A load frequency control algorithm based on a generalized approach

A generalized approach to load frequency control that combines discontinuous control and dual-mode control and uses variable-structure-systems concepts is developed. Using this approach, a novel load-frequency control algorithm is proposed. Studies on a multi-area power system, including generation rate constraint and governor dead-band, demonstrate the effectiveness of the control scheme     

Enhanced Terahertz Receiver Using a Distributed Bragg Reflector Coupled to a Photoconductive Antenna

We report the use of a terahertz (THz) receiver fabricated using a photoconductive antenna mounted upon a distributed Bragg reflector (DBR). It is shown that the relative performance of the device is in accordance with the reflectivity curves of the DBR. At maximum reflectivity the device improved upon the reference THz signal by up to 30%. In addition, we characterize the saturation of the device with laser pump power and it is shown that the device exhibits an improved optical efficiency when compared to the reference receiver.     

蓝青蛙酒廊与录音棚

Serie建筑师事务所是一个国际化事务所,涉及的领域包括建筑、城市的设计。事务所关注于当代城市中建筑类型的进化和变异以及这些智慧形式在空间解决方案上的应用。类型学式的研究,或者用他们的名词,“连续”（SERIES）的思考和探索（利用建筑类型的累积智慧）是Serie作品的关键。     

Development of Polyoxyethylene Zwitterionic Surfactants for High-Salinity High-Temperature Reservoirs

Substantial efforts are underway to improve the recovery factor from existing oil reserves to meet the ever-growing global oil demand. Surfactants are known to increase oil recovery through reducing interfacial tension (IFT) and/or altering the rock wettability. The selection of surfactants for high-salinity high-temperature oil fields is a challenging task owing to poor thermal stability, precipitation, and adsorption of surfactants on reservoir rocks. Sulfobetaine-based polyoxyethylene zwitterionic surfactants have shown excellent thermal and surface properties. However, their solubility in high-salinity brines becomes poor particularly with a long hydrophobic tail (>C17). Recently, we synthesized such types of surfactants by incorporating ethylene oxide (EO) units into the hydrophobic tail, which improved the solubility in formation water (213,734 ppm) and seawater (SW) (57,643 ppm). In this work, we investigated the IFT, thermal stability, rheological behavior, and foaming properties of two polyoxyethylene zwitterionic surfactants having different degrees of ethoxylation. Aging experiments exhibited excellent thermal stability and no change in the chemical structure was detected. The surfactant with lesser EO units (EASB-1a) showed a lower IFT compared to the surfactant with higher EO units (EASB-1b). Rheological studies revealed that the addition of both surfactants reduced the viscosity of the acrylamide copolymer. However, the effect of EASB-1a was more prominent compared to that of EASB-1b. The surfactant with a higher degree of ethoxylation showed lower adsorption compared to the surfactant with a lesser degree of ethoxylation. Both surfactants showed excellent foamability and foam stability compared to the commercial surfactants. Excellent thermal stability, water solubility under harsh reservoir conditions, foaming properties, and lower adsorption make them a suitable choice for high-temperature, high-salinity reservoirs.     

Taxonomic importance of spore morphology in Thelypteridaceae from Northern Pakistan

Spore morphology of Thelypteridaceae species growing in Malakand Division, Northern Pakistan, was studied using both light microscopy and scanning electron microscopy. The taxa are Christella dentata and Glaphyropteridopsis erubescens in the subfamily Thelypteridoideae, and Phegopteris connectilis, Pseudophegopteris pyrrhorhachis, and Pseudophegopteris levingei in the subfamily Phegopteridoideae. The studied species exhibit differences in spore size, exospore thickness, color, and ornamentation. Spores of the studied species are monolete and medium‐sized, and shape is ellipsoidal in both polar and equatorial views. The average measurement of the polar diameter ranges from 27 μm to 31 μm, whereas in the equatorial direction it varied from 20 μm to 40 μm. The exospore thickness ranges from 1.2 μm to 2.4 μm. Reticulate, laevigate with microgranules, cristate, and coarsely echinate surface ornamentation are observed among the species. Multivariate analysis including unweighted pair group method with arithmetic mean and principal component analysis was used for the grouping and discrimination of species and genera.     

Non‐Newtonian squashed flow simulation across Darcy‐Forchheimer sensor

The current mathematical formulation is dedicated to investigate the Darcy‐Forchheimer boundary layer–squeezed hydromagnetic flow of a Casson fluid passing through a sensor surface. The flow phenomenon is occurring in a locally free stream under the combined sway of heat generation and thermic radiation. The energy equation is deliberated with the assistance of Cattaneo‐Christov theory rather than using Fourier's law for conduction of heat. Here, the thermic conductivity is being presumed as a function of temperature. The governing mathematical structure consists of highly nonlinear terms, so a set of regulatory parameters is being accomplished to attain the unpretentious dimensionless equations. This nondimensional structure is then treated numerically to attain the nearly converging results. The significance of substantial parameters such as magnetic factor, radiation parameter, Casson fluid parameter, heat origination, and thermal relaxation time on the flow phenomenon is estimated and presented graphically. Besides this, the factors of engineering interest like the Prandtl number and squeezed flow index with vacillating thermic conductivity have strong effects on the flow behavior of the fluid. It is observed that the magnetic effect causes an expansion in the velocity curve while a reduction is found for squeezed flow index parameter.     

Role of Flaxseed Meal Feeding for Different Durations in the Lipid Deposition and Meat Quality in Broiler Chickens

This study investigated the role of flaxseed meal (FSM), a rich terrestrial source of ω-3 fatty acids, in the alteration of the fatty acid profile and metabolism, health indices, physicochemical properties, and sensory quality of broiler chicken meat. The broiler chickens were fed 100 g FSM kg⁻¹ diet for different time periods (1, 2, 3, 4, and 5 weeks). The results revealed that 100 g FSM feeding in broiler chickens for at least 3 weeks increased (P < 0.01) the EPA, DHA, MUFA, PUFA, ω-3 PUFA, and ω-6 PUFA of broiler chicken meat with the corresponding decrease in palmitic acid, stearic acid, and SFA content. 100 g FSM feeding up to 3 weeks has increased the Δ⁹-desaturases (P < 0.05), thioesterase index (P < 0.01), and Δ⁵-desaturase + Δ⁶-desaturase activity (P < 0.01) along with an improvement in health indices (P < 0.01) of chicken meat. Similarly, a reduction in meat cholesterol and fat content of thigh meat (P < 0.01) was observed by feeding 100 g FSM for at least 3 weeks with no effect on the pH, color scores, and sensory evaluation of broiler chicken meat. The water-holding capacity (WHC) and extract release volume (ERV) decreased, whereas, drip loss of meat increased (P < 0.01) due to the feeding of 100 g FSM beyond 3 weeks. Thus, this study concluded that 100 g FSM feeding for 3 weeks in broiler chickens significantly improves the fatty acid profile, lipid metabolism, and health indices of meat, without compromising the physicochemical properties of broiler chicken meat.     

Pedestrian detection using multiple feature channels and contour cues with census transform histogram and random forest classifier

Pattern Analysis and Applications - This paper presents a reliable and real-time method to detect pedestrians in image scenes that can vary greatly in appearance. To achieve greater reliability in...     

Robust object tracking with crow search optimized multi-cue particle filter

Pattern Analysis and Applications - Particle filter is used extensively for estimation of target nonlinear and non-Gaussian state. However, its performance suffers due to its inherent problem of...