Radiation chemistry in astrochemical models: From the laboratory to the ISM

2019 ◽  
Vol 15 (S350) ◽  
pp. 454-455
Author(s):  
Christopher N. Shingledecker ◽  
Alexei Ivlev ◽  
Johannes Kästner ◽  
Eric Herbst ◽  
Paola Caselli
Keyword(s):  
Ionizing Radiation ◽  
Interstellar Dust ◽  
Large Body ◽  
Radiation Chemistry ◽  
Rate Equations ◽  
Stellar Winds ◽  
X Rays ◽  
Physicochemical Changes ◽  
Standard Rate ◽  
Dust Grain

AbstractMost interstellar and planetary environments are suffused by a continuous flux of several types of ionizing radiation, including cosmic rays, stellar winds, x-rays, and gamma-rays from radionuclide decay. There is now a large body of experimental work showing that these kinds of radiation can trigger significant physicochemical changes in ices, including the dissociation of species (radiolysis), sputtering of surface species, and ice heating. Even so, modeling the chemical effects that result from interactions between ionizing radiation and interstellar dust grain ice mantles has proven challenging due to the complexity and variety of the underlying physical processes. To address this shortcoming, we have developed a method whereby such effects could easily be included in standard rate-equations-based astrochemical models. Here, we describe how such models, thus improved, can fruitfully be used to simulate experiments in order to better understand bulk chemistry at low temperatures.

scholarly journals Differential Effects of Gold Nanoparticles and Ionizing Radiation on Cell Motility between Primary Human Colonic and Melanocytic Cells and Their Cancerous Counterparts

2021 ◽  
Vol 22 (3) ◽  
pp. 1418
Author(s):  
Elham Shahhoseini ◽  
Masao Nakayama ◽  
Terrence J. Piva ◽  
Moshi Geso
Keyword(s):  
Gold Nanoparticles ◽  
Ionizing Radiation ◽  
Cancer Cells ◽  
Cell Lines ◽  
Colorectal Adenocarcinoma ◽  
X Rays ◽  
Cell Adherence ◽  
Cancerous Cell ◽  
Primary Colon ◽  
Radiation Induced

This study examined the effects of gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the viability and motility of human primary colon epithelial (CCD841) and colorectal adenocarcinoma (SW48) cells as well as human primary epidermal melanocytes (HEM) and melanoma (MM418-C1) cells. AuNPs up to 4 mM had no effect on the viability of these cell lines. The viability of the cancer cells was ~60% following exposure to 5 Gy. Exposure to 5 Gy X-rays or 1 mM AuNPs showed the migration of the cancer cells ~85% that of untreated controls, while co-treatment with AuNPs and IR decreased migration to ~60%. In the non-cancerous cell lines gap closure was enhanced by ~15% following 1 mM AuNPs or 5 Gy treatment, while for co-treatment it was ~22% greater than that for the untreated controls. AuNPs had no effect on cell re-adhesion, while IR enhanced only the re-adhesion of the cancer cell lines but not their non-cancerous counterparts. The addition of AuNPs did not enhance cell adherence. This different reaction to AuNPs and IR in the cancer and normal cells can be attributed to radiation-induced adhesiveness and metabolic differences between tumour cells and their non-cancerous counterparts.

HEALTH HAZARDS FROM MOBILE TOWER: A REVIEW

2021 ◽  
pp. 78-79
Author(s):  
Avni KP Skandhan ◽  
Skandhan KP ◽  
Prasad BS
Keyword(s):  
Ionizing Radiation ◽  
Ultraviolet Radiation ◽  
Visible Light ◽  
Mobile Phone ◽  
Gamma Rays ◽  
Health Hazards ◽  
X Rays ◽  
Radio Waves ◽  
Fm Radio ◽  
Smart Tv

Our knowledge on X-rays, gamma rays and ultraviolet radiation is ionising . Non-ionising gadget radiation is from Mobile Phone, Laptop, Tablet Smart TV etc. and harmful radiations is from mobile towers . FM radio waves, Microwaves, Visible light are also other forms of non-ionizing radiation.

