Search results for: laminar forced convection
219 Effects of Prescribed Surface Perturbation on NACA 0012 at Low Reynolds Number
Authors: Diego F. Camacho, Cristian J. Mejia, Carlos Duque-Daza
Abstract:
The recent widespread use of Unmanned Aerial Vehicles (UAVs) has fueled a renewed interest in efficiency and performance of airfoils, particularly for applications at low and moderate Reynolds numbers, typical of this kind of vehicles. Most of previous efforts in the aeronautical industry, regarding aerodynamic efficiency, had been focused on high Reynolds numbers applications, typical of commercial airliners and large size aircrafts. However, in order to increase the levels of efficiency and to boost the performance of these UAV, it is necessary to explore new alternatives in terms of airfoil design and application of drag reduction techniques. The objective of the present work is to carry out the analysis and comparison of performance levels between a standard NACA0012 profile against another one featuring a wall protuberance or surface perturbation. A computational model, based on the finite volume method, is employed to evaluate the effect of the presence of geometrical distortions on the wall. The performance evaluation is achieved in terms of variations of drag and lift coefficients for the given profile. In particular, the aerodynamic performance of the new design, i.e. the airfoil with a surface perturbation, is examined under conditions of incompressible and subsonic flow in transient state. The perturbation considered is a shaped protrusion prescribed as a small surface deformation on the top wall of the aerodynamic profile. The ultimate goal by including such a controlled smooth artificial roughness was to alter the turbulent boundary layer. It is shown in the present work that such a modification has a dramatic impact on the aerodynamic characteristics of the airfoil, and if properly adjusted, in a positive way. The computational model was implemented using the unstructured, FVM-based open source C++ platform OpenFOAM. A number of numerical experiments were carried out at Reynolds number 5x104, based on the length of the chord and the free-stream velocity, and angles of attack 6° and 12°. A Large Eddy Simulation (LES) approach was used, together with the dynamic Smagorinsky approach as subgrid scale (SGS) model, in order to account for the effect of the small turbulent scales. The impact of the surface perturbation on the performance of the airfoil is judged in terms of changes in the drag and lift coefficients, as well as in terms of alterations of the main characteristics of the turbulent boundary layer on the upper wall. A dramatic change in the whole performance can be appreciated, including an arguably large level of lift-to-drag coefficient ratio increase for all angles and a size reduction of laminar separation bubble (LSB) for a twelve-angle-of-attack.Keywords: CFD, LES, Lift-to-drag ratio, LSB, NACA 0012 airfoil
Procedia PDF Downloads 386218 Health Services for Women Refugees: A Quantitative Exploratory Study in Ottawa, Canada
Authors: Kholoud Sheba
Abstract:
Women refugees expectedly are physical, socially and mentally vulnerable due to their past traumatic experiences and their novel circumstances in their receiving countries. They may have a wide range of general, mental, and reproductive health problems, but reportedly avoid visiting health care facilities owing to complex elements. Women refugees are usually unfamiliar with their new country health system and unable to navigate it efficiently. They have limited English language skills, which makes it even harder to access culturally insensitive health services. This study examines barriers to health care for refugee women in Ottawa and offers suggestions to address these challenges. Drawing from culturally congruent health care models in Canada, the United Kingdom, and some parts of the United States, this study highlights the importance of cultivating compassion in the provision of health care for women refugees as a way of addressing some of the disparities in health care in Canada. To address the study purpose, a survey questionnaire was designed and pretested questionnaire and was administrated using SurveyMonkey, a paid source survey application, over a period of two weeks. Snowballing sampling procedures were used to recruit the participants. Data was measured using frequencies, percentages, t-test, ANOVA, and chi-square. The test of significance is set at p < .05. The study asked how refugees perceive their experience in accessing and navigating public health services in Ottawa; what challenges refugees face with healthcare in Canada, and, if gender is related to refugees’ perceptions of the health care system they are forced to use? Results show refugees perceived their experience accessing the healthcare services in Canada to be a positive experience and the health providers to be culturally sensitive and allowing enough time listening to their complaints. The language stood tall in their barriers accessing the services due to low English proficiency and the need for interpretation services to encourage them attending the services.Keywords: women refugee, access barriers, Ottawa, resettlement
Procedia PDF Downloads 144217 Farmers’ Perception and Response to Climate Change Across Agro-ecological Zones in Conflict-Ridden Communities in Cameroon
Authors: Lotsmart Fonjong
Abstract:
The livelihood of rural communities in the West African state of Cameroon, which is largely dictated by natural forces (rainfall, temperatures, and soil), is today threatened by climate change and armed conflict. This paper investigates the extent to which rural communities are aware of climate change, how their perceptions of changes across different agro-ecological zones have impacted farming practices, output, and lifestyles, on the one hand, and the extent to which local armed conflicts are confounding their efforts and adaptation abilities. The paper is based on a survey conducted among small farmers in selected localities within the forest and savanna ecological zones of the conflict-ridden Northwest and Southwest Cameroon. Attention is paid to farmers’ gender, scale, and type of farming. Farmers’ perception of/and response to climate change are analysed alongside local rainfall and temperature data and mobilization for climate justice. Findings highlight the fact that farmers’ perception generally corroborates local climatic data. Climatic instability has negatively affected farmers’ output, food prices, standards of living, and food security. However, the vulnerability of the population varies across ecological zones, gender, and crop types. While these factors also account for differences in local response and adaptation to climate change, ongoing armed conflicts in these regions have further complicated opportunities for climate-driven agricultural innovations, inputs, and exchange of information among farmers. This situation underlines how poor communities, as victims, are forced into many complex problems outsider their making. It is therefore important to mainstream farmers’ perceptions and differences into policy strategies that consider both climate change and Anglophone conflict as national security concerns foe sustainable development in Cameroon.Keywords: adaptation policies, climate change, conflict, small farmers, cameroon
Procedia PDF Downloads 156216 Numerical Investigation of Fluid Outflow through a Retinal Hole after Scleral Buckling
Authors: T. Walczak, J. K. Grabski, P. Fritzkowski, M. Stopa
Abstract:
Objectives of the study are i) to perform numerical simulations that permit an analysis of the dynamics of subretinal fluid when an implant has induced scleral intussusception and ii) assess the impact of the physical parameters of the model on the flow rate. Computer simulations were created using finite element method (FEM) based on a model that takes into account the interaction of a viscous fluid (subretinal fluid) with a hyperelastic body (retina). The purpose of the calculation was to investigate the dependence of the flow rate of subretinal fluid through a hole in the retina on different factors such as viscosity of subretinal fluid, material parameters of the retina, and the offset of the implant from the retina’s hole. These simulations were performed for different speeds of eye movement that reflect the behavior of the eye when reading, REM, and saccadic movements. Similar to other works in the field of subretinal fluid flow, it was assumed stationary, single sided, forced fluid flow in the considered area simulating the subretinal space. Additionally, a hyperelastic material model of the retina and parameterized geometry of the considered model was adopted. The calculations also examined the influence the direction of the force of gravity due to the position of the patient’s head on the trend of outflow of fluid. The simulations revealed that fluid outflow from the retina becomes significant with eyeball movement speed of 100°/sec. This speed is greater than in the case of reading but is four times less than saccadic movement. The increase of viscosity of the fluid increased beneficial effect. Further, the simulation results suggest that moderate eye movement speed is optimal and that the conventional prescription of the avoidance of routine eye movement following retinal detachment surgery should be relaxed. Additionally, to verify numerical results, some calculations were repeated with use of meshless method (method of fundamental solutions), which is relatively fast and easy to implement. The paper has been supported by 02/21/DSPB/3477 grant.Keywords: CFD simulations, FEM analysis, meshless method, retinal detachment
