Search results for: automotive reinforcing agent
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2300

Search results for: automotive reinforcing agent

500 Influence of Geometry on Performance of Type-4 Filament Wound Composite Cylinder for Compressed Gas Storage

Authors: Pranjali Sharma, Swati Neogi

Abstract:

Composite pressure vessels are low weight structures mainly used in a variety of applications such as automobiles, aeronautics and chemical engineering. Fiber reinforced polymer (FRP) composite materials offer the simplicity of design and use, high fuel storage capacity, rapid refueling capability, excellent shelf life, minimal infrastructure impact, high safety due to the inherent strength of the pressure vessel, and little to no development risk. Apart from these preliminary merits, the subsidized weight of composite vessels over metallic cylinders act as the biggest asset to the automotive industry, increasing the fuel efficiency. The result is a lightweight, flexible, non-explosive, and non-fragmenting pressure vessel that can be tailor-made to attune with specific applications. The winding pattern of the composite over-wrap is a primary focus while designing a pressure vessel. The critical stresses in the system depend on the thickness, angle and sequence of the composite layers. The composite over-wrap is wound over a plastic liner, whose geometry can be varied for the ease of winding. In the present study, we aim to optimize the FRP vessel geometry that provides an ease in winding and also aids in weight reduction for enhancing the vessel performance. Finite element analysis is used to study the effect of dome geometry, yielding a design with maximum value of burst pressure and least value of vessel weight. The stress and strain analysis of different dome ends along with the cylindrical portion is carried out in ANSYS 19.2. The failure is predicted using different failure theories like Tsai-Wu theory, Tsai-Hill theory and Maximum stress theory. Corresponding to a given winding sequence, the optimum dome geometry is determined for a fixed internal pressure to identify the theoretical value of burst pressure. Finally, this geometry is used to decrease the number of layers to reach the set value of safety in accordance with the available safety standards. This results in decrease in the weight of the composite over-wrap and manufacturing cost of the pressure vessel. An improvement in the overall weight performance of the pressure vessel gives higher fuel efficiency for its use in automobile applications.

Keywords: Compressed Gas Storage, Dome geometry, Theoretical Analysis, Type-4 Composite Pressure Vessel, Improvement in Vessel Weight Performance

Procedia PDF Downloads 151
499 Glycyrrhizic Acid Inhibits Lipopolysaccharide-Stimulated Bovine Fibroblast-Like Synoviocyte, Invasion through Suppression of TLR4/NF-κB-Mediated Matrix Metalloproteinase-9 Expression

Authors: Hosein Maghsoudi

Abstract:

