66 research outputs found
The Phone Call: A Short Story
No full text"The Phone Call" is a short story about a woman, Nadia, dealing with grief and her deteriorating mental health
Evaluasi Konsentrasi Karboksimetilselulosa-Alginat Formula Pasta Gigi Antiseptik Ekstrak Etanol Daun Seledri (Apium graveolens L.)
No full textMaserasi daun seledri menggunakan pelarut etanol 96% digunakan untuk membuat ekstrak. Pasta gigi diformulasi dengan bahan pengikat karboksimetilselulosa dan alginat. Bahan aktif berupa ekstrak etanol daun seledri berpotensi untuk antibakteri. Tujuan penelitian untuk mengevaluasi konsentrasi karboksimetilselulosa-alginat sediaan pasta gigi antiseptik ekstrak etanol daun seledri. Evaluasi hasil produksi terdiri dari organoleptis, homogenitas, daya sebar, pembentukan busa, keasaman dan kekentalan. Konsentrasi karboksimetilselulosa semakin tinggi maka busa dan daya sebar makin rendah dan viskositas semakin tinggi, sementara konsentrasi alginat malah sebaliknya. Karboksimetilselulosa-alginat berpengaruh terhadap parameter evaluasi sediaan pasta gigi antiseptik ekstrak etanol daun seledri
A comparison of cement and Guar Gum stabilisation of Oxford clay under controlled wetting and drying cycles.
No full textClimate-induced wetting and drying (WD) cycles significantly affect the long-term performance of geotechnical structures. This study explores expansive Oxford clay’s mechanical and volumetric responses stabilised with ordinary Portland cement (OPC) and guar gum (GG) under repeated WD cycles. We prepared 108 samples in total—36 untreated, 36 treated with OPC, and 36 treated with GG. These samples were compacted to 90% of their maximum dry density and subjected to 1, 5, 10, and 15 WD cycles, with nine samples for each treatment at each cycle. During the WD cycles, we monitored volumetric strain and moisture content. Mechanical performance was assessed through unconsolidated undrained triaxial tests conducted at matric suctions of −1500 kPa, −33 kPa, and under saturated conditions. We evaluated the undrained shear strength (Su), secant modulus of elasticity (E50), and modulus of toughness (Ut). The results showed that OPC-treated samples consistently exhibited the highest Su at −1500 kPa across all WD cycles, followed by untreated and GG-treated samples. At −33 kPa, OPC-treated samples again outperformed the others in Su, while GG-treated samples performed better than the untreated ones. Under saturated conditions, GG-treated samples displayed a similar Su to OPC-treated samples, significantly higher than untreated samples. Energy absorption capacity, measured through Ut, peaked for OPC-treated samples at −1500 kPa but favoured GG treatment at −33 kPa and under saturation. X-ray computed tomography (CT) revealed severe degradation in untreated samples, characterised by extensive cracking, minor cracking in OPC-treated samples, and minimal damage in GG-treated samples. This highlights the superior resilience of guar gum to wetting–drying cycles. These findings underscore the potential of guar gum as a sustainable alternative to cement for enhancing the WD resilience of expansive soils, particularly under low-suction or saturated conditions
Impact of Wetting and Drying Cycles on the Hydromechanical Properties of Soil and Implications on Slope Stability
No full textThe soil-based infrastructure is the backbone of the global economy, connecting people, enhancing quality of life, and promoting health and safety. However, its vulnerabilities are becoming apparent due to climate change, mainly through frequent wetting and drying (wd) cycles. Despite few studies in the past, research showing the stability of flood embankments in the long term, incorporating the impact of wetting and drying cycles on the hydromechanical characteristics of soil, is scarce. This study aimed to assess the impact of controlled wd cycles on the hydromechanical properties of clay and silty sand soils and its implications for the stability of a typical flood embankment. Volumetric changes were monitored during the wd cycles. The soil water characteristic curve (SWCC), saturated hydraulic conductivity (ksat), effective cohesion (c′), and effective angle of internal friction (ϕ′) were measured at 1 and 10 wd cycles. The results indicated that the 10 wd cycles decreased the saturated moisture content and resulted in a flatter SWCC compared to the 1 wd cycle for clayey soil. The ksat value was also significantly higher at 10 wd cycles than 1 wd cycle for clayey soil. An insignificant difference was found in both the SWCC and ksat at 1 and 10 wd cycles for silty sand soil. The ϕ′ value for the clayey soil decreased from 28.5 to 20.1 as the wd cycles increased from 1 to 10, while c′ remained unchanged at 10 kN/m2. On the other hand, for the silty sand soil, ϕ′ increased from 34.6 to 37.5 with an increase in wd cycles from 1 to 10, and c′ remained constant at 1 kN/m2. Numerical modelling of transient water flow coupled with a slope stability analysis revealed that the stability of a flood embankment depends on the evolution of soil hydromechanical properties due to wd cycles and the duration of flooding. These findings underscore the need for proactive measures to mitigate landslide risks in regions prone to frequent wd cycles, thereby ensuring the safety and resilience of slopes and associated infrastructure
Evolution of Soil Pore Structure and Shear Strength Deterioration of Compacted Soil under Controlled Wetting and Drying Cycles
