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CLIMATE CHANGE ADAPTATION AND INJUSTICE IN INFORMAL SETTLEMENTS: THE CASE OF EBO TOWN, THE GAMBIA
No full textDiscrete time/cost trade-off project scheduling problem with tardiness bounds - an application to the Ministry of Health in Turkey
No full textWe consider a discrete time/cost trade-off problem with due dates and an upper bound on the total tardiness. Our motivation stems from information technology projects held in the Ministry of Health in Turkey. Our primary objective is to minimise the total cost while obeying the total tardiness bound. We formulate the problem as a mixed integer linear program and propose a heuristic approach that leverages the optimal solutions from the linear programming relaxation of the model. To assess the performances, we conduct tests on instances from relevant literature and the Ministry of Health projects, and report favourable results. We employ the optimal solutions to the constrained optimisation problem to generate the exact non-dominated objective vectors' set with respect to total tardiness and total cost. Additionally, we present an evolutionary algorithm to find an approximate set. The algorithms are demonstrated using the projects of the Ministry of Health in Turkey
Surrogate model based optimization of variable stiffness composite wingbox for improved buckling load with manufacturing and failure constraints
No full textThe buckling load of a wingbox is maximized by applying different automatic fiber placement (AFP) strategies on the skins of the wing having NACA 4412 airfoil profile. Specifically, the effect of single, dual and three region application of AFP on the optimal buckling load is studied to provide an outlook on the improvement of the optimal buckling load by increasing the number of skin panels, between rib stations, over which distinct reference fiber path definitions are made. Buckling load optimizations with manufacturing and failure constraints are performed via two different metaheuristic optimization algorithms to ensure that the global optimum reference fiber paths are obtained. For computational efficiency, separate radial basis function based surrogate models are generated for the buckling and the failure analysis. Our results show that the application of AFP separately with distinct reference fiber path definitions in each skin panel between the rib stations, the buckling load can be improved compared to the application of the AFP to a larger section of the wing skin. For the wingbox studied, compared to the wing with quasi-isotropic skins, 94% increase in the local buckling load of the root panel is obtained with the three region AFP application
Motivation And Barriers of Pre-Service Science Teachers About Outdoor Education
No full textThe purpose of the present study was to investigate pre-service science teachers’ (PST) motivation and barriers about outdoor education (OE). 181 pre-service science teachers participated in Turkey in the study. The survey research design was used, and the survey included closed-ended and open-ended questions. Data were collected by using the “Outdoor Setting Questionnaire,” which was developed by Ernst and Tornabene (2012). Data were analyzed by using quantitative and qualitative analysis methods. The responses to open-ended questions were analyzed qualitatively first, and then the data were transformed into quantitative data. Descriptive statistics analysis showed tendencies of PST’ motivation and barriers about OE. While major barriers were lack of parental support and problems caused by parents, difficulties in providing transportation, and arising safety concerns, the most frequent motivations were found as attaining hands-on learning, gaining physical/health benefits, and reaching variety of materials found in the nature.</p
Improving the geotechnical properties of medium expansive clay using various gradations and percentages of glass
No full textSignificant amounts of waste glass are deposited each year, which poses a significant environmental problem globally. Utilizing waste glass for soil improvement has emerged as an environmentally friendly solution, attracting increased research interest in recent years. This study investigated the effects of waste glass gradation and content ratios on the compaction, strength, and swelling characteristics of medium expansive clayey soil and pulverized glass mixtures. Waste glass was crushed into three different size gradations and mixed with the soil at eight different weight ratios (0%, 4%, 8%, 12%, 16%, 24%, 32%, and 40%). Standard Proctor compaction and unsoaked and soaked California Bearing Ratio (CBR) tests, along with swelling tests, were conducted on each sample. Microstructural analysis was performed through scanning electron microscopy (SEM). The results indicated that adding up to 40% pulverized waste glass reduced the Optimum Moisture Content (OMC), whereas the Maximum Dry Density (MDD) increased. Moreover, the unsoaked and soaked CBR values increased notably with higher pulverized glass ratios. Increases in unsoaked CBR values reached up to 143.5%, 129.8%, and 122.1% for coarse, medium, and fine pulverized glass grades respectively, while those for soaked CBR were 209.2%, 197.2%, and 189.4% respectively. Additionally, the swelling percentage decreased as the pulverized glass content increased. The different grades of pulverized glass showed no significant effect on the swelling percentage at glass contents up to 8%. Statistical analysis revealed strong correlations between the tested parameters. Relationships between the soaked and unsoaked CBR values derived from OMC, MDD, and waste glass ratio were also discussed
The predictive role of relationship maintenance behaviors, irrational relationship beliefs, emotion regulation strategies in long-distance relationship satisfaction
No full textThe purpose of this study is to investigate the predictor roles of relationship maintenance behaviors, irrational relationship beliefs, and reappraisal and suppression strategies of emotion regulation on long-distance relationship satisfaction. In this correlational study, the sample, including 308 (216 female, 91 male, and 1 non-binary) emerging adults who have experienced at least one non-married long-distance relationship lasting a minimum of six months in the last two years, was selected by using convenience sampling. The data were collected by the demographic information form, the Relationship Assessment Scale, the Relationship Maintenance Behaviors Measurement, the Relationship Belief Inventory, and the Emotional Regulation Questionnaire. Hierarchical multiple regression analysis was conducted to analyze the data. The findings demonstrated that relationship maintenance behaviors, irrational relationship beliefs, and reappraisal strategy of emotion regulation were significant but suppression was insignificant predictor of long-distance relationship satisfaction. The last model explained 23.5% of the variance in long-distance relationship satisfaction. Semi-partial variances of relationship maintenance behaviors, irrational relationship beliefs, and reappraisal were found as 15.1%, 4.5%, and 1.8%, respectively. The results and implications of the study, as well as recommendations for future studies were discussed.</p
