Çanakkale Teknik Bilimler Meslek Yüksekokulu Koleksiyonu

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https://hdl.handle.net/20.500.12428/3540

Listeleniyor 1 - 20 / 27

Ultrasonically sprayed cobalt oxide thin films: Enhancing of some physical properties by nickel doping
(Elsevier B.V., 2021) Kuş, Esra; Küçükkarslan, Ayşe; Demirselçuk, Barbaros; Sarıca, Emrah; Akyüz, İdris; Bilgin, Vildan
In this study, the effect of Ni doping (3, 6, 9 at%) on structural, optical, electrical and magnetic properties of Co3O4 films was reported. Films were grown at 300 ± 5 °C substrate temperature via ultrasonic spray pyrolysis (USP) technique. The structural analyses showed that undoped and Ni (3%) doped films exhibit an amorphous structure. Ni doping at higher ratios caused the films to have improved crystallinity. Optical band gap values the films were found to be between 2.03 and 2.08 eV with an additional sub-band corresponding to energies varying between 1.35 and 1.46 eV. The electrical conductivity values of the films increased significantly depending on the Ni doping. The hysteresis curves of the films showed that the films have weak ferromagnetic properties. Ni doping significantly improved the structural and electrical properties of Co3O4 films making them suitable materials for technological applications.
The effect of nanoparticle sizes on the structural, optical and electrical properties of indium sulfide thin films consisting of In2S3 and In6S7 phases
(Elsevier B.V., 2021) Demir, Ramazan; Göde, Fatma; Güneri, Emine; Emen, Fatih Mehmet
Indium sulfide thin films consisting of In2S3 and In6S7 phases were synthesized onto microscope glass substrates with different nanoparticle size using the chemical bath deposition method (CBD). Immediately after obtaining the films, they were annealed at 400°C for 1 h in reduced media in order to get better crystallization. The effect of nanoparticle sizes on the structural, compositional, optical, and electrical properties of the films was investigated. The films were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive x-ray spectrometry (EDS), UV–Vis spectroscopy and sheet resistivity measurements. The XRD spectra revealed the existence of both the cubic In2S3 and monoclinic In6S3 phases. From the SEM micrographs, the deposited films showed dense and good coverage of the surface with cracks. Moreover, nanoparticle sizes increased from 53 nm to 142 nm with increasing deposition time as well as film thickness. With an increase in nanoparticle size, the S/In ratio in the films decreased from 1.74 to 1.21 showing sulfur deficiency in the deposited films. The direct band gap (Eg) of the films decreased from 3.35 eV to 2.70 eV with increasing nanoparticle size. The sheet resistivity of the films decreased from 1.69 × 107Ω/Sq to 4.61 × 103Ω/Sq. The obtained results demonstrate that nanoparticle sizes effected the structural, compositional, optical and sheet resistivity of the films.
Length-weight relationships of fishes caught by stationary uncovered pound nets in the coastal waters of Saros Bay, North Aegean Sea (Turkey)
(Ege University Faculty of Fisheries, 2021) Çolakoğlu, Serhat
Stationary uncovered pound nets are passively fishing gears used for fish catching according to traditional methods in the coastal waters of Saros Bay, North Aegean Sea. The purpose of this study was to determine length-weight relations (LWRs) for a wide range of fish species collected from the traps in the coastal waters of Saros Bay. We are studied in the fish species caught by four traps between April and August (fishing season) in 2010 - 2012. A total of 23 fish species belonging to 12 families were caught individual 2.096. The mean value of the growth pattern (b) was 3.141 +/- 0.042, ranging from 2.711 to 3.577. Whereas they were negative allometric only for two species (Pomatomus saltatrix and Mugil cephalus), from other fish species were observed to be 13 positive allometric and 8 isometrics. The LWR parameters for the positive allometric and isometric fish species were significant (P<0.05). This study provides some general information about the status of the LWR parameters of the fish species caught from the traps.
