RP-HPLC optimization of econea by using artificial neural networks and its antifouling performance on the Turkish coastline

Coverage of artificial surfaces within seawater by fouling organisms is defined as biofouling. Although biofouling is a natural process, it has some disadvantages for shipping industry such as increased fuel consumption, and CO₂ emission. Therefore, the ships' hull must be covered by antifouling (AF) or fouling release type coatings to overcome biofouling. In general, the so-called self-polishing AF paints contain biocides for preventing fouling organisms. Their concentrations and release rates from AF coatings are of great importance and they definitely affect both quality and cost of the coating. In the present study, we aimed at applying a new robust method. In this method, we used a model biocide, i.e., econea, to obtain its RP-HPLC optimization through artificial neural networks (ANN) and to see its antifouling performance. Column temperature, mobile phase ratio, flow rate, concentration and wavelength as input parameters and retention time as an output parameter were used in the ANN modeling. In conclusion, the R&D groups in AF paint industry may use RP-HPLC method supported with ANN modeling in further studies.     

The capability of rosemary extract in preventing oxidation of fish lipid

The effects of rosemary extract at different levels (%1, R1, and %2, R2) on the quality of vacuum‐packed sardine in terms of sensory, biochemical (thiobarbituric acid, total volatile basic nitrogen, peroxide value and free fatty acids) and microbiological analyses (total viable counts) were investigated. Fish were filleted and divided into three groups. First group was used as the control (C) without rosemary extract, second group was treated with 1% rosemary extracts (10 g L^?1) for 2 min (R1), and the third was treated with 2% rosemary extracts (20 g L^?1) for 2 min (R2). Thirty fillets per litre were used. After that, all groups were vacuum‐packed in polyethylene bags. The samples were stored in the refrigerator condition (4 ± 1 °C) over the storage period of 20 days. The results showed that the use of rosemary extract improved the sensory quality of both raw and cooked sardine, most preferably sardine treated with 1% of rosemary. Biochemical analysis showed that the use of 2% of rosemary extract were found to be most effective (P < 0.05) in controlling the rate of lipid oxidation.     

SIRT1/FOXO Signaling Pathway in Breast Cancer Progression and Metastasis

Breast cancer is the second most common cancer in women. The roles of the SIRT and FoxO proteins in tumor progression are known, but their roles in metastasis have not yet been clearly elucidated. In our study, we investigated the roles of SIRT and FoxO proteins their downstream pathways, proteins p21 and p53, in tumor progression and metastasis. We evaluated these proteins in vitro using metastatic 4TLM and 67NR cell lines, as well as their expression levels in tumor-bearing mice. In addition, the regulatory role of SIRT and FoxO proteins in different transduction cascades was examined by IPA core analysis, and clinicopathological evidence was investigated in the TCGA database. In primary tumors, the expression levels of SIRT1, p21, p53, E2F1 and FoxO proteins were higher in 67NR groups. In metastatic tissues, the expression levels of SIRT1, E2F1 and FoxO proteins were found to be enhanced, whereas the levels of p53 and p21 expression were noted to be reduced. IPA analysis also provided empirical evidence of the mechanistic involvement of SIRT and FoxO proteins in tumor progression and metastasis. In conclusion, SIRT1 was found to co-operate with FoxO proteins and to play a critical role in metastasis. Additional research is required to determine why overexpression of SIRT1 in metastatic tissues has oncogenic effects.     

Treatment of originally coloured wools with garlic stem extracts and zinc chloride to ensure anti‐bacterial properties with limited colour changes

In this study, the objective was to ensure anti‐bacterial properties for originally coloured wools with naturally sourced garlic stem extracts. In addition, zinc chloride‐based treatment was also carried out. The aim was to retain the original colours of the wool fibres during these treatments. The effects of both treatments were evaluated in terms of colour changes in the wool fibres. It was found that the colour changes caused by the treatments were high in white/ecru fibres but more limited in black fibres. The colour differences between the treated and untreated black fibres were near 1; they were also quite high in white/ecru fibres. The anti‐bacterial properties of the treated wool fibres against two bacteria species, one gram‐negative and one gram‐positive, were also investigated. It was observed that zinc chloride‐based treatment ensured significant anti‐bacterial efficiencies against the bacteria tested and 99.9% bacterial reduction in all cases. However, the anti‐bacterial effects of garlic stem extract‐based treated wool fibres were limited. It was observed that treatment of wool fibres with garlic stem extracts resulted in no anti‐bacterial efficiency against Escherichia coli but did provide some anti‐bacterial capability against Staphylococcus aureus. The highest bacterial reduction of S. aureus was 80.7% in originally brown‐coloured wool fibre.     

