Search results for: crisis response strategies

Authors: Deepti Kumari, Upamanyu Hore

Abstract:

Cities are an example of a human-modified environment with few fragments of urban green spaces, which are widely considered for urban biodiversity. The study aims to address the avifaunal diversity in urban parks based on the park size and their urbanization intensity. Also, understanding the key factors affecting species composition and structure as birds are a good indicator of a healthy ecosystem, and they are sensitive to changes in the environment. A 50 m-long line-transect method is used to survey birds in 39 urban parks in Delhi, India. Habitat variables, including vegetation (percentage of non-native trees, percentage of native trees, top canopy cover, sub-canopy cover, diameter at breast height, ground vegetation cover, shrub height) were measured using the quadrat method along the transect, and disturbance variables (distance from water, distance from road, distance from settlement, park area, visitor rate, and urbanization intensity) were measured using ArcGIS and google earth. We analyzed species data for diversity and richness. We explored the relation of species diversity and richness to habitat variables using the multi-model inference approach. Diversity and richness are found significant in different park sizes and their urbanization intensity. Medium size park supports more diversity, whereas large size park has more richness. However, diversity and richness both declined with increasing urbanization intensity. The result of CCA revealed that species composition in urban parks was positively associated with tree diameter at breast height and distance from the settlement. On the model selection approach, disturbance variables, especially distance from road, urbanization intensity, and visitors are the best predictors for the species richness of birds in urban parks. In comparison, multiple regression analysis between habitat variables and bird diversity suggested that native tree species in the park may explain the diversity pattern of birds in urban parks. Feeding guilds such as insectivores, omnivores, carnivores, granivores, and frugivores showed a significant relation with vegetation variables, while carnivores and scavenger bird species mainly responded with disturbance variables. The study highlights the importance of park size in urban areas and their urbanization intensity. It also indicates that distance from the settlement, distance from the road, urbanization intensity, visitors, diameter at breast height, and native tree species can be important determining factors for bird richness and diversity in urban parks. The study also concludes that the response of feeding guilds to vegetation and disturbance in urban parks varies. Therefore, we recommend that park size and surrounding urban matrix should be considered in order to increase bird diversity and richness in urban areas for designing and planning.

Keywords: diversity, feeding guild, urban park, urbanization intensity

Procedia PDF Downloads 84

Authors: José Manuel Palma, Paula Pereira, Margarida Tomás

Abstract:

Foreseen the future: Human factors integration in European Horizon Projects The development of new technology as artificial intelligence, smart sensing, robotics, cobotics or intelligent machinery must integrate human factors to address the need to optimize systems and processes, thereby contributing to the creation of a safe and accident-free work environment. Human Factors Integration (HFI) consistently pose a challenge for organizations when applied to daily operations. AGILEHAND and FORTIS projects are grounded in the development of cutting-edge technology - industry 4.0 and 5.0. AGILEHAND aims to create advanced technologies for autonomously sort, handle, and package soft and deformable products, whereas FORTIS focuses on developing a comprehensive Human-Robot Interaction (HRI) solution. Both projects employ different approaches to explore HFI. AGILEHAND is mainly empirical, involving a comparison between the current and future work conditions reality, coupled with an understanding of best practices and the enhancement of safety aspects, primarily through management. FORTIS applies HFI throughout the project, developing a human-centric approach that includes understanding human behavior, perceiving activities, and facilitating contextual human-robot information exchange. it intervention is holistic, merging technology with the physical and social contexts, based on a total safety culture model. In AGILEHAND we will identify safety emergent risks, challenges, their causes and how to overcome them by resorting to interviews, questionnaires, literature review and case studies. Findings and results will be presented in “Strategies for Workers’ Skills Development, Health and Safety, Communication and Engagement” Handbook. The FORTIS project will implement continuous monitoring and guidance of activities, with a critical focus on early detection and elimination (or mitigation) of risks associated with the new technology, as well as guidance to adhere correctly with European Union safety and privacy regulations, ensuring HFI, thereby contributing to an optimized safe work environment. To achieve this, we will embed safety by design, and apply questionnaires, perform site visits, provide risk assessments, and closely track progress while suggesting and recommending best practices. The outcomes of these measures will be compiled in the project deliverable titled “Human Safety and Privacy Measures”. These projects received funding from European Union’s Horizon 2020/Horizon Europe research and innovation program under grant agreement No101092043 (AGILEHAND) and No 101135707 (FORTIS).

Keywords: human factors integration, automation, digitalization, human robot interaction, industry 4.0 and 5.0

Procedia PDF Downloads 38

Authors: Evans V. Mauda, Stefan H. Foord, Thinandavha C. Munyai

Abstract:

The greatest threat to biodiversity is a loss of habitat through landscape fragmentation and attrition. Land use changes are therefore among the most immediate drivers of species diversity. Urbanization and agriculture are the main drivers of habitat loss and transformation in the Savanna biomes of South Africa. Agricultural expansion and the intensification in particular, take place at the expense of biodiversity and will probably be the primary driver of biodiversity loss in this century. Arthropods show measurable behavioural responses to changing land mosaics at the smallest scale and heterogeneous environments are therefore predicted to support more complex and diverse biological assemblages. Ants are premier soil turners, channelers of energy and dominate insect fauna, while spiders are a mega-diverse group that can regulate other invertebrate populations. This study aims to quantify the response of these two taxa in a rural-urban mosaic of a rapidly developing communal area. The study took place in and around two villages in the north-eastern corner of South Africa. Two replicates for each of the dominant land use categories, viz. urban settlements, dryland cultivation and cattle rangelands, were set out in each of the villages and sampled during the dry and wet seasons for a total of 2 villages × 3 land use categories × 2 seasons = 24 assemblages. Local scale variables measured included vertical and horizontal habitat structure as well as structural and chemical composition of the soil. Ant richness was not affected by land use but local scale variables such as vertical vegetation structure (+) and leaf litter cover (+), although vegetation complexity at lower levels was negatively associated with ant richness. However, ant richness was largely shaped by regional and temporal processes invoking the importance of dispersal and historical processes. Spider species richness was mostly affected by land use and local conditions highlighting their landscape elements. Spider richness did not vary much between villages and across seasons and seems to be less dependent on context or history. There was a considerable amount of variation in spider richness that was not explained and this could be related to factors which were not measured in this study such as temperature and competition. For both ant and spider assemblages the constrained ordination explained 18 % of variation in these taxa. Three environmental variables (leaf litter cover, active carbon and rock cover) were important in explaining ant assemblage structure, while two (sand and leaf litter cover) were important for spider assemblage structure. This study highlights the importance of disturbance (land use activities) and leaf litter with the associated effects on ant and spider assemblages across the study area.

Keywords: ants, assemblages, biosphere, diversity, land use, spiders, urbanization

Procedia PDF Downloads 255

Authors: Vineet Agrawal, Deepanjali S., Medha R., Subitha L.

Abstract:

Background. Hospital malnutrition is a highly prevalent issue and is known to increase the morbidity, mortality, length of hospital stay, and cost of care. In India, studies on hospital malnutrition have been restricted to ICU, post-surgical, and cancer patients. We designed this study to assess the impact of hospital malnutrition on 30-day post-discharge and in-hospital mortality in patients admitted in the general medicine department, irrespective of diagnosis. Methodology. All patients aged above 18 years admitted in the medicine wards, excluding medico-legal cases, were enrolled in the study. Nutritional assessment was done within 72 h of admission, using Subjective Global Assessment (SGA), which classifies patients into three categories: Severely malnourished, Mildly/moderately malnourished, and Normal/well-nourished. Anthropometric measurements like Body Mass Index (BMI), Triceps skin-fold thickness (TSF), and Mid-upper arm circumference (MUAC) were also performed. Patients were followed-up during hospital stay and 30 days after discharge through telephonic interview, and their final diagnosis, comorbidities, and cause of death were noted. Multivariate logistic regression and cox regression model were used to determine if the nutritional status at admission independently impacted mortality at one month. Results. The prevalence of malnourishment by SGA in our study was 67.3% among 395 hospitalized patients, of which 155 patients (39.2%) were moderately malnourished, and 111 (28.1%) were severely malnourished. Of 395 patients, 61 patients (15.4%) expired, of which 30 died in the hospital, and 31 died within 1 month of discharge from hospital. On univariate analysis, malnourished patients had significantly higher morality (24.3% in 111 Cat C patients) than well-nourished patients (10.1% in 129 Cat A patients), with OR 9.17, p-value 0.007. On multivariate logistic regression, age and higher Charlson Comorbidity Index (CCI) were independently associated with mortality. Higher CCI indicates higher burden of comorbidities on admission, and the CCI in the expired patient group (mean=4.38) was significantly higher than that of the alive cohort (mean=2.85). Though malnutrition significantly contributed to higher mortality on univariate analysis, it was not an independent predictor of outcome on multivariate logistic regression. Length of hospitalisation was also longer in the malnourished group (mean= 9.4 d) compared to the well-nourished group (mean= 8.03 d) with a trend towards significance (p=0.061). None of the anthropometric measurements like BMI, MUAC, or TSF showed any association with mortality or length of hospitalisation. Inference. The results of our study highlight the issue of hospital malnutrition in medicine wards and reiterate that malnutrition contributes significantly to patient outcomes. We found that SGA performs better than anthropometric measurements in assessing under-nutrition. We are of the opinion that the heterogeneity of the study population by diagnosis was probably the primary reason why malnutrition by SGA was not found to be an independent risk factor for mortality. Strategies to identify high-risk patients at admission and treat malnutrition in the hospital and post-discharge are needed.

