Kastamonu Üniversitesi
  • Kastamonu, Turkey
Recent publications
Mathematical understanding is considered to have a multidimensional structure and an important place in mathematics teaching. The focus of the assessments in mathematics courses is on the multidimensional evaluation of mathematical understanding. However, a review of related literature shows the lack of studies on assessing mathematical understanding using multidimensional structures. For this reason, the current study attempted to develop a scale for assessing teachers' mathematical understanding. The instrument development model, an exploratory sequential mixed methods model, has been used in line with this aim during the scale’s development. The study’s qualitative data were collected through a mathematical understanding assessment form and semi-structured interviews developed by the authors. Qualitative data emerged from 17 mathematics teachers working in middle schools or high schools who were determined using the easy access sampling method. Five themes were arrived at from the content analysis with the obtained qualitative data: applying rules, transferring knowledge, generating questions and solutions, generalizing, and exploring information. The initial version of the instrument prepared in accordance with these themes was applied to a total of 501 primary school mathematics preservice teachers from nine different universities in Turkey during the 2018 spring semester. Cronbach’s alpha (α) assessment was performed for the scale’s reliability. Item-total correlations were calculated as item statistics. Exploratory and confirmatory factor analyses were applied to test the scale’s construct validity. The item loadings for the scale were seen to vary between.431 and.759 in this process; the reliability of the sub-dimensions and the scale’s fit indices were seen to be at sufficient levels. As a result of all the performed analyses, a scale form consisting of 21 items and five sub-dimension was obtained. The results from the scale development process show that the preservice teachers took into account the factor of transferring knowledge the most and the factor of producing questions and solution pathways the least.
Understanding the relative contributions of different spawning habitats to adult fish populations is central to effective fisheries management and species conservation. The Tarek (Alburnus tarichi) is an adfluvial cyprinid that is endemic to the alkaline-saline waters of Lake Van, Turkey. Tarek are culturally and economically important to the region, and also threatened by anthropogenic impacts, including poaching, dams, water diversions, pollution, and habitat degradation. Here we analyzed otoliths from 120 adult fish caught in Lake Van in 2016–2017 to reconstruct the age structure and natal origins of this Tarek population. Ages ranged from 2 to 10 years, with most fish belonging to the 2011–2014 cohorts (age 3–5). We analyzed strontium isotope ratios from water samples collected in 2016 and 2018 to build a baseline map and then used linear discriminant function analysis to classify Tarek to their likely natal origins. We found that adult Tarek originated from at least 7 different major tributaries of Lake Van, with a majority of fish originating from the Gevas and Engil tributaries in the south. Furthermore, the relative contributions of fish from each tributary varied among years, suggesting that a mosaic of natal habitats may be important for population stability. These results suggest that protection of all Lake Van watersheds from anthropogenic disturbance could be valuable for maintaining the stability of the Lake Van Tarek population and fishery.
The effects of alternating and constant magnetic fields on heat transfer characteristics of nanofluid flow in a dimpled tube have not been investigated either numerically or experimentally. In this context, the hydrothermal performance of Fe 3 O 4 /water (1.0 vol%) ferronanofluid flow in the dimpled tube (P/d = 3.75 and 11.25) has been examined under laminar flow regime (1131 ≤ Re≤2102) in this experimental study. While the magnitudes of magnetic fields are 0.16 T, the alternating magnetic field is utilized with square wave type at frequencies of 1, 2, 5 Hz. It is concluded that the dimpled tube causes up to 78.4% increase in Nusselt number compared to the smooth tube, while up to 118.9% increase in Darcy friction factor. The constant magnetic field enhances the Nusselt number up to 4.04% compared to the absence of a magnetic field using ferronanofluid as a working fluid. Higher frequencies of the alternating magnetic field results in higher thermal performance. Alternating magnetic field effect with f = 5 Hz offers 37.3% Nusselt number enhancement compared to the constant magnetic field effect in all tube geometries. It was also seen that P/d = 11.25 gives the highest Performance Evaluation Criteria while the magnetic field effect decreases it in all tube geometries.
