES spectrometer,respectively.The angle tuning method was used for matching the Doppler shift of theσcomponent’s wavelength which was caused by the beam voltage.At the present stage,the MSE system only contains ten channels that would be extended to 23 channels in the future,covering a measurement range from R=1.8 to R=2.27 m with a temporal resolution of 10 ms and a spatial resolution of3 cm.The polarization angle-constrained q profiles and current density profiles were reconstructed with EFIT equilibrium reconstructions.In the sawtooth discharges,the q=1 surface position was validated by the ECE signals,which further verified the rationality of the MSE measurement.

Telecentres in Mountain Regions-A Peruvian Case Study of the Impact of Information and Communication Technologies on Remoteness and Exclusion

Communities in developing country mountain areas,in part due to their remoteness,find themselves excluded from social,political and economic systems; and excluded from access to resources. This paper aims to study the impact of information and communication technologies (ICTs) on remoteness and exclusion. It utilises two models - the resource movement framework,and the "information chain" - to analyse a telecentre in one district of mountainous Huancavelica,Peru's poorest region,set in the high Andes. It finds ICTs enabling new and positive resource flows for the two key user groups:teenaged school students and young farmers. These help to maintain social networks. They also support information searches that have improved agricultural practice where other information chain resources have been available. But non-use and ineffective use of the telecentre are found where information chain resources are lacking. ICTs have some impacts on intangible elements of remoteness. In this particular example,they also offer access to some previously-excluded resources. But they have not really addressed the systematic exclusions faced by mountain communities. And they so far appear to be a technology of inequality; favouring those residents who begin with better resource endowments.The paper concludes by offering some recommendations for mountain ICT project practice.

Assessing the Digital Divide Status of the Jordanian Telecentre

This study investigates the status of digital divide amongst Jordanian Telecentres. The objective of this study is to analyze the impact of the perceived usefulness, the perceived ease-of-use and the facilitating conditions on the behavioral intention of employees. In addition, the study investigates the effect of the three mentioned factors on the user acceptance while the behavioral intention on the user acceptance is used as a mediating factor. The proposed research model was validated by distributing 150 survey questionnaires to the Telecentres in Jordan. Structural equation modeling (SEM) technique was used to analyze the results. One of the main limitations of this study is that the results cannot be universal since the study was limited to Jordan. Similar study needs to be conducted in different courtiers to either support or negate our results.

Design of a real-time fiber-optic infrared imaging system with wide-angle and large depth of field

A key limitation in the observation of instruments used in operations and heart sutures during a procedure is the scattering and absorption during optical imaging in the presence of blood.Therefore,we propose a novel real-time fiber-optic infrared imaging system simultaneously capturing a flexible wide field of view(FOV) and large depth of field infrared image in real time.The assessment criteria for imaging quality of the objective and coupling lens have been optimized and evaluated.Furthermore,the feasibility of manufacturing and assembly has been demonstrated with tolerance sensitivity and the Monte Carlo analysis.The simulated results show that the optical system can achieve a large working distance of 8 to25 mm,a wide FOV of 120°,and the relative illuminance is over 0.98 in the overall FOV.To achieve high imaging quality in the proposed system,the modulation transfer function is over 0.661 at 16.7 Ip/mm for a 320×256 short wavelength infrared camera sensor with a pixel size of 30 μm.