Keywords: hospitalization outcome, length of hospital stay, mortality, malnutrition, subjective global assessment (SGA)

Procedia PDF Downloads 133

Authors: Riddhi Chopra

Abstract:

Alfred Thayer Mahan described the sea as a ‘great common,’ which would serve as a medium for communication, trade, and transport. The seas of Asia are witnessing an intriguing historical anomaly – rise of an indigenous maritime power against the backdrop of US domination over the region. As China transforms from an inward leaning economy to an outward-leaning economy, it has become increasingly dependent on the global sea; as a result, we witness an evolution in its maritime strategy from near seas defense to far seas deployment strategies. It is not only patrolling the international waters but has also built a network of civilian and military infrastructure across the disputed oceanic expanse. The paper analyses the reorientation of China from a naval power to a blue water navy in an era of extensive globalisation. The actions of the Chinese have created a zone of high alert amongst its neighbors such as Japan, Philippines, Vietnam and North Korea. These nations are trying to align themselves so as to counter China’s growing brinkmanship, but China has been pursuing claims through a carefully calibrated strategy in the region shunning any coercive measures taken by other forces. If China continues to expand its maritime boundaries, its neighbors – all smaller and weaker Asian nations would be limited to a narrow band of the sea along its coastlines. Hence it is essential for the US to intervene and support its allies to offset Chinese supremacy. The paper intends to provide a profound analysis over the disputes in South China Sea and East China Sea focusing on Philippines and Japan respectively. Moreover, the paper attempts to give an account of US involvement in the region and its alignment with its South Asian allies. The geographic dynamics is said the breed a national coalition dominating the strategic ambitions of China as well as the weak littoral states. China has conducted behind the scenes diplomacy trying to persuade its neighbors to support its position on the territorial disputes. These efforts have been successful in creating fault lines in ASEAN thereby undermining regional integrity to reach a consensus on the issue. Chinese diplomatic efforts have also forced the US to revisit its foreign policy and engage with players like Cambodia and Laos. The current scenario in the SCS points to a strong Chinese hold trying to outspace all others with no regards to International law. Chinese activities are in contrast with US principles like Freedom of Navigation thereby signaling US to take bold actions to prevent Chinese hegemony in the region. The paper ultimately seeks to explore the changing power dynamics among various claimants where a rival superpower like US can pursue the traditional policy of alliance formation play a decisive role in changing the status quo in the arena, consequently determining the future trajectory.

Keywords: China, East China Sea, South China Sea, USA

Procedia PDF Downloads 223

Authors: Mohammad Ehsani, Iman Zarei, Soudabeh Moazemigoudarzi

Abstract:

The aim of this study is to determine Pro-Environmental Behavioral Intention of Mountain Hikers to the Theory of Planned Behavior. According to many researchers nature-based recreation activities play a significant role in the tourism industry and have provided myriad opportunities for the protection of natural areas. It is essential to investigate individuals' behavior during such activities to avoid further damage to precious and dwindling natural resources. This study develops a robust model that provides a comprehensive understanding of the formation of pro-environmental behavioral intentions among climbers of Mount Damavand National Park in Iran. To this end, we combined the theory of planned behavior (TPB), value-belief-norm theory (VBN), and a hierarchical model of leisure constraints to predict individuals’ pro-environmental hiking behavior during outdoor recreation. It was used structural equation modeling to test the theoretical framework. A sample of 787 climbers was analyzed. Among the theory of planned behavior variables, perceived behavioral control showed the strongest association with behavioral intention (β = .57). This relationship indicates that if people feel they can have fewer negative impacts on national resources while hiking, it will result in more environmentally acceptable behavior. Subjective norms had a moderate positive impact on behavioral intention, indicating the importance of other people on the individual's behavior. Attitude had a small positive effect on intention. Ecological worldview positively influenced attitude and personal belief. Personal belief (awareness of consequences and ascribed responsibility) showed a positive association with TPB variables. Although the data showed a high average score in awareness of consequences (mean = 4.219 out of 5), evidence from Damavand Mount shows that there are many environmental issues that need addressing (e.g., vast amounts of garbage). National park managers need to make sure that their solutions result in awareness about proenvironmental behavior (PEB). Findings showed that negative relationship between constraints and all TPB predictors. Providing proper restrooms and parking spaces in campgrounds, strategies controlling limiting capacity and solutions for removing waste from high altitudes are helpful to decrease the negative impact of structural constraints. In order to address intrapersonal constraints, managers should provide opportunities to interest individuals in environmental activities, such as environmental celebrations or making documentaries about environmental issues. Moreover, promoting a culture of environmental protection in the Damavand Mount area would reduce interpersonal constraints. Overall, the proposed model improved the explanatory power of the TPB by predicting 64.7% of intention compared to the original TPB that accounted for 63.8% of the variance in intention.

Keywords: theory of planned behavior, pro-environmental behavior, national park, constraints

Procedia PDF Downloads 82

Authors: Hasmithaa Neha, Atul Kumar Patidar, Girish Ch Kothyari

Abstract:

The northward convergence of the Indian plate has a dominating influence over the structural and geomorphic development of the Himalayan region. The highly deformed and complex stratigraphy in the area arises from a confluence of exogenic and endogenetic geological processes. This region frequently experiences natural hazards such as debris flows, flash floods, avalanches, landslides, and earthquakes due to its harsh and steep topography and fragile rock formations. Therefore, remote sensing technique-based examination and real-time monitoring of tectonically sensitive regions may provide crucial early warnings and invaluable data for effective hazard mitigation strategies. In order to identify unusual changes in the river gradients, the current study demonstrates a spatial quantitative geomorphic analysis of the upper Alaknanda River basin, Uttarakhand Himalaya, India, using gradient length anomaly analysis (GLAA). This basin is highly vulnerable to ground creeping and landslides due to the presence of active faults/thrusts, toe-cutting of slopes for road widening, development of heavy engineering projects on the highly sheared bedrock, and periodic earthquakes. The intersecting joint sets developed in the bedrocks have formed wedges that have facilitated the recurrence of several landslides. The main objective of current research is to identify abnormal gradient lengths, indicating potential landslide-prone zones. High-resolution digital elevation data and geospatial techniques are used to perform this analysis. The results of GLAA are corroborated with the historical landslide events and ultimately used for the generation of landslide susceptibility maps of the current study area. The preliminary results indicate that approximately 3.97% of the basin is stable, while about 8.54% is classified as moderately stable and suitable for human habitation. However, roughly 19.89% fall within the zone of moderate vulnerability, 38.06% are classified as vulnerable, and 29% fall within the highly vulnerable zones, posing risks for geohazards, including landslides, glacial avalanches, and earthquakes. This research provides valuable insights into the spatial distribution of landslide-prone areas. It offers a basis for implementing proactive measures for landslide risk reduction, including land-use planning, early warning systems, and infrastructure development techniques.

Keywords: landslide vulnerability, geohazard, GLA, upper Alaknanda Basin, Uttarakhand Himalaya

Procedia PDF Downloads 48

Authors: Justin Durham, Chanda Rooney, Robert Mather, Mickie Vanhoy

Abstract:

The psychological construct of empathy is to understand a person’s cognitive perspective and experience the other person’s emotional state. Deciphering emotional states is conducive for interpreting vicarious pain. Observing others' physical pain activates neural networks related to the actual experience of pain itself. The study addresses empathy as a nonlinear dynamic process of simulation for individuals to understand the mental states of others and experience vicarious pain, exhibiting self-organized criticality. Such criticality follows from a combination of neural networks with an excitatory feedback loop generating bistability to resonate permutated empathy. Cortical networks exhibit diverse patterns of activity, including oscillations, synchrony and waves, however, the temporal dynamics of neurophysiological activities underlying empathic processes remain poorly understood. Mu rhythms are EEG oscillations with dominant frequencies of 8-13 Hz becoming synchronized when the body is relaxed with eyes open and when the sensorimotor system is in idle, thus, mu rhythm synchrony is expected to be highest in baseline conditions. When the sensorimotor system is activated either by performing or simulating action, mu rhythms become suppressed or desynchronize, thus, should be suppressed while observing video clips of painful injuries if previous research on mirror system activation holds. Twelve undergraduates contributed EEG data and survey responses to empathy and psychopathy scales in addition to watching consecutive video clips of sports injuries. Participants watched a blank, black image on a computer monitor before and after observing a video of consecutive sports injuries incidents. Each video condition lasted five-minutes long. A BIOPAC MP150 recorded EEG signals from sensorimotor and thalamocortical regions related to a complex neural network called the ‘pain matrix’. Physical and social pain are activated in this network to resonate vicarious pain responses to processing empathy. Five EEG single electrode locations were applied to regions measuring sensorimotor electrical activity in microvolts (μV) to monitor mu rhythms. EEG signals were sampled at a rate of 200 Hz. Mu rhythm desynchronization was measured via 8-13 Hz at electrode sites (F3 & F4). Data for each participant’s mu rhythms were analyzed via Fast Fourier Transformation (FFT) and multifractal time series analysis.

