A novel ultraviolet (UV) optical fiber sensor (UVOFS) based on the scintillating material La2O2S:Eu has been designed, tested, and its performance compared with other scintillating materials and other conventional UV detectors. The UVOFS is based on PMMA (polymethyl methacrylate) optical fiber which includes a scintillating material. Scintillating materials provide a unique opportunity to measure UV light intensity even in the presence of strong electromagnetic interference. Five scintillating materials were compared in order to select the most appropriate one for the UVOFS. The characteristics of the sensor are reported, including a highly linear response to radiation intensity, reproducibility, temperature response, and response time (to pulsed light) based on emission from a UV source (UV fluorescence tube) centered on a wavelength of 308 nm. A direct comparison with the commercially available semiconductor-based UV sensor proves the UVOFS of this investigation shows superior performance in terms of accuracy, long-term reliability, response time and linearity.
21 January 2022 in Biomedical Physics & Engineering Express
Measurements using an Optical Fiber OFS including an inorganic scintillator placed on the surface of a phantom show that the particle energy distribution inside the phantom remains unchanged. The backscattered intensity measured using an Optical Fiber Sensor (OFS) exhibits a linear relationship with the total radiation dose delivered to the phantom, and this relationship shows that the OFS can be used for indirect dose measurement when located on the surface of the phantom i.e. that arising from the energetic backscattered electrons and photons. Such a device can therefore be used as a clinical in-vivo dosimeter, being located on the patient’s body surface. In addition, the measurement results for the same OFS located inside and outside the radiation field of a compound water based phantom are analyzed. The differences in measurement of the fluorescence signal in response to various tissue materials representing bone or tumor tissue in the irradiation field are strongly related to the material’s ability to block the scattered rays from the water phantom, as well as the scattered x-rays generated by the material located within the phantom.
13 March 2023 in Frontiers in Business, Economics and Management
In this paper, farmers in tourist destinations are taken as an example to study the co-creation mechanism of social capital and rural farmers' value under the background of common prosperity. Through the case study and contribution study of the value co-creation mechanism of the consortium, this paper establishes the value co-creation mechanism of farmers in rural tourist destinations with social capital as a universal model, and verifies the accuracy and fitting precision of the model with existing cases. Taking the leading enterprises, the support of government policies, tourism and agricultural products as variables, this paper studies their impact on rural economic income as a whole. Through model research, this paper solves the problems of market mechanism disorder and unfair distribution in the three distributions of common prosperity, and combines the concept of rural tourism development and value co-creation. The research results are universal, providing a reference model for social capital to participate in the development of value co-creation of farmers in tourist destinations, and providing new ideas and ideas for farmers in tourist destinations to achieve common prosperity.
In radiation measurement, optical fiber sensors (OFS) have many advantages compared to commercial dosimeters, including high spatial resolution. Due to the OFS measurement principle (fluorescence), the recorded measurement results differ from the standard dose value, such as that obtained using an ionization chamber. In this study, a physical correction function is established to considerably reduce the difference. This function quantifies the over-response of OFS to low-energy scattered photons and low-energy electrons. The specific expression of the function is derived from experimental measurement results obtained using the OFS and a commercial standard dosimeter when subject to two different radiation field sizes irradiated using a clinical linac. Following the application of the correction of the function, the measurement difference between the OFS and the standard dosimeter is greatly reduced for a range of radiation fields, in which case the maximum difference decreased from 42.2% to 1.5%. The dose correction method is based on existing quality assurance (QA) protocols used in radiotherapy and is simple and convenient to apply. This research has further promoted the application of OFSs in radiation dose measurement, including radiotherapy QA and in-patient use.