Procedia PDF Downloads 343215 Comparison of Multivariate Adaptive Regression Splines and Random Forest Regression in Predicting Forced Expiratory Volume in One Second
Authors: P. V. Pramila , V. Mahesh
Abstract:
Pulmonary Function Tests are important non-invasive diagnostic tests to assess respiratory impairments and provides quantifiable measures of lung function. Spirometry is the most frequently used measure of lung function and plays an essential role in the diagnosis and management of pulmonary diseases. However, the test requires considerable patient effort and cooperation, markedly related to the age of patients esulting in incomplete data sets. This paper presents, a nonlinear model built using Multivariate adaptive regression splines and Random forest regression model to predict the missing spirometric features. Random forest based feature selection is used to enhance both the generalization capability and the model interpretability. In the present study, flow-volume data are recorded for N= 198 subjects. The ranked order of feature importance index calculated by the random forests model shows that the spirometric features FVC, FEF 25, PEF,FEF 25-75, FEF50, and the demographic parameter height are the important descriptors. A comparison of performance assessment of both models prove that, the prediction ability of MARS with the `top two ranked features namely the FVC and FEF 25 is higher, yielding a model fit of R2= 0.96 and R2= 0.99 for normal and abnormal subjects. The Root Mean Square Error analysis of the RF model and the MARS model also shows that the latter is capable of predicting the missing values of FEV1 with a notably lower error value of 0.0191 (normal subjects) and 0.0106 (abnormal subjects). It is concluded that combining feature selection with a prediction model provides a minimum subset of predominant features to train the model, yielding better prediction performance. This analysis can assist clinicians with a intelligence support system in the medical diagnosis and improvement of clinical care.Keywords: FEV, multivariate adaptive regression splines pulmonary function test, random forest
Procedia PDF Downloads 310214 Role of Desire in Risk-Perception: A Case Study of Syrian Refugees’ Migration towards Europe
Authors: Lejla Sunagic
Abstract:
The aim of the manuscript is to further the understanding of risky decision-making in the context of forced and irregular migration. The empirical evidence is collected through interviews with Syrian refugees who arrived in Europe via irregular pathways. Analytically, it has been approached through the juxtaposition between risk perception and the notion of desire. As different frameworks have been developed to address differences in risk perception, the common thread was the understanding that individual risk-taking has been addressed in terms of benefits outweighing risks. However, this framework cannot explain a big risk an individual takes because of an underprivileged position and due to a lack of positive alternatives, termed as risk-taking from vulnerability. The accounts of the field members of this study that crossed the sea in rubber boats to arrive in Europe make an empirical fit to such a postulate by reporting that the risk they have taken was not the choice but the only coping strategy. However, the vulnerability argument falls short of explaining why the interviewees, thinking retrospectively, find the risky journey they have taken to be worth it, while they would strongly advise others to restrain from taking such a huge risk. This inconsistency has been addressed by adding the notion of desire to migrate to the elements of risk perception. Desire, as a subjective experience, was what made the risk appear smaller in cost-benefit analysis at the time of decision-making of those who have realized migration. However, when they reflect on others in the context of potential migration via the same pathway, the interviewees addressed the others’ lack of capacity to avoid the same obstacles that they themselves were able to circumvent while omitting to reflect on others’ desire to migrate. Thus, in the risk-benefit analysis performed for others, the risk remains unblurred and tips over the benefits, given the inability to take into account the desire of others. If desire, as the transformative potential of migration, is taken out of the cost-benefit analysis of irregular migration, refugees might not have taken the risky journey. By casting the theoretical argument in the language of configuration, the study is filling in the gap of knowledge on the combination of migration drivers and the way they interact and produce migration outcomes.Keywords: refugees, risk perception, desire, irregular migration
Procedia PDF Downloads 96213 The Effectiveness of First World Asylum Practices in Deterring Applications, Offering Bureaucratic Deniability, and Violating Human Rights: A Greek Case Study
Authors: Claudia Huerta, Pepijn Doornenbal, Walaa Elsiddig
Abstract:
Rising waves of nationalism around the world have led first-world migration receiving countries to exploit the ambiguity of international refugee law and establish asylum application processes that deter applications, allow for bureaucratic deniability, and violate human rights. This case study of Greek asylum application practices argues that the 'pre-application' asylum process in Greece violates the spirit of international law by making it incredibly difficult for potential asylum seekers to apply for asylum, in essence violating the human rights of thousands of asylum seekers. This study’s focus is on the Greek mainland’s asylum 'pre-application' process, which in 2016 began to require those wishing to apply for asylum to do so during extremely restricted hours via a basic Skype line. The average wait to simply begin the registration process to apply for asylum is 81 days, during which time applicants are forced to live illegally in Greece. This study’s methodology in analyzing the 'pre-application' process consists of hours of interviews with asylum seekers, NGOs, and the Asylum Service office on the ground in Athens, as well as an analysis of the Greek Asylum Service historical asylum registration statistics. This study presents three main findings: the delays associated with the Skype system in Greece are the result of system design, as proven by a statistical analysis of Greek asylum registrations, NGOs have been co-opted by the state to perform state functions during the process, and the government’s use of technology is both purposefully lazy and discriminatory. In conclusion, the study argues that such asylum practices are part of a pattern of first-world migration receiving countries policies’ which discourage asylum seekers from applying and fall short of the standards in international law.Keywords: asylum, European Union, governance, Greece, irregular, migration, policy, refugee, Skype
Procedia PDF Downloads 127212 Carbon Capture and Storage by Continuous Production of CO₂ Hydrates Using a Network Mixing Technology
Authors: João Costa, Francisco Albuquerque, Ricardo J. Santos, Madalena M. Dias, José Carlos B. Lopes, Marcelo Costa
Abstract:
Nowadays, it is well recognized that carbon dioxide emissions, together with other greenhouse gases, are responsible for the dramatic climate changes that have been occurring over the past decades. Gas hydrates are currently seen as a promising and disruptive set of materials that can be used as a basis for developing new technologies for CO₂ capture and storage. Its potential as a clean and safe pathway for CCS is tremendous since it requires only water and gas to be mixed under favorable temperatures and mild high pressures. However, the hydrates formation process is highly exothermic; it releases about 2 MJ per kilogram of CO₂, and it only occurs in a narrow window of operational temperatures (0 - 10 °C) and pressures (15 to 40 bar). Efficient continuous hydrate production at a specific temperature range necessitates high heat transfer rates in mixing processes. Past technologies often struggled to meet this requirement, resulting in low productivity or extended mixing/contact times due to inadequate heat transfer rates, which consistently posed a limitation. Consequently, there is a need for more effective continuous hydrate production technologies in industrial applications. In this work, a network mixing continuous production technology has been shown to be viable for producing CO₂ hydrates. The structured mixer used throughout this work consists of a network of unit cells comprising mixing chambers interconnected by transport channels. These mixing features result in enhanced heat and mass transfer rates and high interfacial surface area. The mixer capacity emerges from the fact that, under proper hydrodynamic conditions, the flow inside the mixing chambers becomes fully chaotic and self-sustained oscillatory flow, inducing intense local laminar mixing. The device presents specific heat transfer rates ranging from 107 to 108 W⋅m⁻³⋅K⁻¹. A laboratory scale pilot installation was built using a device capable of continuously capturing 1 kg⋅h⁻¹ of CO₂, in an aqueous slurry of up to 20% in mass. The strong mixing intensity has proven to be sufficient to enhance dissolution and initiate hydrate crystallization without the need for external seeding mechanisms and to achieve, at the device outlet, conversions of 99% in CO₂. CO₂ dissolution experiments revealed that the overall liquid mass transfer coefficient is orders of magnitude larger than in similar devices with the same purpose, ranging from 1 000 to 12 000 h⁻¹. The present technology has shown itself to be capable of continuously producing CO₂ hydrates. Furthermore, the modular characteristics of the technology, where scalability is straightforward, underline the potential development of a modular hydrate-based CO₂ capture process for large-scale applications.Keywords: network, mixing, hydrates, continuous process, carbon dioxide
