This paper deals with the theory and application of Cellular Automata (CAI for a class of block ciphers and stream ciphers. Based on CA state transitions certain fundamental transformations are defined which are block ciphering functions of the proposed enciphering scheme. These fundamental transformations are found to generate the simple (alternating) group of even permutations which in turn is a subgroup of the permutation group. These functions are implemented with a class of programmable cellular automata (PCA) built around rules 51, 153, and 195. Further, high quality pseudorandom pattern generators built around rule 90 and 150 programmable cellular automata with a rule selector (Le., combining function) has been proposed as running key generators in stream ciphers. Both the schemes provide better security against different types of attacks. With a simple, regular, modular and cascadable structure of CA, hardware implementation of such schemes idealy suit for VLSI implementation.

Marine oil spill cleanup is one of the major challenges in recent years due to its detrimental effect on our ecosystem. Hence, the development of new superhydrophobic oil absorbent materials is in high demand. The third-generation porous materials, namely metal−organic frameworks (MOFs), have drawn great attention due to their fascinating properties. In this work, a superhydrophobic MOF with UiO-66 (SH-UiO-66) topology was synthesized strategically with a new fluorinated dicarboxylate linker to absorb oil selectively from water. The fully characterized superhydrophobic MOF showed extreme water repellency with an advancing water contact angle (WCA) of 160°with a contact angle hysteresis (CAH) of 8°. The newly synthesized porous MOF (S BET = 873 m 2 g −1 ) material with high WCA found its promising application in oil/ water separation. The superhydrophobic SH-UiO-66 MOF was further used for the in-situ coating on naturally abundant cotton fiber to make a superhydrophobic MOF@cotton composite material. The MOF-coated cotton fiber composite (SH-UiO-66@CFs) showed water repellency with a WCA of 163°and a low CAH of 4°. The flexible superhydrophobic SH-UiO-66@CFs showed an oil absorption capacity more than 2500 wt % for both heavy and light oils at room temperature. The superoleophilicity of SH-UiO-66@CFs was further exploited to separate light floating oil as well as sedimentary heavy oil from water. SH-UiO-66@CFs material can also separate oil from the oil/water mixture by gravity-directed active filtration. Hence, the newly developed MOF-based composite material has high potential as an oil absorbent material for marine oil spill cleanup.

The cipher systems based on Cellular Automata proposed by Nandi et al. 3] are a ne and are insecure.

Here, we describe a new dinitro-functionalized Zr(iv) MOF (MOF = metal-organic framework) having a UiO-66 (UiO = University of Oslo) framework topology called UiO-66-(NO) (1). It shows fluorescence turn-on behavior towards HS in simulated biological medium (HEPES buffer, pH = 7.4). By employing solvothermal conditions, 1 was successfully synthesized by reacting ZrCl, HBDC-(NO) [HBDC-(NO) = 2,5-dinitro-1,4-benzenedicarboxylic acid] ligand and benzoic acid with a molar ratio of 1 : 1 : 10 in DMF (DMF = N,N-dimethylformamide) at 130 °C for 24 h. The material was characterized by infrared spectroscopy, X-ray powder diffraction (XRPD) and thermogravimetric (TG) analyses. The compound not only displays highly sensitive fluorometric sensing of HS but also exhibits a visually detectable colorimetric change towards HS in daylight. Moreover, the high selectivity of 1' towards HS is retained even when several other biologically intrusive species co-exist in the sensing medium. The limit of detection (LOD) of the compound is 14.14 μM which lies in the range of the HS concentration found in biological systems. Fluorescence microscopy studies on J774A.1 cells revealed the efficacy of the probe for imaging HS in living cells. Moreover, this material can detect HS in human blood plasma (HBP) and monitor the sulfide concentration in real water samples. All these features clearly demonstrate that the material has huge potential for highly selective sensing of both extracellular and intracellular HS.

A new, azide-functionalized Al(iii)-based metal-organic framework (MOF) denoted as CAU-10-N (1, CAU = Christian-Albrechts-University) and consisting of the 5-azido-isophthalic acid (HIPA-N) ligand was employed as a reaction-based fluorescent turn-on probe for the detection of HS. The activated compound (1') showed fast, selective and highly sensitive sensing properties for extracellular HS in HEPES buffer (10 mM, pH = 7.4). The material retained its high selectivity even in the presence of possibly competing biological species. The limit of detection of 1' for HS is 2.65 μM, which is lower than the earlier reports on MOFs for HS sensing. The material displayed a short response time (420 s) and a significant increase (20-fold and 26-fold after 1 and 7 min of addition of NaS, respectively) in the fluorescence intensity towards HS. Macrophage cells loaded with probe 1' exhibited blue fluorescence with a response time of 15 min after NaS addition, indicating the suitability of the probe for intracellular HS detection. Moreover, CAU-10-N featured excellent detection performance (quick response and 32-fold increment in fluorescence intensity after 7 min of NaS addition) in water. Hence, it can be utilized to regulate the HS level in aqueous samples collected from the environment.

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In this work, we report a new hydrazinefunctionalized Al(III)-based metal−organic framework having MIL-53 (MIL = Material of Institute Lavoisier) framework topology for the sensitive and selective detection of formaldehyde (FA). The phase purity of the thermally activated and as-synthesized forms of the material was examined by X-ray powder diffraction experiments, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The desolvated material (1′) showed great potential for the selective sensing of FA in the existence of other potentially competitive aldehydes in both aqueous and 10 mM HEPES buffer (pH = 7.4) media. The fluorescence "turn-on" behavior of the reaction-based probe can be ascribed to the inhibition of the photoinduced electron transfer process (from the hydrazine group to the phenyl ring) because of the formation of the hydrazone moiety. The detection limit of the probe toward FA in HEPES buffer is 8.37 μM (0.25 ppm), which lies below the intracellular concentration of FA (100−400 μM). A very short response time (1 min) has been displayed by 1′ for FA sensing. Moreover, a remarkable enhancement in the emission intensity (sevenfold and fourfold in aqueous and HEPES buffer media, respectively) of 1′ was observed after 1 min of FA addition. Furthermore, the ability of the probe to detect FA in the vapor phase was demonstrated. Interestingly, the material is also capable to detect endogenous FA in cancer cells. All the above discussed features clearly reveal that the present material has a huge potential for selective recognition of FA in both real water and biological samples.

A new metal-organic-framework (MOF) called UiO-66-NH-COCF3 was prepared using trifluoroacetamido functionalized terephthalic acid ligand. Powder X-ray diffraction (PXRD), infrared (IR) spectroscopy, thermogravimetric analysis (TGA) and Brunauer Emmett-Teller (BET) experiment were...