Rheumatois arthritis (RA) is progressive inflammatory autoimmune diseases that primarily affect the joints, characterized by synovial hyperplasia and inflammatory cell infiltration, deformed and painful joints, which can lead tissue destruction, functional disability systemic complications, and early dead and socioeconomic costs. The cause of rheumatoid arthritis is unknown, but genetic and environmental factors are contributory and the prognosis is guarded. However, advances in understanding the pathogenesis of the disease have fostered the development of new therapeutics, with improved outcomes. The current treatment strategy, which reflects this progress, is to initiate aggressive therapy soon after diagnosis and to escalate the therapy, guided by an assessment of disease activity, in pursuit of clinical remission. The pathobiology of RA is multifaceted and involves T cells, B cells, fibroblast-like synoviocyte (FLSc) and the complex interaction of many pro-inflammatory cytokine. Novel biologic agents that target tumor necrosis or interlukin (IL)-1 and Il-6, in addition T- and B-cells inhibitors, have resulted in favorable clinical outcomes in patients with RA. Despite this, at least 30% of RA patients are résistance to available therapies, suggesting novel mediators should be identified that can target other disease-specific pathway or cell lineage. Among the inflammatory cell population that might participated in RA pathogenesis, FLSc are crucial in initiaing and driving RA in concert of cartilage and bone by secreting metalloproteinase (MMPs) into the synovial fluid and by direct invasion into extracellular matrix (ECM), further exacerbating joint damage. Invasion of fibroblast-like synoviocytes (FLSc) is critical in the pathogenesis of rheumatoid-arthritis. The metalloproteinase (MMPs) and activator of Toll-like receptor 4 (TLR4)/nuclear factor- κB pthway play a critical role in RA-FLS invasion induced by lipopolysaccharide (LPS). The present study aimed to explore the anti-invasion activity of Glycyrrhizic Acid as a pharmacologically safe phytochemical agent with potent anti-inflammatory properties on IL-1beta and TNF-alpha signalling pathways in Bovine fibroblast-like synoviocyte ex- vitro, on LPS-stimulated bovine FLS migration and invasion as well as MMP expression and explored the upstream signal transduction. Results showed that Glycyrrhizic Acid suppressed LPS-stimulated bovine FLS migration and invasion by inhibition MMP-9 expression and activity. In addition our results revealed that Glycyrrhizic Acid inhibited the transcriptional activity of MMP-9 by suppression the nbinding activity of NF- κB in the MMP-9 promoter pathway. The extract of licorice (Glycyrrhiza glabra L.) has been widely used for many centuries in the traditional Chinese medicine as native anti-allergic agent. Glycyrrhizin (GL), a triterpenoidsaponin, extracted from the roots of licorice is the most effective compound for inflammation and allergic diseases in human body. The biological and pharmacological studies revealed that GL possesses many pharmacological effects, such as anti-inflammatory, anti-viral and liver protective effects, and the biological effects, such as induction of cytokines (interferon-γ and IL-12), chemokines as well as extrathymic T and anti-type 2 T cells. GL is known in the traditional Chinese medicine for its anti-inflammatory effect, which is originally described by Finney in 1959. The mechanism of the GL-induced anti-inflammatory effect is based on different pathways of the GL-induced selective inhibition of the prostaglandin E2 production, the CK-II- mediated activation of both GL-binding lipoxygenas (gbLOX; 17) and PLA2, an anti-thrombin action of GL and production of the reactive oxygen species (ROS; GL exerts liver protection properties by inhibiting PLA2 or by the hydroxyl radical trapping action, leading to the lowering of serum alanine and aspartate transaminase levels. The present study was undertaken to examine the possible mechanism of anti-inflammatory properties GL on IL-1beta and TNF-alpha signalling pathways in bovine fibroblast-like synoviocyte ex-vivo, on LPS-stimulated bovine FLS migration and invasion as well as MMP expression and explored the upstream signal transduction. Our results clearly showed that treatment of bovine fibroblast-like synoviocyte with GL suppressed LPS-induced cell migration and invasion. Furthermore, it revealed that GL inhibited the transcription activity of MMP-9 by suppressing the binding activity of NF-κB in the MM-9 promoter. MMP-9 is an important ECM-degrading enzyme and overexpression of MMPs in important of RA-FLSs. LPS can stimulate bovine FLS to secret MMPs, and this induction is regulated at the transcription and translational levels. In this study, LPS treatment of bovine FLS caused an increase in MMP-2 and MMP-9 levels. The increase in MMP-9 expression and secretion was inhibited by ex- vitro. Furthermore, these effects were mimicked by MMP-9 siRNA. These result therefore indicate the the inhibition of LPS-induced bovine FLS invasion by GL occurs primarily by inhibiting MMP-9 expression and activity. Next we analyzed the functional significance of NF-κB transcription of MMP-9 activation in Bovine FLSs. Results from EMSA showed that GL suppressed LPS-induced NF-κB binding to the MMP-9 promotor, as NF-κB regulates transcriptional activation of multiple inflammatory cytokines, we predicted that GL might target NF-κB to suppress MMP-9 transcription by LPS. Myeloid differentiation-factor 88 (MyD88) and TIR-domain containing adaptor protein (TIRAP) are critical proteins in the LPS-induced NF-κB and apoptotic signaling pathways, GL inhibited the expression of TLR4 and MYD88. These results demonstrated that GL suppress LPS-induced MMP-9 expression through the inhibition of the induced TLR4/NFκB signaling pathway. Taken together, our results provide evidence that GL exerts anti-inflammatory effects by inhibition LPS-induced bovine FLSs migration and invasion, and the mechanisms may involve the suppression of TLR4/NFκB –mediated MMP-9 expression. Although further work is needed to clarify the complicated mechanism of GL-induced anti-invasion of bovine FLSs, GL might be used as a further anti-invasion drug with therapeutic efficacy in the treatment of immune-mediated inflammatory disease such as RA.

