Optoelectronic Characterization and Properties of Single-walled Carbon Nanotubes in a Liquid Dispersion Form

Carbon nanotubes (CNTs) are very promising nanodevices due to their extraordinary electrical, thermal, and optical properties. However, as-grown single-walled CNTs (SWCNTs) contain a mixture of semiconducting and metallic species with great features versatility and variation. Solution-based processing of this nanomaterial is vital for further implementation in applicable platforms. In this paper, important optoelectronic intrinsic properties of SWCNTs in dispersions are studied applying a semi-empirical approach of optical characterization and Tauc/Davis-Mott relation and Max-Planck equations. SWCNTs are found to have a direct bandgap of 2.20 eV, an indirect bandgap of 0.27 eV, an optical conductivity of about 107 S cm-1, and exhibited a metamaterial behavior ascribed to the high negative permittivity. In addition, the optimum parameters for the dispersion of SWCNTs, and the separation of the semiconducting species using simple mechanical methods of ultrasonication and density gradient ultracentrifugation, respectively, without using surfactants are also presented

Fabrication and Characterization of the Micro-Heater and Temperature Sensor for PolyMUMPs-Based MEMS Gas Sensor

This work describes the fabrication and characterization of a Micro-Electro-Mechanical System (MEMS) sensor for gas sensing applications. The sensor is based on standard PolyMUMPs (Polysilicon Multi-Users MEMS Process) technology to control the temperature over the sensing layer. Due to its compact size and low power consumption, micro-structures enable a well-designed gas-sensing-layer interaction, resulting in higher sensitivity compared to the ordinary materials. The aim of conducting the characterization is to compare the measured and calculated resistance values of the micro-heater and the temperature sensor. The temperature coefficient of resistance (TCR) of the temperature sensor has been estimated by raising and dropping the temperature throughout a 25–110 °C range. The sensitivity of these sensors is dependent on the TCR value. The temperature sensor resistance was observed to rise alongside the rising environmental temperatures or increasing voltages given to the micro-heater, with a correlation value of 0.99. When compared to the TCR reported in the literature for the gold material 0.0034 °C−1, the average TCR was determined to be 0.00325 °C−1 and 0.0035 °C−1, respectively, indicating inaccuracies of 4.6% and 2.9%, respectively. The variation between observed and reported values is assumed to be caused by the fabrication tolerances of the design dimensions or material characteristics

Fabrication and Characterization of the Micro-Heater and Temperature Sensor for PolyMUMPs-Based MEMS Gas Sensor

This work describes the fabrication and characterization of a Micro-Electro-Mechanical System (MEMS) sensor for gas sensing applications. The sensor is based on standard PolyMUMPs (Polysilicon Multi-Users MEMS Process) technology to control the temperature over the sensing layer. Due to its compact size and low power consumption, micro-structures enable a well-designed gas-sensing-layer interaction, resulting in higher sensitivity compared to the ordinary materials. The aim of conducting the characterization is to compare the measured and calculated resistance values of the micro-heater and the temperature sensor. The temperature coefficient of resistance (TCR) of the temperature sensor has been estimated by raising and dropping the temperature throughout a 25–110 °C range. The sensitivity of these sensors is dependent on the TCR value. The temperature sensor resistance was observed to rise alongside the rising environmental temperatures or increasing voltages given to the micro-heater, with a correlation value of 0.99. When compared to the TCR reported in the literature for the gold material 0.0034 °C−1, the average TCR was determined to be 0.00325 °C−1 and 0.0035 °C−1, respectively, indicating inaccuracies of 4.6% and 2.9%, respectively. The variation between observed and reported values is assumed to be caused by the fabrication tolerances of the design dimensions or material characteristics

Data_Sheet_2_In response to the Saudi healthcare reform: a cross-sectional study of awareness of and attitudes toward the public health model among health students.PDF

BackgroundSaudi Arabia’s health sector is experiencing a significant transformation toward an emphasis on the public health model. This model is a population-based approach to preventing and controlling disease, and its importance becomes evident during infectious outbreaks and pandemics, such as COVID-19. This study aimed to assess the awareness and attitudes of health students in Jazan toward the public health model.MethodsThis study applied a cross-sectional online survey. Data were collected from 3–18 November 2020 using Google Forms. A convenience sampling method was used with a final sample of 425 participants.ResultsMost participants (71%) were aware of the public health model, with an average score of 11.36 out of 16. Multiple regression analysis revealed a significant association between the awareness level of the public health model and participants’ demographics, namely, gender, major of study, year of study, and prior training in public health. Participants who completed public health training (β = 0.220) had higher awareness scores than others. On the other hand, participants from public health (β = −0.342), medicine (β = 0.164), and nursing in Jazan (β = 0.128) had higher awareness of the public health model than the reference group (Nursing at Addayer College). Addayer is an area located in the rural northeast of the Jazan region. In addition, final-year students (β = 0.113) had higher awareness of the public health model than the reference group (year 2 pre-final students). Female participants (β = −0.142) had lower awareness of the public health model than male participants. Most participants (95.3%) believed that the clinical care and public health models are essential for promoting people’s health. However, 4.7% of participants believed that clinical health care is more important than public health.ConclusionHealth students, who are future healthcare professionals, must understand and value the public health model to support the planned health system reforms. It is recommended to evaluate how the education and training of students in public health, medicine, and nursing in Jazan impact the understanding and views of this cohort on the public health model compared to those of students in other health-related majors.</p

Data_Sheet_1_In response to the Saudi healthcare reform: a cross-sectional study of awareness of and attitudes toward the public health model among health students.PDF

BackgroundSaudi Arabia’s health sector is experiencing a significant transformation toward an emphasis on the public health model. This model is a population-based approach to preventing and controlling disease, and its importance becomes evident during infectious outbreaks and pandemics, such as COVID-19. This study aimed to assess the awareness and attitudes of health students in Jazan toward the public health model.MethodsThis study applied a cross-sectional online survey. Data were collected from 3–18 November 2020 using Google Forms. A convenience sampling method was used with a final sample of 425 participants.ResultsMost participants (71%) were aware of the public health model, with an average score of 11.36 out of 16. Multiple regression analysis revealed a significant association between the awareness level of the public health model and participants’ demographics, namely, gender, major of study, year of study, and prior training in public health. Participants who completed public health training (β = 0.220) had higher awareness scores than others. On the other hand, participants from public health (β = −0.342), medicine (β = 0.164), and nursing in Jazan (β = 0.128) had higher awareness of the public health model than the reference group (Nursing at Addayer College). Addayer is an area located in the rural northeast of the Jazan region. In addition, final-year students (β = 0.113) had higher awareness of the public health model than the reference group (year 2 pre-final students). Female participants (β = −0.142) had lower awareness of the public health model than male participants. Most participants (95.3%) believed that the clinical care and public health models are essential for promoting people’s health. However, 4.7% of participants believed that clinical health care is more important than public health.ConclusionHealth students, who are future healthcare professionals, must understand and value the public health model to support the planned health system reforms. It is recommended to evaluate how the education and training of students in public health, medicine, and nursing in Jazan impact the understanding and views of this cohort on the public health model compared to those of students in other health-related majors.</p