ITS Standards in the Context of Transportation and Telecommunication Infrastructure

Product standards have become increasingly important due toincreased technological complexity. A barrier to implementingintelligent transportation systems (ITS) technologies has beenthe development of compatible products and systems. Telecommunicationsinfrastructure has been considered one of the core elementsof ITS. Relevant communications options include wireline, wirelessand dedicated short-range communication systems. This paperpresents a case study on the emerging ITS industry, focusingon the communications aspect of the industry, and the complexityof the standardization process in the context of modern, interdependenttechnologies.     

Performance of catalytically activated anodes in the electrowinning of metals

The performance of titanium anodes coated with oxides of Ir–Co or Ir–Ta has been compared using long term polarization techniques under simulated electrowinning conditions. Possible reasons for anode failure are explained from SEM and XRD. Potentiodynamic studies in 2m H2SO4 indicate that approximately 450mV reduction in anode potential can be achieved with Ti/(Ir–Co) as against lead. This anode is also suitable in chloride contaminated sulfate electrolyte. The anode potential measurements in different electrowinning electrolytes indicate that a potential saving up to 370– 420mV can be achieved. It is interesting to note that mixed electrolyte containing sulfate and chloride behaves similarly to pure chloride electrolyte with respect to anode potential.     

Cut-off frequency of a heterojunction transistor†

Indiffusion of impurities into a semiconductor takes place at high temperatures. In the case of hotorojunction transistors, tho impurity concentration on the emitter side of the base approaches or even exceeds the intrinsic concentration of electrons and holes at the temperature of impurity indiffnaion. As a result, the profile of impurity concentration in the base is not the complementary error function for an infinite source. This is duo to field-aided diffusion by ionized impurities resulting in a variable diffusion coefficient for such impurities.     

Role of Intergranular Damage-Induced Decrease in Young's Modulus in the Nonlinear Deformation and Fracture of an Alumina at Elevated Temperatures

The effect of the time-dependent decrease in Young's modulus due to damage accumulation by pore growth and intergranular cracking on the stress-strain behavior of a coarse-grained polycrystalline alumina deformed under conditions of displacement control at elevated temperatures was investigated. Considerable nonlinearity in stress-strain behavior, which increased with decreasing strain rate, was noted. At the higher strain rates, the failure stress was found to be independent of strain rate, thought to be due to a strain-rate-dependent fracture toughness due to the growth of microcracks at the tip of the failure-initiating macrocrack, which offsets the expected strain-rate sensitivity due to the growth of a single macrocrack only. Pore growth and intergranular cracking, accompanied by major reduction in Young's modulus by as much as a factor of 5, was most pronounced at the intermediate values of strain rate. This decrease in Young's modulus, under conditions of displacement-controlled loading, results in a decrease in stress, referred to as strain softening, which contributed to the observed nonlinear deformation. This conclusion was confirmed by a theoretical analysis, which showed that in addition to diffusional creep, time-dependent decreases in Young's modulus (elastic creep) by crack growth can make significant contributions to nonlinear deformation.     

ANTIFUNGAL,AFLATOXIN INHIBITORY AND FREE RADICAL‐SCAVENGING ACTIVITIES OF SOME MEDICINAL PLANTS EXTRACTS

ABSTRACT

The antifungal, aflatoxin inhibitory and antioxidant activity of methanol–aqueous extract (2:1) of 62 medicinal plants was explored. Based on the antifungal results, the extracts of 25 plants showed more than 50% antifungal activity and were further investigated for their aflatoxin inhibition and antioxidant properties. Methanol–aqueous extracts of Phyllanthus emblica and Terminalia chebula fruits caused 100% inhibition of aflatoxin production by the toxigenic strain of Aspergillus flavus in semisynthetic medium at 1 mg/mL. In addition, P. emblica (IC₅₀ = 4.1 µg/mL) and T. chebula (IC₅₀ = 6.9 µg/mL) fruits extracts exhibited strong antioxidant activity during the 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging assay in comparison with butylated hydroxytoluene (IC₅₀ = 8.1 µg/mL) and butylated hydroxyanisole (IC₅₀ = 6 µg/mL).

