Yayınlar
Koleksiyondaki öğeler
- MakaleAçık Erişim2018Scopus SJRQ2On the new wave solutions to a nonlinear model arising in plasma physics
Ilhan, Onur Alp; Sulaiman, Tukur Abdulkadir; Bulut, Hasan; Baskonus, Haci Mehmet
In this paper, we utilize the sine-Gordon expansion method and construct some travelling wave solutions to the (3+1)-dimensional modified KdV-Zakharov-Kuznetsev equation which arises in plasma physics. We successfully obtain some hyperbolic function solutions to this equation. By choosing some suitable values of parameters, we perform the numerical simulation of all the obtained solutions in this study. We observed that our result may be useful in detecting some ion-acoustic waves behaviors in a magnetized plasma. All the computations and graphic plots in this article are performed with the aid of the Mathematica package.
AtıfScopus27OpenAlex29
İncele - MakaleYalnız künye2019Scopus SJRQ1TUNCELİ-ANBAR FORTRESS AND THE URARTIAN MULTIROOMED ROCK-CUT TOMB
Danışmaz, Harun
This study aims to evaluate Anbar Fortress and its multi-roomed rock-cut tomb, located in the Tunceli region. It is a place rarely mentioned in archaeological literature. For the first time the plan of the rock-cut tomb of Anbar is presented here and accordingly the fortress’ place in the Urartian administration system is evaluated. In addition, material culture residues from the site, such as wall foundations, mortared walls, rock steps, cisterns/storage spaces and a rock chapel were analysed and their connection to the tomb is explained. Traces of two different periods are detected in Anbar Fortress. While the wall foundations, multi-roomed rock-cut tomb, and a part of the rock steps can be associated with the Urartian period, the mortared walls, towers, rock steps, cisterns/storage spaces and rock chapel that is located in the southwest of the fortress is dated to the Medieval period.
AtıfScopus1İncele - MakaleAçık Erişim2018Scopus SJRQ2A research on coliform bacteria in the golden Horn Estuary (Sea of Marmara, Turkey)
Karabas, Necati; Tas, Seyfettin; Erguven, Gokhan Onder; Bayhan, Hurrem
Spatio-temporal variation of the total and fecal coliform groups as bacteriological indicators in the marine environment was investigated in surface water of the Golden Horn Estuary in monthly intervals between June 2012 and May 2013. Temperature, salinity, Secchi depth, pH, dissolved oxygen and oxygen saturation were measured at 10 stations simultaneously with bacteriological analyses. Highest total coliform counts in surface water was 940×103 CFU/100 ml at the Alibeykoy Creek in November and highest fecal coliform was 178×103 CFU/100 ml at the same area in October. The lowest coliform counts were observed during summer, while the highest counts were in autumn. During rainy days, some domestic wastewater overflowing from sewerages are discharged to the estuary, which those water adversely affect water quality. The total and fecal coliform counts in surface water increased gradually from the lower to upper section of the estuary. Although the Black Sea water pumping from the Strait of Istanbul to the Golden Horn by Kagithane Creek is an important factor in the decrease of pollution and better water quality, there are still some runoff materials including uncontrolled discharges particularly in the Alibeykoy Creek. The results of this study showed that that the bacteriological pollution increased due to municipal wastewater resulting from overflow after the precipitation and the surrounding waters of the Golden Horn basin mix with surface waters. Thus, the most important factor in order to decrease the bacteriological pollution is to provide a full control of the surface discharges.
AtıfScopus10WoS10OpenAlex13İncele - MakaleYalnız künye2020Scopus SJRQ1Evaluation of the radiation shielding capabilities of the Na2B4O7–SiO2–MoO3-Dy2O3 glass quaternary using Geant4 simulation code and Phy-X/PSD database
Aşkın, A.
