lif, mg and ti cubical tld chips (known as tld-100) are widely used for dosimetry purposes. the repeatability of tl dosimetry is investigated by exposing them to doses of (81, 162 and 40.5 mgy) with 662kev photons of cs-137. a group of 40 cubical tld chips was randomly selected from a batch and the values of element correction coefficient (ecc) were obtained 4 times by irradiating them to doses...

If you were to setup a new top-level domain (TLD), how many authoritative servers would you deploy? Figure 1 shows that most TLDs (∼ 50%) nowdays use 4 servers. Where would you deploy them (geographically)? And would you use anycast services (local on CDNs/ISPs, global elsewhere), unicast services or a combination of both? For existing TLDs, how can you optimize your authoritative servers setup...

The purpose of this comparative study was to test the accuracy of anisotropic analytical algorithm (AAA) and pencil beam convolution (PBC) algorithms of Eclipse treatment planning system (TPS) for dose calculations in the low- and high-dose buildup regions. AAA and PBC algorithms were used to create two intensity-modulated radiotherapy (IMRT) plans of the same optimal fluence generated from a c...

The aim of the TLD pilot study was to investigate and to reduce the uncertainties involved in the measurements of absorbed dose and to improve the consistency in dose determination in the regional radiotherapy centres in Poland. The intercomparison was organized by the SSDL. It covered absorbed dose measurements under reference conditions for Co-60, high energy X-rays and electron beams. LiF po...

Quantitative information on photon scattering around brachytherapy sources is needed to develop dose calculation formalisms capable of predicting dosimetric parameters with minimal empiricism. Photon absorption and scatter around brachytherapy sources can be characterized using the tissue attenuation factor, defined as the ratio of dose in water to water kerma in free space. In this study, the ...

Myostatin is a transforming growth factor beta family member that acts as a negative regulator of skeletal muscle growth. Myostatin circulates in the blood of adult mice in a noncovalently held complex with other proteins, including its propeptide, which maintain the C-terminal dimer in a latent, inactive state. This latent form of myostatin can be activated in vitro by treatment with acid; how...

In preparing of thermoluminescent dosimeters (TLD) it is common to use as agglutinator the polytetrafluoroethylene (PTFE), called Teflon. In this paper the physical, morphological and dosimetric characteristics of Teflon were evaluated aiming its application in thermoluminescent dosimetry. The differential thermal analysis (DTA) and thermogravimetry (TG) results showed that the Teflon glass tra...

As of October 1996 there are more than 90 radiation-contaminated steel supported rebar buildings (containing more than 1000 apartments) dispersed in the northern part of Taiwan. These apartments were contaminated with cobalt-60 at a total activity ranging from 1-140/tSv/yr. In this paper, a method is developed for evaluating external dose equivalent and dose equivalent rates encountered by the ...

Introduction Radiotherapy is regarded as the first treatment of choice for nasopharyngeal carcinoma. Despite the advantages of radiotherapy, patients may suffer from a wide range of side-effects due to the presence of many sensitive normal tissues in these regions. If the absorbed dose exceeds the tolerance level in parotid glands and the spinal cord, myelopathy, Lhermitte's sign and xerostomia...

PURPOSE To design, construct, and evaluate an anthropomorphic phantom for evaluation of intensity-modulated radiation therapy (IMRT) dose planning and delivery, for protocols developed by the Radiation Therapy Oncology Group (RTOG) and other cooperative groups. METHODS AND MATERIALS The phantom was constructed from a plastic head-shaped shell and water-equivalent plastics. Internal structures...