The optimum support design selection by using AHP method for the main haulage road in WLC Tuncbilek colliery

The engineers can frequently encounter with the situation to select the optimum option among the alternatives related with mining operations. The optimum choice can be selected by the experienced engineers taking into consideration their judgement and intuition. However, decision-making methods can offer to the engineers to support their optimum selection for a particular application in the scientific way. The Analytical Hierarchy Process (AHP) is one of the multi attribute decision-making (MADM) methods utilizing structured pair-wise comparisons. This paper presents an application of the AHP method to the selection of the optimum support design for the main transport road, which has been planned for deep coal seam panels of Western Lignite Corporation (WLC) Tuncbilek in Turkiye. The methodology considers eight main objectives, namely: four different displacement values for determined history locations, factor of safety (FOS), cost, labour and applicability factor for the selection of support design. The displacements and stress values were obtained by using the finite difference program FLAC^3D as the numerical studies have been widely used by the engineers examining the response of any opening in underground, in advance. After carrying out several numerical models for different support design, the AHP method was incorporated to evaluate these support designs according to the pre-determined criteria. The result of this study shows that such AHP application can assist the engineers to effectively evaluate the support system alternatives for an underground mine.     

The degradation of an azo dye in a batch slurry photocatalytic reactor

The photocatalytic degradation of a commercial azo-reactive textile dye, Remazol Red F-3B, has been investigated in a batch slurry reactor using semiconductor catalysts like, ZnO and TiO₂, and two UV sources emitting mainly at 254 and 365 nm. Non-irradiated catalysts and non-catalyzed UV irradiation have negligible effect on the dye degradation. Initial pH, dye concentration, light power and catalyst loading as well as the catalyst type and UV wavelength are considered as process variables. The results showed that decolorization and TOC removal efficiencies of ZnO are higher under 365 nm UV. On the other hand, when two photocatalysts are compared, the decolorization performance of ZnO is higher than TiO₂ under 365 nm UV_, while TiO₂ performs better under 254 nm UV. Furthermore, from the TOC removal point, TiO₂ performs better than ZnO irrespective of the UV wavelength. TiO₂ irradiated under 254 nm UV degrades successfully both benzene and naphthalene derivatives.     

The Effect of Ageing at a Low Temperature on the Rheological Properties of Kahramanmaras-Type Ice Cream Mix

The aim of this article was to investigate the effect of ageing on the rheological parameters of ice cream mix. We prepared the model mix in accordance with the traditional Kahramanmaras-type ice-cream manufacturing method. The apparent viscosity (η_a) of the samples was measured as a function of shear rate, and the Power Law model was used to determine flow behavior (n) and consistency indices (K). The η_a of sample was significantly affected from ageing time as it increased up to 24 hours then decreased. The values of n and K of the samples ranged in 0.336 to 0.359 and 3719.72 – 4328.73 mPa.sⁿ, respectively. After 24 hours of ageing, K and η_a of the mix reached the highest, while the n reached the lowest values. These results suggested that 24 hours of waiting would be a proper ageing time for the ice cream mix. It could be recommended that ice cream mix may be aged at 0°C for about 24 hours before proceeding to the freezing step of ice cream manufacturing.     

Steady, Dynamic, Creep, and Recovery Analysis of Ice Cream Mixes Added with Different Concentrations of Xanthan Gum

Different xanthan gum concentrations (0–0.8 %) were tested, and the rheological properties of ice cream mixes were characterized as linear viscoelastic solids. Ostwald de Waele was successfully used to fit the steady shear data of ice cream mixes exhibiting a pseudoplastic flow (R ²?>?0.982). The samples with xanthan gum were characterized as strong gel-like macromolecular dispersions with G′ much greater than G″ but without a cross-point in the whole range of frequency applied. Cox–Merz rule was not applicable to the ice cream mixes. Steady and dynamic rheology of the ice cream mixes changed with increasing xanthan gum concentration. Besides, the four-component Burger model consisted of the association in series of the Maxwell model and the Kelvin–Voigt model was used to characterize the viscoelasticity. It was also found that the final percentage recovery parameters; J _SM, J _∞, J _KV, and %R (compliance of Maxwell spring and dashpot, Kelvin–Voigt element and R, respectively) of the ice cream mixes were dramatically changed by the xanthan gum concentration, increasing the internal structure parameters G ₀, G ₁, η ₀, and η ₁ (elastic moduli of Maxwell and Kelvin–Voigt springs and corresponding dashpot viscosities, respectively).     