The important gamma and neutron radiation shielding parameters of the Dy3+ doped (65-x)Na2B4O7–15SiO2–20MoO3-xDy2O3 (x = 0, 5, 10, 15, 20 mol%) glass quaternary system were investigated to provide decisive information for their application in radiation environment. Gamma and neutron attenuation properties of the glass systems studied here were evaluated in terms of the mass attenuation coefficient (μm), transmission fraction (TF), half value layer (HVL), mean free path (MFP), effective atomic number (Zeff), exposure buildup factors (EBF) and fast neutron removal cross-section (∑R) parameters. Investigation of the each aforementioned parameter was performed thanks to the utilization of Monte Carlo simulations along with the Phy-X/PSD database. The photon attenuation characteristics were evaluated for gamma ray energies varying between 0.284 and 5.0 MeV. This study indicated that increase of the Dy2O3 content from 0% to 20% mole, enhances the gamma shielding capability due to the increase of the parameters μm and Zeff. In this study it was also observed that ∑R increases from 0.099 to 0.107 cm−1 as the molar fraction of Dy2O3 increases.
AtıfScopus75WoS74OpenAlex82İncele - MakaleYalnız künye2019Scopus SJRQ4Water quality changes and goldfish growth (carassius auratus) in microgreen aquaponic and recirculating systems
Kizak, Volkan; Kapaligoz, Serdar
Goldfish (Carassius auratus) growth was studied comparatively in microgreen aquaponic (APS) and sump filter systems (SFS), and the ef fects of these two different filter systems on water quality parameters were investigated. Arugula (Eruca vesicaria) was used in APS and produced as microgreens. NH3-N, NO2-N, NO3-N, POj and NH4 were measured at specific periods for 60 days. No statistical differences were found between both systems in terms of food conversion ratio (FCR), specific growth rate (SGR), survival and mean body weight of goldfish. In the beginning of the experi-ment, water pH level was around 8.5 while trend towards declining at the end of period. Nitrification process was successful in both systems, and declin ing pH towards from basic medium to approaching neutral levels made positive contribution to perfor mance of nitrifying bacteria. Although there was a significant decrease in the level of NH4, the level of NO3-N increased continously after the 30,h day in APS. According to these results, arugula micro-greens used mostly NH4 instead of NO3-N in higher pH level. Goldfish-arugula microgreen aquaponic system is similar with SFS in terms of keeping water quality in optimal conditions and any adverse effect on goldfish growth and welfare was not ob served in both systems. Although in high pH, it was also seen that arugula seedlings can be produced efficiently as microgreens.
AtıfScopus7İncele - MakaleYalnız künye2020Scopus SJRQ2Optimization of open channels using particle swarm optimization algorithm
Saplioglu, Kemal; Ozturk, Tulay Sugra Kucukerdem; Acar, Ramazan
Due to recent increasing water demand, planning and projecting of water resources has resulted in increased costs. There-fore, it is important to obtain optimum results in project planning. In this study, dimensioning of open channels used espe-cially for irrigation purposes has been studied using a particle swarm optimization algorithm to investigate optimum base width, channel height, and slope angles. The results are summarized in graphs and tables. In the study, it was found that the optimum slope angle varied between 0. 200. 45. Furthermore, it was found that increasing the slope angle significant-ly increased costs. Finally, the increase in flow increases costs but the rate of increase diminishes.
AtıfScopus6WoS6OpenAlex9İncele - MakaleAçık Erişim2019THE BRYOPHYTE FLORA OF THE SAMANLI MOUNTAINS (SAKARYA, KOCAELI, YALOVA, BURSA) IN NORTH-WEST TURKEY; [ФЛОРА МХОВ ГОР САМАНЛИ (ОБЛАСТИ САКАРЬЯ, КОДЖАЭЛИ, ЯЛОВА И БУРСА) НА СЕВЕРО-ЗАПАДЕ ТУРЦИИ]
Gözcü, Merve Can; Uyar, Güray; Ören, Muhammet; Ezer, Tülay; Alataş, Mevlüt
The present study was performed on the Samanlı Mountains, which is extending from Sakarya province to Yalova province, in North-West Turkey. During this study, eight field trips were organized to the research area at different seasons between the years 2013 and 2016. Throughout these studies, with an examination of 3630 bryophyte specimens collected from 189 stations, together with 2 from Anthocerotophyta (hornworts), 61 from Marchantiophyta (liverworts), 306 from Bryophyta (mosses), in total 369 specific and infraspecific taxa, belonging to 70 families and 156 genera, have been identified. According to grid square system of Turkey which was adopted by Henderson, 68 taxa for A1 square and 24 taxa for A2 square are new records. Among them, Fissidens curvatus Hornsch., Thamnobryum neckeroides (Hook.) E.Lawton, Plagiothecium neckeroideum Schimp. and Riccia beyrichiana Hampe were recorded for the second time in Turkey. In addition, the present paper reports the first records of Cephaloziella massalongi (Spruce) Müll.Frib, which has been classified as rare (R) in the Red data book of European bryophytes, and Scapania scandica (Arnell et H.Buch) Macvicar in Turkey. Some morphological features, the ecological characteristics and the distribution map of the species are given, along with photographs of diagnostic details.