Simultaneous glycolysis and hydrolysis of polyethylene terephthalate and characterization of products by differential scanning calorimetry

Simultaneous glycolysis and neutral hydrolysis of waste polyethylene terephthalate (PET) has been carried out at 170 and 190 °C with constant amount of ethylene glycol (EG) and increasing amounts of water, in the presence of xylene. The organic solvent made it possible to employ very low amounts of reactants as well as application of lower temperatures and pressures in contrast with previous methods, yielding intermediates suitable for PET or other polymeric materials. These intermediates were characterized by acid value (AV), hydroxyl value (HV) determinations as well as by differential scanning calorimetry (DSC). A water soluble crystallizable fraction with high purity, consisting of mono 2-hydroxy ethyl ester of terephthalic acid (monohydroxyethyl terephthalate, MHT) monomer has been obtained with significant yield and its polymerization tendency has been compared with that of bis(2-hydroxy ethyl) terephthalate (BHET) by application of multiple heating/cooling cycles in DSC.     

Utilization of polyampholyte hydrogels for simultaneous removal of textile dyes from aqueous solutions

The study aimed to create hydrogel structures with greater functionality, otherwise known as polyampholytes (PAHs), and to use these in simultaneous removal studies for remazol-type dyes found in environmental waste waters. Adsorption studies were accomplished at 20°C and 35°C, indicated that adsorption process was exothermic in nature. The Q_m values for the PAH-dye systems were in the interval 111–122 mg dye/g PAH with Ads% from 94% to 98%. The ability of PAH hydrogels to adsorb two different species of dye molecules at the same time is an advantage of PAH adsorbents compared to other hydrogel adsorbents prepared in this area.     

A dimensionless analysis of heat and mass transport in an adsorber with thin fins; uniform pressure approach

A numerical study on heat and mass transfer in an annular adsorbent bed assisted with radial fins for an isobaric adsorption process is performed. A uniform pressure approach is employed to determine the changes of temperature and adsorbate concentration profiles in the adsorbent bed. The governing equations which are heat transfer equation for the adsorbent bed, mass balance equation for the adsorbent particle, and conduction heat transfer equation for the thin fin are non-dimensionalized in order to reduce number of governing parameters. The number of governing parameters is reduced to four as Kutateladze number, thermal diffusivity ratio, dimensionless fin coefficient and dimensionless parameter of Γ which compares mass diffusion in the adsorbent particle to heat transfer through the adsorbent bed. Temperature and adsorbate concentration contours are plotted for different values of defined dimensionless parameters to discuss heat and mass transfer rate in the bed. The average dimensionless temperature and average adsorbate concentration throughout the adsorption process are also presented to compare heat and mass transfer rate of different cases. The values of dimensionless fin coefficient, Γ number and thermal diffusivity ratio are changed from 0.01 to 100, 1 to 10^− 5 and 0.01 to 100, respectively; while the values of Kutateladze number are 1 and 100. The obtained results revealed that heat transfer rate in an adsorbent bed can be enhanced by the fin when the values of thermal diffusivity ratio and fin coefficient are low (i.e., α^? = 0.01, Λ = 0.01). Furthermore, the use of fin in an adsorbent bed with low values of Γ number (i.e. Γ = 10^− 5) does not increase heat transfer rate, significantly.     

Coke minimization via SiC formation in dry reforming of methane conducted in the presence of Ni-based core–shell microsphere catalysts

Mesoporous Ni/Si microsphere catalysts were synthesized with a modified sol–gel microencapsulation method and their activity was tested in dry reforming of methane (DRM) reaction. Results indicated comparable conversion values and H₂/CO ratios with other catalysts reported in literature. Activity loss of 5% determined with time on stream analysis of 5% Ni/Si catalyst revealed that sustainable production could have been possible in the presence of these catalysts. Coke deposition which was frequently stated as the reason of activity loss was not observed with Ni/Si microsphere catalysts. Taking into account the impossibility of eliminating methane cracking and Boudard reaction during DRM, we should come up with an explanation of the absence of coke. This explanation was provided by silicon carbide (SiC) formation which consumed the coke deposited on the catalyst. Characterization analyses conducted at spent catalysts validated both the absence of coke and formation of SiC during DRM.     

Cost analysis of wind-electrolyzer-fuel cell system for energy demand in Pınarbaşı-Kayseri

In this study, the hydrogen production potential and costs by using wind/electrolysis system in P?narba??-Kayseri were considered. In order to evaluate costs and quantities of produced hydrogen, for three different hub heights (50 m, 80 m and 100 m) and two different electrolyzer cases, such as one electrolyzer with rated power of 120 kW (Case-I) and three electrolyzers with rated power of 40 kW (Case-II) were investigated. Levelised cost of electricity method was used in order to determine the cost analysis of wind energy and hydrogen production. The results of calculations brought out that the electricity costs of the wind turbines and hydrogen production costs of the electrolyzers are decreased with the increase of turbine hub height. The maximum hydrogen production quantity was obtained 14192 kgH₂/year and minimum hydrogen cost was obtained 8.5 $/kgH₂ at 100 m hub height in the Case-II.