Application of the accelerated shelf life testing method (ASLT) to study the survival rates of freeze‐dried Lactococcus starter cultures

The survival rates of two freeze‐dried strains, Lactococcus lactis var diacetylactis and Lactococcus lactis var lactis, were evaluated using the Accelerated Shelf Life Testing (ASLT) method. The strains were initially isolated from a brand of a Tunisian fermented milk product. Lactococcus cell survival observed at higher temperatures was used to extrapolate to shelf life at a lower storage temperature of 4 °C. The apparent kinetics of the survival rate loss were estimated and the effect of storage temperature was quantified by determining the inactivation energies for various samples. The work has shown an overall higher survival rate of the strain Lactococcus lactis var diacetylactis. An average half‐life of a strain maintained at 25 °C was equal to about 7 days as compared with about 43 days at 4 °C. The addition of lyoprotectants such glycerol, saccharose and calcium carbonate to the drying medium, improved the survival of such bacteria. © 2001 Society of Chemical Industry     

Memory Subsystems in High-End Routers

As Internet routers scale to support next-generation networks, their memory subsystems must also scale. Several solutions combine static RAM and dynamic RAM buffering but still have major scaling limitations. Using a parallel architecture and distributed memory-management algorithms with hybrid SRAM/DRAM improves buffering performance. The parallel hybrid SRAM/DRAM memory system is also work conserving, which is particularly important under light traffic conditions.     

Nanoarchitectonics of Niobium-Doped,Lead-Free BLT (Ba0.97La0.02Ti0.98Nb0.016O3) for Electrical Properties with Unusual d.c Bias Voltage Independence

Polycrystalline sample of Ba_0.97La_0.02Ti_0.98Nb_0.016O₃ (distinguished as BLTi_0.98Nb_0.016) has been prepared through Molten-Salt-Flux reaction route. The XRD, surface morphology, absorption spectra, impedance, and dielectric behaviors were employed to typify the prepared polycrystalline ceramic. The XRD analysis reflects that obtained perovskite having the pure-tetragonal structure with space group P4/mmm. As of the absorption spectra, the optical band gap (Eg), Urbach energy (Eu), and refractive index values have designed. The electrical properties of synthesized compound have been inspected via complex impedance spectroscopy vs. frequency (f) (10² Hz–10⁶ Hz) within the d.c-bias voltage range [0.5 V–5 V]. The fitting of the Nyquist plot exposes that both intra- and intra grains contribute to relaxation and the grain limits are more resistive and capacitive than the grains. Modulus analysis confirms that relaxation in our sample is of non-Debye nature and d.c-bias voltages dependent. Depending on the frequency, the change of ε′ can be discussed founded on the principle of interfacial polarization of the Maxwell–Wagner category. BLTi_0.98Nb_0.016 shows notable frequency independent relative studied properties, it is a potential candidate for devices.

     

A Secure Hardware Implementation for Elliptic Curve Digital Signature Algorithm

Since the end of the 1990s, cryptosystems implemented on smart cards have had to deal with two main categories of attacks: side-channel attacks and fault injection attacks. Countermeasures have been developed and validated against these two types of attacks, taking into account a well-defined attacker model. This work focuses on small vulnerabilities and countermeasures related to the Elliptic Curve Digital Signature Algorithm (ECDSA) algorithm. The work done in this paper focuses on protecting the ECDSA algorithm against fault-injection attacks. More precisely, we are interested in the countermeasures of scalar multiplication in the body of the elliptic curves to protect against attacks concerning only a few bits of secret may be sufficient to recover the private key. ECDSA can be implemented in different ways, in software or via dedicated hardware or a mix of both. Many different architectures are therefore possible to implement an ECDSA-based system. For this reason, this work focuses mainly on the hardware implementation of the digital signature ECDSA. In addition, the proposed ECDSA architecture with and without fault detection for the scalar multiplication have been implemented on Xilinx field programmable gate arrays (FPGA) platform (Virtex-5). Our implementation results have been compared and discussed. Our area, frequency, area overhead and frequency degradation have been compared and it is shown that the proposed architecture of ECDSA with fault detection for the scalar multiplication allows a trade-off between the hardware overhead and the security of the ECDSA.     

Federated learning-based intrusion detection system for Internet of Things

International Journal of Information Security - Intrusion detection in the Internet of Things is becoming increasingly important as the number of connected devices grows. Machine learning...     

Parametric analysis of the damage characterization tests of aluminum bulk material

Journal of Mechanical Science and Technology - Several models have been developed to study materials behaviors under different states of stress. In manufacturing processes, several types of...     

A Study on Outstanding High-Temperature Wear Resistance of High-Entropy Alloys

Wear property is a main reason for failure, especially for those parts which are mechanically moving and interacting with each other in industrial utilization. High-entropy alloys (HEAs) are considered promising candidates to possess outstanding tribological factors of performance at high temperatures compared with conventional engineering alloys, which have drawn much attention from academic and industrial points of view. This study is performed to survey the influence of microstructure, grain size, precipitation, reinforcement, and elements addition on the wear resistance of HEAs over a wide temperature range. In this respect, the worn microstructure, wear rate, friction coefficient, hardness, wear track, and subsurface are precisely checked. This review also explores the high-temperature wear resistance of thermally sprayed and additively manufactured HEAs associated with emphasizing the dominant wear mechanisms through in a wide range of temperatures.