Procedia PDF Downloads 52211 Reduction of Residual Stress by Variothermal Processing and Validation via Birefringence Measurement Technique on Injection Molded Polycarbonate Samples
Authors: Christoph Lohr, Hanna Wund, Peter Elsner, Kay André Weidenmann
Abstract:
Injection molding is one of the most commonly used techniques in the industrial polymer processing. In the conventional process of injection molding, the liquid polymer is injected into the cavity of the mold, where the polymer directly starts hardening at the cooled walls. To compensate the shrinkage, which is caused predominantly by the immediate cooling, holding pressure is applied. Through that whole process, residual stresses are produced by the temperature difference of the polymer melt and the injection mold and the relocation of the polymer chains, which were oriented by the high process pressures and injection speeds. These residual stresses often weaken or change the structural behavior of the parts or lead to deformation of components. One solution to reduce the residual stresses is the use of variothermal processing. Hereby the mold is heated – i.e. near/over the glass transition temperature of the polymer – the polymer is injected and before opening the mold and ejecting the part the mold is cooled. For the next cycle, the mold gets heated again and the procedure repeats. The rapid heating and cooling of the mold are realized indirectly by convection of heated and cooled liquid (here: water) which is pumped through fluid channels underneath the mold surface. In this paper, the influences of variothermal processing on the residual stresses are analyzed with samples in a larger scale (500 mm x 250 mm x 4 mm). In addition, the influence on functional elements, such as abrupt changes in wall thickness, bosses, and ribs, on the residual stress is examined. Therefore the polycarbonate samples are produced by variothermal and isothermal processing. The melt is injected into a heated mold, which has in our case a temperature varying between 70 °C and 160 °C. After the filling of the cavity, the closed mold is cooled down varying from 70 °C to 100 °C. The pressure and temperature inside the mold are monitored and evaluated with cavity sensors. The residual stresses of the produced samples are illustrated by birefringence where the effect on the refractive index on the polymer under stress is used. The colorful spectrum can be uncovered by placing the sample between a polarized light source and a second polarization filter. To show the achievement and processing effects on the reduction of residual stress the birefringence images of the isothermal and variothermal produced samples are compared and evaluated. In this comparison to the variothermal produced samples have a lower amount of maxima of each color spectrum than the isothermal produced samples, which concludes that the residual stress of the variothermal produced samples is lower.Keywords: birefringence, injection molding, polycarbonate, residual stress, variothermal processing
Procedia PDF Downloads 283210 Acculturation and Urban Related Identity of Turk and Kurd Internal Migrants
Authors: Melek Göregenli, Pelin Karakuş
Abstract:
This present study explored the acculturation strategies and urban related identity of Turk and Kurd internal migrants from different regions of Turkey who resettled in three big cities in the west. Besides we aimed at a comparative analysis of acculturation strategies and urban-related identity of voluntary and internally displaced Kurd migrants. Particularly we explored the role of migration type, satisfaction with migration decision, urban-related identity and several socio demographic variables as predictors of Kurds’ integration strategy preference. The sample consisted of 412 adult participants from Izmir (64 females, 86 males); Ankara (76 females, 75 males); and Istanbul (43 females, 64 males and four unreported). In terms of acculturation strategies, assimilation was found to be the most preferred acculturation attitude among Turks whereas separation was found to be most endorsed acculturation attitude among Kurds. The migrants in Izmir were found to prefer assimilation whereas the migrants in Ankara prefer separation. Concerning urban-related identity mean scores, Turks reported higher urban-related identity scores than Kurds. Furthermore the internal migrants in Izmir were found to score higher in urban-related identity than the migrants living in Istanbul and Ankara. The results of the regression analysis revealed that gender, length of residence and migration type were the significant predictors of integration preference of Kurds. Thus, whereas gender and migration type had significant negative associations; length of residence had positive significant associations with Kurds integration preference. Compared to female Kurds, male Kurds were found to be more integrated. Furthermore, voluntary Kurd migrants were more favour of integration than internally displaced Kurds. The findings supported the significant associations between acculturation strategies and urban-related identity with either group.Keywords: acculturation, forced migration, internal displacement, internal migration, Turkey, urban-related identity
Procedia PDF Downloads 363209 Identification of Genes Regulating Differentiation and Stemness of Human Mesenchymal Stem Cells for Gene Therapy in Regenerative Medicine
Authors: Tong Ming Liu
Abstract:
Human mesenchymal stem cells (MSCs) represent the most used stem cells for clinical application, which have been used in over 1000 clinical trials to treat over 30 diseases due to multilineage differentiation potential, secretome and immunosuppression. Gene therapies of MSCs hold great promise in the treatment of many diseases due to enhanced MSC-based clinical outcomes. To identify genes for gene therapy of MSCs, by comparing gene expression profile before and after MSC differentiation following by functional screening, we have identified ZNF145 that regulated MSC differentiation. Forced expression of ZNF145 resulted in enhanced in vitro chondrogenesis of MSCs as an upstream factor of SOX9 and improved osteochondral repair upon implant into osteochondral defects in rodents. By comparing gene expression profile during differentiation of iPSCs toward MSCs, we also identified gene HOX regulating MSC stemness, which was much downregulated in late-passaged MSCs. Knockdown of this gene greatly compromised MSC stemness including abolished proliferation, decreased CFU-F, promoted senescence and reduced expression of cell surface antigens linked to the MSC phenotype. In addition, multi-linage differentiation was also greatly impaired. Notably, HOX overexpression resulted in improved multi-lineage differentiation. In the mechanism, HOX expression significantly deceased in late passage of MSCs compared with early passage of MSCs, correlating with MSC important genes. ChIP-seq data shown that HOX binds to genes related to MSC self-renewal and differentiation. Most importantly, most HOX binding sites are lost in late passage of MSCs. HOX exerts its effects by directing binding Twist1, one important gene of MSCs. The identification of the genes regulating MSC differentiation and stemness will provide and promising strategies for gene therapy of MSCs in regenerative medicine.Keywords: mesenchymal stem cell, novel transcription factor, stemness, gene therapy, cartilage repair, signaling pathway
Procedia PDF Downloads 57208 Post Harvest Losses and Food Security in Northeast Nigeria What Are the Key Challenges and Concrete Solutions
Authors: Adebola Adedugbe
Abstract:
The challenge of post-harvest losses poses serious threats for food security in Nigeria and the north-eastern part with the country losing about $9billion annually due to postharvest losses in the sector. Post-harvest loss (PHL) is the quantitative and qualitative loss of food in various post-harvest operations. In Nigeria, post-harvest losses (PHL) have been a major challenge to food security and improved farmer’s income. In 2022, the Nigerian government had said over 30 percent of food produced by Nigerian farmers perish during post-harvest. For many in northeast Nigeria, agriculture is the predominant source of livelihood and income. The persistent communal conflicts, flood, decade-old attacks by boko haram and insurgency in this region have disrupted farming activities drastically, with farmlands becoming insecure and inaccessible as communities are forced to abandon ancestral homes, The impact of climate change is also affecting agricultural and fishing activities, leading to shortage of food supplies, acute hunger and loss of livelihood. This has continued to impact negatively on the region and country’s food production and availability making it loose billions of US dollars annually in income in this sector. The root cause of postharvest losses among others in crops, livestock and fisheries are lack of modern post-harvest equipment, chemical and lack of technologies used for combating losses. The 2019 Global Hunger Index showed Nigeria’s case was progressing from a ‘serious to alarming level’. As part of measures to address the problem of post-harvest losses experienced by farmers, the federal government of Nigeria concessioned 17 silos with 6000 metric tonne storage space to private sector to enable farmers to have access to storage facilities. This paper discusses the causes, effects and solutions in handling post-harvest losses and optimize returns on food security in northeast Nigeria.Keywords: farmers, food security, northeast Nigeria, postharvest loss
Procedia PDF Downloads 72207 Evaluation and Control of Cracking for Bending Rein-forced One-way Concrete Voided Slab with Plastic Hollow Inserts
Authors: Mindaugas Zavalis
Abstract:
Analysis of experimental tests data of bending one-way reinforced concrete slabs from various articles of science revealed that voided slabs with a grid of hollow plastic inserts inside have smaller mechani-cal and physical parameters compared to continuous cross-section slabs (solid slabs). The negative influence of a reinforced concrete slab is impacted by hollow plastic inserts, which make a grid of voids in the middle of the cross-sectional area of the reinforced concrete slab. A formed grid of voids reduces the slab’s stiffness, which influences the slab’s parameters of serviceability, like deflection and cracking. Prima-ry investigation of data established during experiments illustrates that cracks occur faster in the tensile surface of the voided slab under bend-ing compared to bending solid slab. It means that the crack bending moment force for the voided slab is smaller than the solid slab and the reduction can variate in the range of 14 – 40 %. Reduce of resistance to cracking can be controlled by changing a lot of factors: the shape of the plastic hallow insert, plastic insert height, steps between plastic in-serts, usage of prestressed reinforcement, the diameter of reinforcement bar, slab effective depth, the bottom cover thickness of concrete, effec-tive cross-section of the concrete area about reinforcement and etc. Mentioned parameters are used to evaluate crack width and step of cracking, but existing analytical calculation methods for cracking eval-uation of voided slab with plastic inserts are not so exact and the re-sults of cracking evaluation in this paper are higher than the results of analyzed experiments. Therefore, it was made analytically calculations according to experimental bending tests of voided reinforced concrete slabs with hollow plastic inserts to find and propose corrections for the evaluation of cracking for reinforced concrete voided slabs with hollow plastic inserts.Keywords: voided slab, cracking, hallow plastic insert, bending, one-way reinforced concrete, serviceability
Procedia PDF Downloads 68206 (De)Criminalising Sex Toys in Thailand: A Law and Economics Approach
Authors: Piyanee Khumpao
Abstract:
Under the Thai Penal Code and Customs Act, sex toys are criminalized and completely prohibited through the legal interpretation as obscene objects by law enforcement, despite there is no explicit legal sanction against them. The purpose of preventing people from accessing sex toys is to preserve public morals. However, sex toys are still available, exposed, and sold publicly in main cities throughout Thailand. They are easily observed by people of any age. This paper argues that sexuality is human nature and human right. Human deserves sexual pleasure as long as getting sexual pleasure does not inflict any harm on others. Using sex toys in private (individually and/or as a couple with mutual consent) does not constitute any harm nor degrade public moral. Therefore, the complete ban of sex toys shall be lifted and decriminalized. Nevertheless, the economic analysis illustrates that criminalization and prohibition of sex toys would lead to its black market – higher price and lower quantity. Although it is socially desirable to have fewer sex toys in the market, there will usually be high demand for them because sexual pleasure is natural and, hence, people have a lower price elasticity of demand for such things, including pornography. Thus, its deterrent effect is not very effective. Moreover, sex toys vendors still always exist because higher price incentivizes them to act illegally and may gain benefits from selling low-quality sex toys. Consequently, consumers do not have a choice to select high-quality sex toys at a reasonable price. Then, they are forced to purchase low quality sex toys at a higher price. They also may suffer from health issues as well as other harms from its dangerous/toxic substances since lower quality products are manufactured poorly to save costs. A law and economics approach supports the decriminalization of sex toys in Thailand. Other measures to control its availability shall be adopted to protect the vulnerable, such as children. Options are i) zoning or regulation on-premises selling sex toys as in Singapore, Japan, and China, ii) regulations of sex toys as medical apparatus like in the state of Alabama, and iii) the prevention of sex toys exposure in the real (physical) appearance (i.e., allowing virtual exposure of sex toys) like in India.Keywords: human nature, law and economics approach, sex toys, sexual pleasure
Procedia PDF Downloads 127205 Promising Anti-Displacement Practices for High Cost Cities
Authors: Leslie M. Mullins
Abstract:
In the face of dramatically shifting demographic trends and macroeconomic pressures on affordable housing in high-cost cities, municipalities and developers have been forced to develop new models of sustainable development that integrates elements of substantial rehabilitation and new construction while controlling for relocation and mass displacement. Community development partners in the San Francisco Bay Area of Northern California are starting to prioritize anti-displacement strategies when rehabilitating severely neglected public housing developments. This study explored the community-driven efforts to transform four dilapidated public housing sites (N=2,600 households) into thriving mixed-income housing communities. Eight interviews were conducted with frontline workers (property managers and service providers), who directly worked with residents throughout critical stages of the relocation and leasing process. Interviews were audio-recorded, transcribed, and analyzed by a systematic procedure for qualitative analysis to identify key themes on the topics of interest. Also, an extensive literature analysis was conducted to determine promising practices throughout the industry. This study highlighted that resident’s emotional attachment to their homes (regardless of the deteriorating conditions of their unit) could both a) impede the relocation process and substantially impact the budget and timeline, while b) simultaneously providing a basis for an enhanced sense of belonging and community cohesion. This phenomenon often includes the welcoming of new residents and cultures. Resident centered workshops, healing centered rituals, and extensive 'hands-on' guidance was highlighted as promising practices that resulted in residential retention rates that were two to three times the national average and positively impacted the overall project’s budget and timeline.Keywords: anti-displacement strategies, community based practices, community cohesion, cultural preservation, healing-centered, public housing, relocation, trauma-informed
Procedia PDF Downloads 136204 The Role of Short-Term Study Abroad Experience on Intercultural Communication Competence
Authors: Zeynep Aksoy
Abstract:
Since global mobility of capital, information and people increase more and more, intercultural communication and management become a growing study field of investigating various aspects of the interaction between people from different cultural backgrounds. Human mobility, caused by several intentions from tourism to forced migration, often put people in facing communication barriers, issues or sometimes conflicts. This reality naturally enforces education institutions to develop international policies and programs for students in order to improve their intercultural experiences along with the educative objectives. Study-abroad programs, particularly the student exchanges in higher education provide an environment for participants to encounter with cultural differences. Therefore, international exchange programs (i.e. Erasmus Student Mobility, Global Exchange Program) are accepted to bring opportunities for intergroup contact, which may lead students to obtain new perspectives about the host culture, either in positive or negative ways, and new intercultural communication skills. This study aims to explore the role of short-term study abroad experience on intercultural communication competence with a qualitative approach. It attempts to reveal a comparative analysis, which is derived from two field studies conducted in Izmir (Turkey) and in Amsterdam (the Netherlands) in 2015 and 2016. They were both organized in two phases as pre-and-posttest to gain an insight into the changes (if any) in students’ attitudes and knowledge regarding the host culture, and their further motivations towards cross-cultural interactions. With this aim, focus group sessions and in-depth interviews have been taken place with participants at the beginning of their stay and at the end of the semester. The sample covers students mainly from Erasmus program (20 students in Izmir and 14 students in Amsterdam), and few from Global Exchange Program (5 students in Amsterdam). Data obtained from both studies were thematically analyzed and essential themes were identified within the framework of intercultural communication competence.Keywords: Erasmus student mobility, intercultural communication competence, student exchange, short-term study abroad
Procedia PDF Downloads 262203 Pandemic-Era WIC Participation in Delaware, U.S.: Participants' Experiences and Challenges
Authors: McKenna Halverson, Allison Karpyn
Abstract:
Introduction: The COVID-19 pandemic posed unprecedented challenges for families with young children in the United States. The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), a federal nutrition assistance program that provides low-income mothers and young children with access to healthy foods (e.g., infant formula, milk, and peanut butter), mitigated some financial challenges for families. However, the U.S. experienced a national infant formula shortage and rising inflation rates during the pandemic, which likely impacted WIC participants’ shopping experiences and well-being. As such, this study aimed to characterize how the COVID-19 pandemic and related events impacted Delaware WIC participants’ in-store benefit redemption experiences and overall well-being. Method: The authors conducted semi-structured interviews with 51 WIC participants in Wilmington, Delaware. Survey measures included demographic questions and open-ended questions regarding participants’ experiences with WIC benefit redemption during the COVID-19 pandemic. Data were analyzed using a hybrid inductive and deductive coding approach. Findings: The COVID-19 pandemic significantly impacted WIC participants’ shopping experiences and well-being. Specifically, participants were forced to alter their shopping behaviors to account for rising food prices (e.g., used coupons, bought less food, used food banks). Additionally, WIC participants experienced significant distress during the national infant formula shortage resulting from difficulty finding formula to feed their children. Participants also struggled with in-store benefit redemption due to inconsistencies in shelf labelling, the WIC app, and low stock of WIC foods. These findings highlight the need to reexamine WIC operations and emergency food response policy in the United States during times of crisis to optimize public health and ensure federal nutrition assistance programs meeting the needs of low-income families with young children.Keywords: benefit redemption, COVID-19 pandemic, infant formula shortage, inflation, shopping, WIC
Procedia PDF Downloads 75202 Magnetofluidics for Mass Transfer and Mixing Enhancement in a Micro Scale Device
Authors: Majid Hejazian, Nam-Trung Nguyen
Abstract:
Over the past few years, microfluidic devices have generated significant attention from industry and academia due to advantages such as small sample volume, low cost and high efficiency. Microfluidic devices have applications in chemical, biological and industry analysis and can facilitate assay of bio-materials and chemical reactions, separation, and sensing. Micromixers are one of the important microfluidic concepts. Micromixers can work as stand-alone devices or be integrated in a more complex microfluidic system such as a lab on a chip (LOC). Micromixers are categorized as passive and active types. Passive micromixers rely only on the arrangement of the phases to be mixed and contain no moving parts and require no energy. Active micromixers require external fields such as pressure, temperature, electric and acoustic fields. Rapid and efficient mixing is important for many applications such as biological, chemical and biochemical analysis. Achieving fast and homogenous mixing of multiple samples in the microfluidic devices has been studied and discussed in the literature recently. Improvement in mixing rely on effective mass transport in microscale, but are currently limited to molecular diffusion due to the predominant laminar flow in this size scale. Using magnetic field to elevate mass transport is an effective solution for mixing enhancement in microfluidics. The use of a non-uniform magnetic field to improve mass transfer performance in a microfluidic device is demonstrated in this work. The phenomenon of mixing ferrofluid and DI-water streams has been reported before, but mass transfer enhancement for other non-magnetic species through magnetic field have not been studied and evaluated extensively. In the present work, permanent magnets were used in a simple microfluidic device to create a non-uniform magnetic field. Two streams are introduced into the microchannel: one contains fluorescent dye mixed with diluted ferrofluid to induce enhanced mass transport of the dye, and the other one is a non-magnetic DI-water stream. Mass transport enhancement of fluorescent dye is evaluated using fluorescent measurement techniques. The concentration field is measured for different flow rates. Due to effect of magnetic field, a body force is exerted on the paramagnetic stream and expands the ferrofluid stream into non-magnetic DI-water flow. The experimental results demonstrate that without a magnetic field, both magnetic nanoparticles of the ferrofluid and the fluorescent dye solely rely on molecular diffusion to spread. The non-uniform magnetic field, created by the permanent magnets around the microchannel, and diluted ferrofluid can improve mass transport of non-magnetic solutes in a microfluidic device. The susceptibility mismatch between the fluids results in a magnetoconvective secondary flow towards the magnets and subsequently the mass transport of the non-magnetic fluorescent dye. A significant enhancement in mass transport of the fluorescent dye was observed. The platform presented here could be used as a microfluidics-based micromixer for chemical and biological applications.Keywords: ferrofluid, mass transfer, micromixer, microfluidics, magnetic
Procedia PDF Downloads 225201 Determining the Policy Space of the Partido Socialista Obrero Español Government in Managing Spain's Economic and Financial Crisis
Authors: A. Pascual Ramsay
Abstract:
Accounts of the management of the economic and euro crisis in Spain have been dominated by an emphasis on external constraints. However, this approach leaves unanswered important questions about the role of domestic political factors. Using systematic qualitative primary research and employing elite interviewing and process tracing, this paper aims to fill this gap for the period of the Partido Socialista Obrero Español (PSOE) administration. The paper shows that domestic politics played a crucial role in the management of the crisis, most importantly by determining the shape of the measures undertaken. In its three distinct stages – downplaying/inaction, reaction/stimulus, and austerity/reform – the PSOE's response was certainly constrained by external factors, most notably EMU membership and the actions of sovereign-bond investors, the ECB and Germany. Yet while these external constraints forced the government to act, domestic political factors fundamentally shaped the content of key measures: the fiscal stimulus, the labour, financial and pension reforms, the refusal to accept a bailout or the reform of the Constitution. Seven factors were particularly influential: i) electoral and political cost, ii) party and partisanship, iii) organised interests, iv) domestic institutions, v) ideological preferences, vi) ineffective decision-making, and vii) judgement and personal characteristics of decision-makers. In conclusion, domestic politics played an important role in the management of the crisis, a role that has been underestimated by dominant approaches focusing on external constraints and weak domestic policy autonomy. The findings provide empirical evidence to support research agendas that identify significant state discretion in the face of international economic integration and an important role for domestic political factors such as institutions, material interests, partisanship and ideology in shaping economic outcomes.Keywords: economic crisis, Euro, PSOE, Spain
