Results of a parametric study of carbon nanotube production by the double-pulse laser oven process are presented. The effect of various operating parameters on the production of single-wall carbon nanotubes (SWCNTs) is estimated by characterizing the nanotube material using analytical techniques, including scanning electron microscopy, transmission electron microscopy, thermo gravimetric analysis and Raman spectroscopy. The study included changing the sequence of the laser pulses, laser energy, pulse separation, type of buffer gas used, operating pressure, flow rate, inner tube diameter, as well as its material, and oven temperature. It was found that the material quality and quantity improve with deviation from normal operation parameters such as laser energy density higher than 1.5 J/cm2, pressure lower than 67 kPa, and flow rates higher than 100 sccm. Use of helium produced mainly small diameter tubes and a lower yield. The diameter of SWCNTs decreases with decreasing oven temperature and lower flow rates.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1166/jnn.2004.087 | DOI Listing |
Med Sci Monit
December 2024
Department of Ultrasound Diagnosis, General Hospital of Northern Theater Command, Shenyang, Liaoning, China.
BACKGROUND Solitary thyroid nodules present a challenge in differentiating between benign and malignant conditions using ultrasound (US). Arrival time parameter imaging (At-PI) following contrast-enhanced ultrasound (CEUS) can effectively visualize the vascular architectural patterns of the nodules, providing valuable diagnostic information. This study aimed to explore the application value of At-PI in differentiating thyroid nodules, specifically focusing on a sample of 127 cases.
View Article and Find Full Text PDFBrain Res
December 2024
Department of Radiology, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China. Electronic address:
Introduction: Prior researches have reported abnormal changes of thalamus in patients with subcortical ischemic vascular disease (SIVD), which was usually analyzed as a whole. However, it was currently unclear whether the structure, function and connectivity of thalamic subregions were differentially affected by this disease and affected different cognitive functions.
Methods: This study recruited 30 SIVD patients with cognitive impairment (SIVD-CI), 30 SIVD patients with cognitive unimpaired (SIVD-CU) and 32 normal controls.
Magn Reson Imaging
December 2024
Department of Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China. Electronic address:
Background And Purpose: Punctate White Matter Lesion (PWML) is common in neonates. Multi-parametric MR imaging with flexible design (MULTIPLEX, MTP) generates multiple requires only about 6 min for full-head coverage. This study aimed to evaluate the value of T1WI and aT1WI contrasts of MTP in detecting neonatal punctate white matter lesions.
View Article and Find Full Text PDFGeorgian Med News
October 2024
Azerbaijan Medical University, Department of Obstetrics and Gynecology II, Baku, Azerbaijan.
The Aim Of The Study: to examine the pathomorphological and clinical characteristics of the uterus in the combined form of fibroids and adenomyosis.
Methods: The research work was conducted within the framework of the scientific program of the Department of Obstetrics and Gynecology II at Azerbaijan Medical University for the years 2021-2024. In the course of this study, a comprehensive clinical, laboratory, and instrumental prospective examination was conducted on 113 patients aged 30 to 50 years (mean age 42,0±1,8 years) with combined adenomyosis and uterine fibroids.
Probl Radiac Med Radiobiol
December 2024
State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine», 53 Yuriia Illienka Str., Kyiv, 04050, Ukraine.
Objective: to study the features of cognitive disorders in the remote period following exposure to ionizing radiation (IR) in the elderly participants of the liquidation of the consequences of the Chornobyl NPP accident (Chornobyl clean-up workers) with chronic cerebrovascular disorders.
Materials And Methods: The retrospective and prospective cohort study with the external and internal controlgroups. The randomized sample of the male elderly participants (attained age more than 60 years old) in liquidationof the consequences of the accident (Chornobyl clean-up workers, liquidators) at the Chornobyl nuclear power plant(ChNPP) in 1986-1987 (main group, n = 52) recruited from the Clinico-epidemiological registry (CER) of StateInstitution «National Research Center for Radiation Medicine, Hematology and Oncology of The National Academyof Medical Sciences of Ukraine» (NRCRMHO) with verified chronic cerebrovascular disorders (CVD) was examined.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!