Formation of water-impermeable crust on sand surface using biocement

This paper examines the feasibility of using calcium-based biocement to form an impermeable crust on top of a sand layer. The biocement used was a mixture of calcium salt, urea, and bacterial suspension, which hydrolyzed urea with production of carbonate and an increase of the pH level. Applying 0.6 g of Ca per cm² of sand surface, the permeability of the biocemented sand can be reduced from 10⁻⁴ m/s to 1.6·10⁻⁷ m/s (or 14 mm/day) due to formation of the crust on sand surface. The rupture modulus (maximum bending stress) of the crust was 35.9 MPa, which is comparable with that of limestone. The formation of a water-impermeable and high strength crust layer on sand surface could be useful for the construction of aquaculture ponds in sand, stabilization of the sand dunes, dust fixation in the desert areas, and sealing of the channels and reservoirs in sandy soil.     

Impossible Differential Attacks on 13-Round CLEFIA-128

CLEFIA,a new 128-bit block cipher proposed by Sony Corporation,is increasingly attracting cryptanalysts’ attention.In this paper,we present two new impossible differential attacks on 13 rounds of CLEFIA-128.The proposed attacks utilize a variety of previously known techniques,in particular the hash table technique and redundancy in the key schedule of this block cipher.The first attack does not consider the whitening layers of CLEFIA,requires 2 109.5 chosen plaintexts,and has a running time equivalent to about 2 112.9 encryptions.The second attack preserves the whitening layers,requires 2 117.8 chosen plaintexts,and has a total time complexity equivalent to about 2 121.2 encryptions.     

A novel randomized bit-level two-dimensional hyperchaotic image encryption algorithm

Multimedia Tools and Applications - In this paper, we designed a new hyperchaotic two-dimensional map with wide distribution and two large positive Lyapunov exponents. Then, we used it to construct...     

ESIV: an end-to-end secure internet voting system

Nowadays, with the growing popularity of e-Government services, security of client platforms and violation of citizen e-rights are of great concerns. Since Internet-voting protocols have no control over voter-side platforms, bribery/coercion and breaching vote’s privacy and voter’s anonymity are feasible. In fact, the voter-side platform (voter’s PC) is easily vulnerable to malicious software (cyber-attacks) and can totally breach security of the entire voting protocol. We have proposed ESIV: an end-to-end secure internet-voting system that highly guarantees: voter and server-side platform’s security, verifiability, fairness, resistance to bribery/coercion and voting authorities collusion besides simultaneous election support while preserving eligibility, anonymity, privacy and trust. In addition, we utilize Java Card 3 technology as an independent secure web-server which is connected directly to network in order to send/receive HTTP(S) requests using high-speed interfaces. This technology brings about independence from utilizing any trusted device at voter-side and provides end-to-end security. Finally, an implementation of ESIV is presented and ESIV security features are evaluated.     

Mapping Quaternary faults in the west of Kavir Plain,north-central Iran,from satellite imageries

Numerous Quaternary faults are found in north-central Iran with an insignificant history of seismic activity. Having either strike-slip or thrust mechanisms, these faults are potentially active and therefore capable of creating destructive earthquakes. In this paper, Landsat Enhanced Thematic Mapper Plus (ETM+) images were used, for the first time, to map these Quaternary faults located in an abandoned area to the west of Kavir Plain in north-central Iran. We also demonstrate the use of satellite imagery to identify Quaternary faults in an unpopulated area using geomorphological features, such as deformed quaternary alluviums, deflected stream channels, shutter ridges and sag ponds, and also fault scarps. The major mapped faults have two main northwest and northeast trends. These faults are following the trends of their counterparts in the eastern and western Alborz range. Despite the evidence of activity in the Quaternary faults, no large earthquakes have been recorded in the study area and therefore they can be considered as only potentially active faults. This is because of the lack of historically recorded earthquakes in the abandoned area in the past centuries or to extensively developed evaporate layers at depths that cause most of the recent deformations to occur aseismically.     

Study of electrophoretic deposition of ZnS:Ag/CNT composites for luminescent applications

In present work, electrophoretic deposition of novel photoluminescence (PL) composites of ZnS:Ag/carbon nano tube (CNT) on the surface of Al substrates was investigated. In deposition process, CNT concentration and applied coating voltage were studied as the effective parameters. Deposition weight showed the reverse relationship with the amount of concentration and direct dependence to the applied voltages. Furthermore, current densities were decreased with increasing CNT concentrations up to 12.5 wt%, and increased strongly with further CNT concentrations. Moreover, applied voltage and current density show the same positive trends. Other results revealed that PL emission intensities were significantly quenched with increasing the CNT concentration. Nevertheless, PL intensities were improved with increasing applied voltage up to 300 V, but reduced with further voltage increase. Morphological studies of ZnS:Ag/CNT composites confirmed that the intertwined architecture was formed by wrapping of CNTs on the surfaces of ZnS microsize particles.     

Chemical and biological characteristics of Cuminum cyminum and Rosmarinus officinalis essential oils

Essential oils extracted by hydrodistillation from Cuminum cyminum and Rosmarinus officinalis were characterized by means of GC and GC–MS. C. cyminum and R. officinalis contained α-pinene (29.1%, 14.9%), 1,8-cineole (17.9%, 7.43%) and linalool (10.4%, 14.9%), respectively, as the major compounds. C. cyminum oil exhibited stronger antimicrobial activity than did R. officinalis oil against E. coli, S. aureus and L. monocytogenes. Complete death time on exposure to Cuminum cyminum L. and Rosmarinus officinalis L. oils were 20 and 25 min 180 and 240 min and 90 and 120 min for E. coli, S. aureus and L. monocytogenes, respectively. Radical-scavenging and antioxidant properties were tested by means of 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the β-carotene bleaching test. These properties were compared to those of Thymus x-porlock essential oil, used as a reference ingredient. The radical scavenging performance of the rosemary oil was better than that of C. cyminum. Results from the antioxidant test were better than those provided by the radical-scavenging activity. C. cyminum and R. officinalis essential oils may be considered as potent agents in food preservation.     

Postbuckling and ultimate state of stresses in steel plate girders

In [1], nonlinear large deflection finite element analysis was implemented to depict the characteristics of the shear failure mechanism of steel plate girders. That paper aimed at clarifying how–when–why and where plastic hinges form in flanges. The present paper extends those results to the state of stresses in web plates. It is shown that although the principal compressive stresses in the center of the web plates remain constant after an elastic buckling, they do increase considerably in other regions. In addition, the angles at which tension fields form; and the ultimate strength of plate girders is discussed and compared to those obtained by different theoretical and experimental hypotheses.