Keywords: desynchronization, dynamical systems theory, electroencephalography (EEG), empathy, multifractal time series analysis, mu waveform, neurophysiology, pain simulation, social cognition

Procedia PDF Downloads 270

Authors: Ashir Ahmed

Abstract:

Generally, radicalization happens when a person's thinking and behaviour become significantly different from how most of the members of their society and community view social issues and participate politically. Radicalization often leads to violent extremism that refers to the beliefs and actions of people who support or use violence to achieve ideological, religious or political goals. Studies on radicalization negate the common myths that someone must be in a group to be radicalised or anyone who experiences radical thoughts is a violent extremist. Moreover, it is erroneous to suggest that radicalisation is always linked to religion. Generally, the common motives of radicalization include ideological, issue-based, ethno-nationalist or separatist underpinning. Moreover, there are number of factors that further augments the chances of someone being radicalised and may choose the path of violent extremism and possibly terrorism. Since there are numbers of factors (and sometimes quite different) contributing in radicalization and violent extremism, it is highly unlikely to devise a single solution that could produce effective outcomes to deal with radicalization, violent extremism and terrorism. The pathway to deradicalization, like the pathway to radicalisation, is different for everyone. Considering the need of having customized deradicalization resolution, this study proposes a multi-tier framework, called ‘pyramid of deradicalization’ that first help identifying the stage at which an individual could be on the radicalization pathway and then propose a customize strategy to deal with the respective stage. The first tier (tier 1) addresses broader community and proposes a ‘universal approach’ aiming to offer community-based design and delivery of educational programs to raise awareness and provide general information on possible factors leading to radicalization and their remedies. The second tier focuses on the members of community who are more vulnerable and are disengaged from the rest of the community. This tier proposes a ‘targeted approach’ targeting the vulnerable members of the community through early intervention such as providing anonymous help lines where people feel confident and comfortable in seeking help without fearing the disclosure of their identity. The third tier aims to focus on people having clear evidence of moving toward extremism or getting radicalized. The people falls in this tier are believed to be supported through ‘interventionist approach’. The interventionist approach advocates the community engagement and community-policing, introducing deradicalization programmes to the targeted individuals and looking after their physical and mental health issues. The fourth and the last tier suggests the strategies to deal with people who are actively breaking the law. ‘Enforcement approach’ suggests various approaches such as strong law enforcement, fairness and accuracy in reporting radicalization events, unbiased treatment by law based on gender, race, nationality or religion and strengthen the family connections.It is anticipated that the operationalization of the proposed framework (‘pyramid of deradicalization’) would help in categorising people considering their tendency to become radicalized and then offer an appropriate strategy to make them valuable and peaceful members of the community.

Keywords: deradicalization, framework, terrorism, violent extremism

Procedia PDF Downloads 245

Authors: Simon Grossemy, Peggy P. Y. Chan, Pauline M. Doran

Abstract:

Nerve tissue engineering is the main field of research aimed at finding an alternative to autografts as a treatment for nerve injuries. Scaffolds are used as a support to enhance nerve regeneration. In order to successfully design novel scaffolds and in vitro cell culture systems, a deep understanding of the factors affecting nerve regeneration processes is needed. Physical and biological parameters associated with the culture environment have been identified as potentially influential in nerve cell differentiation, including electrical stimulation, exposure to extracellular-matrix (ECM) proteins, dynamic medium conditions and co-culture with glial cells. The mechanisms involved in driving the cell to differentiation in the presence of these factors are poorly understood; the complexity of each of them raises the possibility that they may strongly influence each other. Some questions that arise in investigating nerve regeneration include: What are the best protein coatings to promote neural cell attachment? Is the scaffold design suitable for providing all the required factors combined? What is the influence of dynamic stimulation on cell viability and differentiation? In order to study these effects, scaffolds adaptable to bioreactor culture conditions were designed to allow electrical stimulation of cells exposed to ECM proteins, all within a dynamic medium environment. Gold coatings were used to make the surface of viscose rayon microfiber scaffolds (VRMS) conductive, and poly-L-lysine (PLL) and laminin (LN) surface coatings were used to mimic the ECM environment and allow the attachment of rat PC12 neural cells. The robustness of the coatings was analyzed by surface resistivity measurements, scanning electron microscope (SEM) observation and immunocytochemistry. Cell attachment to protein coatings of PLL, LN and PLL+LN was studied using DNA quantification with Hoechst. The double coating of PLL+LN was selected based on high levels of PC12 cell attachment and the reported advantages of laminin for neural differentiation. The underlying gold coatings were shown to be biocompatible using cell proliferation and live/dead staining assays. Coatings exhibiting stable properties over time under dynamic fluid conditions were developed; indeed, cell attachment and the conductive power of the scaffolds were maintained over 2 weeks of bioreactor operation. These scaffolds are promising research tools for understanding complex neural cell behavior. They have been used to investigate major factors in the physical culture environment that affect nerve cell viability and differentiation, including electrical stimulation, bioreactor hydrodynamic conditions, and combinations of these parameters. The cell and tissue differentiation response was evaluated using DNA quantification, immunocytochemistry, RT-qPCR and functional analyses.

Keywords: bioreactor, electrical stimulation, nerve differentiation, PC12 cells, scaffold

Procedia PDF Downloads 221

Authors: Juan Bernal-Martinez, Zoe Quinones-Jurado, Miguel Waldo-Mendoza, Elias Perez

Abstract:

Introduction and Objective: Ag-TiO2 nanoparticles (NP) have been characterized as effective antibacterial compounds against E. aureous, E. coli, Salmonella and others. Because these nanoparticles have been used in plastic-food containers, there is a concern about the toxicity of Ag-TiO2 NP for higher organisms from protozoan, invertebrates, and mammals. The objective of this study is to evaluate the cytotoxic effect of Ag-TiO2 NP on the survival and swimming behavior of the unicellular organism Paramecium tetraurelia. Material and Methods: Preparation of metallic silver on TiO2 surface was based on chemical reduction route of AgNO3. Aqueous suspension of TiO2 nanoparticles was preparing by adding 5 g of TiO2 to 250 ml of deionized water and followed by sonication for 10 min. The required amount of AgNO3 solutions was added to TiO2 suspension, maintaining heating and stirring. Silver concentration was 0.5, 1.5, 5.0, 25, 35 and 45 % w/w versus TiO2. Paramecium tetraurelia (Carolina Biological, Cat. # 131560) was used as a biological preparation. It was cultured in artificial culture media made as follows: Stigmasterol 5 mg/ml of ethanol, Caseaminoacids 0.3 gr/lt.; KCl 4mM; CaCl2 1mM; MgCl2 100uM and MOPS 1mM, pH 7.3. This media was inoculated with Enterobacter-sp. Paramecium was concentrated after 24 hours of incubation by centrifugation. The pellet of cells was resuspended in 4.1.1 solution prepared as follows (in mM): KCl, 4 mM; CaCl2, 1mM and Trizma, 1mM; pH 7.3. Transmission electron microscopy (TEM) studies were performed to evaluate the appropriate dispersion and topographic distribution AgNPs deposited on TiO2. The experimental solutions were prepared as follows: 50 mg of Polyvinyhlpirolidone were added to 5 ml of 4.1.1. solution. Then, 50 mg of powder 25-Ag-TiO2 was added, mixing for 10 min and sonicated for 60 min. Survival of Paramecium and possible toxic effects after 25-Ag-TiO2 treatment was observed through an inverted microscope. The Paramecium swimming behavior and possible dead cells were recorded for periods of approximately 20-50 seconds by using a digital USB camera adapted to the microscope. Results and Discussion: TEM micrographs demonstrated the topographic distribution of AgNPs deposited on TiO2. 25Ag-TiO2 NP was efficiently dissolved and dispersed in 4.1.1 solution at concentrations from 0.1, 1 and 10 mg/ml. When Paramecium were treated with 25Ag-TiO2 NP at 100 ug/ml, it was observed that cells started swimming backwards. This backward swimming behavior is the typical avoiding reaction of the ciliate in response to a noxious stimulus. After 10 min of incubation, it was observed that Paramecium stopped swimming backwards and exploited. We can argue that this toxic effect of 25Ag-TiO2 NP is probably due to the calcium influx and calcium accumulation during the long-lasting swimming backwards. Conclusions: Here we have demonstrated that 25Ag-TiO2 NP has a specific toxic effect on an organism higher than bacteria such as the protozoan Paremecium. Probably these toxic phenomena could be expected to be observed in a higher organism such as invertebrates and mammals.

Keywords: Ag-TiO2, calcium permeability, cytotoxicity, paramecium

Procedia PDF Downloads 275

Authors: Fentie Bishaw Wagayie

Abstract:

This study was carried out with the objective of studying the response of Farta sheep in feed intake and live weight change when fed on hay supplemented with noug seed cake (NSC), wheat bran (WB), and their mixtures. The digestibility trial of 7 days and 90 days of feeding trial was conducted using 25 intact male Farta sheep with a mean initial live weight of 16.83 ± 0.169 kg. The experimental animals were arranged randomly into five blocks based on the initial live weight, and the five treatments were assigned randomly to each animal in a block. Five dietary treatments used in the experiment comprised of grass hay fed ad libitum (T1), grass hay ad libitum + 300 g DM WB (T2), grass hay ad libitum + 300 g DM (67% WB: 33% NSC mixture) (T3), grass hay ad libitum + 300 g DM (67% NSC: 33% WB) (T4) and 300 g DM/ head/day NSC (T5). Common salt and water were offered ad libitum. The supplements were offered twice daily at 0800 and 1600 hours. The experimental sheep were kept in individual pens. Supplementation of NSC, WB, and their mixtures significantly increased (p < 0.01) the total dry matter (DM) (665.84-788 g/head/day) and (p < 0.001) crude protein (CP) intake. Unsupplemented sheep consumed significantly higher (p < 0.01) grass hay DM (540.5g/head/day) as compared to the supplemented treatments (365.8-488 g/h/d), except T2. Among supplemented sheep, T5 had significantly higher (p < 0.001) CP intake (99.98 g/head/day) than the others (85.52-90.2 g/head/day). Supplementation significantly improved (p < 0.001) the digestibility of CP (66.61-78.9%), but there was no significant effect (p > 0.05) on DM, OM, NDF, and ADF digestibility between supplemented and control treatments. Very low CP digestibility (11.55%) observed in the basal diet (grass hay) used in this study indicated that feeding sole grass hay could not provide nutrients even for the maintenance requirement of growing sheep. Significant final and daily live weight gain (p < 0.001) in the range of 70.11-82.44 g/head/day was observed in supplemented Farta sheep, but unsupplemented sheep lost weight by 9.11g/head/day. Numerically, among the supplemented treatments, sheep supplemented with a higher proportion of NSC in T4 (201 NSC + 99 g WB) gained more weight than the rest, though not statistically significant (p > 0.05). The absence of statistical difference in daily body weight gain between all supplemented sheep indicated that the supplementation of NSC, WB, and their mixtures had similar potential to provide nutrients. Generally, supplementation of NSC, WB, and their mixtures to the basal grass hay diet improved feed conversion ratio, total DM intake, CP intake, and CP digestibility, and it also improved the growth performance with a similar trend for all supplemented Farta sheep over the control group. Therefore, from a biological point of view, to attain the required level of slaughter body weight within a short period of the growing program, sheep producer can use all the supplement types depending upon their local availability, but in the order of priority, T4, T5, T3, and T2, respectively. However, based on partial budget analysis, supplementation of 300 g DM/head /day NSC (T5) could be recommended as profitable for producers with no capital limitation, whereas T4 supplementation (201 g NSC + 99 WB DM/day) is recommended when there is capital scarcity.