Keywords: glycyrrhizic acid, bovine fibroblast-like synoviocyte, tlr4/nf-κb, metalloproteinase-9

Procedia PDF Downloads 392
498 Hesperidin through Acting on Proliferating Cell Nuclear Antigen and Follicle Stimulating Hormone Receptor Expression Decreased Ovarian Toxicity Induced by Malathion

Authors: Mahnaz Zarein, Hamed Shoorei

Abstract:

Background: Malathion is one of the most toxic agents widely used in agriculture throughout the world. This agent has adverse effects on the functions of multiple organs such as the reproductive system in both male and female genders. On the one hand, daily use of antioxidant supplementations such as hesperidin is capable to neutralize the deleterious impacts of malathion. Therefore, in this experimental study, the protective effects of hesperidin against ovarian toxicity induced by malathion were investigated. Material & Methods: Balb/c adult mice (n=32) were randomly divided into 4 groups including 1) the control group, treated with normal saline, 2) the Mal group, treated with 30mg/kg malathion, daily for 1 month, 3) Mal + Hes group, treated with 20 mg/kg malathion and 20 mg/kg hesperidin, daily for 1 month, and 5) Hes group, treated with 20 mg/kg hesperidin. At the end of the experimental period, mice were anesthetized and their drops of blood were collected to the assessment of some hormones such as LH, FSH, E2, and P4. Also, the right ovaries were used to H&E staining, and the left ovaries were used for IHC staining (PCNA and FSHR). Results: Histopathological assessments showed that the number of follicles, i.e. primordial, primary, and secondary, significantly decreased, while the atretic follicle counts remarkably increased compared to the control group (p<0.05). Hormonal levels revealed that the production of all mentioned hormones decreased in the Mal group in comparison with the control group (p<0.05). The expression of PCNA, as a proliferative marker, and FHSR, as a marker showing maturation, decreased when mice received malathion compared to the control group (p<0.05). Interestingly, treatment with hesperidin significantly neutralized the adverse effects of malathion on all mentioned parameters. Conclusion: Daily use of antioxidant supplementations such as hesperidin could alleviate the ovarian toxicity induced by malathion.

Keywords: malathion, ovary, antioxidant hesperidin, FSHR PCNA, ovary

Procedia PDF Downloads 78
497 Effects of Injectable Thermosensitive Hydrogel Containing Chitosan as a Barrier for Prevention of Post-operative Peritoneal Adhesion in Rats

Authors: Sara Javanmardi, Sepehr Aziziz, Baharak Divband, Masoumeh Firouzamandi

Abstract:

Post-operative adhesions are the most common cause of intestinal obstruction, female infertility and chronic abdominal pain. We developed a novel approach for preventing post-operative peritoneal adhesions using a biodegradable and thermosensitive curcumin hydrogel in rats. Thirteen male Sprague-Dawley rats were assigned randomly into five groups of six animals each: In SHAM group, the cecum was exteriorized, gently manipulated and sent back into the abdomen. In CONTROL group, the surgical abrasion was performed with no further treatment. In Hydrogel group, surgical abrasion was performed with local application of blank hydrogel (1 mL). In Curcumin group, surgical abrasion was performed with local application of curcumin (1 mL). In CUR/HGEL group, surgical abrasion was performed with local application of curcumin hydrogel (1 mL). On day 10, adhesions were assessed using a standardized scale (Evans model), and samples were collected for the Real-time PCR. Real-time PCR was performed to determine mRNA levels of VCAM-1, ICAM-1 and GAPDH. The macroscopic adhesion intensity showed statistically significant differences between the CUR/HGEL and other groups (P=0.0005). The findings of the present study revealed there were statistically significant differences between the groups regarding adhesion band length and numbers (P<0.0001). The protein and mRNA expression of VCAM-1 and ICAM-1 in secal tissues were significantly down regulated due to curcumin-hydrogel application in CUR/HGEL compared to other groups (p<0.05). The thermosensitive hydrogel could reduce the severity and even prevent formation of intra-abdominal adhesion. Curcumin hydrogel could serve as a potential barrier agent to prevent post-operative peritoneal adhesion in rats.