Evaluation of Static Performance of Optoelectronic Semiconductor Devices under X-Rays Irradiation

2010 ◽  
Vol 173 ◽  
pp. 1-6 ◽  
Author(s):  
Haider F. Abdul Amir ◽  
Fuei Pien Chee
Keyword(s):  
Ionizing Radiation ◽  
Light Emitting Diode ◽  
Optoelectronic Devices ◽  
Third Party ◽  
Infrared Light ◽  
X Rays ◽  
Total Ionizing Dose ◽  
Light Emitting ◽  
Static Performance ◽  
Current Drives

In this research, optoelectronic devices consisted of an infrared light emitting diode and a phototransistor with no special handling or third party-packaging were irradiated to ionizing radiation utilizing x-rays. It was found that the devices under test (DUTs) undergo performance degradation in their functional parameters during exposure to x-rays. These damaging effects are depending on their current drives and also the Total Ionizing Dose (TID) absorbed. The TID effects by x-rays are cumulative and gradually take place throughout the lifecycle of the devices exposed to radiation.

scholarly journals What Do We Really Know About the Winds of Massive Stars?

2007 ◽  
Vol 3 (S250) ◽  
pp. 89-96
Author(s):  
D. John Hillier
Keyword(s):  
Mass Loss ◽  
Massive Stars ◽  
Standard Theory ◽  
Stellar Winds ◽  
X Rays ◽  
X Ray ◽  
Stellar Photosphere ◽  
Weak Winds ◽  
Ionization Balance ◽  
Loss Rates

AbstractThe standard theory of radiation driven winds has provided a useful framework to understand stellar winds arising from massive stars (O stars, Wolf-Rayet stars, and luminous blue variables). However, with new diagnostics, and advances in spectral modeling, deficiencies in our understanding of stellar winds have been thrust to the forefront of our research efforts. Spectroscopic observations and analyses have shown the importance of inhomogeneities in stellar winds, and revealed that there are fundamental discrepancies between predicted and theoretical mass-loss rates. For late O stars, spectroscopic analyses derive mass-loss rates significantly lower than predicted. For all O stars, observed X-ray fluxes are difficult to reproduce using standard shock theory, while observed X-ray profiles indicate lower mass-loss rates, the potential importance of porosity effects, and an origin surprisingly close to the stellar photosphere. In O stars with weak winds, X-rays play a crucial role in determining the ionization balance, and must be taken into account.

scholarly journals The effect of low LET (Linear Energy Transfer) ionizing radiation to catalase activity of wistar’s submandibular gland

2016 ◽  
Vol 1 (3) ◽  
pp. 145
Author(s):  
Nevy T. Putri ◽  
Sarianoferni Sarianoferni ◽  
Endah Wahjuningsih
Keyword(s):  
Energy Transfer ◽  
Ionizing Radiation ◽  
Submandibular Gland ◽  
Rattus Norvegicus ◽  
Catalase Activity ◽  
Linear Energy Transfer ◽  
Submandibular Salivary Gland ◽  
X Rays ◽  
X Ray ◽  
Bonferroni Test