No full textThis study investigates the evolution of soil pore structure and shear strength deterioration in compacted clayey soil under controlled wetting and drying (wd) cycles, which are expected to become more frequent due to climate change. Thirty soil samples were compacted at optimal moisture content and 90% maximum dry density. These samples were then subjected to 0, 1, 5, 10, and 15 controlled wd cycles from saturation to the wilting point, and volumetric changes were recorded during each cycle. After the wd treatment, the soil samples were scanned using X-ray computed tomography (CT) at 50 μm resolution and then sheared under unconsolidated–undrained and consolidated–undrained conditions in a triaxial test. Significant shrinkage and swelling of soil samples were observed during wd cycles, with average volumetric strain fluctuating between +12% at saturation and −5% at the wilting point. X-ray CT visualisation and analysis revealed higher porosity, more prominent pores, and increased pore length in soil samples with increasing wd cycles. Both undrained and effective soil shear strength markedly decreased with increasing wd cycles. CT-derived macroporosity and pore length were significant predictors of the soil’s undrained and effective shear strength when exposed to wd cycles. The findings emphasise the considerable impact of climate change, specifically wd cycles, on clayey soil, highlighting the need for consideration in the design of earth-based infrastructure
Understanding abscisic acid-mediated stress signaling to affect rice development under stress
No full textIntroductionRice is a vital staple food for many countries, and its yield is known to be significantly affected by various abiotic stresses, which are expected to intensify with climate change, posing a threat to global food security. Abscisic acid (ABA), a crucial plant growth regulator, plays a crucial role in plant responses to these abiotic stresses. It influences several processes, such as seed dormancy, leaf gas exchange, reactive oxygen species (ROS) scavenging, ion toxicity reduction, and root elongation, all of which contribute to enhancing plant survival under stress.MethodsThis article reviews recent research on ABA-mediated gene responses and expressions involved in rice plant architecture and its response to abiotic stress.Results and discussionAbscisic acid responses were primarily driven by changes in gene expression. Expression analyses of the gene related to ABA biosynthesis or catabolism indicated several changes in plant architecture, such as changes in leaf angle, delayed flowering, and modifications in growth regulators. Additionally, tolerance-related mechanisms, such as increased ROS scavenging, reduced membrane leakage, and vacuolar compartmentation of toxic radicals, were activated under single or multiple stress conditions. While these adaptations may improve plant survival and yield sustainability under stress, they may not necessarily enhance yield potential in environments affected by drought, salinity, or heat stress. ABA expression was also associated with improved pollen viability, grain-filling potential, and seed setting under abiotic stresses such as heat, which could enhance seed yield in such challenging environments
A Teacher’s Autoethnography: The impact of lifelong experiences in shaping worldviews and teacher identity
No full textLiterature has explored education and its values, highlighting the significance of experience in learning. However, a paucity of research has investigated the importance of teachers’ lifelong experiences in shaping their views toward education. Employing a collaborative autoethnographic methodology, this study attempts to provide insights into the significance of teachers’ lifelong experiences in shaping their views and their teacher identity. The narratives highlight the influence of the living environment and life events in shaping worldviews, along with affirmation of the individual’s agency in self-regulation. A dynamic accumulation of various lifelong experiences like losing Author 1’s father, war, and harassment at school shaped his teacher identity. Understanding the significance of this process helps teachers to appreciate their experiences and recognise their role in shaping students’ views and identifies. In conclusion, teachers’ socially constructed identity shapes their educational perspectives, reminding them of teachers’ role in shaping students’ experiences. This knowledge could be valuable in future teacher education programs and developing educational material for learners.
Exchanges Discourse Podcast
In Conversation with Mehdi Moharami [16:30
Evolution of Soil Pore Structure and Shear Strength Deterioration of Compacted Soil under Controlled Wetting and Drying Cycles
No full textThe study investigates the evolution of soil pore structure and shear strength deterioration in compacted clayey soil under controlled wetting and drying (wd) cycles, which are expected to become more frequent due to climate change. Thirty soil samples were compacted at optimal moisture content and 90% of maximum dry density. These samples were then subjected to 0, 1, 5, 10, and 15 controlled wd cycles from saturation to the wilting point, and volumetric changes were recorded during each cycle. After the wd treatment, the soil samples were scanned using X-ray Computed Tomography (CT) at 50 μm resolution and then sheared under unconsolidated-undrained and consolidated-undrained conditions in a triaxial test. Significant shrinkage and swelling of soil samples were observed during wd cycles, with average volumetric strain fluctuating between +12% at saturation and -5% at the wilting point. X-ray CT visualisation and analysis revealed higher porosity, more prominent pores and increased pore length in soil samples with increasing wd cycles. Both undrained and effective soil shear strength markedly decreased with increasing wd cycles. CT-derived macroporosity and pore length were significant predictors of the soil's undrained and effective shear strength when exposed to wd cycles. The findings emphasise the considerable impact of climate change, specifically wd cycles, on clayey soil, highlighting the need for consideration in the design of earth-based infrastructure
Design analysis and optimization of ground grid mesh of extra high voltage substation using an intelligent software
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