At the Crossroads of Social Inclusion and Exclusion: The Experience of Muslim ‘Adjarians’
No full textThis study explores the intricate relationship between religious conversion and social inclusion among the Muslim population of Adjara, a region marked by its diverse religious heritage. Amidst the backdrop of post-Soviet Georgia, where Orthodox Christianity plays a pivotal role in national identity, Muslim Georgians of Adjara encounter unique challenges to social integration. Through comprehensive fieldwork, including interviews conducted in Batumi, Kobuleti and Tbilisi from 2015 to 2018, this research investigates how conversion to Georgian Orthodox Christianity emerges as a pathway to belonging for some in the Muslim community. The findings illuminate the nuanced dynamics of identity, belonging and marginalization, highlighting how religious affiliation influences perceptions of Georgian identity. This study contributes to the broader discourse on the complexities of religious conversion, social cohesion and the quest for inclusion in a rapidly changing sociopolitical landscape
Stimuli responsive hollow layer-by-layer microcapsules for enzymatic cascade reactions
No full textStimuli-responsive hollow polymer capsules were prepared through layer-by-layer self-assembly (LbL) technique for use as microreactors. pH-sensitive Tannic Acid (TA), temperature-sensitive poly(2-isopropyl-2-oxazoline) (PiPOX), and the cascade reaction enzymes glucose oxidase (GOx) and horseradish peroxidase (HRP) were used as LbL building blocks. Multilayers were deposited on silica microparticles to form two different stacks. The first stack contained GOx immobilized between PiPOX and TA layers, while the second stack had HRP included between the polymer layers. To obtain a compartmentalized structure, these stacks were separated using a TA/poly-L-lysine (PLL) pair. The effect of stimuli-induced conformational rearrangement within the capsule wall on the enzymatic cascade reactions was examined at varying pH and temperature conditions. Enzymatic cascade activity was greater under slightly acidic conditions than that at pH 7.4. Activity increased at temperature values (e.g. 37 °C) close to the critical temperature of PiPOX, especially when the number of PiPOX layers between the enzyme layers was increased. HeLa cells incubated with LbL capsules showed dose-dependent viability and the capsules exhibited a marked interaction with the cell membrane. Overall, this study generated fundamental knowledge on the structure–property relationship in stimuli-responsive polymer/enzyme hybrid LbL capsules for enzymatic cascade reactions
Impact of accelerated UV aging on chemical structure and sorption behavior of low-density polyethylene microplastics
No full textThis study investigates the effect of UV aging on the chemical structure of low-density polyethylene (LDPE) microplastics (MPs) and its impact on the sorption of organic compounds using malachite green (MG) as the model compound. Fourier Transform Infrared (FTIR) analysis revealed discernible structural changes in UV-aged LDPE MPs, including the formation of new functional groups such as -C=O, -OH, and unsaturation, along with shifts in band positions, changes in intensity, and an increase in carbonyl index (CI) values with higher UV doses. Exposure to progressively higher UV doses also caused a rise in melting temperature, while the crystallinity initially increased and then decreased but still surpassed that of the pristine sample. Surface alterations and fragment formation, increased surface area, changes in zeta potential, and contact angle values were also observed. LDPE MPs subjected to only thermal aging, on the other hand, exhibited the highest crystallinity, with no evidence of formation of new functional groups, as indicated by their FTIR spectra. Isotherm experiments with MG revealed that sorption increases ten-fold as LDPE MPs age. Furthermore, sorption which follows a linear trend with pristine LDPE, becomes non-linear with the aged sorbent. It is proposed that MG sorption is dominantly a partitioning process within the amorphous regions of pristine LDPE, while increased hydrophilic sorption sites of aged LDPE promoted adsorption in addition to partitioning. Our findings underscore the significant role of UV aging in altering the properties of MPs and their interactions, potentially modifying their impact on ecosystems
Seismic performance assessment of base isolation systems in five hospitals during the Mw7.8 and Mw7.6 2023 earthquakes in Southeast Turkey
No full textThe February 6, 2023, Kahramanmaraş earthquakes (Mw7.8 and Mw7.6) in Southeast Turkey ruptured a 300 km section of the East Anatolian Fault, resulting in severe ground motions. These two strong earthquakes occurred 9 hours apart and were followed by large-magnitude aftershocks. Strong ground motions from the Kahramanmaraş earthquakes were recorded by more than 280 strong motion stations. Nine base-isolated hospital buildings located at distances less than 50 km from the ruptured fault were subjected to strong ground shaking. This paper examines five of the nine hospitals for which seismic isolation designs were available to the authors. The ground motions acting on these hospital buildings were recorded by strong motion stations situated in close proximity. Consequently, the February 6 earthquakes have presented a unique opportunity to assess the seismic performance of base isolation systems during severe earthquakes. All five hospitals were equipped with double spherical sliding (friction pendulum) seismic isolation devices. Subsequently, the authors conducted site visits to the hospitals following the February 6 earthquakes and collected data on maximum and residual response displacements at their isolation levels, as well as on the seismic response of structural and nonstructural components. The maximum response displacements measured at the isolation levels are compared with the maximum displacements calculated by nonlinear response history analysis under the ground motions recorded at the strong motion stations in close proximity to the hospitals