AtıfScopus2OpenAlex14İncele - MakaleYayıncıda açık erişim2018Scopus SJRQ3Spectral, thermal and antimicrobial properties of novel mixed ligand-metal complexes derived from saccharinate complexes and azo dye ligand
Adiguzel, Ragip; Turan, Nevin; Buldurun, Kenan; Korkoca, Hanifi
Background and Objective: Saccharin and saccharinate (sac) complexes and its anion have critical importance with biological, biochemical and pharmacological properties. The main objective of this study was to synthesize the novel mixed ligand complexes from the complexes [M(Sac)2(H2O)4]·2H2O [M: Mn(II), Co(II), Ni(II), Cu(II) and Cd(II)] with a second neutral ligand [L:(mmppa): 5-Methyl-4-(4-methylphenylazo)-2H-pyrazole-3-ylamine]. Methodology: The structures of the complexes were characterized by elemental analysis, magnetic susceptibility, FT-IR, mass and electronic spectral studies and thermal analysis. Antimicrobial (antibacterial and anticandidal) activities of the complexes were tested against Enterococcus faecalis ATCC 51299, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 35218, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 700603 and Candida albicans ATCC 64548. Results: According to the experimental results, it was determined that in Mn(II), Co(II) and Cd(II) complexes, two coordinated H2O molecules are replaced with two neutral ligands, on the other hand, in Ni(II) and Cu(II) complexes, all coordinated H2O molecules are replaced with four neutral ligands. It was established that the second neutral ligand was coordinated to the metal ions via nitrogen atom of-NH2 group in pyrazole ring. In antimicrobial activity, study was determined to occur significant inhibition zones (20-24 mm) against Candida albicans ATCC 64548 strain. Conclusion: As a result, mononuclear and monomeric structure in octahedral geometry including both saccharin and azo dye ligands were synthesized and their characterizations were accomplished. The result of this study shows that novel mixed ligand-saccharinate complexes can be utilized for the development of anticandidal agents.
AtıfScopus11WoS10OpenAlex11İncele - MakaleYalnız künye2019Scopus SJRQ1Measuring development levels of NUTS-2 regions in Turkey based on capabilities approach and multi-criteria decision-making
Ozdemir, Yasal; Gul, Muhammet
Regional development seeks to better understand the issues and problems facing the regions because of the contemporary economic and social changes, including the formulation of territorial policies accordingly. In Turkey, in order to coordinate regional development, 26 regional development agencies were founded relating to the nomenclature of territorial units for statistics-2 (NUTS-2) regions. Since these regions have different development levels, it is useful for stakeholders to determine performance measures related to the regional development and propose a ranking model among these regions to provide a balance in delivering financial support mechanisms. Therefore, in this study, an iterative multi-criteria decision-making (MCDM) model is proposed. Firstly, Pythagorean Fuzzy Analytic Hierarchy Process (PFAHP) is used to assign weights to indicators of well-being index for provinces (WiP) in Turkey. Then, a TODIM (an acronym in Portuguese of interactive and multiple attribute decision making) based ranking model for 26 regions was applied. Also, this model takes capabilities and well-being approach into account differently from traditional utilitarian development models which take only some macro-economic and financial parameters. In order to do this, the model uses data from WiP. On conclusion, a comparative ranking projection with two other MCDM methods and WiP is provided and an effective and broader point of view was gained by the regional development performance measuring model.