Keywords: weight gain, supplement, Farta sheep, hay as basal diet

Procedia PDF Downloads 42

Authors: Laila Albughayl

Abstract:

The purpose of this qualitative case study was to explore Saudi females’ leadership journeys as they navigate the labyrinth of leadership in higher education. To gain a better understanding of how these leaders overcame challenges and accessed support as they progressed through the labyrinth to top positions in Saudi higher education. The significance of this research derived from the premise that leaders need to acquire essential leadership competencies such as knowledge, skills, and practices to effectively lead through economic transformation, growing globalism, and rapidly developing technology in an increasingly diverse world. In addition, understanding Saudi women’s challenges in the labyrinth will encourage policymakers to improve the situation under which these women work. The metaphor ‘labyrinth’ for Eagly and Carli (2007) encapsulates the winding paths, dead ends, and maze-like pathways that are full of challenges and supports that women traverse to access and maintain leadership positions was used. In this study, ‘labyrinth’ was used as the conceptual framework to explore women leaders’ challenges and opportunities in leadership in Saudi higher education. A proposed model for efficient navigation of the labyrinth of leadership was used. This model focused on knowledge, skills, and behaviours (KSB) as the analytical framework for examining responses to the research questions. This research was conducted using an interpretivist qualitative approach. A case study was the methodology used. Semi-structured interviews were the main data collection method. Purposive sampling was used to select ten Saudi leaders in three public universities. In coding, the 6-step framework of thematic analysis for Braun and Clarke was used to identify, analyze, and report themes within the data. NVivo software was also used as a tool to assist with managing and organizing the data. The resultant findings showed that the challenges identified by participants in navigating the labyrinth of leadership in Saudi higher education replicated some of those identified in the literature. The onset findings also revealed that the organizational barriers in Saudi higher education came as the top hindrance to women’s advancement in the labyrinth of leadership, followed by societal barriers. The findings also showed that women’s paths in the labyrinth of leadership in higher education were still convoluted and tedious compared to their male counterparts. In addition, the findings revealed that Saudi women leaders use significant strategies to access leadership posts and effectively navigate the labyrinth; this was not indicated in the literature. In addition, the resultant findings revealed that there are keys that assisted Saudi female leaders in effectively navigating the labyrinth of leadership. For example, the findings indicated that spirituality (religion) was a powerful key that enabled Saudi women leaders to pursue and persist in their leadership paths. Based on participants' experiences, a compass for effective navigation of the labyrinth of leadership in higher education was created for current and aspirant Saudi women leaders to follow. Finally, the findings had several significant implications for practice, policy, theory, and future research.

Keywords: women, leadership, labyrinth, higher education

Procedia PDF Downloads 66

Authors: Merve Uzuner Sahin, Kumru D. Atalay, Berna Dengiz

Abstract:

In today’s competitive market, there are many alternative products that can be used in similar manner and purpose. Therefore, the utility of the product is an important issue for the preferability of the brand. This utility could be measured in terms of its functionality, durability, reliability. These all are affected by the system capabilities. Reliability is an important system design criteria for the manufacturers to be able to have high availability. Availability is the probability that a system (or a component) is operating properly to its function at a specific point in time or a specific period of times. System availability provides valuable input to estimate the production rate for the company to realize the production plan. When considering only the corrective maintenance downtime of the system, mean time between failure (MTBF) and mean time to repair (MTTR) are used to obtain system availability. Also, the MTBF and MTTR values are important measures to improve system performance by adopting suitable maintenance strategies for reliability engineers and practitioners working in a system. Failure and repair time probability distributions of each component in the system should be known for the conventional availability analysis. However, generally, companies do not have statistics or quality control departments to store such a large amount of data. Real events or situations are defined deterministically instead of using stochastic data for the complete description of real systems. A fuzzy set is an alternative theory which is used to analyze the uncertainty and vagueness in real systems. The aim of this study is to present a novel approach to compute system availability using representation of MTBF and MTTR in fuzzy numbers. Based on the experience in the system, it is decided to choose 3 different spread of MTBF and MTTR such as 15%, 20% and 25% to obtain lower and upper limits of the fuzzy numbers. To the best of our knowledge, the proposed method is the first application that is used fuzzy MTBF and fuzzy MTTR for fuzzy system availability estimation. This method is easy to apply in any repairable production system by practitioners working in industry. It is provided that the reliability engineers/managers/practitioners could analyze the system performance in a more consistent and logical manner based on fuzzy availability. This paper presents a real case study of a repairable multi-stage production line in lead-acid battery production factory in Turkey. The following is focusing on the considered wet-charging battery process which has a higher production level than the other types of battery. In this system, system components could exist only in two states, working or failed, and it is assumed that when a component in the system fails, it becomes as good as new after repair. Instead of classical methods, using fuzzy set theory and obtaining intervals for these measures would be very useful for system managers, practitioners to analyze system qualifications to find better results for their working conditions. Thus, much more detailed information about system characteristics is obtained.

Keywords: availability analysis, battery production system, fuzzy sets, triangular fuzzy numbers (TFNs)

Procedia PDF Downloads 202

Authors: Heiko Jessen, Laura Tanus, Slobodan Ruzicic

Abstract:

Objectives: The efficacy of Stribild®, an integrase strand transfer inhibitor (INSTI) -based STR, has been evaluated in randomized clinical trials and it has demonstrated durable capability in terms of achieving sustained suppression of HIV-1 RNA-levels. However, differences in monitoring frequency, existing selection bias and profile of patients enrolled in the trials, may all result in divergent efficacy of this regimen in routine clinical settings. The aim of this study was to assess the virologic outcomes, safety and tolerability profile of Stribild® in a routine clinical setting. Methods: This was a retrospective monocentric analysis on HIV-1-infected patients, who started with or were switched to Stribild®. Virological failure (VF) was defined as confirmed HIV-RNA>50 copies/ml. The minimum time of follow-up was 24 weeks. The percentage of patients remaining free of therapeutic failure was estimated using the time-to-loss-of-virologic-response (TLOVR) algorithm, by intent-to-treat analysis. Results: We analyzed the data of 197 patients (56 ART-naïve and 141 treatment-experienced patients), who fulfilled the inclusion criteria. Majority (95.9%) of patients were male. The median time of HIV-infection at baseline was 2 months in treatment-naïve and 70 months in treatment-experienced patients. Median time [IQR] under ART in treatment-experienced patients was 37 months. Among the treatment-experienced patients 27.0% had already been treated with a regimen consisting of two NRTIs and one INSTI, whereas 18.4% of them experienced a VF. The median time [IQR] of virological suppression prior to therapy with Stribild® in the treatment-experienced patients was 10 months [0-27]. At the end of follow-up (median 33 months), 87.3% (95% CI, 83.5-91.2) of treatment-naïve and 80.3% (95% CI, 75.8-84.8) of treatment-experienced patients remained free of therapeutic failure. Considering only treatment-experienced patients with baseline VL<50 copies/ml, 83.0% (95% CI, 78.5-87.5) remained free of therapeutic failure. A total of 17 patients stopped treatment with Stribild®, 5.4% (3/56) of them were treatment-naïve and 9.9% (14/141) were treatment-experienced patients. The Stribild® therapy was discontinued in 2 (1.0%) because of VF, loss to follow-up in 4 (2.0%), and drug-drug interactions in 2 (1.0%) patients. Adverse events were in 7 (3.6%) patients the reason to switch from therapy with Stribild® and further 2 (1.0%) patients decided personally to switch. The most frequently observed adverse events were gastrointestinal side effects (20.0%), headache (8%), rash events (7%) and dizziness (6%). In two patients we observed an emergence of novel resistances in integrase-gene. The N155H evolved in one patient and resulted in VF. In another patient S119R evolved either during or shortly upon switch from therapy with Stribild®. In one further patient with VF two novel mutations in the RT-gene were observed when compared to historical genotypic test result (V106I/M and M184V), whereby it is not clear whether they evolved during or already before the switch to Stribild®. Conclusions: Effectiveness of Stribild® for treatment-naïve patients was consistent with data obtained in clinical trials. The safety and tolerability profile as well as resistance development confirmed clinical efficacy of Stribild® in a daily practice setting.

