Mrinal Kanti Mandal

An Image Encryption Process based on Chaotic Logistic Map

Abstract This paper proposes a high security image encryption technique using logistic map. The proposed image encryption algorithm is described in detail along with its security analysis such as key space analysis, statistical analysis and differential analysis. A comparison in terms of correlation between the initial and transformed images, Number of pixels change rate and unified average changing intensity is also done. The present algorithm has been tested using different images to prove that the encryption method has a great potential and has a good ability to achieve the high confidential security.

Symmetric key image encryption using chaotic Rossler system

In this article, an algorithm for encryption of digital image based on chaos theory is proposed. This encryption algorithm includes two main operations of image element shuffling and pixel replacement. The analysis of cryptographic strength resistance attack has been performed to confirm the fact. The results of several experimental tests, such as key space analysis, key sensitivity analysis, and statistical analysis, show that the proposed algorithm for image cryptosystems provides an efficient and secure way for image encryption and the hacker cannot decrypt an encrypted image without original key. A comparison in terms of correlation between the original and encrypted images, number of pixels change rate, unified average changing intensity, and mean absolute error is performed, which proves that the plain image is very different from the encrypted one. We have also performed fixed point analysis to know how many pixels remain fixed after pixel shuffling operation. Copyright

Production of biodiesel from microalgae through biological carbon capture: a review

Gradual increase in concentration of carbon dioxide (CO2) in the atmosphere due to the various anthropogenic interventions leading to significant alteration in the global carbon cycle has been a subject of worldwide attention and matter of potential research over the last few decades. In these alarming scenario microalgae seems to be an attractive medium for capturing the excess CO2 present in the atmosphere generated from different sources such as power plants, automobiles, volcanic eruption, decomposition of organic matters and forest fires. This captured CO2 through microalgae could be used as potential carbon source to produce lipids for the generation of biofuel for replacing petroleum-derived transport fuel without affecting the supply of food and crops. This comprehensive review strives to provide a systematic account of recent developments in the field of biological carbon capture through microalgae for its utilization towards the generation of biodiesel highlighting the significance of certain key parameters such as selection of efficient strain, microalgal metabolism, cultivation systems (open and closed) and biomass production along with the national and international biodiesel specifications and properties. The potential use of photobioreactors for biodiesel production under the influence of various factors viz., light intensity, pH, time, temperature, CO2 concentration and flow rate has been discussed. The review also provides an economic overview and future outlook on biodiesel production from microalgae.

Bit-plane Encrypted Image Cryptosystem Using Chaotic, Quadratic, and Cubic Maps

ABSTRACT Recently, in chaotic cryptography several new techniques have been suggested to develop efficient and secure image encryption algorithm for communication of image over insecure/public channels. Some of these techniques are computationally less complex but fails to provide sufficient security, and some techniques are though highly secured but increases computational overhead for encryption and decryption. This paper presents an efficient bit-plane encryption algorithm using chaotic, quadratic, and cubic maps. The proposed algorithm is based on the confusion, diffusion, and pixel randomisation processes. The encryption security of this technique for different bit-plane has been tested through key space analysis, statistical analysis, entropy analysis, and sensitivity analysis for real time image encryption and transmission. The presented algorithm shows the strength of security in terms of information entropy, peak signal-to-noise ratio (PSNR), number of pixels change rate (NPCR), unified average changing intensity (UACI), and correlation coefficient with the number of encrypted bit planes. It is clear that the strength of security increases with the number of encrypted bit planes, but the presented results demand that the level of security reached to the requirements (expected theoretically according to [C. Fu, et al., Optic Express, 20, 2363–78, Jan. 2012]) after encryption of four to six bit planes with reasonable small encryption/decryption time. This features proved the novelty of the proposed work. The algorithm is tested by the random and pseudo-random sequence of test standard SP 8000-22 released by National Institute of Standard and Technology Commission (NIST).

Slurry photocatalytic membrane reactor technology for removal of pharmaceutical compounds from wastewater: Towards cytostatic drug elimination

The potential of photocatalytic membrane reactors (PMR) to degrade cytostatic drugs is presented in this work as an emerging technology for wastewater treatment. Cytostatic drugs are pharmaceutical compounds (PhCs) commonly used in cancer treatment. Such compounds and their metabolites, as well as their degraded by-products have genotoxic and mutagenic effects. A major challenge of cytostatic removal stands in the fact that most drugs are delivered to ambulant patients leading to diluted concentration in the municipal waste. Therefore safe strategies should be developed in order to collect and degrade the micro-pollutants using appropriate treatment technologies. Degradation of cytostatic compounds can be achieved with different conventional processes such as chemical oxidation, photolysis or photocatalysis but the treatment performances obtained are lower than the ones observed with slurry PMRs. Therefore the reasons why slurry PMRs may be considered as the next generation technology will be discussed in this work together with the limitations related to the mechanical abrasion of polymeric and ceramic membranes, catalyst suspension and interferences with the water matrix. Furthermore key recommendations are presented in order to develop a renewable energy powered water treatment based on long lifetime materials.

Free radical induced grafting of acrylonitrile on pre-treated rice straw for enhancing its durability and flame retardancy

Graphical abstract

Characteristics of a variable length ring oscillator and its use in PLL based systems

This paper describes the properties of a multiplexer based variable length ring oscillator and the effects of using it as a voltage controlled oscillator (VCO) in a phase locked loop (PLL) based system. The application of the proposed VCO in a PLL used as an FM demodulator or as a frequency synthesizer has been examined and it has been shown that the length control facility of the VCO could be used for improving the performances of those systems. Hardware experimental results confirm the predictions regarding the performance enhancement.

Novel phase tracking loops for burst signal synchronisation

A fully digital phase tracking loop based on a phase frequency detector and a digitally control phase shifter has been proposed to extract the continuous carrier signal from the burst-like input signal, whose frequency is very close to or same as that of the frequency of the local oscillator used in the loop. The phase drift of the loop is negligible during the off interval of the input signal. This property makes it useful in synchronising bursty signals. The performance of the proposed system has been verified through hardware experiment.

A ring oscillator based frequency synthesizer without using frequency divider

A novel indirect frequency synthesizer (FS) circuit comprising a multiplexer (MUX) controlled ring oscillator (RO) and a Hogge phase detector has been proposed. The circuit will synthesize signals having better spectral purity and will consume less power compared to conventional indirect FS circuits. The MUX controlled RO will provide higher flexibility in frequency control and the voltage controlled oscillator (VCO) sensitivity can be varied easily to keep loop gain fixed for different values of synthesized signal frequencies. Hardware experimental results have been given to establish theoretical anticipations.

Alternative Approach of Developing Optical Binary Adder Using Reversible Peres Gates

All-optical devices will play a very significant and crucial role in the modern all-optical network by eliminating the bottleneck of opto-electro-opto- (O-E-O-) conversion. Unfortunately, the conventional logic gates lose information at the output, and the states of the outputs cannot give any credible impressions of the states of the inputs. In this article, at first, the authors have proposed a method of designing an optical three-input-three-output reversible Peres gate. Authors have deployed polarization switching characteristic of Semiconductor Optical Amplifier (SOA) for designing this circuit. The authors have also proposed a method of designing an optical reversible full adder, using two such Peres gates and subsequently a data recovery circuit which can recover the input data of the adder. The authors have chosen frequency encoded data for processing the operation. The proposed scheme has been verified by simulation results.