Discharge Capacity of Labyrinth Side Weir Located on a Straight Channel

Side weirs, also known as lateral weirs, are flow diversion devices widely used in irrigation as a head regulator of distributaries and escapes, land drainage, and urban sewage systems. The studies on the subject have been generally focused on rectangular and triangular side weirs located on a straight channel. However, the same is not true for labyrinth side weirs. The current studies deal with sediment transport and scour problems around side weirs and lateral structures. The investigation of the hydraulic effects of labyrinth side weirs to increase discharge capacity of them has been studied in this particular work. In the study, 2,830 laboratory tests were conducted for determining discharge coefficient of labyrinth side weirs, and results were analyzed to find the influence of the dimensionless weir length L/b, the dimensionless effective length L/?, the dimensionless weir height p/h1, triangular labyrinth side weir included angle θ, and upstream Froude number F1 on the discharge coefficient, water surface profile and velocities in the channel along the side weir. It has been found that discharge coefficient of labyrinth side weirs gives pretty higher coefficient value compare to that of classical side weirs and a reliable equation for discharge coefficient of labyrinth weirs is presented. Discharge coefficient of the labyrinth side weir is 1.5–4.5 times higher than rectangular side weir.     

Progress in modification of sunflower oil to expand its industrial value

Increasing the sunflower seed oil content as well as improving its quality makes it compatible for industrial demands. This is an important breeding objective of sunflower which increases its market value and ensures high returns for the producers. The present review focuses on determining the progress of improving sunflower seed oil content and modifying its quality by empirical and advanced molecular breeding methods. It is known that the sunflower oil content and quality have been altered through empirical selection methods and mutation breeding programmes in various parts of the world. Further improvement in seed oil content and its components (such as phytosterols, tocopherols and modified fatty acid profile) has been slowed down due to low genetic variation in elite germplasm and complex of hereditary traits. Introgression from wild species can be carried out to modify the fatty acids profile and tocopherol contents with linkage drags. Different transgenes introduced through biotechnological methods may produce novel long‐chain fatty acids within sunflower oil. Bio‐engineering of sunflower oil could allow it to be used in diverse industrial products such as bio‐diesel or bio‐plastics. These results showed that past and current trends of modifying sunflower oil quality are essential for its further expansion as an oilseed crop. © 2017 Society of Chemical Industry     

An elastic–plastic and residual stress analysis steel reinforced thermoplastic composite cantilever beam

In the present study an analytical elastic–plastic stress analysis is carried out for a low-density homogeneous polyethylene thermoplastic cantilever beam reinforced by steel fibers. The beam is loaded by a constant single force at its free end. The expansion of the region and the residual stress component of σ_x are determined for 0°, 15°, 30°, 45°, 60°, 75° and 90° orientation angles. Yielding begins for 0° and 90° orientation angles at the upper and lower surfaces of the beam at the same distances from the free end. Although it starts first at the upper surface for 15°, 30° and 45°, it starts first at the lower surface for 60° and 75° orientation angles. The elastic–plastic analysis is carried out for both the plastic region which spreads only at the upper surface and the plastic region which spreads at the upper and lower surfaces together. The residual stress components of σ_x and τ_xy are also determined. The intensity of the residual stress component is maximum at the upper and lower surfaces of the beam, but the residual stress component of τ_xy is maximum on or around the х-axis. The beam can be strengthened by using the residual stresses. The distance between the plastically collapsed point and the free end is calculated for the same load in the beam for 0°, 15°, 30°, 45°, 60°, 75° and 90° orientation angles.     

The effect of the combustion channels on the compressive strength of porous NiTi shape memory alloy fabricated by SHS as implant material

Porous NiTi shape memory alloy (SMA) with ideal porosity and high compressive strength as an implant material was fabricated by self-propagating high-temperature synthesis (SHS). In this study, a new ignition technique “high voltage electric arc” was used to ignite the green specimens and control the orientation of combustion channels which effect compressive strength. It was determined that the compressive strength of specimens was increased when the combustion channels were parallel along the specimen axis, and the compressive strength was decreased when the combustion channels were perpendicular to specimen axis. The desired phases such as B2(NiTi) and B19′ (NiTi) were dominant while the second phases (Ni₄Ti₃ and NiTi₂) in small amount. The undesired phases (such as pure Ni and Ni₃Ti) for biocompatibility are not found in the structure. The transformation temperatures were higher for medical applications by heat treatment and partly decreased at every next thermal cycle where the heating rate of the specimen was increased.     

Fracture analysis of anisotropic materials using enriched crack tip elements

Enriched finite element methodology, which employs special crack tip elements, is extended for cracks in anisotropic materials. Enrichment formulation is described briefly and three validation examples using single crystal, directionally solidified, and orthotropic material properties are presented to demonstrate the accuracy and effectiveness of the methodology. In addition to validation examples, the effect of material anisotropy on stress intensity factors is investigated using the common compact tension specimen and the results are compared to the ASTM solution for isotropic materials. It is shown that the effect of anisotropy on the computed stress intensity factors can be significant, depending on the degree of anisotropy, material orientation, and a/W ratio in the compact tension specimen geometry.     

Modelling 3D spatial enclosure of urban open spaces

Existing urban open space typologies within dense urban fabrics cannot meet society’s open space requirements in developing countries’ metropolitan cities, such as Istanbul. Because of high building densities, it is a challenging task to create new open spaces within urban cores. Developing new tools that work with the existing built environment is crucial to reveal ‘opportunity spaces’ that can act as breathing points within dense urban fabrics. In this research, a new model is developed to evaluate the 3D spatial enclosure of open spaces using basic geometrical properties and geographic information system (GIS) tools. As a case study, Istanbul’s changing spatial organization is analyzed using this model.     

Game theory approach to use of noncommercial power plants undertime-of-use pricing

The authors use the game theory approach for evaluating the impact of the introduction of customer-owned noncommercial power plants (NCP) when time-of-use pricing is used. Various results from this analysis are derived, some of which are that the conflict between NCP customer and the supplier forces the supplier to reduce the price of NCP customers. Perception of the situation in which they are involved in plays an important role in this conflict. The game model analysis presented provides a detailed quantitative information on electricity prices and on the ways of using NCP     

Zeta potential of soils with surfactants and its relevance to electrokinetic remediation

There are numerous studies on the application of electrokinetic decontamination technique to remediate heavy metal contaminated fine-grained soils. In recent studies, surfactants have been used to increase the efficiency of contaminant removal. However, there is limited data available on how physicochemical parameters such as zeta potential (ζ) of soils changes in the presence of surfactants. Understanding the ζ potential variations of soils with surfactant addition is important because it controls the direction and magnitude of electro-osmotic permeability, which plays important role on the efficiency of electrokinetic remediation. In this study, ζ potentials of kaolinite, montmorillonite and quartz powder with Li⁺, Ca⁺², Cu⁺², Pb⁺² and Al⁺³ in the presence of anionic, cationic and non-ionic surfactants were determined. The results indicate that anionic surfactants produce negative ζ potentials. The other surfactants produce both positive and negative ζ potentials depending on soil type and ion present in the system. The results also indicate that the ζ potential of kaolinite and quartz powder with surfactants showed similar trends; however, the absolute magnitude of the ζ potential of quartz powder is higher than that of kaolinite. The ζ potential of montmorillonite commonly shows a different trend from those of kaolinite and quartz powder. Based on the test results, it is recommended that ζ potential of soils be determined before the electrokinetic decontamination in order to maximize the efficiency of the technique.