توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱A Reversible Data Embedding Scheme Based on Search Order Coding for VQ Index Tables
اطلاعات انتشار: هشتمین کنفرانس انجمن رمز ایران، سال
تعداد صفحات: ۴
This paper proposes a reversible data hiding scheme for vector quantization (VQ)–compressed images based on search order coding (SOC). Data is embedded by choosing one of the possible ways to represent each embeddable index and outputted code is legitimate SOC code. The proposed scheme has two advantages. First it is more secure, comparing with previous SOC based schemes that generate non–legitimate codes as output. Second it can be used beside other schemes to embed more data and also it is a solution for the problem of transmission of side information of schemes which their outputs are legitimate VQ codes.<\div>

۲A Neuro–fuzzy modeling tool to predict the photocatalytic activity of nano crystalline TiO2 films doped by SiO2
اطلاعات انتشار: اولین همایش ملی تکنولوژی های نوین در شیمی و پتروشیمی، سال
تعداد صفحات: ۱۲
In recent years novel approaches such as adaptive neuro–fuzzy inference system (ANFIS) have been applied to develop predictive models to describe desired processes. It can be claimed that these calculus methods are considered as alternatives for statistical tools. Due to the complexity and the non–linear nature of TiO2 nanocrystalline film's photocatalytic activity which has been synthesized by sol–gel method, An ANFIS model has been applied to simulate the methyl orange (MO) concentration variations as an index of photocatalytic activity of produced films. The predicted results were compared to the experimental observations. The obtained correlation (R2>0.99) shows the excellent agreement between the simulated and the experimental data. Therefore ANFIS approach can be successfully used to model the photocatalytic performance of thin films of TiO2 doped by SiO2.<\div>

۳Assessing and simulation of photocatalytic activityof TiO2 films doped by SiO2
اطلاعات انتشار: اولین کنفرانس ملی نانو فناوری در صنایع نفت، گاز و پتروشیمی، سال
تعداد صفحات: ۵
The aim of the current study is to model the photocatalytic activity of TiO2thin films doped by SiO2 additives with the variations in SiO2 concentrationand MO degradation time. The nano crystalline TiO2:xSiO2 (x: molepercentage) films were prepared by sol–gel method and settled on glasssurface. The final films were achieved after a calcination procedure andUV irradiation in contact with Methyl Orange (MO) solution. Nonlinearbehavior of photocatalytic activity of synthesized films made the authorseager to use Fuzzy Logic (FL) model to simulate and calculate the MOconcentration variation with SiO2 concentration and MO degradation time.The statistical reported values which denote the agreement between thepredicted and experimental data sets were about 96% for all cases. Theresults of modeling approved the excellent agreement between thepredicted values by the model and the experimental observations.Therefore it can be concluded that FL is an appropriate tool to simulatesuch processes.<\div>

۴Investigation of photocatalytic deninitrification of ZnO:Cu photocatalyst
نویسنده(ها): ، ،
اطلاعات انتشار: پانزدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۶
ZnO:Cu photocatalyst is prepared with reacting media namely water method and also wet impregnation method is used for precipitation of Cu on ZnO nano particles. X–ray diffraction (XRD) was used for determination size of ZnO:Cu particles. Field Emission Scanning Electron Microscope (FESEM) was used to study nanoparticles morphology. Prepared ZnO:Cu nanoparticles were contacted with ammonium nitrate aqueous solution (50 mg.L–1) and irradiated with UV. Results indicated that ZnO:Cu photocatalyst has high photocalytic activity to degradation of nitrate from aqueous solution. The results showed that complete degradation was achieved after 2.5 hr.<\div>
نمایش نتایج ۱ تا ۴ از میان ۴ نتیجه