AtıfScopus31WoS25OpenAlex34İncele - MakaleYalnız künye2020Scopus SJRQ3Potential anesthetic properties of bay leaf (Laurus nobilis) essential oil compared with 2-phenoxyethanol on blue dolphin cichlid, cyrtocara moorii
Kizak, Volkan; Can, Erkan; Seyhaneyildiz Can, Şafak
The efficacy of Bay leaf (Laurus nobilis) essential oil (LnEO) as a herbal anesthetic agent was evaluated with 2-Phenoxyethanol (2-PE) in Blue Dolphin Cichlid, Cyrtocara moorii. Fish were exposed to different anesthetic concentrations and the lowest effective concentrations (LECs) were determined according to deep anesthesia (AD<3 min) and full recovery (RF<5 min) times. LnEO showed anesthetic properties, and all applied concentrations of both agents induced AD in C. moorii. The LECs of LnEO and 2-PE for C. moorii were determined as 800 µl L-1 (AD; RF → 183 ± 6.3 s; 191 ± 2.6 s) and 600 µl L-1 (AD; RF → 171 ± 3.2 s; 239 ± 4.9 s), respectively. Significant differences were found between anesthetic agents in terms of deep anesthesia and full recovery times for the same concentrations (p<0.05). Induction and recovery times decreased with increasing in LnEO concentrations. On the other hand, anesthesia times were decreased with increasing of 2-PE concentrations, while recovery times increased. Induction and recovery times for LnEO were significantly dependent on concentrations and positive relationships were recorded between AD and RF, whereas the relationship was negative in 2-PE. Bay leaf essential oil has not been used as an anesthetic agent in fish until now. Our results showed that LnEO was an effective anesthetic agent with some minor side effects on C. moorii.
AtıfScopus2OpenAlex2İncele - MakaleYalnız künye2020Scopus SJRQ1Assessment of occupational risks from human health and environmental perspectives: a new integrated approach and its application using fuzzy BWM and fuzzy MAIRCA
Gul, Muhammet; Ak, M. Fatih
Occupational safety issues encountered in the worksite environment are the issues that companies should consider in improving their operations with a view to human health and environmental awareness. Many methods with different rationales have been existed in the literature to prioritize hazards according to their risk levels and to mitigate their consequences. In this study, a new model is developed for occupational risk assessment by merging two well-known multi-criteria decision-making methods named best and worst method (BWM) and multi attribute ideal real comparative analysis (MAIRCA) under fuzzy environment. The proposed model differentiates from other similar models by three aspects. First, it considers severity of a hazard and its associated risk from the human and environmental riskiness perspectives. Secondly, it applies fuzzy BWM (F-BWM) to calculate the relative importance of three risk factors named as “probability, frequency and severity” of traditional Fine–Kinney method. Thirdly, it applies fuzzy MAIRCA (F-MAIRCA) to rank hazards according to their risk level using importance values obtained by F-BWM. To show applicability of the approach, a case study of risk assessment in a marble factory is fulfilled. Additionally, a number of validation studies including benchmarking analysis with fuzzy VIKOR and fuzzy TOPSIS methods; a sensitivity analysis by varying importance weights of risk factors are carried out to highlight the solidity of the proposed approach.
AtıfScopus80WoS70İncele - MakaleYalnız künye2020Scopus SJRQ1Teaching Shakespeare digitally: the Turkish experience
Öğütcü, Murat
Although teaching Shakespeare in Turkey naturally creates barriers of language, space and time, the use of digital humanities helped me to overcome these obstacles. My experiences at Hacettepe University, Ankara, Turkey, showed me that combining conventional methods of teaching Shakespeare in Turkey with digital tools helps to familiarise students with Shakespeare's plays both in the Early Modern English and Modern Turkish contexts. To motivate students to study Shakespeare's plays within and without the classroom environment, I used conventional methods like teacher-led assignments and methods including the use of social media and social projects which were then unconventional.