PRACTICAL APPLICATIONS

Based on the results of the present study, methanol–aqueous extracts of Phyllanthus emblica and Terminalia chebula, being endowed with strong antifungal, aflatoxin inhibitory and antioxidant activity, may be recommended as plant‐based preservatives for the enhancement of shelf life of food items and their protection from the undesirable harmful effects of molds, aflatoxin and free radical‐mediated damages.     

DYNAMIC FUZZY ADAPTIVE CONTROLLER FOR pH

Control of pH processes is very difficult due to nonlinear dynamics, high sensitivity at the neutral point, and changes in the concentrations of known or unknown chemical species. In this study, a dynamic fuzzy adaptive controller (DFAC) with a new inference mechanism is proposed and applied for the control of pH processes. The DFAC consists of a low-level basic control phase with a minimum rule base and a high-level dynamic learining phase with an updating mechanism to interact and modify the control rule base. The DFAC can self-adjust its fuzzy control rules using information from the process during on-line control and create new fuzzy control rules or modify the present control rules using its learning capability from past control trends. The controller is evaluated by applying it to a weak acid-strong base pH process with input disturbances and to another pH process that involve that has changes in acidic/buffering streams. The results of the DFAC with the new inference mechanism are compared with the known inference mechanisms, the fuzzy controller, the conventional PI controller, and also with an adaptive PID controller. The proposed DFAC provides better performance for set point tracking of the pH and rejection of load disturbances and buffering affects.     

OPTIMIZATION OF DEHYDRATED EGG QUALITY BY MICROWAVE ASSISTED FREEZE-DRYING AND HYDROCOLLOID INCORPORATION

Enhancement of the physical and sensory properties of rehydrated egg products as a consequence of microwave assisted freeze-drying and addition of hydrocolloids to the formulation was assessed. When compared to conventional freeze-drying (CFD), microwave assisted freeze-drying (MFD) led to products with greater water-holding capacity and reduced elastic modulus. Comparisons were also made of moisture sorption rates. The addition of xanthan gum and, to a lesser extent, microcrystalline cellulose increased both water-holding capacity and elastic modulus. Magnitude estimation by a trained texture panel of critical sensory properties (chewiness, rubberiness, moistness, moisture release, and roughness) revealed that MFD samples were superior to CFD samples and that MFD samples containing xanthan were closest to the "optimal" for the egg products. It was concluded that the more uniform and less heat stressing process of microwave assisted freeze-drying coupled with the presence of xanthan gum leads to a rehydrated product that best retains its structural     

Creep Analysis of Bend Specimens Subject to Tensile Cracking

Expressions are derived which permit the analysis of creep data, obtained in bending, for poly crystalline ceramics subject to tensile cracking. A numerical example based on literature data indicates that by considering the effect of cracks much better agreement is obtained between diffusion coefficients inferred from the creep data and those obtained by direct diffusion measurements.     

Butein imparts free radical scavenging,anti-oxidative and proapoptotic properties in the flower extracts of <i>Butea monosperma</i>

The flower of Butea monosperma (Lam.) (Fabaceae) has been used in traditional Indian medicine in the treatment of many ailments including liver disorders. To understand the pharmacological basis of its beneficial effects, the extracts of dried flowers in water, methanol, butanol, ethyl acetate and acetone were evaluated for free radical scavenging and pro-apoptotic activities in cell cultures (human hepatoma Huh-7 cell line and immortalized AML-12 mouse hepatocytes). Butrin and butein -the active constituents of flower extracts- were used as reference molecules. The levels of cell injury markers like lactate dehydrogenase, glutathione and lipid peroxidation and primary antioxidant enzymes glutathione S-transferase and catalase were also measured. The aqueous and butanolic extracts exhibited better 2,2-diphenyl-1-picrylhydrazyl scavenging and cytotoxic activities in hepatoma cells than in immortalized hepatocytes. Interestingly, butein inhibited 2,2-diphenyl-1-picrylhydrazyl radical better than butrin. The aqueous and butanolic extracts were further investigated for hepatoprotection against carbon tertrachloride-induced biochemical changes and cell death. Both extracts, just as butrin and butein, significantly reversed the cellular glutathione levels and lipid peroxidation, and glutathione–S-transferase activity. Lactate dehydrogenase leakage and cell death were also prevented. However, only butein revived the catalase activity. Thus, the butein content of Butea monosperma flower extracts is important for free radical scavenging activity, apoptotic cell death and protection against oxidative injury in hepatic cells.