Stabilisation of lavender essential oil extracted by microwave-assisted hydrodistillation: Characteristics of starch and soy protein-based microemulsions
(Elsevier B.V., 2021) Çelebi Uzkuç, Nesrin Merve; Uzkuç, Hasan; Berber, Mehmet Mert; Tarhan Kuzu, Kübra; Togay, Sine Özmen; Kırca Toklucu, Ayşegül; Kurt, Saliha B.; Şahiner, Nurettin; Karagül Yüceer, Yonca
In this work, microwave-assisted hydrodistillation (MAHD) technique was used to obtain lavender essential oil (LEO) with a yield of 5.5 %. Oil in water microemulsions of LEO were prepared with starch and soy protein by ultrasonic emulsification. Total phenolic content and antioxidant capacity of the samples were evaluated. Microemulsions exhibited antimicrobial effect against S. aureus and B. cereus. The major volatiles of LEO were linalool L (29.0 %), 1,8-cineole (13.9 %), camphor (12.3 %) and linalyl acetate (11.9 %). Camphene, 1,8-cineole, (Z)-ocimene, linalool, and 2,6-nonadienal were determined as aroma-active compounds by gas chromatography-olfactometry. The stability of emulsions at different pH (3, 6 and 9) and temperatures (4 and 25 °C) were evaluated by measuring their size distribution, zeta potential, viscosity and color during storage. The stable droplets of LEO microemulsion that ranged between 392 and 732 nm were obtained with starch at pH 6. The formulated starch-based emulsions of LEO at pH 6 revealed the highest stability at 25 °C.
Effects of protease-hydrolyzed egg white on the meringue batter properties and meringue textural and sensory properties during storage
(AZTI-Tecnalia, 2021) Yüceer, Muhammed; Caner, Cengiz
This study was focused to analyze the effects of different concentrations (0.5, 1.0, 1.5 w/v) of protease hydrolyzed liquid egg white (LEW) on meringues batter and cookies. The color (L*, a*, b*, ΔE), physical and aeration properties (batter specific density (BSD), cooked meringues specific volume (MSV)), water activity, texture analysis and sensorial profiles of the meringues during three months of extended storage at ambient temperature (23 ± 2°C) was investigated. Additionally, the creep recovery compliance parameters, colors, and physico-chemical characteristics of freshly whipped meringue batter were also evaluated. Protease hydrolyzed samples exhibited higher L* and lower b* parameter. The BSD values (g/cm3) for control - 0 % (0.51 ± 0.01) was significantly decreased (p < 0.05) after enzymatic treatment, lower values obtained in 1 % (0.37 ± 0.01) and 1.5 % (0.35 ± 0.01). The MSV values of cooked meringue was significantly increased (p < 0.05) depends on the protease concentrations. The strength of the meringue batter is increased after hydrolysis. However, the enzymatic hydrolysis reduced consumer satisfaction. This research points out the optimum (1.0 %) hydrolyzed LEW in preparation of meringue improved functionality, such as BSD and MSV parameters.
Improvement of structural, optical and magnetic properties of cobalt oxide thin films by doping with iron
(Springer Science and Business Media Deutschland GmbH, 2021) Küçükarslan, Ayşe; Kuş, Esra; Sarıca, Emrah; Akyüz, İdris; Bilgin, Vildan; Demirselçuk, Barbaros
In this study, using the ultrasonic spray pyrolysis technique, undoped and Fe-doped (at 2, 4, 6%) Co3O4 films were deposited on microscope glass substrates at 300 ± 5 °C, and the effect of Fe doping on some physical properties of Co3O4 films was examined. The structural, optical, magnetic and morphological properties of all films were analyzed using X-ray diffractometer, UV–Vis spectrophotometer, vibrating sample magnetometer and atomic force microscope, respectively. Band gap values of Co3O4:Fe films were found to be between 1.98 and 2.12 eV with an additional sub-band corresponding to energies varying between 1.48 and 1.50 eV for all samples. Structural analysis showed that crystallization levels of the films were improved with the Fe doping. Also, hysteresis curves of the films showed weak ferromagnetic characteristics and the magnetic behavior of the films was found to be sensitive to doping amount of Fe. It was found that Fe doping has beneficial effect on some physical properties of Co3O4 films.