Keywords: ART, HIV, integrase inhibitor, stribild

Procedia PDF Downloads 268

Authors: Pedro J. Rolim-Neto, Leslie R. M. Ferraz, Fabiana L. A. Santos, Pablo A. Ferreira, Ricardo T. L. Maia-Jr., Magaly A. M. Lyra, Danilo A F. Fonte, Salvana P. M. Costa, Amanda C. Q. M. Vieira, Larissa A. Rolim

Abstract:

Initially developed as an antimalarial agent, hydroxychloroquine (HCQ) sulfate is often used as a slow-acting antirheumatic drug in the treatment of disorders of connective tissue. The United States Pharmacopeia (USP) 37 provides a reversed-phase HPLC method for quantification of HCQ. However, this method was not reproducible, producing asymmetric peaks in a long analysis time. The asymmetry of the peak may cause an incorrect calculation of the concentration of the sample. Furthermore, the analysis time is unacceptable, especially regarding the routine of a pharmaceutical industry. The aiming of this study was to develop a fast, easy and efficient method for quantification of HCQ sulfate by High Performance Liquid Chromatography (HPLC) based on the Quality by Design (QbD) methodology. This method was optimized in terms of peak symmetry using the surface area graphic as the Design of Experiments (DoE) and the tailing factor (TF) as an indicator to the Design Space (DS). The reference method used was that described at USP 37 to the quantification of the drug. For the optimized method, was proposed a 33 factorial design, based on the QbD concepts. The DS was created with the TF (in a range between 0.98 and 1.2) in order to demonstrate the ideal analytical conditions. Changes were made in the composition of the USP mobile-phase (USP-MP): USP-MP: Methanol (90:10 v/v, 80:20 v/v and 70:30 v/v), in the flow (0.8, 1.0 and 1.2 mL) and in the oven temperature (30, 35, and 40ºC). The USP method allowed the quantification of drug in a long time (40-50 minutes). In addition, the method uses a high flow rate (1,5 mL.min-1) which increases the consumption of expensive solvents HPLC grade. The main problem observed was the TF value (1,8) that would be accepted if the drug was not a racemic mixture, since the co-elution of the isomers can become an unreliable peak integration. Therefore, the optimization was suggested in order to reduce the analysis time, aiming a better peak resolution and TF. For the optimization method, by the analysis of the surface-response plot it was possible to confirm the ideal setting analytical condition: 45 °C, 0,8 mL.min-1 and 80:20 USP-MP: Methanol. The optimized HPLC method enabled the quantification of HCQ sulfate, with a peak of high resolution, showing a TF value of 1,17. This promotes good co-elution of isomers of the HCQ, ensuring an accurate quantification of the raw material as racemic mixture. This method also proved to be 18 times faster, approximately, compared to the reference method, using a lower flow rate, reducing even more the consumption of the solvents and, consequently, the analysis cost. Thus, an analytical method for the quantification of HCQ sulfate was optimized using QbD methodology. This method proved to be faster and more efficient than the USP method, regarding the retention time and, especially, the peak resolution. The higher resolution in the chromatogram peaks supports the implementation of the method for quantification of the drug as racemic mixture, not requiring the separation of isomers.

Keywords: analytical method, hydroxychloroquine sulfate, quality by design, surface area graphic

Procedia PDF Downloads 619

Authors: Yang Yang, Luciana Magalhães Rebelo Alencar, Martha Sahylí Ortega Pijeira, Beatriz da Silva Batista, Alefe Roger Silva França, Erick Rafael Dias Rates, Ruana Cardoso Lima, Sara Gemini-Piperni, Ralph Santos-Oliveira

Abstract:

Radium-²²³ dichloride ([²²³Rₐ]RₐCl₂) is an alpha particle-emitting radiopharmaceutical currently approved for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases, and no known visceral metastatic disease. [²²³Rₐ]RₐCl₂ is bone-seeking calcium mimetic that bonds into the newly formed bone stroma, especially osteoblastic or sclerotic metastases, killing the tumor cells by inducing DNA breaks in a potent and localized manner. Nonetheless, the successful therapy of osteosarcoma as primary bone tumors is still a challenge. Nanomicelles are colloidal nanosystems widely used in drug development to improve blood circulation time, bioavailability, and specificity of therapeutic agents, among other applications. In addition, the enhanced permeability and retention effect of the nanosystems, and the renal excretion of the nanomicelles reported in most cases so far, are very attractive to achieve selective and increased accumulation in tumor site as well as to increase the safety of [²²³Rₐ]RₐCl₂ in the clinical routine. In the present work, [²²³Rₐ]RₐCl₂ nanomicelles were produced, characterized, in vitro evaluated, and compared with pure [²²³Rₐ]RₐCl2 solution using SAOS2 osteosarcoma cells. The [²²³Rₐ]RₐCl₂ nanomicelles were prepared using the amphiphilic copolymer Pluronic F127. The dynamic light scattering analysis of freshly produced [²²³Rₐ]RₐCl₂ nanomicelles demonstrated a mean size of 129.4 nm with a polydispersity index (PDI) of 0.303. After one week stored in the refrigerator, the mean size of the [²²³Rₐ]RₐCl₂ nanomicelles increased to 169.4 with a PDI of 0.381. Atomic force microscopy analysis of [223Rₐ]RₐCl₂ nanomicelles exhibited spherical structures whose heights reach 1 µm, suggesting the filling of 127-Pluronic nanomicelles with [²²³Rₐ]RₐCl₂. The viability assay with [²²³Rₐ]RₐCl₂ nanomicelles displayed a dose-dependent response as it was observed using pure [²²³Rₐ]RₐCl2. However, at the same dose, [²²³Rₐ]RₐCl₂ nanomicelles were 20% higher efficient in killing SAOS2 cells when compared with pure [²²³Rₐ]RₐCl₂. These findings demonstrated the effectiveness of the nanosystem validating the application of nanotechnology in targeted alpha therapy with [²²³Ra]RₐCl₂. In addition, the [²²³Rₐ]RaCl₂nanomicelles may be decorated and incorporated with a great variety of agents and compounds (e.g., monoclonal antibodies, aptamers, peptides) to overcome the limited use of [²²³Ra]RₐCl₂.

Keywords: nanomicelles, osteosarcoma, radium dichloride, targeted alpha therapy

Procedia PDF Downloads 99

Authors: Shawn P. Daly

Abstract:

Communities heavily engaged in the tourism industry discover their values intersect, meld, and conflict with those of visitors. Maintaining cultural integrity in the face of powerful external pressures causes stress among society members. This effect represents a less studied aspect of sustainable tourism. The present paper brings a perspective unique to the tourism literature: biculturalism. The grounded theories, coherent hypotheses, and validated constructs and indicators of biculturalism represent a sound base from which to consider sociocultural issues in sustainable tourism. Five models describe the psychological state of individuals operating at cultural crossroads: assimilation (joining the new culture), acculturation (grasping the new culture but remaining of the original culture), alternation (varying behavior to cultural context), multicultural (maintaining distinct cultures), and fusion (blending cultures). These five processes divide into two units of analysis (individual and society), permitting research questions at levels important for considering sociocultural sustainability. Acculturation modelling has morphed into dual processes of acculturation (new culture adaptation) and enculturation (original culture adaptation). This dichotomy divides sustainability research questions into human impacts from assimilation (acquiring new culture, throwing away original), separation (rejecting new culture, keeping original), integration (acquiring new culture, keeping original), and marginalization (rejecting new culture, throwing away original). Biculturalism is often cast in terms of its emotional, behavioral, and cognitive dimensions. Required cultural adjustments and varying levels of cultural competence lead to physical, psychological, and emotional outcomes, including depression, lowered life satisfaction and self-esteem, headaches, and back pain—or enhanced career success, social skills, and life styles. Numerous studies provide empirical scales and research hypotheses for sustainability research into tourism’s causality and effect on local well-being. One key issue in applying biculturalism to sustainability scholarship concerns identification and specification of the alternative new culture contacting local culture. Evidence exists for tourism industry, universal tourist, and location/event-specific tourist culture. The biculturalism paradigm holds promise for researchers examining evolving cultural identity and integrity in response to mass tourism. In particular, confirmed constructs and scales simplify operationalization of tourism sustainability studies in terms of human impact and adjustment.

Keywords: biculturalism, cultural integrity, psychological and sociocultural adjustment, tourist culture

Procedia PDF Downloads 387

Authors: Wu Liching

Abstract:

Aim This case aims to discuss the pathogenesis, clinical manifestations and medical treatment of strokes caused by mitochondrial gene mutations. Methods Diagnosis of ischemic stroke caused by mitochondrial gene defect by means of "next-generation sequencing mitochondrial DNA gene variation detection", imaging examination, neurological examination, and medical history; this study took samples from the neurology ward of a medical center in northern Taiwan cases diagnosed with acute cerebral infarction as the research objects. Result This case is a 49-year-old married woman with a rare disease, mitochondrial gene mutation inducing ischemic stroke. She has severe hearing impairment and needs to use hearing aids, and has a history of diabetes. During the patient’s hospitalization, the blood test showed that serum Lactate: 7.72 mmol/L, Lactate (CSF) 5.9 mmol/L. Through the collection of relevant medical history, neurological evaluation showed changes in consciousness and cognition, slow response in language expression, and brain magnetic resonance imaging examination showed subacute bilateral temporal lobe infarction, which was an atypical type of stroke. The lineage DNA gene has m.3243A>G known pathogenic mutation point, and its heteroplasmic level is 24.6%. This pathogenic point is located in MITOMAP and recorded as Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) , Leigh Syndrome and other disease-related pathogenic loci, this mutation is located in ClinVar and recorded as Pathogenic (dbSNP: rs199474657), so it is diagnosed as a case of stroke caused by a rare disease mitochondrial gene mutation. After medical treatment, there was no more seizure during hospitalization. After interventional rehabilitation, the patient's limb weakness, poor language function, and cognitive impairment have all improved significantly. Conclusion Mitochondrial disorders can also be associated with abnormalities in psychological, neurological, cerebral cortical function, and autonomic functions, as well as problems with internal medical diseases. Therefore, the differential diagnoses cover a wide range and are not easy to be diagnosed. After neurological evaluation, medical history collection, imaging and rare disease serological examination, atypical ischemic stroke caused by rare mitochondrial gene mutation was diagnosed. We hope that through this case, the diagnosis of rare disease mitochondrial gene variation leading to cerebral infarction will be more familiar to clinical medical staff, and this case report may help to improve the clinical diagnosis and treatment for patients with similar clinical symptoms in the future.