Procedia PDF Downloads 120200 Evaluation of Wheat Varieties on Water Use Efficiency under Staggering Sowing times and Variable Irrigation Regimes under Timely and Late Sown Conditions
Authors: Vaibhav Baliyan, Shweta Mehrotra, S. S. Parihar
Abstract:
The agricultural productivity is challenged by climate change and depletion in natural resources, including water and land, which significantly affects the crop yield. Wheat is a thermo-sensitive crop and is prone to heat stress. High temperature decreases crop duration, yield attributes, and, subsequently, grain yield and biomass production. Terminal heat stress affects grain filling duration, grain yield, and yield attributes, thus causing a reduction in wheat yield. A field experiment was conducted at Indian Agricultural Research Institute, New Delhi, for two consecutive rabi seasons (2017-18 and 2018-19) on six varieties of wheat (early sown - HD 2967, HD 3086, HD 2894 and late sown - WR 544, HD 3059, HD 3117 ) with three moisture regimes (100%, 80%, and 60% ETc, and no irrigation) and six sowing dates in three replications to investigate the effect of different moisture regimes and sowing dates on growth, yield and water use efficiency of wheat for development of best management practices for mitigation of terminal heat stress. HD3086 and HD3059 gave higher grain yield than others under early sown and late sown conditions, respectively. Maximum soil moisture extraction was recorded from 0-30 cm soil depth across the sowing dates, irrigation regimes, and varieties. Delayed sowing resulted in reducing crop growth period and forced maturity, in turn, led to significant deterioration in all the yield attributing characters and, there by, reduction in yield, suggesting that terminal heat stress had greater impact on yield. Early sowing and irrigation at 80% ETc resulted in improved growth and yield attributes and water use efficiency in both the seasons and helped to some extent in reducing the risk of terminal heat stress of wheat grown on sandy loam soils of semi-arid regions of India.Keywords: sowing, irrigation, yield, heat stress
Procedia PDF Downloads 97199 Study of the Hydrodynamic of Electrochemical Ion Pumping for Lithium Recovery
Authors: Maria Sofia Palagonia, Doriano Brogioli, Fabio La Mantia
Abstract:
In the last decade, lithium has become an important raw material in various sectors, in particular for rechargeable batteries. Its production is expected to grow more and more in the future, especially for mobile energy storage and electromobility. Until now it is mostly produced by the evaporation of water from salt lakes, which led to a huge water consumption, a large amount of waste produced and a strong environmental impact. A new, clean and faster electrochemical technique to recover lithium has been recently proposed: electrochemical ion pumping. It consists in capturing lithium ions from a feed solution by intercalation in a lithium-selective material, followed by releasing them into a recovery solution; both steps are driven by the passage of a current. In this work, a new configuration of the electrochemical cell is presented, used to study and optimize the process of the intercalation of lithium ions through the hydrodynamic condition. Lithium Manganese Oxide (LiMn₂O₄) was used as a cathode to intercalate lithium ions selectively during the reduction, while Nickel Hexacyano Ferrate (NiHCF), used as an anode, releases positive ion. The effect of hydrodynamics on the process has been studied by conducting the experiments at various fluxes of the electrolyte through the electrodes, in terms of charge circulated through the cell, captured lithium per unit mass of material and overvoltage. The result shows that flowing the electrolyte inside the cell improves the lithium capture, in particular at low lithium concentration. Indeed, in Atacama feed solution, at 40 mM of lithium, the amount of lithium captured does not increase considerably with the flux of the electrolyte. Instead, when the concentration of the lithium ions is 5 mM, the amount of captured lithium in a single capture cycle increases by increasing the flux, thus leading to the conclusion that the slowest step in the process is the transport of the lithium ion in the liquid phase. Furthermore, an influence of the concentration of other cations in solution on the process performance was observed. In particular, the capturing of the lithium using a different concentration of NaCl together with 5 mM of LiCl was performed, and the results show that the presence of NaCl limits the amount of the captured lithium. Further studies can be performed in order to understand why the full capacity of the material is not reached at the highest flow rate. This is probably due to the porous structure of the material since the liquid phase is likely not affected by the convection flow inside the pores. This work proves that electrochemical ion pumping, with a suitable hydrodynamic design, enables the recovery of lithium from feed solutions at the lower concentration than the sources that are currently exploited, down to 1 mM.Keywords: desalination battery, electrochemical ion pumping, hydrodynamic, lithium
Procedia PDF Downloads 208198 From Cultural Policy to Social Practice: Literary Festivals as a Platform for Social Inclusion in Pakistan
Authors: S. Jabeen
Abstract:
Though Pakistan has a rich cultural history and a diverse population; its global image is tarnished with labels of Muslim ‘fundamentalism’ and ‘extremism.’ Cultural policy is a tool that can be used by the government of Pakistan to ameliorate this image, but instead, this fundamentalist reputation is reinforced in the 2005 draft of Pakistan’s cultural policy. With its stern focus on a homogenized cultural identity, this 2005 draft bases itself largely on forced participation from the largely Muslim public and leaves little or no benefits to them or cultural minorities in Pakistan. The effects of this homogenized ‘Muslim’ identity linger ten years later where the study and celebration of the cultural heritage of Pakistan in schools and educational festivals focus entirely on creating and maintaining a singular ‘Islamic’ cultural identity. The current lack of inclusion has many adverse effects that include the breeding of extremist mindsets through the usurpation of minority rights and lack of safe cultural public spaces. This paper argues that Pakistan can improve social inclusivity and boost its global image through cultural policy. The paper sets the grounds for research by surveying the effectiveness of different cultural policies across nations with differing socioeconomic status. Then, by sampling two public literary festivals in Pakistan as case studies, the National Youth Peace Festival hosted with a nationalistic agenda using public funds and the Lahore Literary Festival (LLF) that aims to boost the cultural literacy scene of Lahore using both private and public efforts, this paper looks at the success of the private, more inclusive LLF. A revision of cultural policy is suggested that combines public and private efforts to host cultural festivals for the sake of cultural celebration and human development, without a set nationalistic agenda. Consequently, this comparison which is grounded in the human capabilities approach, recommends revising the 2005 draft of the Cultural Policy to improve human capabilities in order to support cultural diversity and ultimately contribute to economic growth in Pakistan.Keywords: cultural policy, festivals, human capabilities, Pakistan
Procedia PDF Downloads 138197 Experimental Study Analyzing the Similarity Theory Formulations for the Effect of Aerodynamic Roughness Length on Turbulence Length Scales in the Atmospheric Surface Layer
Authors: Matthew J. Emes, Azadeh Jafari, Maziar Arjomandi
Abstract:
Velocity fluctuations of shear-generated turbulence are largest in the atmospheric surface layer (ASL) of nominal 100 m depth, which can lead to dynamic effects such as galloping and flutter on small physical structures on the ground when the turbulence length scales and characteristic length of the physical structure are the same order of magnitude. Turbulence length scales are a measure of the average sizes of the energy-containing eddies that are widely estimated using two-point cross-correlation analysis to convert the temporal lag to a separation distance using Taylor’s hypothesis that the convection velocity is equal to the mean velocity at the corresponding height. Profiles of turbulence length scales in the neutrally-stratified ASL, as predicted by Monin-Obukhov similarity theory in Engineering Sciences Data Unit (ESDU) 85020 for single-point data and ESDU 86010 for two-point correlations, are largely dependent on the aerodynamic roughness length. Field measurements have shown that longitudinal turbulence length scales show significant regional variation, whereas length scales of the vertical component show consistent Obukhov scaling from site to site because of the absence of low-frequency components. Hence, the objective of this experimental study is to compare the similarity theory relationships between the turbulence length scales and aerodynamic roughness length with those calculated using the autocorrelations and cross-correlations of field measurement velocity data at two sites: the Surface Layer Turbulence and Environmental Science Test (SLTEST) facility in a desert ASL in Dugway, Utah, USA and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) wind tower in a rural ASL in Jemalong, NSW, Australia. The results indicate that the longitudinal turbulence length scales increase with increasing aerodynamic roughness length, as opposed to the relationships derived by similarity theory correlations in ESDU models. However, the ratio of the turbulence length scales in the lateral and vertical directions to the longitudinal length scales is relatively independent of surface roughness, showing consistent inner-scaling between the two sites and the ESDU correlations. Further, the diurnal variation of wind velocity due to changes in atmospheric stability conditions has a significant effect on the turbulence structure of the energy-containing eddies in the lower ASL.Keywords: aerodynamic roughness length, atmospheric surface layer, similarity theory, turbulence length scales