Thermal energy storage (TES) through the use of construction materials incorporating phase change materials (PCMs) can prevent temperature fluctuations and allow energy saving in buildings. With this background, aim of this work is to develop new kind eco-friendly foam concrete (FC) containing lauryl alcohol (LA)-impregnated rice husk ash (RHA) composite PCM. RHA, an agricultural waste product, was used as a carrier material to eliminate the leakage problem of LA. Thus, leakage-free composite PCM (LFCPCM) was first prepared, and then such an RHA-based LFCPCM was integrated with cementitious FC for the first time in this study. The fabricated novel FCs were subjected to detailed examinations in terms of morphological, mechanical, physical, and TES properties. The DSC outcomes indicated that LFCPCM showed melting phase change at 19.97 °C and had a latent heat TES capacity of 99.60 J/g, while the PCM into FC-LFCPCM50 melted at 20.01 °C and had a latent heat TES capacity of 16.55 J/g. Solar thermoregulation performance test results revealed that compared to the reference FC (RFC), the FC-LFCPCM50 wallboard provided about 1.29 °C warmer indoor temperature during the cold weather hours, whereas the room center temperature was about 2.8 °C lower during the daytime in hot weather conditions. An energy-saving of 14.28 kW h per day is obtained by FC-LFCPCM50 wallboard. The carbon emission equivalences of this energy-saving amount account for 38 kg-CO2, 37.7 kg-CO2, and 6.19 kg-CO2 for coal, natural gas, and electricity, respectively. These results suggest that the fabricated novel FC-LFCPCM50 can be effectively evaluated as green building materials for thermo-regulation and energy saving of buildings.
Noting the growing literature on relational bibliometrics and prevailing methodological challenges in hospitality and tourism research – inadequate bibliometric-focused structure and methodological transparency – this study contributes to knowledge about applicable analytical procedures. The authors uncover methodological issues by content analyzing 85 relational bibliometric articles published in 19 hospitality and tourism journals. The findings provide a basis for best practice recommendations. Four guiding principles are proposed for the scholarly deployment of relational bibliometrics, namely: (1) using multiple relational techniques to ensure a rich and comprehensive coverage of the pertinent field, (2) providing sufficient methodological disclosure, particularly language selection, data extraction from the applicable sampling, data cleaning and supplemental materials provided, (3) following a best practice work flow, including relational study methodologies, and (4) ensuring methodological adherence to three desired attributes – structured, comprehensive and transparent. The latter can potentially improve the thoroughness, clarity, and trustworthiness of future studies. The study concludes with a discussion of the findings, and a future research agenda which presents significant insights offering encouragement for bibliometric analyses, as well as acknowledging potential limitations.
To follow resource conservation, the production of optimized and sustainable structures through the use of insulating materials such as foam concrete has become a trend in construction industry. Although foam concrete has numerous benefits, the larger use of Portland cement in its mixture and its relatively low thermo-durability properties because of the low quantity of solid materials are major concerns, challenging its large applications. In that respect, this research evaluates the use of recycled fine concrete aggregate, limestone and bottom ash sand as the main aggregate materials to evaluate the physical, mechanical and thermo-durability properties of foam concrete. To that end, 25 mixes have been produced and a comprehensive series of tests including flowability, compressive and flexural strength, water absorption, apparent porosity, drying shrinkage, sorptivity, abrasion resistance, thermal conductivity, along with the effect of elevated temperature and its respective cooling regime on foam concretes have been conducted in this study. On this basis, it is found that foam concretes manufactured with bottom ash and recycled fine aggregates develop a considerably lower thermal conductivity values despite being outperformed in physico-mechanical properties by those mixes produced with limestone sand. Nonetheless, the inclusion of bottom ash sand is found to produce foam concretes with a comparable physico-mechanical and thermo-durability properties to mixes with limestone. The results of this study are found to point to the suitability of utilizing alternative fine-sized aggregates such as recycled fine aggregates along with bottom ash sand in the production of foam concrete without compromising the insulating properties.