AtıfScopus4WoS3İncele - MakaleYalnız künye2018Scopus SJRQ2Survey of wild food plants for human consumption in Karaisalı (Adana-Turkey)
Güneş, Suzan; Savran, Ahmet; Paksoy, Mehmet Yavuz; Çakılcıoğlu, Uğur
This study identified not only the wild plants collected for food purposes by local people of Karaisalı County in the Mediterranean Region, but also the uses and local names of these plants. Field study was carried out over a period of approximately 2 years (2008–2010). During this period, 76 vascular plant specimens were collected. Demographic characteristics of participants, vernacular plant names, edible parts and utilization methods of the plants were investigated and recorded. In the scope of the study, the plant species were collected; herbarium materials were prepared; and the specimens were entitled. In addition, the use-value of the species was determined and was calculated for the food plants included in the study. A total of 76 food plants belonging to 30 families were identified in the region. The most common families are: Asteraceae (12 plants), Lamiaceae (10 plants), Rosaceae (9 plants), Polygonaceae (5 plants), Apiaceae (4 plants). The study showed that the plants used are either eaten raw or ripe, cooked as vegetable dish, consumed as jam, consumed as coffee, as spice, frying in oil or baked to be served as dishes such as stew, pie made by roasting the leaves, prepared sour souce is added to food. During this ethnobotanical research, it was verified that wild edible plants play an important role in diet in Karaisalı. We examined whether the plants used had literature records or not. Varied usages of a number of plants have been recorded for the first time by us. Tree of those plant are endemic. The plant flora of Karaisalı is threatened by such factors as grazing, expansion of new agricultural lands, and unsustainable picking of plants to generate income. Steps should be taken immediately to ensure the inclusion of relevant flora within conservation designations.
AtıfScopus40İncele - MakaleYalnız künye2021Scopus SJRQ1Investigation of Some Metal Accumulation Ability of Phragmites australis from Poultry Slaughterhouse Wastewaters
Topal, Murat
In this study, the bioaccumulation of some metals by Phragmites australis plants exposed to poultry slaughterhouse wastewater was investigated. For this aim, Mo, As, Cd, Se, Cu, Zn, Cr, Ba, Ti, Fe, Al, and Mn metals were determined in slaughterhouse wastewaters, P. australis plants, and sediment samples. The uptake of metals by P. australis was investigated. Also, BCF and TF values were calculated and compared with reference plant values. The maximum metal accumulation in P. australis plants exposed to poultry slaughterhouse wastewaters was 5900% for Al and 33.5% for Mn when compared with reference plant values. According to the BCF values, P. australis was bioaccumulative for Mo, Se, and Al. As a result, it was determined that P. australis plant can be used in the remediation of metals found in poultry slaughterhouse wastewaters and would be a good accumulator.
AtıfScopus2WoS1OpenAlex4İncele - MakaleYalnız künye2020Scopus SJRQ1Mechanical, thermal, and morphological properties of powder coating waste reinforced acetal copolymer
Kismet, Yilmaz; Wagner, Manfred H.
The present study investigates the individual effects of three different thermosetting waste materials, used as fillers, on the mechanical, thermal and flow properties of acetal copolymers (POM). Different amounts ranging from 5% to 30% by weight of hydrolyzed powder coating recyclates were mixed as filler material in POM. The matrix and the fillers were first dry-mixed and then compounds were prepared through melt extrusion. The resulting compounds were cooled, granulated, and then standard tensile test bars were produced through use of an injection-molding machine. We investigated the mechanical and thermal properties of test specimens, and tensile strength, bending strength and impact strength were evaluated as a function of type and amount of filler material in the POM matrix. In addition, the change in melt flow index of POM/filler mixtures was determined, before and after extrusion. Furthermore, the morphology of the specimens was examined via electron microscopy. The results of this investigation are encouraging and present an innovative approach to reutilize hydrolyzed electrostatic powder coating wastes with thermoset structures as fillers in acetal copolymers.
