Amirkabir University of Technology

About: Amirkabir University of Technology is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Nonlinear system & Fuzzy logic. The organization has 15254 authors who have published 31165 publications receiving 487551 citations. The organization is also known as: Tehran Polytechnic & Tehran Polytechnic University.

Degumming of Persian silk with mixed proteolytic enzymes

Abstract: The feasibility of degumming Persian silk with alcalase, savinase, and mixtures of these enzymes with different alcalase/savinase weight ratios (0/1, 0.25/0.75, 0.5/0.5, 0.75/0.25, and 1/0 g/L) was investigated. The results were compared with those of soap degumming, which is a common silk degumming process. The effectiveness of parameters such as the treatment time, concentration of enzymes, and liquid ratio on degumming was studied. The enzymatic degumming process was performed at 55°C with an operation time of approximately 30 min, whereas the soap degumming process was carried out around the boiling point in 120 min. The evaluation of the data was carried out through the measurement of the weight loss, strength, and elongation of the samples. The optimum amount of sericin removed was 21.52 wt % for alcalase in 30 min, 20.08 wt % for savinase in 60 min, and 22.58 wt % for soap in 120 min. Also, the enzymatic treatment improved properties of the silk yarn such as the strength (33.76 cN/tex for alcalase and 32.03 cN/tex for savinase) and elongation (20.08% for alcalase and 18.42% for savinase). The obtained values were better than the strength (29.90 cN/tex) and elongation (18.59%) from the soap degumming method. Through the use of an enzyme mixture (0.5/0.5 g/L), good weight loss (22.43%), strength (33.22 cN/tex), and elongation (17.74%) were achieved in 30 min. Scanning electron micrographs confirmed and supported the observed data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

A taxonomy of Botnet detection techniques

Abstract: Among the diverse forms of malware, Botnet is the most widespread and serious threat which occurs commonly in today's cyber attacks. Botnets are collections of compromised computers which are remotely controlled by its originator (BotMaster) under a common Commond-and-Control (C&C) infrastructure. They provide a distributed platform for several illegal activities such as launching distributed denial of service (DDOS) attacks against critical targets, malware distribution, phishing, and click fraud. Most of the existing Botnet detection approaches concentrate only on particular Botnet command and control (C&C) protocols (e.g., IRC, HTTP) and structures (e.g., centralized), and can become ineffective as Botnets change their structure and C&C techniques. The detection of Botnet has been a major research topic in recent years. Different techniques and approaches have been proposed for detection and tracking of Botnet. This survey classifies Botnet detection techniques into two approaches. One approach is based on setting up honeynets and another approach is based on Intrusion Detection System( IDS) which has been categorized into signature-based and anomaly-based detection techniques.

Silk degumming using microwave irradiation as an environmentally friendly surface modification method

Abstract: Degumming is a surface modification process of natural fibers such as silk. In this paper, the feasibility of degumming of Persian silk by microwave irradiation as an environmentally friendly surface modification technique was investigated. The physical properties of the degummed silk were investigated. The effectiveness of parameters such as microwave irradiation time, surfactant, soap, and degumming time on silk degumming were studied. The evaluation of the data was carried out through the measurement of the weight loss, strength, and elongation of the samples. The scanning electron microscope images were obtained for degummed silk samples. The findings of this research support the potential production of new environmentally friendly textile fibers using microwave irradiation.

Effect of changing solvents on poly(ε-caprolactone) nanofibrous webs morphology

Abstract: Polycaprolactone nanofibers were prepared using five different solvents (glacial acetic acid, 90% acetic acid, methylene chloride/DMF 4/1, glacial formic acid, and formic acid/acetone 4/1) by electrospinning process. The effect of solution concentrations (5%, 10%, 15% and 20%) and applied voltages during spinning (10KV to 20KV) on the nanofibers formation, morphology, and structure were investigated. SEM micrographs showed successful production of PCL nanofibers with different solvents. With increasing the polymer concentration, the average diameter of nanofibers increases. In glacial acetic acid solvent, above 15% concentration bimodal web without beads was obtained. In MC/DMF beads was observed only at 5% solution concentration. However, in glacial formic acid a uniform web without beads were obtained above 10% and the nanofibers were brittle. In formic acid/acetone solution the PCL web formed showed lots of beads along with fine fibers. Increasing applied voltage resulted in fibers with larger diameter.