The belief in a just world is a mindset that facilitates our ability to cope with life events by fostering a sense of control. Nursing students' beliefs in a just world and their attitudes towards death can influence how they will care for their patients. The intent of this descriptive and cross-sectional study was to examine the relationship between nursing students and their beliefs in a just world and their attitudes towards death. Quantitative data was collected using the Descriptive Characteristics Questionnaire, the Belief in a Just World Scale, and the Attitude towards Death Scale. The sample included 270 participants. It was determined that as nursing students’ beliefs in a just world increased, they developed positive attitudes towards death. It is recommended that discussions on the subject should be included in the education curriculum to increase nursing students' beliefs in a just world and their awareness about death.
This study investigates new soliton-type solutions to the new generalized KdV (ngKdv) equation. For this purpose, the homogeneous balance method is used to create Auto-Bäcklund transformations of the regarded equation and with the help of the transformations, abundant exact and explicit solutions have been found. We found complexiton solutions to the dealt equation by using the extended transformed rational function technique. We have also given the 3D graphics of the obtained solutions.
Carbapenems are the most effective agents for treating clinical P. aeruginosa (PsA) infections. During an infection, a quorum-sensing (QS) system and its regulating virulence genes have a great role. The aim of the study was to detect the presence of a las and rhl QS system and related virulence genes, biofilm formation and a class 1 (Cls1) integron. A total of 52 carbapenem-resistant PsA (CRPsA) isolates obtained from Kastamonu, Turkey was analyzed. For the isolation and identification of CRPsA isolates, a conventional culture method, an automated VITEK-2 compact system, and oprL gene-based molecular technique were applied. The two QS system genes were detected in 51 (98.1%), and co-existed of four two QS system genes (lasI/R and rhIl/R genes) were determined in 41 (78.8%) of the isolates. algD, lasB, toxA and aprA genes were detected in between 46.1 and 88.5%, and co-existence of four two QS system genes with four virulence genes were detected in 40.4% of the isolates. Biofilm formation using microtiter plate assay and slime production using Congo Red Agar and Cls1 integron were determined in 84.6%, 67.3% and 51.9% of the isolates, respectively. According to statistical analyses results, there was a significant positive correlation (p < .10) between the las and the rhl systems and a strongly and positive correlation (p < .01 or p < .05) between the rhl system—three virulence genes and slime production—and among some virulence genes. In conclusion, the CRPsA isolates tested in the study are highly virulent and QS systems have a significant role in pathogenesis.
The change in soil quality due to soil pollution significantly affects the ecosystem. The pollutants in the air also pass to the soil after a while, and therefore the soil is also the environment that best reflects the pollution level. Heavy metals are among soil and environmental pollutants; they are especially notorious because many of them can be toxic to living things even at low concentrations, tend to bioaccumulate in living things, and stay in nature for a long time. Therefore, monitoring heavy metal concentrations is of great importance. In this study, it is aimed to determine and map the Ni and Co pollution with the help of top soils in the city center. Top soil samples were taken from these regions and Ni and Co analyses were made, and the obtained values were evaluated statistically. Additionally, the data were transferred to geographic information systems (GIS) using ArcGIS 10.7 software, and then modeled with the kriging method, one of the interpolation methods, and pollution maps were created. As a result of the study, it was determined that the areas with the highest Ni and Co concentrations were generally located in the center of the study area. This shows that Ni and Co pollution increases in areas with high levels of human activities.