AtıfScopus10WoS8OpenAlex13İncele - MakaleYalnız künye2020Scopus SJRQ1Geochemical characteristics of the adakite-like Dodurga Pluton (Central Pontides, N Turkey): implications for Middle Triassic continental arc magmatism in southern Black Sea region
Çimen, Okay
The tracing of Triassic arc magmatism is much-debated for a long time along the Sakarya Composite Terrane in Turkey and the southern Black Sea region. The Dodurga Pluton is located in the Central Pontides (N Turkey), one of the most complicated regions around the Black Sea region, and represents the first documented middle Triassic continental arc in the region. This pluton comprises of dacite porphyry and granodiorite, and displays calc-alkaline signatures, which is in agreement with arc-related and I-type magmas. The PM-normalized multi element and CN-normalized REE patterns are akin to volcanic arc granites, and characterized by LILEs and LREEs enrichments relative to HFSEs and HREEs coupled with negative Nb anomalies, which confirm derivation in a subduction-related tectonic setting. Moreover, the major and trace element systematics of the samples including higher Sr/Y ratios (22.93–101.36) and lower Yb contents (0.31–1.30 ppm) are consistent with those from adakitic melts compared to classical arc magmas. Therefore, this pluton also represents the first middle Triassic adakite-like magmatic occurrence in Turkey. Overall petrographic and geochemical signatures reported here indicate that the Dodurga Pluton might have been derived from a heterogeneous source, mixed by melts from subducted oceanic slab and lower continental crust in an active continental margin. Based on the Tethyan evolution in the Anatolian realm, three geodynamic scenarios are possible for its formation, and it could have been formed as a result of northward or southward-subduction of the Paleotethys Ocean or northward-subduction of the northern branch of Neotethys Ocean during the middle Triassic.
AtıfScopus8WoS8OpenAlex4İncele - MakaleYalnız künye2019Scopus SJRQ2Modelling cadmium bioaccumulation in Gammarus pulex by using experimental design approach
Serdar, Osman; Pala, Aysegul; Ince, Muharrem; Onal, Ali
Recently, although dynamic approaches have been used increasingly to describe metal bioaccumulation in aquatic organisms, the validation of such laboratory-derived modelling is rarely assessed under environmental conditions. The present study aims to evaluate and verify statistical and mathematical models for the bioaccumulation of cadmium (Cd) and to evaluate the suitability of Gammarus pulex as a biomonitor for Cd. To optimise Cd2+ ion bioaccumulation conditions a Box–Behnken design was used and whether G. pulex can be used as an estimated tool to assess aquatic quality was investigated. A Box–Behnken experimental design combined with response surface modelling (RSM) was employed for Cd2+ bioaccumulation in G. pulex. Independent variables including temperature, contact time and Cd2+ ion concentration significance and their interactions were tested using analysis of variance. The selected variables’ optimum values were obtained by solving the quadratic regression model along with by analysing the response surface contour plots. Based on Box–Behnken design, the applied model is significant because model F-value and R2 were obtained as 5121.49, 0.9998, respectively. Bioaccumulation of Cd amount was analysed using electrothermal atomic absorption spectrophotometer. The obtained data suggest that G. pulex can be evaluated as Cd biomonitor.
AtıfScopus3WoS3OpenAlex6İncele - MakaleAçık Erişim2020Scopus SJRQ1Evaluation of hospital disaster preparedness by a multi-criteria decision making approach: The case of Turkish hospitals
Ortiz-Barrios, Miguel; Gul, Muhammet; López-Meza, Pedro; Yucesan, Melih; Navarro-Jiménez, Eduardo
Considering the unexpected emergence of natural and man-made disasters over the world and Turkey, the importance of preparedness of hospitals, which are the first reference points for people to get healthcare services, becomes clear. Determining the level of disaster preparedness of hospitals is an important and necessary issue. This is because identifying hospitals with low level of preparedness is crucial for disaster preparedness planning. In this study, a hybrid fuzzy decision making model was proposed to evaluate the disaster preparedness of hospitals. This model was developed using fuzzy analytic hierarchy process (FAHP)-fuzzy decision making trial and evaluation laboratory (FDEMATEL)-technique for order preference by similarity to ideal solutions (TOPSIS) techniques and aimed to determine a ranking for hospital disaster preparedness. FAHP is used to determine weights of six main criteria (including hospital buildings, equipment, communication, transportation, personnel, flexibility) and a total of thirty-six sub-criteria regarding disaster preparedness. At the same time, FDEMATEL is applied to uncover the interdependence between criteria and sub-criteria. Finally, TOPSIS is used to obtain ranking of hospitals. To provide inputs for TOPSIS implementation, some key performance indicators are established and related data is gathered by the aid of experts from the assessed hospitals. A case study considering 4 hospitals from the Turkish healthcare sector was used to demonstrate the proposed approach. The results evidenced that Personnel is the most important factor (global weight = 0.280) when evaluating the hospital preparedness while Flexibility has the greatest prominence (c + r = 23.09).