Keywords: acute stroke, MELAS, lactic acidosis, mitochondrial disorders

Procedia PDF Downloads 53

Authors: Waseem Akram, Hafiz Azhar Ali Khan

Abstract:

Unplanned urbanization together with change in life from simple to more technologically advanced style with flow of rural masses to urban areas has played a vital role in pilling loads of solid wastes in our environment. The cities and towns have expanded beyond boundaries. Even the uncontrolled population expansion has caused the overall environmental burden. Thus, today the indifference remains as one of the biggest trash that has come up due to the non-responsive behavior of the people. Everyday huge amount of solid waste is thrown in the streets, on the roads, parks, and in all those places that are frequently and often visited by the human beings. This behavior based response in many countries of the world has led to serious health concerns and environmental issues. Over 80% of our products that are sold in the market are packed in plastic bags. None of the bags are later recycled but simply become a permanent environment concern that flies, choke lines or are burnt and release toxic gases in the environment or form dumps of heaps. Lack of classification of the daily waste generated from houses and other places lead to worst clogging of the sewerage lines and formation of ponding areas which ultimately favor vector borne disease and sometimes become a cause of transmission of polio virus. Solid waste heaps were checked at different places of the cities. All of the wastes on visual assessments were classified into plastic bags, papers, broken plastic pots, clay pots, steel boxes, wrappers etc. All solid waste dumping sites in the cities and wastes that were thrown outside of the trash containers usually contained wrappers, plastic bags, and unconsumed food products. Insect populations seen in these sites included the house flies, bugs, cockroaches and mosquito larvae breeding in water filled wrappers, containers or plastic bags. The population of the mosquitoes, cockroaches and houseflies were relatively very high in dumping sites close to human population. This population has been associated with cases like dengue, malaria, dysentery, gastro and also to skin allergies during the monsoon and summer season. Thus, dumping of the huge amount of solid wastes in and near the residential areas results into serious environmental concerns, bad smell circulation, and health related issues. In some places, the same waste is burnt to get rid of mosquitoes through smoke which ultimately releases toxic material in the atmosphere. Therefore, a proper environmental strategy is needed to minimize environmental burden and promote concepts of recycled products and thus, reduce the disease burden.

Keywords: solid waste accumulation, disease burden, mosquitoes, vector borne diseases

Procedia PDF Downloads 260

Authors: Faith Abdul Rasak Asharaf

Abstract:

Every city has a threshold known as urban carrying capacity based on which it can withstand a particular density of people, above which the city might need to resort to measures like expanding its boundaries or growing vertically. As a result of this circumstance, the number of squatter communities is growing, as is the claustrophobic feeling of being confined inside a "concrete jungle." The expansion of suburbs, commercial areas, and industrial real estate in the areas surrounding medium-sized cities has resulted in changes to their landscapes and urban forms, as well as a systematic shift in their role in the urban hierarchy when functional endowment and connections to other territories are considered. The urban carrying capacity idea provides crucial guidance for city administrators and planners in better managing, designing, planning, constructing, and distributing urban resources to satisfy the huge demands of an evergrowing urban population. An ecological footprint is a criterion of urban carrying capacity, which is the amount of land required to provide humanity with renewable resources and absorb its trash. However, as each piece of land has its unique carrying capacity, including ecological, social, and economic considerations, these metropolitan areas begin to reach a saturation point over time. Various city models have been tried throughout the years to meet the increasing urban population density by moving the zones of work, life, and leisure to achieve maximum sustainable growth. The current scenario is that of a vertical city and compact city concept, in which the maximum density of people is attempted to fit into a definite area using efficient land use and a variety of other strategies, but this has proven to be a very unsustainable method of growth, as evidenced by the COVID-19 period. Due to a shortage of housing and basic infrastructure, densely populated cities gave rise to massive squatter communities, unable to accommodate the overflowing migrants. To achieve optimum carrying capacity, planning measures such as polycentric city and diffuse city concepts can be implemented, which will help to relieve the congested city core by relocating certain sectors of the town to the city periphery, which will help to create newer spaces for design in terms of public space, transportation, and housing, which is a major concern in the current scenario. The study's goal is focused on suggesting design options and solutions in terms of placemaking for better urban quality and urban life for the citizens once city centres have been de-densified based on urban carrying capacity and ecological footprint, taking the case of Kochi as an apt example of a highly densified city core, focusing on Edappally, which is an agglomeration of many urban factors.

Keywords: urban carrying capacity, urbanization, urban sprawl, ecological footprint

Procedia PDF Downloads 60

Authors: Ammar Asma, Bouafia Nabiha, Ben Cheikh Asma, Ezzi Olfa, Mahjoub Mohamed, Sma Nesrine, Chouchène Imed, Boussarsar Hamadi, Njah Mansour

Abstract:

Background: Ventilator-associated pneumonia (VAP) is currently recognized as one of the most relevant causes of morbidity and mortality among intensive care unit (ICU) patients worldwide. Identifying modifiable risk factors for VAP could be helpful for future controlled interventional studies aiming at improving prevention of VAP. The purposes of this study were to determine the incidence and risk factors for VAP in in a Tunisian medical ICU. Materials / Methods: A retrospective case-control study design based on the prospective database collected over a 14-month period from September 15th, 2015 through November 15th, 2016 in an 8-bed medical ICU. Patients under ventilation for over 48 h were included. The number of cases was estimated by Epi-info Software with the power of statistical test equal to 90 %. Each case patient was successfully matched to two controls according to the length of mechanical ventilation (MV) before VAP for cases and the total length of MV in controls. VAP in the ICU was defined according to American Thoracic Society; Infectious Diseases Society of America guidelines. Early onset or late-onset VAP were defined whether the infectious process occurred within or after 96 h of ICU admission. Patients’ risk factors, causes of admission, comorbidities and respiratory specimens collected were reviewed. Univariate and multivariate analyses were performed to determine variables associated with VAP with a p-value < 0.05. Results: During the period study, a total of 169 patients under mechanical ventilation were considered, 34 patients (20.11%) developed at least one episode of VAP in the ICU. The incidence rate for VAP was 14.88/1000 ventilation days. Among these cases, 9 (26.5 %) were early-onset VAP and 25 (73.5 %) were late-onset VAP. It was a certain diagnosis in 66.7% of cases. Tracheal aspiration was positive in 80% of cases. Multi-drug resistant Acinerobacter baumanii was the most common species detected in cases; 67.64% (n=23). The rate of mortality out of cases was 88.23% (n= 30). In univariate analysis, the patients with VAP were statistically more likely to suffer from cardiovascular diseases (p=0.035) and prolonged duration of sedation (p=0.009) and tracheostomy (p=0.001), they also had a higher number of re-intubation (p=0.017) and a longer total time of intubation (p=0.012). Multivariate analysis showed that cardiovascular diseases (OR= 4.44; 95% IC= [1.3 - 14]; p=0.016), tracheostomy (OR= 4.2; 95% IC= [1.16 -15.12]; p= 0.028) and prolonged duration of sedation (OR=1.21; 95% IC= [1.07, 1.36]; p=0.002) were independent risk factors for the development of VAP. Conclusion: VAP constitutes a therapeutic challenge in an ICU setting, therefore; strategies that effectively prevent VAP are needed. An infection control-training program intended to all professional heath care in this unit insisting on bundles and elaboration of procedures are planned to reduce effectively incidence rate of VAP.