In addition to the facilities historical sites offer to city-dwellers, they play an important role in shaping a city. Over time, these places experience change through restoration, and changes are observed in plant presence and plant composition. This situation causes alienation between people-places. Plants represent many concepts with both their physical features and the meaning given to them by society from past to present. This study investigates the evaluation of plants as elements strengthening the meaning of historical places. Among the 28 plants most frequently used and best recognized by the public, the plants identified with historical places in İstanbul were revealed with this study. Additionally, the presence of a correlation between these plants, categorized according to characteristic properties and size, with the historical places was examined and which plant categories were associated with which historical places. In order to reveal the plant-place identification, a survey study was completed with a total of 500 people, including 100 primary school students, 100 middle school students, 100 high school students, 100 university students and 100 university graduates in İstanbul. In conclusion, for historical places, the Platanus, Pinus, Rosa, Salix and Cercis species came to the forefront with broad-leaved and conifer trees and flowering bushes chosen in terms of characteristic properties, while trees and shrubs were chosen in terms of size. Additionally, chi-square analysis revealed that educational level and gender differences were effective on plant-place identification. Thus, plants were determined to be used as effective identifying markers for places. Article HighlightsWe determined the assessment of plants as elements strengthening the meaning of placesWe revealed the plant-historical place identificationWe revealed that Platanus, Pinus, Rosa, Salix and Cercis species are identified with historical places.We revealed that broad-leaved and conifer trees and flowering bushes are preferred for historical places in terms of characteristic properties.We revealed that trees and shrubs are preferred for historical places in terms of size. We determined the assessment of plants as elements strengthening the meaning of places We revealed the plant-historical place identification We revealed that Platanus, Pinus, Rosa, Salix and Cercis species are identified with historical places. We revealed that broad-leaved and conifer trees and flowering bushes are preferred for historical places in terms of characteristic properties. We revealed that trees and shrubs are preferred for historical places in terms of size.
Fekete, Jordán and Kaszanitzky (Graphs Combin 31:585–599, 2015) characterised the graphs which can be realised as 2-dimensional, infinitesimally rigid, bar-joint frameworks in which two given vertices are coincident. We formulate a conjecture which would extend their characterisation to an arbitrary set T of vertices and verify our conjecture when |T|=3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$|T|=3$$\end{document}.
The majority of existing research have repeatedly embedded problem solving and problem posing in the assessment of students’ mathematical creativity, but there is a lack of studies focusing on the relationship between these two regarding mathematical creativity. In this study, we aimed to examine whether there is a relationship between the constructs of creative ability in mathematical problem posing (CAMPP) and creative ability in mathematical problem solving (CAMPS) and to examine the structure of this relationship through confirmatory factor analysis. The participants were 187 sixth-grade students in Turkey. Data were collected by two creative ability tests, namely CAMPP and CAMPS. We used a rubric to characterize mathematical creativity by interpreting scores of in the dimensions of creative ability (fluency, flexibility, and originality) in the context of problem solving and problem posing. The findings showed that mathematical problem posing and mathematical problem solving both constituted the constructs of CAMPP and CAMPS respectively, based on the dimensions of creative ability. Moreover, the structure of the relationship between the constructs of CAMPP and CAMPS can be explained better with a constituted higher-order factor of Creative Ability in Mathematics (CAM) rather than placing one of these factors as a sub-construct under the other one.
In this study, the effects of climate factors such as temperature, moisture and precipitation on soil moisture in Scots Pine (Pinus sylvestris L.) stands with different crown closure were investigated. As a result of the study, it was revealed whether soil moisture values differ in Scots Pine (Pinus sylvestris L.) stands in the same aspect, depth and slope group. Study area is Çamlıdere district of Ankara province. The effects of some climate elements (air temperature, air humidity and rainfall) on the soil moisture values in the areas where the Scots Pine in different crown closures were investigated in the Fuat Adalı Research Forest. We took 6 different forest plots in the same depth, slope and aspect group. According to the results obtained from the measurements made between September 2014 and October 2016, the average soil moisture values was found 23.91% in Open forest plot (POF), 26.84% in P1 plot (Low crown closure scots pine stand), 16.72% in P2 (Medium crown closure scots pine stand), 16.00% in P3 (Full crown closure scots pine stand), 30.79% in Simulation plot (PS) and 28.62% in Erosion plot (PE). It was determined that the lowest average soil moisture values were found in the P2 and P3 plots and the highest soil moisture values were in the PS and PE plots.