Levels of PAHs, PCBs, and toxic metals inRuditapes philippinarumandDonax trunculusin Marmara Sea, Turkey
(John Wiley and Sons Ltd, 2021) Künili, İbrahim Ender; Çolakoğlu, Serhat; Çolakoğlu, Fatma
BACKGROUND: The manila clam Ruditapes philippinarum and the wedge clam Donax trunculus are economic bivalve species which constitute an important part of the natural bivalve beds in the Marmara Sea, Turkey. Toxic chemicals such as, dioxins, dioxin-like polychlorinated biphenyls (PCBs), polycyclic hydrocarbons (PAHs), and toxic metals are recognized as important health risk factors that threaten public health via food or directly in the environment. In the present study, we aimed to determine and monitor levels of these toxic chemicals in both clam species, R. philippinarum and D. trunculus, between 2013 and 2017. RESULTS: According to the results, maximum levels of dioxins, PAHs, and toxic metals (lead, cadmium, mercury) during the period were determined as 0.18 pg g−1, 2.43 mg kg−1, and 0.44–0.53-0.1 mg kg−1, respectively. The level of contaminants in both clam species were determined to be below the threshold or tolerable daily intake values established by the European Commission, European Food Safety Authority (EFSA), and Food and Agriculture Organization/World Health Organization (FAO/WHO). Seasonal fluctuations were observed to be similar in both species and also in seasons, but elevated levels of PCBs and PAHs were detected in warmer months during the period. CONCLUSION: As a consequence, toxic chemicals in both clam species were found at low concentrations in this study from the point of view of public health concerns; however, the contaminants should be closely monitored in the future due to their elevated levels in samples.
Electrochemical, Spectroelectrochemical, and Electrocatalytic Dioxygen Reducing Properties of Peripheral Tetra-2,6-dimethoxyphenoxy Substituted Phthalocyanines
(John Wiley and Sons Inc, 2021) Orman, Efe Baturhan; Pişkin, Mehmet; Odabaş, Zafer; Özkaya, Ali Rıza
By using of peripherally tetrakis-2,6-dimethoxyphenoxy substituted Co(II), Fe(III), and Mn(III) phthalocyanines was observed to extend the redox richness of the phthalocyanine ring with the addition of reversible metal-based electron transfer couples to the phthalocyanine ring-based electron transfer processes in solution. The emergence of highly steady anionic and cationic redox species with clear spectral and colour changes both in solution and in the film during in situ spectroelectrochemical and in situ electrocolorimetric measurements pointed out their applicability as electrochromic materials. Furthermore, the phthalocyanine complexes demonstrated strong interaction with dioxygen and thus, high electrocatalytic enforcement for its reduction.
Amatör Balıkçılık: Çanakkale İli Örneği
(Çanakkale Onsekiz Mart Üniversitesi, 2022) Aytepe, Hüseyin Gökhan; Dalyan, Orkun; Dalyan, Hatice; Pişkin, Mehmet
In this study, the socio-demographic status of the amateur fishermen, whose numbers are increasing rapidly in our country, and their knowledge levels about amateur fishing in Çanakkale were determined. A survey consisting of 63 questions was conducted in Çanakkale during the period FebruaryMay 2022. The survey data answered by 107 randomly selected amateur fishermen were analyzed with the Statistics Program for Social Sciences 24.0. The data in this study were compared to those of other related studies conducted in different regions of our country. Findings indicated that 85% of the participants were male and 69.2% were married and 57.9% of the participants were between the ages of 26-35. In addition, 47.7% of the participants were high school graduates and 88.8% were actively working. The ratio of participants who did not have an amateur fisherman's license was 77.6%. In this study, it was determined that participants with an amateur fisherman's license who perform fishing activity only in saltwater and go fishing everyday had higher levels of knowledge and awareness. Although the participants had sufficient knowledge on fishing and the environment, they had limited knowledge on safety issues on fishing boats.
Çanakkale İlinde Hizmet Veren Balıkçı Teknelerinde İş Sağlığı ve Güvenliği
(Çanakkale Onsekiz Mart Üniversitesi, 2021) Aytepe, Hüseyin Gökhan; Dalyan, Orkun; Pişkin, Mehmet
In this study, the attitudes of fishermen in Çanakkale region towards occupational health and safety measures have been investigated. For this purpose, a questionnaire consisting of 26 questions was conducted in June 2021 with fishermen working in fishing boats registered to Çanakkale Central Port Authority. Data obtained from responses of 103 randomly selected fishermen indicated that 99 participants (96.1%) were male and 63 (61.2%) were married. Fifty-two of the participants (50.5%) were between the ages of 25-35. Only 26 (25.2 %) of the participants received higher education. 55 (53.4%) of the participants had 1-5 years of professional experience. Fishermen between the ages of 19-24, with an associate degree and less than 1 year of professional experience gave more positive answers regarding the occupational health and safety efforts in fishing activities compared to those expressed by the personnel in other groups. There was a significant difference between the occupational health and safety perception and age and professional experience variables in fishing activities. The data obtained indicated insufficient efforts on fishing activities by the authorized public organizations and institutions, docking problems of fishing boats, lack of OHS service in fishing activities. Involvement of fishermen in the planning of fisheries related programs and informing employers about the necessity of mandatory OHS services provided by the Ministry of Labor and Social Security may solve identified problems.
