The effects of pre-treatment with vitamin B6 on memory retrieval in rats

The effects of pre-treatment with vitamin B₆ on memory retrieval in adult male Wistar rats were evaluated using a step-through passive avoidance task. The rats were divided into three groups of 10 each. All animals were fed standard rodent chow. Vitamin B₆ (50 or 100 mg/kg) was administered intraperitoneally (i.p.) every other day for 1 month before training was initiated. Three retention tests were performed to assess the memory of the rats. Vitamin B₆ (100 mg/kg) significantly increased the step-through latency of the passive avoidance response compared with the control in the first retention test of the passive avoidance paradigm (p < 0.05). In addition, vitamin B₆ at 100 mg/kg significantly increased memory retrieval in the second and third retention tests conducted 2 days and 1 week after training, respectively, compared with the control (p < 0.05). These results indicate that pre-treatment with vitamin B₆ potentially enhances memory retrieval.     

Cryptanalysis of mCrypton—A lightweight block cipher for security of RFID tags and sensors

mCrypton is a 64‐bit lightweight block cipher designed for use in low‐cost and resource‐constrained applications such as RFID tags and sensors in wireless sensor networks. In this paper, we investigate the strength of this cipher against related‐key impossible differential cryptanalysis. First, we construct two 6‐round related‐key impossible differentials for mCrypton‐96 and mCrypton‐128. Then, using these distinguishers, we present 9‐round related‐key impossible differential attacks on these two versions. The attack on mCrypton‐96 requires 2^59.9 chosen plaintexts, and has a time complexity of about 2^74.9 encryptions. The data and time complexities for the attack on mCrypton‐128 are 2^59.7 chosen plaintexts and 2^66.7 encryptions, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

The impact of connate water saturation and salinity on oil recovery and CO2 storage capacity during carbonated water injection in carbonate rock

Carbonated water injection (CWI) is known as an efficient technique for both CO₂ storage and enhanced oil recovery (EOR). During CWI process, CO₂ moves from the water phase into the oil phase and results in oil swelling. This mechanism is considered as a reason for EOR. Viscous fingering leading to early breakthrough and leaving a large proportion of reservoir un-swept is known as an unfavorable phenomenon during flooding trials. Generally, instability at the interface due to disturbances in porous medium promotes viscous fingering phenomenon. Connate water makes viscous fingers longer and more irregular consisting of large number of tributaries leading to the ultimate oil recovery reduction. Therefore, higher in-situ water content can worsen this condition. Besides, this water can play as a barrier between oil and gas phases and adversely affect the gas diffusion, which results in EOR reduction. On the other hand, from gas storage point of view, it should be noted that CO₂ solubility is not the same in the water and oil phases. In this study for a specified water salinity, the effects of different connate water saturations (S_wc) on the ultimate oil recovery and CO₂ storage capacity during secondary CWI are being presented using carbonate rock samples from one of Iranian carbonate oil reservoir. The results showed higher oil recovery and CO₂ storage in the case of lower connate water saturation, as 14% reduction of S_wc resulted in 20% and 16% higher oil recovery and CO₂ storage capacity, respectively.     

Recent advances in structure and reactivity of dissolved organic matter: radiation chemistry of non-isolated natural organic matter and selected model compounds

The importance of natural organic matter (NOM) as a source of carbon in natural waters, as the source of reactive oxygen species, or for the complications its presence causes in treatment of natural waters, is undeniable. Recent studies have also pointed to the major photochemical role of triplet excited state of natural organic matter in the environmental fate of pharmaceutical and personal care products (PPCPs) in waters. However, the characterization of NOM is problematic due to its complex molecular structure. One approach to better understand NOM chemistry is the use of model compounds. As the condensation of a plant's phenolic compounds leads to humification and the formation of NOM, a structurally broad group of nine phenolic compounds were selected as model compounds for this study. With methods used in the discipline of radiation chemistry, the oxidative chemistry and transient spectra of these phenols were studied. In addition, the oxidative chemistry and transient spectra of a sample of NOM from the Black River, North Carolina, USA, was characterized. This natural water sample was used as received and represents the first studies of non-isolated NOM by pulsed radiolysis. The results of the transient spectra of the NOM revealed that the radical intermediates were very long lived. This phenomenon was not captured using the nine model compounds suggesting that more complex compounds are needed to further our understanding of the oxidation chemistry of NOM.     

Spam query detection using stream clustering

Nowadays, search engines play a gateway role for users to access their needed information in the Web. However, malicious users can also use them to facilitate their attacks by submitting excessive amounts of bot-generated queries, called spam queries. In this paper, we propose a novel semi-supervised method which can effectively detect spam queries in a practical manner. We first train a model to characterize normal and malicious users, using the linguistic properties of queries as well as the behavioral characteristics of users and IP addresses. Then, we use the trained model to predict the label of arriving requests with a fast and efficient algorithm which works based on the stream clustering approach. The results of our evaluation with the real log of a local search engine show that the proposed algorithm yields an accuracy of about %94, while incurring a low response-time and memory overhead.     