The adsorption analysis of some organic inhibitors consisting of Pyridine, 2-Methylpyridine, 3-Methylpyridine, 4-Methylpyridine and 2, 4-Dimethylpyridine onto aluminum (111) metal surface based on optimized coordination of binding on the Al (111) metal surface has been accomplished. In this research, the ONIOM approach has been performed with a three-layered level of high level of DFT method using 6–31 + G* and LANL2DZ basis sets by the physico-chemical software of Gaussian 09, a medium semi-active part that includes important electronic contributions, and a low level part that has been handled using MM2 force field approaches. The physico-chemical properties of adsorption -surface complexes are one of the principal parameters for determining and choosing the adsorption. The characteristic of the metal (111)-lattice in solutions of hydrochloric acid and nitric acid by some heterocyclic compounds including Pyridine, 2-Methylpyridine, 3-Methylpyridine, 4-Methylpyridine and 2, 4-Dimethylpyridine has been estimated through NMR and IR results. Nitrogen atom in pyridine cycle with the most influence on the NMR shielding of isotropic and anisotropic tensors has leaded us toward the active site for adsorption onto Al (111) surface. Moreover, the IR spectrum for each of these heterocyclic compounds consisting of Pyridine, 2-Methylpyridine, 3-Methylpyridine, 4-Methylpyridine and 2, 4-Dimethylpyridine has been indicted in the frequency range between 500 cm⁻¹ and 3250 cm⁻¹ by the strongest peaks about 550 cm⁻¹, 1500 cm⁻¹, and 3250 cm⁻¹. In this work, the co-adsorption of Cl⁻ / NO3⁻ anions with H⁺ads cation onto aluminum-surface through the optimized adsorption energy for these compounds on a top site of metal (111) has been accomplished. Our calculations have illustrated that the adsorption stability energy of pyridine and its derivatives depends on the structure, the adsorption site and the acidic media.
We investigated death anxiety among parents of children with disabilities and its associations with coping attitudes and psycho-demographic factors. Surveys were administered to 382 parents of children who possess a severe disability and data were analyzed via descriptive and inferential statistics. Findings revealed that parents experienced high levels of death anxiety; the level of death anxiety changed according to some psycho-demographic factors, such as external support, type of disability, and death-related beliefs; and death anxiety was significantly explained by demographic variables, death-related thoughts, and experiences, and adaptive and maladaptive coping attitudes.
This study aimed to evaluate the human health risk posed by potentially toxic elements (PTEs) in 59 bottled mineral water (BMW) samples of 25 different brands marketed in Turkey. The concentrations of Ag, Al, As, Cd, Cr, Co, Cu, Fe, Mn, Ni, and Pb in the BMW samples were analyzed using an ICP-OES and compared with maximum allowable concentrations (MACs). A higher concentration of As than MAC was detected in five BMW samples. The concentrations of Cd, Pb, Cr, Ni, and Al in the majority of BMW samples are higher than the MACs. The human health risk was evaluated for adults estimating non-carcinogenic risk index (HI), incremental lifetime cancer risk (ILCR) and total cancer risk (TCR). All HI values estimated for PTEs in BMW samples are less than one, except for one sample. ILCR values for Cd in approximately half of the BMW samples are above the upper limit.