Characterization of O/W model system meat emulsions using shear creep and creep recovery tests based on mechanical simulation models and their correlation with texture profile analysis (TPA) parameters

The effects of different oil and temperature levels on the viscoelastic behavior of O/W model system meat emulsions were assessed using creep and creep recovery tests. The viscoelastic behavior of such emulsions was characterized using the Burgers model parameters. In addition, texture profile analysis (TPA) of cooked meat emulsions was carried out to find a possible relationship between the creep and creep recovery data and TPA parameters. The final percentage recovery of the emulsions remarkably increased with oil content, but decreased with temperature level. Significant correlations among the creep-recovery data and TPA parameters were observed, this enabling meat processor to predict TPA parameters by resorting to shorter and less material consuming creep and creep recovery tests.     

Upgrading of iron ores using microwave assisted magnetic separation followed by dephosphorization leaching

This paper describes the development of a flowsheet using a combination of sample preparation, magnetic separation (in a range 0.4–1?T), microwave treatment (in a range 0.54–0.9?kW), and leaching operations (HCl, in a range 0.25–1.25?M) for the beneficiation of iron ores (Total Fe [T_FE]: 55.48%). The work was aimed at recovering T_FE from the non-magnetic product by increasing its magnetic susceptibility through microwave treatment. It was found that goethite mineral in the non-magnetic product at a temperature of around 200^oC was converted to paramagnetic (hematite) or ferromagnetic minerals (maghemite and magnetite) by microwave treatment and overall beneficiation recovery was improved. The phosphorus (P) content in the final product was then removed by leaching in 0.25?M HCl. The iron loss from the final concentrate during leaching was found to be 0.78%, which was negligible. Overall, a final concentrate assaying 61.78% T_FE with a recovery of 94.97%, and containing 0.04% P with 94.73% removal was obtained providing satisfactory results for use in the industry. This study gives an alternative way for possible future studies to produce an iron concentrate with a high recovery from problematic iron ores, which can be categorised due to its P content.     

Development of FPGA based power flow monitoring system in a microgrid

In recent decades, smart grid has become increasingly attractive to both energy producers and consumers. Amongst the main challenges for the successful realization of smart grid includes the integration of renewable energy resources, real time demand response and management of intermittent energy resources. Apart from smart grid, the development of micro-grids should take into consideration of issues such as the system performance, modelling, monitoring and controlling of the micro-grids. In particular, the recent advancements in information and communication technologies (ICTs) could facilitate the effective development of the future micro-grid system. The goal of the study is design of a system, based on FPGA, which monitors the power flow of the Microgrids. First of all a MG system installed in the laboratory of Firat University Electrical and Electronics Engineering Department consists of 1.2 kWp grid connected PV system, 5 kW micro hydro turbine, 0.5 kW wind turbine and 0.1 kW fuel cell unit was introduced. Afterwards, for smart-grids, a system of power flow that has a powerful high sampling rate was dwelt upon. During implementations, the data collected from the power system was transmitted to the FPGA cards located in open area by wireless data-monitoring card. This study has contributed to studies of other researchers by means of the monitoring system which has a high sampling frequency.     

新疆地区密点麻蜥不同亚种及其不同部位总磷脂含量的比较

本实验以密点麻蜥不同亚种(库氏亚种、叶城亚种)及其断尾体与尾巴为研究对象,主要用紫外-可见分光光度计对密点麻蜥不同亚种及其不同部位总磷脂进行了分析.结果显示:叶城亚种体内磷脂的含量高于库氏亚种磷脂的含量,叶城亚种尾巴中磷脂的含量明显高于叶城亚种断尾体中磷脂的含量,库氏亚种断尾体与库氏亚种尾巴中磷脂含量相差不大.