The shellac and shellac nanocomposite coatings on enhanced the storage stability of fresh eggs for sustainable packaging
(Elsevier B.V., 2024) Şahansoy, Hakan; Caner, Cengiz; Yüceer, Muhammed
Shellac bio-coatings can enhance to improve quality and storage stability of fresh egg qualities with improved shell strength therefore minimizing the reduction the egg losses. Shellac bio-chitosan at 3 concentrations (1 %, 4 % and 8 % w/w) and shellac-1 % montmorillonite nanocomposites were applied as biocoatings to improve storage stability. Shellac-8 % (SH-8 %) coated eggs exhibited the lowest weight loss (1.28 %), significantly. The weight loss of shellac 1 % + MMT and 4 % shellac (SH-4 %) coated eggs was similar each other and had lower weight loss than 1 % shellac (SH-1 %). The Haugh Unit (HU) of eggs with SH-8 % (63.75) had the significantly the highest HU. The SH-4 % (60.24) and SH-1 %/MMT-1 % (58.04) were similar, and the control was the lowest one. The albumin pH of SH-8 % (9.15) coated exhibited a significantly lower than SH-4 % (9.21) and SH-1 %/MMT-1 % (9.24), while the control (9.39) was the highest value at end of storage. For the shellac coated group, total soluble values of albumen reached 12.87 (initial) to 16.331 (SH-1 %), 15.96 (SH-4 %), 15.60 (SH-8 %) and 16.15 (SH-%1-MMT-1 %) at the end of storage. The RWC and foam stability of SH-8 %, SH-4 % and SH-1 % MMT-1 % were similar and higher than 1 % SH and uncoated egg samples. The rheology behaviors were maintained with increasing shellac concentration through the storage. SH-8 % biocoatings were very most effective in filling and sealing the porous in the eggshell and protecting the storage stability and enhancing the strength of the eggshell. Shellac bio-coatings acted as a tiny layer for an effective protective barrier to gas permeability for enhancing the storage stability of the fresh eggs. Higher shellac concentrations (4 and 8 %) and 1 %-MMT were enhanced the storage stability and can be vital solutions for improving shell strength, so it decreases breakage rates.
Solution of MHD-stokes flow in an L-shaped cavity with a local RBF-supported finite difference
(2024) Çelik, Ebutalib; Gürbüz-Caldağ, Merve
One of the popular meshless methods for solving governing equations in applied sciences is a local radial basis function-finite difference (RBF-FD). In this paper, we proposed a new idea for an L- shaped (or like T- and Z-shaped) domain based on the domain decomposition. RBF-FD formulation is used at the interface points to get a better solution, while the classical FD is applied to all sub-regions. We use the algorithm based on the Gaussian-RBF (RBF-GA) in the stable calculation of the weights to avoid choosing optimal shape parameters. Stencil size is considered the nearest n-points (9,12,15) and benchmark results are presented for divided-lid driven cavity. Further, Navier–Stokes equations adding the Lorentz force term with Stokes approximation for a single-lid L-shaped cavity exposed to inclined magnetic field are solved by the devised numerical method. The flow structure is analyzed in aspect of streamline topology under the various magnetic field rotation (0∘≤α≤90∘ ) and its strength (M=10,30,50,100 ).