Intraoral periapical radiograph examination is the additional examination which is the most widely used in Dentistry. This radiograph examination using an x-ray ionizing radiation with low LET (Linear Energy Transfer), and may affect submandibular salivary gland. Ionizing radiation exposure can cause damage by inducing a series of changes at the molecular and cellular level. This study aimed to prove the effects of x-ray ionizing radiation with low LET towards the catalase activity of Rattus norvegicus strain Wistar’s submandibular gland. The subjects were 28 male Wistar rats and divided into 4 groups (n=7). Three groups were exposed 4, 8 and 14 times to radiation with 0.002 µSv for each exposure. The catalase activity of each rat was examined by a spectrophotometer. Data were analyzed using one-way ANOVA followed by Bonferroni test. The results showed the average of catalase activity on Wistar rat’s submandibular gland, respectively for: 0.150±0.0895 (KK), 0.1405±0.0607 (K1), 0.1228±0.0290 (K2), 0.1227±0.0556 (K3). Data showed significant differences of catalase activity between test groups, but showed not significant differences of catalase activity between each groups of Rattus norvegicus strain Wistar’s submandibular gland. In this study concluded decreased catalase activity of Rattus norvegicus strain Wistar’s submandibular gland resulting from x-rays ionizing radiation by 4 times, 8 times and 14 times exposures.

scholarly journals Evaluation the Safety and Security Procedures used In X-ray Clinics in Al-Harthiya-Baghdad

2021 ◽  
Vol 2114 (1) ◽  
pp. 012009
Author(s):  
Thuraya A. Abdul Hussian ◽  
Anwar kh. Farman
Keyword(s):  
Ionizing Radiation ◽  
X Rays ◽  
X Ray ◽  
Beta Particles ◽  
Medical Clinics ◽  
Γ Rays ◽  
Health Laws ◽  
Different Sources ◽  
Α Particles ◽  
Security Procedures

Abstract Radiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as one of the important areas in Iraq to attract and treat patients. It’s found that most of the commitment of radiography clinics by safety and security procedures. Most of the radiology clinics abide by most of the Iraqi Ministry of Health laws. However, some clinics did not implement some of the security and safety conditions

scholarly journals An in vitro of radiation dose enhancement using gold nanorods and plasmonic photothermal therapy

2021 ◽  
Author(s):  
Daniel DiCenzo DiCenzo
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Gold Nanorods ◽  
Near Infrared ◽  
Infrared Light ◽  
Nuclear Localization Sequence ◽  
X Rays ◽  
Dose Enhancement ◽  
Near Infrared Light ◽  
Pc3 Cells

Gold nanoparticles (GNP) have been shown to highly absorb ionizing radiation compared to tissue. GNPs have also been shown to be high absorbers of non-ionizing radiation with a peak absorbance at a wavelength dependent on their shape and size. This study investigated radiation dose enhancement in PC3 cells when in the presence of gold nanorods (NR) and near infrared light (IR). The PC3 cells were incubated with either PEGylated NRs (PNR) or anti prostate stem cell antigen antibody with nuclear localization sequence peptide conjugated NRs (AbNR). They were exposed to near infrared light at a wavelength of 810 nm to achieve a temperature of 42 ºC to 43 ºC for 60 minutes. They were also exposed to 160 kVp x-rays. It was found that both targeted and non-targeted GNPs when exposed to radiation and near infrared light synergistically enhanced radiation dose. It was also found that AbNRs provide greater dose enhancement than PNRs.

scholarly journals Stellar Winds in Massive X-ray Binaries

2016 ◽  
Vol 12 (S329) ◽  
pp. 355-358
Author(s):  
Peter Kretschmar ◽  
Silvia Martínez-Núñez ◽  
Enrico Bozzo ◽  
Lidia M. Oskinova ◽  
Joachim Puls ◽  
...  
Keyword(s):  
Compact Object ◽  
High Mass ◽  
Stellar Winds ◽  
X Rays ◽  
X Ray ◽  
Current State ◽  
Wide Range ◽  
Strong Winds ◽  
The One ◽  
X Ray Binaries

AbstractStrong winds from massive stars are a topic of interest to a wide range of astrophysical fields. In High-Mass X-ray Binaries the presence of an accreting compact object on the one side allows to infer wind parameters from studies of the varying properties of the emitted X-rays; but on the other side the accretor’s gravity and ionizing radiation can strongly influence the wind flow. Based on a collaborative effort of astronomers both from the stellar wind and the X-ray community, this presentation attempts to review our current state of knowledge and indicate avenues for future progress.

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