Introduction:To compare the sleeping habits of children who attempt suicide with healthy children, to detect disorders, to identify children with risk factors and to take measures to prevent suicide attempts.Methods:Patients who applied to the Pediatric Emergency Service of University of Health Sciences Turkey, Ankara Training and Research Hospital between April 2019 and April 2020 with suicide attempt were included in the study group, and healthy children who had never attempted suicide before were included in the control group. It has been done prospectively and cross-sectionally. The data were analyzed using SPSS 18.0 package program and Microsoft Office Excel 2003 program.Results:The total number of patients participating in our study was 248, 138 (55.6%) of whom had attempted suicide, 110 (44.4%) were from the control group who did not attempt suicide for any other reason. Of the patients in the group who attempted suicide, 102 (73.9%) were female, 36 (26.1%) were male, 67 (60.9%) of the patients in the control group were female, and 43 (39.1%) were male. The median age of the patients in the group who attempted suicide was 16 (minimum: 13, maximum: 18), and the median age of the patients in the control group was 16 (minimum: 12, maximum: 18). Social and physical problems were more common in the group who attempted suicide than in the control group (p=0.001, p=0.004). In the sleep habits questionnaire applied to the patients; the patients in the group who attempted suicide had more problems falling asleep, frequent waking up, and difficulty in waking up compared to the control group (p=0.001, p=0.047 p=0.003). In addition, daytime sleepiness, change in sleep time, listening to music before sleep, and playing with a mobile phone were higher in the group who attempted suicide compared to the control group (p=0.012, p=0.001 p=0.022, p=0.005). In addition, nightmares, sleepwalking, and snoring were more common in the group who attempted suicide (p=0.046).Conclusion:Suicide attempt is an increasing problem in adolescents, it should be ensured that the risk factors are determined well, the awareness of families and physicians is increased and preventive measures should be taken. It is very important to take sleep problems more seriously in this age group and to convey the importance of this to families.
The present study evaluated the effects of a dietary mix of marine sulphated polysaccharides, named Algimun® (AL), supplementation to gilthead seabream (Sparus aurata) juveniles in terms of growth performance, immune responses, and resistance against Photobacterium damselae sbsp. piscicida. A total of 240 fish (initial mean weight of 6.00 ± 0.03 g) was randomly separated into 12 tanks (400 L, 20 fish per tank) distributed in four replicates. Fish were fed three experimental diets: a basal diet (Control); and a basal diet with two inclusion rates of Algimun®: 3 g/kg (AL0.3) and 5 g/kg (AL0.5) for 30 days before bacterial infection with P. damselae sbsp. piscicida. After a 30-day feeding-period, growth performance was significantly improved in AL0.3 and AL0.5 groups compared to the control group (P < 0.05). AL0.3 and AL0.5 groups showed significantly higher lysozyme activity and myeloperoxidase activity when compared to the control group (P < 0.05). The gene expression of immune mediators (IL-1β, IL-6, IL-10, IL-18, TNF-α, and COX-2) was significantly upregulated in the intestine, spleen and head kidney in AL0.3 and AL0.5 groups when compared to the control group (P < 0.05). Eight days post-challenge, the survival rate against P. damselae sbsp. piscicida was numerically higher in fish within AL0.3 and AL0.5 groups compared to control (+20%). The study findings suggest that marine sulphated polysaccharides (Algimun®) could be used as an immunomodulator in gilthead seabream to support animal's health and boost resistance in case of disease outbreak.
This study provides a bibliometric review of emotion-focused research in the service discipline by examining the main research themes and concepts, conceptual foundations, and the most recent research fields. Six-hundred forty-seven documents on emotions were extracted and examined by performing co-citation and bibliographic coupling analyses as well as qualitative content analysis. Co-citation analysis results show that ‘emotions’ is a defined research area with six fundamental themes; namely, positive customer emotions, emotional reactions to service failure and recovery, measurement of emotions, empirical analysis of emotions, brand love, and customer delight. In addition, various theoretical foundations could be employed in various empirical contexts, among which conservation of resources and social exchange play a great role. An examination of the most recent documents via bibliographic coupling analysis clarifies six appealing research trends and releases various recommendations on the occasions for further investigation to be drawn.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
1,041 members
Gökhan Şen
  • Forestry Economics
Talip Çeter
  • Department of Biology
Ibrahim Akar
  • Gifted Education
Seyma Sengil Akar
  • Department of Elementary Education
Kuzay Kent, 37150, Kastamonu, Turkey