Modification and magnetization of MOF (HKUST-1) for the removal of Sr2+ from aqueous solutions. Equilibrium,kinetic and thermodynamic modeling studies

In this research, metal-organic framework MOF(HKUST-1) was synthesized, magnetized and modified by hexacyanoferrate in order to prepare an efficient adsorbent for the removal of Sr²⁺ from aqueous solutions. The synthesized adsorbent was characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy, thermal methods (TG-DTG[Themogravimetry- Derivative Theromogravimetry]), Fourier transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) surface area and scanning electron microscopy (SEM). The non-magnetized (MOF/KNiFC[potassium nickel hexacyanoferrate]) and magnetized (MOF/Fe₃O₄/KNiFC) adsorbents were then employed for the removal of Sr²⁺ from aqueous solutions. The adsorption capacity of 110 and 90 mg.g^?1 was obtained, respectively, for MOF/KNiFC and MOF/Fe₃O₄/KNiFC. The adsorption process was kinetically fast and the equilibration was established within 45 min. The magnetic capability of the adsorbent examined by the vibrating sample magnetometer (VSM) technique indicated that the used adsorbent was capable of separating from the solution by applying an external magnetic field. The adsorbent showed good selectivity toward Sr²⁺ in the presence of Cs⁺, Na⁺, Mg²⁺, Ca²⁺ and Ba²⁺. The regenerated adsorbent retained more than 90% of its initial capacity. Different isotherm models including Langmuir, Freundlich, Tempkin, Sips and Redlich–Peterson were employed to examine the applicability of the isotherms to the experimental data. It was concluded that the data was best fitted to the Langmuir isotherm model. The thermodynamic parameters showed that the process was endothermic.     

On computational complexity of impossible differential cryptanalysis

Impossible differential cryptanalysis is one of the conventional methods in the field of cryptanalysis of block ciphers. In this paper, a general model of an impossible differential attack is introduced. Then, according to this model, the concept of an ideal impossible differential attack is defined and it is proven that the time complexity of an ideal attack only depends on the number of involved round key bits in the attack.     

Transverse failure of carbon fiber composites: Analytical sensitivity to the distribution of fiber/matrix interface properties

An analytic differentiation method is presented to calculate the sensitivity of the transverse failure response of carbon fiber composite laminates to the distribution parameters of the fiber/matrix interface properties. The method starts with the evaluation of the sensitivities of the transverse failure response with respect to the interface properties of each fiber, ie, the cohesive failure strength and the critical displacement jump. These individual sensitivities are then used to calculate the sensitivities with respect to the mean and standard deviation of the interface properties. The derived sensitivities are implemented in a nonlinear interface-enriched generalized finite element method solver specially developed for this application. The interface-enriched generalized finite element method solver combines a cohesive modeling of the fiber/matrix interface failure with finite element meshes that do not conform to the composite microstructure. The approach is first demonstrated on a model material involving a one-dimensional domain containing N cohesive interfaces described by randomly selected cohesive failure properties. The method is then applied to the more complex problem of a composite laminate involving a large number of fibers.     

Evaluating the effect of hydroxyapatite nanoparticles on morphology,thermal stability and dynamic mechanical properties of multicomponent blend systems based on polylactic acid/Starch/Polycaprolactone

A hybrid of hydroxyapatite (HA) nanoparticles and encapsulated triclosan (LATC) was utilized to improve the overall performance of Polylactic acid/Starch/Polycaprolactone ternary blends. The morphological evaluations demonstrated that the starch component becomes gelatinized during the melt mixing process in the absence of LATC particles. However, once encapsulated triclosan particles were also added to the formulation, the granular structure of starch phase was retained indicating no gelatinization during the preparation process. In the case of nanocomposite samples, only 1 wt% of HA nanoparticles was found to exhibit a uniform distribution throughout the whole system whereas the higher concentrations resulted in the aggregation of nanoparticles dividing the system into HA‐poor and HA‐rich areas. Thermogravimetric analysis (TGA) was utilized to prove that those HA‐rich areas were formed around the starch domains due to the strong chemical affinity. Moreover, TGA also showed that only 1 wt% of HA nanoparticles acts efficiently in delaying the initiation of thermal decomposition. Dynamic mechanical analysis results also confirmed that HA nanoparticles had a strong tendency to be absorbed onto the starch domains within the system. J. VINYL ADDIT. TECHNOL., 25:E83–E90, 2019. © 2018 Society of Plastics Engineers