China
Africa
Explore chapters and articles related to this topic
Survey of Image Steganography and Steganalysis
Published in Frank Y. Shih, Multimedia Security, 2017
JPeg–JSteg is also available as freeware and can be readily downloaded from steg-anography sites on the Internet. The JPeg–JSteg (JSteg) software was developed by Derek Upham. JSteg runs at the DOS prompt using the commands cjpeg and djpeg. Although JSteg outputs stego-images as JPEG files, it does not read the JPEG file format. Cover images are converted using the DOS command djpeg to the Targa image file (.tga file extension). The cover image converted to the Targa image format and the hidden text file are input to JSteg using the DOS command cjpeg which produces the stego-image.
Enhanced optical properties and photocatalytic activity of TiO2 nanotubes by using magnetic activated carbon: evaluating photocatalytic reduction of Cr(VI)
Published in Environmental Technology, 2021
Seyed Ghorban Hosseini, Javad Vahabzadeh Pasikhani
The TGA analysis was performed to investigate the heat endurance of TNTs/MAC (2%) photocatalyst as well as the evaluation of MAC content in the sample. The TGA thermogram of as-prepared TNTs/MAC (2%) is presented in Figure 8. The slight increase in weight at the early stage of thermolysis is due to the buoyancy effect of TGA equipment which influences the apparent mass during TGA analysis [40]. Based on Figure 8, the result indicated two stages of mass loss. An insignificant weight loss (0.4%) in the first stage below 250°C is attributed to the evaporation of physically adsorbed water to the photocatalyst surface. Another stage in the range 250–800°C with a loss percentage of 1.7% is associated with the photocatalyst surface dehydroxylation, oxidation of Fe3O4, and thermal decomposition of carbon skeleton [41]. Therefore, one can conclude that TNTs/MAC (2%) photocatalyst is thermally stable over the entire temperature range 25–800°C. Moreover, the weight of TiO2 remained unchanged during the heating process. Hence, this result implies that we can consider the mass content of MAC in TNTs/MAC (2%) photocatalyst is 1.7 wt%.