Improving food security as disaster relief using intermediate moisture foods and active packaging technologies
(Elsevier B.V., 2024) Aydın, Alper; Yüceer, Muhammed; Ulugergerli, Emin Uğur; Caner, Cengiz
This study aims to present alternative solutions for food aid that meet the needs of disaster victims after significant disasters. Food support in post-disasters period is a vital humanitarian service that enables disaster victims to survive and maintain their health. Providing that, the food must have a long shelf life and be nutritious and safe. Intermediate moisture foods (IMF) are shelf-stable products and have a high potential for use in disasters. Recent developments in active packaging (AP) technologies helps to enhance the quality and extend the storage stability of food, including the IMF. This study shows that AP technologies with antimicrobial agents, oxygen and moisture absorbers can improve the storage stability of food and reduce the risk of microbial contamination. Furthermore, using these technologies in food packaging can provide sustainable alternative to conventional packaging and increase the stability of food in potential future disasters.
Anti-bacterial, anti-oxidant activities of polymer-based metal complexes and their catalyst effects in presence of H2O2
(Springer Science and Business Media Deutschland GmbH, 2024) Şenol Bahçeci, Dilek; Aydın Kocaeren, Aysel; Demir, Neslihan; Dalgıç, Büşra
4-{[(3-Hydroxynaphthalen-2-yl)imino]methyl}benzene-1,2,3-triol Schiff-base, abbreviated as ligand (L), was synthesized and additionally, its polymer was obtained through oxidative polycondensation and named as poly-4-{[(3-hydroxynaphthalen-2-yl)imino]methyl}benzene-1,2,3-triolpoly-ligand (PL). The ammonium persulfate (NH4)2S(2)O(8) was used as an oxidant in this reaction. The metal complexes of PL were synthesized in the presence of various metal ions such as Cu2+, Hg2+, Ni2+, Pb2+,and Zn2+. The synthesized structures of PL and metal complexes were confirmed by FTIR, UV-vis, H-1 and C-13 NMR, and elemental analysis. Moreover, SEM and TGA analyses were performed for characterization. In this study, the anti-oxidant, anti-bacterial and catalytic properties of PL and its metal complexes were investigated. For anti-oxidant properties, 2,2-diphenyl-1-picryl-hydrazyl (DPPH) detection methods were studied. Also, for anti-bacterial activities they were tested against various bacteria using the minimum inhibitory concentration (MIC) method. It was observed that [Ni(PL)(2)] and [Pb(PL)(2)] metal complexes showed quite good anti-oxidant activities when they were compared with PL at its highest concentration of 100 ppm. The anti-bacterial activity results showed that [Hg(PL)(2)] had the highest MIC value of all the mentioned materials. The obtained catalytic activity results revealed that the synthesized poly-ligand metal [M(PL)(2)] complexes could be considered as an alternative catalyst to remove various organic pollutants from the aqueous environment. From this point of view, it is possible to say that [M(PL)(2)] complexes synthesized within the scope of the study could be used as polymeric agents to reduce environmental pollution.
Length - Weight Relationships, Meat Yield and Morphometric Indices of Five Commercial Bivalve Species Collected from the Çanakkale Strait (Türkiye)
(Istanbul University Faculty of Aquatic Sciences, 2024) Çolakoğlu, Serhat; Çolakoglu, Fatma; Kunili, İbrahim Ender
This study was conducted to determine the meat yield, morphometric characteristics, length-weight relationships (LWRs) and their correlations with environmental variables of five commercial bivalve species collected monthly between 2014 and 2015 from the coastal waters of the canakkale Strait. A total of 8588 individuals were examined, and different ranges for both shell length (9.00-108.50 mm) and total weight (0.30-234.20 g) were determined according to species. The highest meat yields from Donax trunculus (16.40-23.34%), Mytilus galloprovincialis (14.89-34.35%) and Ostrea edulis (5.91-26.24%) were determined in spring, while Ruditapes philippinarum (10.80-29.53%) and Chamelea gallina (12.26-18.92%) had maximum yield in late summer and early autumn (p<0.05). Elongation index (SH/SL), compactness index (SW/SL), convexity index (SW/SH), and density indexes (TW/SL) were significant (p<0.05) and had high correlation coefficients (r=0.806-0.975). The mean value of the allometry coefficient (b) was 3.257 +/- 0.168, ranging from 2.291 to 4.058. Four species had negative allometries, namely D. trunculus (2.738), C. gallina (2.889), M. galloprovincialis (2.597) and O. edulis (2.728), while R. philippinarum (3.137) displayed positive allometry. The morphometric indices show high morphological resemblances. As a result, it is thought that the data obtained in this study can both provide data in the fields of biology and ecology for current scientific studies on these species, and can be used as a resource for the sustainable production of these commercial species.