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İncele - MakaleAçık Erişim2019Ghanaian Mangrove Wetland Endophytic Fungus, Penicillium herquei strain BRS2A-AR produces (9Z, 11E)-13-oxooctadeca-9,11-dienoic acid with activity against Trichomonas mobilensis
Hayibor, Kennedy; Kwain, Samuel; Osei, Enoch; Nartey, Adwoa Padiki; Tetevi, Gilbert Mawuli; Owusu, Kofi Baffour-Awuah; Camas, Mustafa; Camas, Anil Sazak; Kyeremeh, Kwaku
Sub-Sahara Africa is burdened with a high incidence of parasitic infections, including schistosomiasis, trypanosomiasis, trichomoniasis, and leishmaniasis. Currently, there is a rapid widespread development of resistance to prescription drugs for these neglected diseases. Microbes provide the largest chemical and biological diversity in drug discovery screening programs; therefore, our project seeks to explore microbes in the sub-region for new drugs. The oxylipin (9Z,11E)-13-oxooctadeca-9,11-dienoic acid (1) was isolated from the Ghanaian endophytic fungus, Penicillium herquei strain BRS2A-AR obtained from the leaves of a Laguncularia racemosa tree growing on the banks of the River Butre in the Western Regional wetlands of Ghana. Compound 1 was isolated on reverse phase HPLC at tR of 34.3 minutes. The structure of compound 1 was confirmed by a combination of mass spectrometry, 1D and 2D-NMR techniques. Compound 1 showed minimal antiparasitic activity when tested against Plasmodium falciparum 3d7 (IC50>100µM; aretesunate, IC50 36nm), Trypanosoma brucei brucei (IC50>100µM; Coptis japonica, IC50 8.20µM), Leishmani donovani (IC50>100µM; amphotericin B, IC50 0.32µM) and Leishmania major (IC50>100µM; amphotericin B, IC50 0.31µM). Compound 1 produced IC50 of 44.47µM when tested against Trichomonas mobilensis with metronidazole (IC50 5.20µM) as standard. These results show the potential to further engineer the structure of compound 1 into a potent anti-Trichomonas scaffold.
AtıfScopus13OpenAlex13İncele - MakaleAçık Erişim2018Scopus SJRQ4The effect of hygrothermal aging on the glass and carbon reinforced epoxy composites for different stacking sequences
Dogan, Akar; Arman, Yusuf
The present paper examines the effects of hygrothermal aging on the reinforced epoxy composites. The roles of reinforcement types and stacking sequence on the mechanical properties of composites under hygrothermal aging are investigated. Four different composite materials with different stacking sequence were produced. Unidirectional E-glass and carbon fabrics with an areal density 300 gr/m2 as reinforcement and epoxy as matrix were used. Composites were manufactured using vacuum-assisted resin infusion molding. In order to determine the mechanical properties of the composites, specimens were prepared according to the ASTM standards. The aging process was carried out in climatic test cabin at a temperature of 90oC and a humidity of 90%. As a result of the tests, while the tensile strength of the glass reinforced composites decreased with aging time, no significant change was observed for carbon and hybrid composites. On the other hand, the tensile strength decreased in the transverse direction for all types of composites. XPS analysis was used to understand the distribution of atoms on the surface of specimens.
AtıfScopus22WoS19OpenAlex23İncele