Keywords: case control study, intensive care unit, risk factors, ventilator associated pneumonia

Procedia PDF Downloads 379

Authors: Glauberto S. Quirino, Emanuelly V. Pereira, Amana S. Figueiredo, Antonia T. F. Santos, Paulo R. A. Firmino, Denise F. F. Barbosa, Caroline B. Q. Aquino, Eveliny S. Martins, Cinthia G. P. Calou, Ana K. B. Pinheiro

Abstract:

Introduction: During pregnancy there are adjustments in the physical, emotional, existential and sexual areas, which may contribute to changes in sexual behavior. The objective was to analyze the sexual behavior of pregnant women. Methods: Quantitative, exploratory-descriptive study, approved by the Ethics and Research Committee of the Regional University of Cariri. For data collection, it was used the Sexuality Questionnaire in Gestation and Sexual Quotient - Female Version. It was carried out in public institutions in the urban and rural areas of three municipalities of the Metropolitan Region of Cariri, south of Ceará, Brazil from February to September 2016. The sampling was proportional stratified by convenience. A total of 815 pregnant women who were literate and aged 20 years or over were broached. 461 pregnant women were excluded because of high risk, adolescence, saturation of the extract, incomplete filling of the instrument, mental and physical handicap, without sexual partner, and the sample was 354 pregnant. The data were grouped, organized and analyzed in the statistical program R Studio (version 386 3.2.4). Descriptive frequency statistics and non-parametric tests were used to analyze the variables, and the results were shown in graphs and tables. Results: The women presented a minimum age of 20, maximum 35 and average of 26.9 years, predominantly urban area residents, with a monthly income of up to one minimum wage (US$ 275,00), high school, catholic, with fixed partner, heterosexuals, multiparous, multiple sexual partners throughout life and with the beginning of sexual life in adolescence (median age 17 years). There was a reduction in sexual practices (67%) and when they were performed, they were more frequent in the first trimester (79.7%) and less frequent in the third trimester (30.5%). Preliminary sexual practices did not change and were more frequent in the second trimester (46.6%). Throughout the gestational trimesters, the partner was referred as the main responsible for the sexual initiative. The women performed vaginal sex (97.7%) and provided greater pleasure (42.8%) compared to non-penetrative sex (53.9%) (oral sex and masturbation). There was also a reduction in the sexual disposition of pregnant women (90.7%) and partner (72.9%), mainly in the first trimester (78.8%), and sexual positions. Sexual performance ranged from regular to good (49.7%). Level of schooling, marital status, sexual orientation of the pregnant woman and the partner, sexual practices and positions, preliminaries, frequency of sexual practices and importance attributed to them were variables that influenced negatively sexual performance and satisfaction. It is concluded that pregnancy negatively changes the sexual behavior of the women and it is suggested to further investigations and approach of the partner, in order to clarify the influence of these variables on the sexual function and subsidize intervention strategies, with a view to the integrality of sexual and reproductive health.

Keywords: obstetric nursing, pregnant women, sexual behavior, women's health

Procedia PDF Downloads 304

Authors: Peter Kus, Anna Ostroverkh, Yurii Yakovlev, Yevheniia Lobko, Roman Fiala, Ivan Khalakhan, Vladimir Matolin

Abstract:

Hydrogen economy is a concept of low-emission society which harvests most of its energy from renewable sources (e.g., wind and solar) and in case of overproduction, electrochemically turns the excess amount into hydrogen, which serves as an energy carrier. Proton exchange membrane water electrolyzers (PEMWE) are the backbone of this concept. By fast-response electricity to hydrogen conversion, the PEMWEs will not only stabilize the electrical grid but also provide high-purity hydrogen for variety of fuel cell powered devices, ranging from consumer electronics to vehicles. Wider commercialization of PEMWE technology is however hindered by high prices of noble metals which are necessary for catalyzing the redox reactions within the cell. Namely, platinum for hydrogen evolution reaction (HER), running on cathode, and iridium for oxygen evolution reaction (OER) on anode. Possible way of how to lower the loading of Pt and Ir is by using conductive high-surface nanostructures as catalyst supports in conjunction with thin-film catalyst deposition. The presented study discusses unconventional technique of membrane electron assembly (MEA) preparation. Noble metal catalysts (Pt and Ir) were magnetron sputtered in very low loadings onto the surface of porous sublayers (located on gas diffusion layer or directly on membrane), forming so to say localized three-phase boundary. Ultrasonically sprayed corrosion resistant TiC-based sublayer was used as a support material on anode, whereas magnetron sputtered nanostructured etched nitrogenated carbon (CNx) served the same role on cathode. By using this configuration, we were able to significantly decrease the amount of noble metals (to thickness of just tens of nanometers), while keeping the performance comparable to that of average state-of-the-art catalysts. Complex characterization of prepared supported catalysts includes in-cell performance and durability tests, electrochemical impedance spectroscopy (EIS) as well as scanning electron microscopy (SEM) imaging and X-ray photoelectron spectroscopy (XPS) analysis. Our research proves that magnetron sputtering is a suitable method for thin-film deposition of electrocatalysts. Tested set-up of thin-film supported anode and cathode catalysts with combined loading of just 120 ug.cm⁻² yields remarkable values of specific current. Described approach of thin-film low-loading catalyst deposition might be relevant when noble metal reduction is the topmost priority.

Keywords: hydrogen economy, low-loading catalyst, magnetron sputtering, proton exchange membrane water electrolyzer

Procedia PDF Downloads 147

Authors: Leto Leandra, Guaitini Caterina, Agosti Anna, Del Vecchio Lorenzo, Guarrasi Valeria, Cirlini Martina, Chiancone Benedetta

Abstract:

To the best of our knowledge, this study represents the first attempt to investigate the in vitro germination response of Rhus coriaria L., and its sprout chemical characterization. Rhus coriaria L., a species belonging to the Anacardiaceae family, is commonly called "sumac" and is cultivated, in different countries of the Mediterranean and the Middle East regions, to produce a spice with a sour taste, obtained from its dried and ground fruits. Moreover, since ancient times, many beneficial properties have been attributed to this plant that has been used, in the traditional medicine of several Asian countries, against various diseases, including liver and intestinal pathologies, ulcers and various inflammatory states. In the recent past, sumac was cultivated in the Southern regions of Italy to treat leather, but its cultivation was abandoned, and currently, sumac plants grow spontaneously in marginal areas. Recently, in Italy, the interest in this species has been growing again, thanks to its numerous properties; thus, it becomes imperative to deepen the knowledge of this plant. In this study, in order to set up an efficient in vitro seed germination protocol, sumac seeds collected from spontaneous plants grown in Sicily, an island in the South of Italy, were, firstly, subjected to different treatments, scarification (mechanical, physical and chemical), cold stratification and imbibition, to break their physical and physiological dormancy, then, treated seeds were in vitro cultured on media with different gibberellic acid (GA3) concentrations. Results showed that, without any treatment, only 5% of in vitro sown seeds germinated, while the germination percentage increased up to 19% after the mechanical scarification. A further significative improvement of germination percentages was recorded after the physical scarification, with (40.5%) or without (36.5%) 8 weeks of cold stratification, especially when seeds were sown on gibberellin enriched cultured media. Vitro-derived sumac sprouts, at different developmental stages, were chemically characterized, in terms of polyphenol and tannin content, as well as for their antioxidant activity, to evaluate this matrix as a potential novel food or as a source of bioactive compounds. Results evidenced how more developed sumac sprouts and, above all, their leaves are a wealthy source of polyphenols (78.4 GAE/g SS) and tannins (21.9 mg GAE/g SS), with marked antioxidant activity. The outcomes of this study will be of support the nursery sector and sumac growers in obtaining a higher number of plants in a shorter time; moreover, the sprout chemical characterization will contribute to the process of considering this matrix as a new source of bioactive compounds and tannins to be used in food and non-food sectors.

Keywords: bioactive compounds, germination pre-treatments, rhus coriaria l., tissue culture

Procedia PDF Downloads 74

Authors: Leto Leandra, Guaitini Caterina, Agosti Anna, Del Vecchio Lorenzo, Guarrasi Valeria, Cirlini Martina, Chiancone Benedetta

Abstract:

To the best of our knowledge, this study represents the first attempt to investigate the in vitro germination response of Rhus coriaria L. and its sprout chemical characterization. Rhus coriaria L., a species belonging to the Anacardiaceae family, is commonly called "sumac” and is cultivated, in different countries of the Mediterranean and the Middle East regions, to produce a spice with a sour taste, obtained from its dried and ground fruits. Moreover, since ancient times, many beneficial properties have been attributed to this plant that has been used, in the traditional medicine of several Asian countries, against various diseases, including liver and intestinal pathologies, ulcers, and various inflammatory states. In the recent past, sumac was cultivated in the Southern regions of Italy to treat leather, but its cultivation was abandoned, and currently, sumac plants grow spontaneously in marginal areas. Recently, in Italy, the interest in this species has been growing again, thanks to its numerous properties; thus, it becomes imperative to deepen the knowledge of this plant. In this study, in order to set up an efficient in vitro seed germination protocol, sumac seeds collected from spontaneous plants grown in Sicily, an island in the South of Italy, were, firstly, subjected to different treatments, scarification (mechanical, physical and chemical), cold stratification and imbibition, to break their physical and physiological dormancy, then, treated seeds were in vitro cultured on media with different gibberellic acid (GA3) concentrations. Results showed that, without any treatment, only 5% of in vitro sown seeds germinated, while the germination percentage increased up to 19% after the mechanical scarification. A further significative improvement of germination percentages was recorded after the physical scarification, with (40.5%) or without (36.5%) 8 weeks of cold stratification, especially when seeds were sown on gibberellin enriched cultured media. Vitro-derived sumac sprouts, at different developmental stages, were chemically characterized, in terms of polyphenol and tannin content, as well as for their antioxidant activity, to evaluate this matrix as a potential novel food or as a source of bioactive compounds. Results evidenced how more developed sumac sprouts and, above all, their leaves are a wealthy source of polyphenols (78.4 GAE/g SS) and tannins (21.9 mg GAE/g SS), with marked antioxidant activity. The outcomes of this study will be of support the nursery sector and sumac growers in obtaining a higher number of plants in a shorter time; moreover, the sprout chemical characterization will contribute to the process of considering this matrix as a new source of bioactive compounds and tannins to be used in food and non-food sectors.