Procedia PDF Downloads 124196 CO2 Capture in Porous Silica Assisted by Lithium
Authors: Lucero Gonzalez, Salvador Alfaro
Abstract:
Carbon dioxide (CO2) and methane (CH4) are considered as the compounds with higher abundance among the greenhouse gases (CO2, NOx, SOx, CxHx, etc.), due to its higher concentration, this two gases have a greater impact in the environment pollution and provokes global warming. So, recovery, disposal and subsequent reuse, are of great interest, especially from the ecological and health perspective. By one hand, porous inorganic materials are good candidates to capture gases, because these type of materials are higher stability from the point view of thermal, chemical and mechanical under adsorption gas processes. By another hand, during the design and the synthetic preparation of the porous materials is possible add other intrinsic properties (physicochemical and structural) by adding chemical compounds as dopants or using structured directed agents or surfactants to improve the porous structure, the above features allow to have alternative materials for separation, capture and storage of greenhouse gases. In this work, ordered mesoporous materials base silica were prepared using Surfynol as surfactant. The surfactant micelles are commonly used as self-assembly templates for the development of new structure porous silica’s, adding a variety of textures and structures. By another hand, the Surfynol is a commercial surfactant, is non-ionic, for that is necessary determine its critical micelles concentration (cmc) by the pyrene I1/I3 ratio method, before to prepare silica particles. One time known the CMC, a precursor gel was prepared via sol-gel process at room temperature using TEOS as silica precursor, NH4OH as catalyst, Surfynol as template and H2O as solvent. Then, the gel precursor was treatment hydrothermally in a Teflon-lined stainless steel autoclave with a volume of 100 mL and kept at 100 ºC for 24 h under static conditions in a convection oven. After that, the porous silica particles obtained were impregnated with lithium to improve the CO2 adsorption capacity. Then the silica particles were characterized physicochemical, morphology and structurally, by XRD, FTIR, BET and SEM techniques. The thermal stability and the CO2 adsorption capacity was evaluated by thermogravimetric analysis (TGA). According the results, we found that the Surfynol is a good candidate to prepare silica particles with an ordered structure. Also the TGA analysis shown that the particles has a good thermal stability in the range of 250 °C and 800 °C. The best materials had, the capacity to adsorbing 70 and 90 mg per gram of silica particles and its CO2 adsorption capacity depends on the way to thermal pretreatment of the porous silica before of the adsorption experiments and of the concentration of surfactant used during the synthesis of silica particles. Acknowledgments: This work was supported by SIP-IPN through project SIP-20161862.Keywords: CO2 adsorption, lithium as dopant, porous silica, surfynol as surfactant, thermogravimetric analysis
Procedia PDF Downloads 268195 Abridging Pharmaceutical Analysis and Drug Discovery via LC-MS-TOF, NMR, in-silico Toxicity-Bioactivity Profiling for Therapeutic Purposing Zileuton Impurities: Need of Hour
Authors: Saurabh B. Ganorkar, Atul A. Shirkhedkar
Abstract:
The need for investigations protecting against toxic impurities though seems to be a primary requirement; the impurities which may prove non - toxic can be explored for their therapeutic potential if any to assist advanced drug discovery. The essential role of pharmaceutical analysis can thus be extended effectively to achieve it. The present study successfully achieved these objectives with characterization of major degradation products as impurities for Zileuton which has been used for to treat asthma since years. The forced degradation studies were performed to identify the potential degradation products using Ultra-fine Liquid-chromatography. Liquid-chromatography-Mass spectrometry (Time of Flight) and Proton Nuclear Magnetic Resonance Studies were utilized effectively to characterize the drug along with five major oxidative and hydrolytic degradation products (DP’s). The mass fragments were identified for Zileuton and path for the degradation was investigated. The characterized DP’s were subjected to In-Silico studies as XP Molecular Docking to compare the gain or loss in binding affinity with 5-Lipooxygenase enzyme. One of the impurity of was found to have the binding affinity more than the drug itself indicating for its potential to be more bioactive as better Antiasthmatic. The close structural resemblance has the ability to potentiate or reduce bioactivity and or toxicity. The chances of being active biologically at other sites cannot be denied and the same is achieved to some extent by predictions for probability of being active with Prediction of Activity Spectrum for Substances (PASS) The impurities found to be bio-active as Antineoplastic, Antiallergic, and inhibitors of Complement Factor D. The toxicological abilities as Ames-Mutagenicity, Carcinogenicity, Developmental Toxicity and Skin Irritancy were evaluated using Toxicity Prediction by Komputer Assisted Technology (TOPKAT). Two of the impurities were found to be non-toxic as compared to original drug Zileuton. As the drugs are purposed and repurposed effectively the impurities can also be; as they can have more binding affinity; less toxicity and better ability to be bio-active at other biological targets.Keywords: UFLC, LC-MS-TOF, NMR, Zileuton, impurities, toxicity, bio-activity
Procedia PDF Downloads 194194 The Numerical and Experimental Analysis of Compressed Composite Plate in Asymmetrical Arrangement of Layers
Authors: Katarzyna Falkowicz
Abstract:
The work focused on the original concept of a thin-walled plate element with a cut-out, for use as a spring or load-bearing element. The subject of the study were rectangular plates with a cut-out with variable geometrical parameters and with a variable angle of fiber arrangement, made of a carbon-epoxy composite with high strength properties in an asymmetrical arrangement, subjected to uniform compression. The influence of geometrical parameters of the cut-out and the angle of fiber arrangement on the value of critical load of the structure and buckling form was investigated. Uniform thin plates are relatively cheap to manufacture, however due to their low bending stiffness; they can carry relatively small loads. The lowest form of loss of plate stability, which is the bending form, leads to its rapid destruction due to high deflection increases, with a slight increase in compressive load - low rigidity of the structure. However, the stiffness characteristics of the structure change significantly when the work of plate is forcing according to the higher flexural-torsional form of buckling. The plate is able to carry a much higher compressive load while maintaining much stiffer work characteristics in the post-critical range. The calculations carried out earlier show that plates with forced higher form of buckling are characterized by stable, progressive paths of post-critical equilibrium, enabling their use as elastic elements. The characteristics of such elements can be designed in a wide range by changing the geometrical parameters of the cut-out, i.e. height and width as well as by changing the angle of fiber arrangement The commercial ABAQUS program using the finite element method was used to develop the discrete model and perform numerical calculations. The obtained results are of significant practical importance in the design of structures with elastic elements, allowing to achieve the required maintenance characteristics of the device.Keywords: buckling mode, numerical method, unsymmetrical laminates, thin-walled elastic elements
Procedia PDF Downloads 104193 The Desire for Significance & Memorability in Popular Culture: A Cognitive Psychological Study of Contemporary Literature, Art, and Media
Authors: Israel B. Bitton
Abstract:
“Memory” is associated with various phenomena, from physical to mental, personal to collective and historical to cultural. As part of a broader exploration of memory studies in philosophy and science (slated for academic publication October 2021), this specific study employs analytical methods of cognitive psychology and philosophy of memory to theorize that A) the primary human will (drive) is to significance, in that every human action and expression can be rooted in a most primal desire to be cosmically significant (however that is individually perceived); and B) that the will to significance manifests as the will to memorability, an innate desire to be remembered by others after death. In support of these broad claims, a review of various popular culture “touchpoints”—historic and contemporary records spanning literature, film and television, traditional news media, and social media—is presented to demonstrate how this very theory is repeatedly and commonly expressed (and has been for a long time) by many popular public figures as well as “everyday people.” Though developed before COVID, the crisis only increased the theory’s relevance: so many people were forced to die alone, leaving them and their loved ones to face even greater existential angst than what ordinarily accompanies death since the usual expectations for one’s “final moments” were shattered. To underscore this issue of, and response to, what can be considered a sociocultural “memory gap,” this study concludes with a summary of several projects launched by journalists at the height of the pandemic to document the memorable human stories behind COVID’s tragic warped speed death toll that, when analyzed through the lens of Viktor E. Frankl’s psychoanalytical perspective on “existential meaning,” shows how countless individuals were robbed of the last wills and testaments to their self-significance and memorability typically afforded to the dying and the aggrieved. The resulting insight ought to inform how government and public health officials determine what is truly “non-essential” to human health, physical and mental, at times of crisis.Keywords: cognitive psychology, covid, neuroscience, philosophy of memory
Procedia PDF Downloads 184192 Experimental Investigation of Nano-Enhanced-PCM-Based Heat Sinks for Passive Thermal Management of Small Satellites
Authors: Billy Moore, Izaiah Smith, Dominic Mckinney, Andrew Cisco, Mehdi Kabir
Abstract:
Phase-change materials (PCMs) are considered one of the most promising substances to be engaged passively in thermal management and storage systems for spacecraft, where it is critical to diminish the overall mass of the onboard thermal storage system while minimizing temperature fluctuations upon drastic changes in the environmental temperature within the orbit stage. This makes the development of effective thermal management systems more challenging since there is no atmosphere in outer space to take advantage of natural and forced convective heat transfer. PCM can store or release a tremendous amount of thermal energy within a small volume in the form of latent heat of fusion in the phase-change processes of melting and solidification from solid to liquid or, conversely, during which temperature remains almost constant. However, the existing PCMs pose very low thermal conductivity, leading to an undesirable increase in total thermal resistance and, consequently, a slow thermal response time. This often turns into a system bottleneck from the thermal performance perspective. To address the above-mentioned drawback, the present study aims to design and develop various heat sinks featured by nano-structured graphitic foams (i.e., carbon foam), expanded graphite (EG), and open-cell copper foam (OCCF) infiltrated with a conventional paraffin wax PCM with a melting temperature of around 35 °C. This study focuses on the use of passive thermal management techniques to develop efficient heat sinks to maintain the electronics circuits’ and battery module’s temperature within the thermal safety limit for small spacecraft and satellites such as the Pumpkin and OPTIMUS battery modules designed for CubeSats with a cross-sectional area of approximately 4˝×4˝. Thermal response times for various heat sinks are assessed in a vacuum chamber to simulate space conditions.Keywords: heat sink, porous foams, phase-change material (PCM), spacecraft thermal management
Procedia PDF Downloads 12191 Citizen Becoming: ‘In-between’ State and Tibetan Self-Fashioning (1946- 1986)
Authors: Noel Mariam George
Abstract:
This paper explores the history of Tibetan citizenship, one of the primary non-partition refugee communities, and their negotiation of 'in-betweenness' as a mode of political and legal belonging in India. While South Asian citizenship histories have primarily centered around the 1947 and 1971 Partitions, this paper uncovers an often-overlooked period, spanning the 1950s, 60s, and 70s, when Tibetans began to assert their claims within the Indian state. This paper challenges the conventional teleological narrative of partition by highlighting a distinct period when the Indian state negotiated boundaries of belonging for non-partition refugees differently. It explores how Tibetans occupied an 'in-between' status, existing as both foreigners and potential citizens, thereby complicating the traditional citizen-refugee binary. Moreover, it underscores that citizenship during this era was not solely determined by legal frameworks. Instead, it was a dynamic process shaped by historical contexts, practices, and relationships. Tibetans pursued citizen-like claims through legal battles, lobbying, protests, volunteering, and collective solidarity, revealing citizenship as an 'act' embedded in their daily lives. Tibetan liminality is characterized by their simultaneous maintenance of exile identity and pursuit of citizen-like claims in India. The cautious Indian state, reluctant to label Tibetans as either 'refugees' or 'citizens,' has contributed to this liminal status. This duality has intensified Tibetans' precarity but has also led to creative and transformative practices that have expanded the boundaries of democracy and citizenship in India. Beyond traditional narratives of Indian benevolence, this paper scrutinizes the geopolitical factors driving Indian support for Tibetans. Additionally, it challenges 'common-sensical' narratives by demonstrating how Tibetans strategically navigated Indian citizenship. Using archival sources from the British Library and the National Archives in London and Delhi along with digitized materials, the paper reveals citizenship as a multi-faceted historical process. It examines how Tibetans exercised agency within the Indian state despite their liminal status.Keywords: citizenship, borderlands, forced displacement, refugees in India
Procedia PDF Downloads 76190 The Positive Effects of Social Distancing on Individual Work Outcomes in the Context of COVID-19
Authors: Fan Wei, Tang Yipeng
Abstract:
The outbreak of COVID-19 in early 2020 has been raging around the world, which has severely affected people's work and life. In today's post-pandemic era, although the pandemic has been effectively controlled, people still need to maintain social distancing at all times to prevent the further spread of the virus. Based on this, social distancing in the context of the pandemic has aroused widespread attention from scholars. At present, most studies exploring the influencing factors of social distancing are studying the negative impact of social distancing on the physical and mental state of special groups from the inter-individual level, and their more focus on the forced complete social distancing during the severe period of the pandemic. Few studies have focused on the impact of social distancing on working groups in the post-pandemic era from the within-individual level. In order to explore this problem, this paper constructs a cross-level moderating model based on resource conservation theory from the perspective of psychological resources. A total of 81 subjects were recruited to fill in the three-stage questionnaires each day for 10 working days, and 661valid questionnaires were finally obtained. Through the empirical tests, the following conclusions were finally obtained: (1) At the within-individual level, daily social distancing is positively correlated with the second day’s recovery, and the individual’s low sociability regulates the relationship between social distancing and recovery. The indirect effect of daily social distancing through recovery has positive relationship employees’ work engagement and work-goal progress only when the individual has low sociability. For individuals with high sociability, none of these paths are significant. (2) At the within-individual level, there is a significant relationship between individual's recovery and work engagement and work-goal progress, indicating that the recovery of resources can produce positive work outcomes. According to the results, this study believes that in the post-pandemic era, social distancing can not only effectively prevent and control the pandemic but also have positive impacts. Employees can use the time and energy originally saved for social activities through social distancing to invest in things that can provide resources and help them recover.Keywords: social distancing, recovery, work engagement, work goal progress, sociability
Procedia PDF Downloads 133