Three-Dimensional Modeling of Density Current in a Straight Channel

Dense underflows are continuous currents that move downslope due to their density being heavier than that of the ambient water. In this work, a steady density current with a uniform velocity and concentration from a narrow sluice gate enters into a wide channel of lighter ambient fluid and moves forward downslope. Experiments varying inlet velocity and concentration and hence inlet Richardson numbers were conducted. Numerical simulations were also performed with a low-Reynolds number k–ε model. The results of numerical simulation agree well with the experimental data.     

Effect of elevated temperature on the mechanical properties of concrete produced with finely ground pumice and silica fume

This study investigated the effect of elevated temperature on the mechanical and physical properties of concrete specimens obtained by substituting cement with finely ground pumice (FGP) at proportions of 5%, 10%, 15% and 20% by weight. To determine the effect of silica fume (SF) additive on the mechanical and physical properties of concrete containing FGP, SF has been added to all series except for the control specimen, which contained 10% cement by weight instead. The specimens were heated in an electric furnace up to 400, 600 and 800 °C and kept at these temperatures for one hour. After the specimens were cooled in the furnace, ultrasonic pulse velocity (UPV), compressive strength and weight loss values were determined. The results demonstrated that adding the mineral admixtures to concrete decreased both unit weight and compressive strength. Additionally, elevating the temperature above 600 °C affected the compressive strength such that the weight loss of concrete was more pronounced for concrete mixtures containing both FGP and SF. These results were also supported by scanning electron microscope (SEM) studies.     

Exogenous coenzyme Q10 modulates MMP-2 activity in MCF-7 cell line as a breast cancer cellular model

Background/Aims  

Matrix Metalloproteinases 2 is a key molecule in cellular invasion and metastasis. Mitochondrial ROS has been established as a mediator of MMP activity. Coenzyme Q₁₀ contributes to intracellular ROS regulation. Coenzyme Q₁₀ beneficial effects on cancer are still in controversy but there are indications of Coenzyme Q₁₀ complementing effect on tamoxifen receiving breast cancer patients.     

Purification and Characterization of Polyphenol Oxidase from Hemşin Apple (Malus communis L.)

The polyphenol oxidase (PPO) enzyme was purified and characterized from Hem?in Apple (Malus communis L.), which was organically grown in Hem?in, in the Rize province of Turkey. Enzyme (PPO) activation was determined with catechol substrate. Apples were homogenized with homogenate buffer (pH 8.5). This process was followed by precipitation with (20–80%) saturated solid (NH₄)₂SO₄ and dialysis. Finally, purification with DE52-Cellulose ion-exchange and Sephadex G-25 columns was performed. Experiments were performed at an optimum pH (5.5) and optimum temperature (30–40°C). The kinetic and thermal parameters Km (3.40 mM), Vmax (333.3 EU/mL.min), Ea (3.57 kcal), ?H (2.968 kcal/mol), Q₁₀ (1.33), k_cat (24.57 min^?1) and V₀ (7.2x10³ mM^?1.min^?1) were assessed. Additionally, the effects of Mg²⁺, Pb ²⁺, Fe²⁺, Fe³⁺, Cd²⁺, Cu²⁺, Zn²⁺, Co²⁺, Al³⁺, Mn²⁺ and Na⁺ on enzyme activity was recorded, and the IC₅₀ values, K_? values and inhibition types were determined.     

Mass diffusivity of different species of wood in convective drying

This study is devoted to the determination of the diffusion coefficient in convective drying of four local wood species: Aleppo pine, Stone pine, Zeen oak and date palm. A numerical method based on a diffusive model is used which consists of three complementary steps: experimentation, analysis of experimental data and minimization of the gap between experimental drying kinetics data and calculated ones. The coefficient of water for the four wood species is considered depending on both temperature and moisture content, and is obtained by the numerical solution of the conservation equation of the solid phase and the water transfer equation coupled to the shrinkage rate of the solid phase. The found values of diffusion coefficient are consistent with the range of variation in the literature. The mass diffusion coefficient varies with increase in temperature between 1.510^?11 and 4.10^?11 (m²/s) for the Aleppo pine, Stone pine and Zeen oak woods, however for the “palm wood”, it varies from 10 to 11 to 6.10^?11 (m²/s). Arrhenius type relationship allows determining the activation energy, which varies between 135.64 and 150.49 (kJ/mol) for all species of wood treated, and these values are comparable with those of other species cited in literature.     

CONNECTION BETWEEN THE THERMOELASTIC POTENTIAL AND THE STATE SPACE FORMULATION OF THERMOELASTICITY

The connection between the thermoelastic potential and the state space approach to thermoelasticity is established. It is shown that a formulation based on a state vector that consists of the Laplace transforms of the thermoelastic potential and its three spatial derivatives has advantages owing to the simpler nature of the matrix involved.     

MRF Reinforcer: A Probabilistic Element for Space Redundancy in Nanoscale Circuits

Shrinking devices to nanoscale, increasing integration densities, and reducing voltage levels to the thermal limit-all conspire to produce faulty systems. A possible solution is a fault-tolerant probabilistic framework based on Markov random fields. This article introduces a new redundancy element, the MRF reinforcer, which achieves significant immunity to single-event upsets and noise     

Optimal detection and identification of Mycobacterium haemophilum in specimens from pediatric patients with cervical lymphadenopathy

Acid-fast bacilli from pediatric patients with lymphadenopathy were detected in the BACTEC radiometric system and in MB Redox broth, but not on L?wenstein Jensen medium. PCR amplification identified the isolates as Mycobacterium haemophilum, which has special nutrition requirements (iron supplements) for growth. Suitable culture medium ensures optimal recovery of this microorganism, avoiding underdiagnosis.     

Designing emergency response networks for hazardous materials transportation

Undesirable consequences of dangerous goods incidents can be mitigated by quick arrival of specialized response teams at the accident site. We present a novel methodology to determine the optimal design of a specialized team network so as to maximize its ability to respond to such incidents in a region. We show that this problem can be represented via a maximal arc-covering model. We discuss two formulations for the maximal arc-covering problem, a known one and a new one. Through computational experiments, we establish that the known formulation has excessive computational requirements for large-scale problems, whereas the alternative model constitutes a basis for an efficient heuristic. The methodology is applied to assess the emergency response capability to transport incidents, that involve gasoline, in Quebec and Ontario. We point out the possibility of a significant improvement via relocation of the existing specialized teams, which are currently stationed at the shipment origins.