Combined effect of electrolyzed water (EW) and sonication with equilibrium modified atmosphere packaging for prolonging storage stability of fresh strawberry
(SAGE Publications Inc., 2024) Caner, Cengiz; Tiryaki, Kübra; Pala, Çiğdem Uysal; Yüceer, Muhammed
This research focuses on the effectiveness of electrolyzed water (50 and 100 ppm for 3 min), ultrasonication (80 W for 3 min), and their combinations on fresh strawberries, which are then packaged using microperforated film to enhance their storage stability. The gas composition in the headspace, pH, soluble solids, color (L*, a*, b*, and ΔE* values), anthocyanins, total phenolics, and texture profile was evaluated for the 35 days of storage at +4 °C. The lowest weight loss was measured at about 100 ppm electrolyzed water (EW; 0.47%), and the highest one was in the control group (0.57%) after storage. At the end of the storage, O2 in the headspace decreased from 20.90% to 10.50–8.10% and CO2 was accumulated from 0.03% to 16.4–14.34%. The results showed that soluble solids decreased (9.95 to 8.48–7.85 °Bx) and pH values increased (3.34 to 3.79–3.91) during storage. At the end of the storage, the total phenolics in the control group decreased by the most during storage (from 1209.09 ppm to 808.00 ppm), whereas the 50 ppm EW group had the highest (931.66 ppm). Further, the significantly highest anthocyanin amount was found to be 143.86 ppm in the 100 ppm EW group at the end of 28 days of storage. The EW can significantly delay the degradation of anthocyanin over the storage period. The sonication at 100 ppm EW damages strawberry tissues, reducing their hardness. The lowest decay rate was found in fruits treated with 100 ppm EW (41.67%), followed by 50 ppm EW (58.33%), compared to the control (75.00%). This study reveals that applications of the 50 ppm EW and also 50 pm EW combined with ultrasonication have great potential in the extending storage stability of the fresh strawberries.
Combined effect of sonication and equilibrium-modified atmosphere packaging to improve storage stability of "Angelino" plums during extended storage
(John Wiley and Sons Inc, 2023) Caner, Cengiz; Yumak Alnıak, Nesrin; Yüceer, Muhammed
This work focuses on the combined effects of ultrasound treatment (100, 200, and 300 W for 5 min) and equilibrium-modified atmosphere packaging (EMAP) to enhance the storage stability based on pH, aw, gas compositions in headspace, color changes (L*, a*, b*), organic acids, and texture profile of fresh “Angelino” plums for 120 days at 4°C. The results were expressed that pH values were increased (3.19-initial to 3.69/300 W–3.86/control) and Brix values were decreased (16.9-initial to 14.70/control–15.3/100 W) during storage. At the end of the storage, except the control group, O2 in the headspace decreased from 20.9%-initial to 16%/300 W–18.5%/200 W and CO2 was accumulated from 0.03%-initial to 4.9/%200 W–6.5%/300 W. Hardness (from 11,677, 6124 gf), gumminess (from 4344 g to 4335–6715 g), and chewiness (from 3831 and 2326–2638 g) consistently decreased as a function of storage. The hardness of “Angelino” plums had been maintained after the sonication combined with EMAP compared with the control during storage. The 100 W and 200 W sonication could significantly delay the degradation of malic (from 8957 to 4227–4236 mg/L) and tartaric (1796 to 1703–1722 mg/L) acid in flesh plums, but not citric acid and malonic acid over the storage period. The sonication (200 W) combined with EMAP enhanced the storage stability. Practical Applications: This research demonstrates that packaging fresh Angelino plums with micro-perforated lid films and subjecting them to sonication can enhance their storage stability, allowing for longer distribution via sea freight at a considerably reduced cost compared with air freight. This can potentially expand the producer's reach in international markets. Sonication had great potentials in stabilizing cell wall and maintaining hardness in the plums during storage. Moreover, the application of sonication, especially 200-W for enhancing storage stability without any detrimental effects on physicochemical properties and natural main organic acids (malic acid) of “Angelino” plums during the storage.