Keywords: bioactive compounds, germination pre-treatments, rhus coriaria l., tissue culture

Procedia PDF Downloads 77

Authors: Samuel N. Forjuoh, Marcia G. Ory, Jaewoong Won, Samuel D. Towne, Suojin Wang, Chanam Lee

Abstract:

The public health burden of obesity is well established as is the influence of physical activity (PA) on the health and wellness of individuals who are obese. This study examined the influence of selected demographic, health, and socioenvironmental factors on the walking behaviors of middle-aged and older overweight and obese adults. Online and paper surveys were administered to community-dwelling overweight and obese adults aged ≥ 50 years residing in four cities in central Texas and seen by a family physician in the primary care clinic from October 2013 to June 2014. Descriptive statistics were used to characterize participants’ anthropometric and demographic data as well as their health conditions and walking, socioenvironmental, and more broadly defined PA behaviors. Then Pearson chi-square tests were used to assess differences between participants who reported walking the recommended ≥ 150 minutes for any purpose in a typical week as a proxy to meeting the U.S. Centers for Disease Control and Prevention’s PA guidelines and those who did not. Finally, logistic regression was used to predict walking the recommended ≥ 150 minutes for any purpose, controlling for covariates. The analysis was conducted in 2016. Of the total sample (n=253, survey response rate of 6.8%), the majority were non-Hispanic white (81.7%), married (74.5%), male (53.5%), and reported an annual household income of ≥ $50,000 (65.7%). Approximately, half were employed (49.6%), or had at least a college degree (51.8%). Slightly more than 1 in 5 (n=57, 22.5%) reported walking the recommended ≥150 minutes for any purpose in a typical week. The strongest predictors of walking the recommended ≥ 150 minutes for any purpose in a typical week in adjusted analysis were related to education and a high favorable perception of the neighborhood environment. Compared to those with a high school diploma or some college, participants with at least a college degree were five times as likely to walk the recommended ≥ 150 minutes for any purpose (OR=5.55, 95% CI=1.79-17.25). Walking the recommended ≥ 150 minutes for any purpose was significantly associated with participants who disagreed that there were many distracted drivers (e.g., on the cell phone while driving) in their neighborhood (OR=4.08, 95% CI=1.47-11.36) and those who agreed that there are sidewalks or protected walkways (e.g., walking trails) in their neighborhood (OR=3.55, 95% CI=1.10-11.49). Those employed were less likely to walk the recommended ≥ 150 minutes for any purpose compared to those unemployed (OR=0.31, 95% CI=0.11-0.85) as were those who reported some difficulty walking for a quarter of a mile (OR=0.19, 95% CI=0.05-0.77). Other socio-environmental factors such as having care-giver responsibilities for elders, someone to walk with, or a dog in the household as well as Walk Score™ were not significantly associated with walking the recommended ≥ 150 minutes for any purpose in a typical week. Neighborhood perception appears to be an important factor associated with the walking behaviors of middle-aged and older overweight and obese individuals. Enhancing the neighborhood environment (e.g., providing walking trails) may promote walking among these individuals.

Keywords: determinants of walking, obesity, older adults, physical activity

Procedia PDF Downloads 238

Authors: Alexandru-Ion Marinescu

Abstract:

There exist a plethora of methods in the scientific literature which tackle the well-established task of credit score evaluation. In its most abstract form, a credit scoring algorithm takes as input several credit applicant properties, such as age, marital status, employment status, loan duration, etc. and must output a binary response variable (i.e. “GOOD” or “BAD”) stating whether the client is susceptible to payment return delays. Data imbalance is a common occurrence among financial institution databases, with the majority being classified as “GOOD” clients (clients that respect the loan return calendar) alongside a small percentage of “BAD” clients. But it is the “BAD” clients we are interested in since accurately predicting their behavior is crucial in preventing unwanted loss for loan providers. We add to this whole context the constraint that the algorithm must yield an actual, tractable mathematical formula, which is friendlier towards financial analysts. To this end, we have turned to genetic algorithms and genetic programming, aiming to evolve actual mathematical expressions using specially tailored mutation and crossover operators. As far as data representation is concerned, we employ a very flexible mechanism – LINQ expression trees, readily available in the C# programming language, enabling us to construct executable pieces of code at runtime. As the title implies, they model trees, with intermediate nodes being operators (addition, subtraction, multiplication, division) or mathematical functions (sin, cos, abs, round, etc.) and leaf nodes storing either constants or variables. There is a one-to-one correspondence between the client properties and the formula variables. The mutation and crossover operators work on a flattened version of the tree, obtained via a pre-order traversal. A consequence of our chosen technique is that we can identify and discard client properties which do not take part in the final score evaluation, effectively acting as a dimensionality reduction scheme. We compare ourselves with state of the art approaches, such as support vector machines, Bayesian networks, and extreme learning machines, to name a few. The data sets we benchmark against amount to a total of 8, of which we mention the well-known Australian credit and German credit data sets, and the performance indicators are the following: percentage correctly classified, area under curve, partial Gini index, H-measure, Brier score and Kolmogorov-Smirnov statistic, respectively. Finally, we obtain encouraging results, which, although placing us in the lower half of the hierarchy, drive us to further refine the algorithm.

Keywords: expression trees, financial credit scoring, genetic algorithm, genetic programming, symbolic evolution

Procedia PDF Downloads 101

Authors: Md Kamrul Hassan

Abstract:

Adaptation interventions are the common response to manage the vulnerabilities of climate change. The nature of adaptation intervention depends on the degree of vulnerability and the capacity of a society. The coping interventions can take the form of hard adaptation – utilising technologies and capital goods like dykes, embankments, seawalls, and/or soft adaptation – engaging knowledge and information sharing, capacity building, policy and strategy development, and innovation. Hard adaptation is quite capital intensive but provides immediate relief from climate change vulnerabilities. This type of adaptation is not real development, as the investment for the adaptation cannot improve the performance – just maintain the status quo of a social or ecological system, and often lead to maladaptation in the long-term. Maladaptation creates a two-way loss for a society – interventions bring further vulnerability on top of the existing vulnerability and investment for getting rid of the consequence of interventions. Hard adaptation is popular to the vulnerable groups, but it focuses so much on the immediate solution and often ignores the environmental issues and future risks of climate change. On the other hand, soft adaptation is education oriented where vulnerable groups learn how to live with climate change impacts. Soft adaptation interventions build the capacity of vulnerable groups through training, innovation, and support, which might enhance the resilience of a system. In consideration of long-term sustainability, soft adaptation can contribute more to resilience than hard adaptation. Taking a developing society as the study context, this study aims to investigate and understand the effectiveness of the adaptation interventions of the coastal community of Sundarbans mangrove forest in Bangladesh. Applying semi-structured interviews with a range of Sundarbans stakeholders including community residents, tourism demand-supply side stakeholders, and conservation and management agencies (e.g., Government, NGOs and international agencies) and document analysis, this paper reports several key insights regarding climate change adaptation. Firstly, while adaptation interventions may offer a short-term to medium-term solution to climate change vulnerabilities, interventions need to be revised for long-term sustainability. Secondly, soft adaptation offers advantages in terms of resilience in a rapidly changing environment, as it is flexible and dynamic. Thirdly, there is a challenge to communicate to educate vulnerable groups to understand more about the future effects of hard adaptation interventions (and the potential for maladaptation). Fourthly, hard adaptation can be used if the interventions do not degrade the environmental balance and if the investment of interventions does not exceed the economic benefit of the interventions. Overall, the goal of an adaptation intervention should be to enhance the resilience of a social or ecological system so that the system can with stand present vulnerabilities and future risks. In order to be sustainable, adaptation interventions should be designed in such way that those can address vulnerabilities and risks of climate change in a long-term timeframe.

Keywords: adaptation, climate change, maladaptation, resilience, Sundarbans, sustainability, vulnerability

Procedia PDF Downloads 173

Authors: Hamed Yaghoubi, Esmaeil Salahi, Fateme Taati

Abstract:

The effective shear and bulk viscosity, as well as dynamic viscosity, describe the rheological properties of the ceramic body during the liquid phase sintering process. The rheological parameters depend on the physical and thermomechanical characteristics of the material such as relative density, temperature, grain size, and diffusion coefficient and activation energy. The main goal of this research is to acquire a comprehensive understanding of the response of an incompressible viscose ceramic material during liquid phase sintering process such as stress-strain relations, sintering and hydrostatic stress, the prediction of anisotropic shrinkage and heterogeneous densification as a function of sintering time by including the simultaneous influence of gravity field, and frictional force. After raw materials analysis, the standard hard porcelain mixture as a ceramic body was designed and prepared. Three different experimental configurations were designed including midpoint deflection, sinter bending, and free sintering samples. The numerical method for the ceramic specimens during the liquid phase sintering process are implemented in the CREEP user subroutine code in ABAQUS. The numerical-experimental procedure shows the anisotropic behavior, the complete difference in spatial displacement through three directions, the incompressibility for ceramic samples during the sintering process. The anisotropic shrinkage factor has been proposed to investigate the shrinkage anisotropy. It has been shown that the shrinkage along the normal axis of casting sample is about 1.5 times larger than that of casting direction, the gravitational force in pyroplastic deformation intensifies the shrinkage anisotropy more than the free sintering sample. The lowest and greatest equivalent creep strain occurs at the intermediate zone and around the central line of the midpoint distorted sample, respectively. In the sinter bending test sample, the equivalent creep strain approaches to the maximum near the contact area with refractory support. The inhomogeneity in Von-Misses, pressure, and principal stress intensifies the relative density non-uniformity in all samples, except in free sintering one. The symmetrical distribution of stress around the center of free sintering sample, cause to hinder the pyroplastic deformations. Densification results confirmed that the effective bulk viscosity was well-defined with relative density values. The stress analysis confirmed that the sintering stress is more than the hydrostatic stress from start to end of sintering time so, from both theoretically and experimentally point of view, the sintering process occurs completely.

Keywords: anisotropic shrinkage, ceramic material, liquid phase sintering process, rheological properties, numerical-experimental procedure

Procedia PDF Downloads 327