Effects of types and concentrations of modified Cloisite Clays on properties of chitosan nanocomposites for food packaging
(John Wiley and Sons Ltd, 2023) Caner, Cengiz; Rahvalı, Fatih; Yüceer, Muhammed; Oral, Ayhan
Biodegradable chitosan has excellent film-forming properties compared to other biodegradables but also some limitations, such as poor water barrier and low mechanical strength. Thus, in this research, the effects of various types (Cloisite Ca, 15A, 20A, and 30B) and concentrations (0.5, 1, 2.5, and 5 wt%) of Cloisite on barrier, mechanical, structural and thermal properties on chitosan films were investigated. Cloisite was revealed to significantly lower the lightness (L*) depending on the type and concentration of Cloisite. The films containing Cloisite significantly improved oxygen barrier properties by 34.5%-73.6% compared to control, particularly Cloisite 30B. Cloisite 20A and Ca were found to significantly improve the water barrier by up to 84.61%, and Cloisite 20A and 30 B the tensile properties by up to 30%. The chitosan with less Cloisite content exhibited better smoothness and elongation. The dispersed Cloisite clays improved the thermal stability and enhanced the barrier and tensile properties of the chitosan with the increased Cloisite loading.
Potential distribution of two lynx species in europe under paleoclimatological scenarios and anthropogenic climate change scenarios
(Federal University of Lavras, 2021) Kıraç, Akın
Background: Today’s European fauna was formed under the influence of Paleoclimatic change. The distribution of two wild cat species of Europe, Lynx pardinus and Lynx lynx, 22,000 and 6,000 years ago were determined by the MaxEnt method in relation to the Paleoclimatological scenarios (LGM and Mid-Holocene) and fossil records. Then, the current climate conditions and their distributions under the effect of anthropogenic climate change scenarios were analyzed with the current existence records. Results: It was determined that these two wild cats were distributed according to preys on which they specialized, rather than the climate change that lasted for thousands of years. It was observed that Lynx Pardinus, which specialized only on European rabbit hunting, could not expand its distribution from past to present. Lynx lynx, on the other hand, expanded its distribution throughout the Palearctic region and adapted to different ecosystem varieties by means of its specialization on many preys from mouse to moose. Based on the climate envelope model results created with the help of MaxEnt which considers anthropogenic climate change scenarios (RCP2.6, RCP4.5, RCP6.0 and RCP8.5 2070) and today’s data of two existing Lynx species, suitable habitats for L. pardinus will decrease and suitable habitats will emerge in Western France. L. lynx, on the other hand, will limit its wide distribution to the North, except for the Alps, the Carpathians and the Caucasus, which will serve as refugial areas. Conclusion: These results therefore require that measurements such as reducing climate change impacts over the next 50 years, protecting existing and potential habitats in advance, and reducing anthropogenic impact should be enforced.
Synthesis, characterization, thermal and photophysical properties of novel strontium (II) phthalocyanine
(Springer Science and Business Media B.V., 2022) Pişkin, Mehmet
Newly phthalocyanine derivative which carries 2,6-dimethoxyphenoxy bioactive groups as tetrakis from non-peripheral positions of the phthalocyanine ring and contains strontium (II) as an alkaline earth metal ion in its cavity was synthesized. Its structure was characterized by elemental analysis, fourier transform infrared, ultraviolet–visible, proton nuclear magnetic resonance, carbon-13 nuclear magnetic resonance and matrix assisted laser desorption/ionization time-of-flight mass spectroscopic techniques. Its thermal properties were determined using thermogravimetric analysis and differential scanning calorimetry. The solubility and aggregation behavior in polar protic, polar aprotic and non-polar solvents were determined. Also, its aggregation behavior was studied at a range of different concentrations in dimethyl sulfoxide. The photophysical properties (fluorescence quantum yield, fluorescence lifetime, natural radiation lifetime, non-radiative lifetime, rate constant for fluorescence, non-radiative rate constant and observed fluorescence decay rate constant values) of newly strontium(II) phthalocyanine were determined in dimethyl sulfoxide. In addition, the spectroscopic, thermal and photophysical properties of newly strontium(II) phthalocyanine were also compared with its counterparts reported in the literature. The findings of this work can be useful to those systems involving changes in the forms analogous to the compound studied. In addition, newly strontium(II) phthalocyanine with particularly sufficient and enhanced photophysical properties, could be a photosensitizer candidate for photocatalytic applications.

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