Keywords: peritoneal adhesion, hydrogel, curcumijn, ICAM-1, VCAM-1

Procedia PDF Downloads 94
496 Parameter Fitting of the Discrete Element Method When Modeling the DISAMATIC Process

Authors: E. Hovad, J. H. Walther, P. Larsen, J. Thorborg, J. H. Hattel

Abstract:

In sand casting of metal parts for the automotive industry such as brake disks and engine blocks, the molten metal is poured into a sand mold to get its final shape. The DISAMATIC molding process is a way to construct these sand molds for casting of steel parts and in the present work numerical simulations of this process are presented. During the process green sand is blown into a chamber and subsequently squeezed to finally obtain the sand mould. The sand flow is modelled with the Discrete Element method (DEM) and obtaining the correct material parameters for the simulation is the main goal. Different tests will be used to find or calibrate the DEM parameters needed; Poisson ratio, Young modulus, rolling friction coefficient, sliding friction coefficient and coefficient of restitution (COR). The Young modulus and Poisson ratio are found from compression tests of the bulk material and subsequently used in the DEM model according to the Hertz-Mindlin model. The main focus will be on calibrating the rolling resistance and sliding friction in the DEM model with respect to the behavior of “real” sand piles. More specifically, the surface profile of the “real” sand pile will be compared to the sand pile predicted with the DEM for different values of the rolling and sliding friction coefficients. When the DEM parameters are found for the particle-particle (sand-sand) interaction, the particle-wall interaction parameter values are also found. Here the sliding coefficient will be found from experiments and the rolling resistance is investigated by comparing with observations of how the green sand interacts with the chamber wall during experiments and the DEM simulations will be calibrated accordingly. The coefficient of restitution will be tested with different values in the DEM simulations and compared to video footages of the DISAMATIC process. Energy dissipation will be investigated in these simulations for different particle sizes and coefficient of restitution, where scaling laws will be considered to relate the energy dissipation for these parameters. Finally, the found parameter values are used in the overall discrete element model and compared to the video footage of the DISAMATIC process.

Keywords: discrete element method, physical properties of materials, calibration, granular flow

Procedia PDF Downloads 490
495 Immunomodulatory Activity of Polysaccharide-Protein Complex Isolated from the Sclerotia of Polyporus Rhinocerus in Murine Macrophages

Authors: Chaoran Liu

Abstract:

Bioactive polysaccharides and polysaccharide-protein complex derived from mushrooms and fungi have a wide range of immunomodulatory activity with low side-effects and have therefore the potential to be developed as an adjuvant in cancer therapies. Mushrooms sclerotium is rich in polysaccharides and the polysaccharides isolated from the sclerotium of Polyporus rhinocerus have shown potent in vivo and in vitro immunomodulatory effects. Macrophages are considered to be an important component of the innate immune response against bacterial infection and cancer. To better understanding the immunomodulatory effects and its underlying mechanisms of sclerotial water-soluble polysaccharides extracted from P. rhinocerus on macrophages, the objectives of this study are to purify the water-soluble novel sclerotial polysaccharides and to characterize the structure and properties as well as to study the detailed molecular mechanisms of the in vitro immunomodulating effects in murine macrophages. The hot water-soluble fraction PRW from the sclerotium of P. rhinocerus was obtained using solvent extraction. PRW was further fractionated by membrane ultrafiltration to a give a fraction (PRW1) with molecular mass less than 50 kDa. PRW1 was characterized to be a polysaccharide-protein complex composed of 45.7% polysaccharide and 44.2% protein. The chemical structure of the carbohydrate moiety of PRW1 was elucidated by GC and FTIR to be mainly beta-D-glucan with trace amount of galactose and mannose. The immunomodulatory effects of PRW1 on murine RAW 264.7 macrophages were demonstrated in terms of the increase in nitric oxide production and cytokine production. Mechanistically, PRW1 initiates ERK phosphorylation to activate macrophages within 15 min and significantly improves the expression level of inducible NOS (iNOS) from 6 h after treatment. In summary, this study indicates that PRW1 is a potent immunomodulatory agent for macrophages and suggests that mushroom sclerotia from Polyporus rhinocerus requires for further investigation in cancer research.

Keywords: Polyporus rhinocerus, mushroom sclerotia, Polysaccharide-Protein Complex, macrophage activation

Procedia PDF Downloads 236
494 Valorisation of Mango Seed: Response Surface Methodology Based Optimization of Starch Extraction from Mango Seeds

Authors: Tamrat Tesfaye, Bruce Sithole

Abstract:

Box-Behnken Response surface methodology was used to determine the optimum processing conditions that give maximum extraction yield and whiteness index from mango seed. The steeping time ranges from 2 to 12 hours and slurring of the steeped seed in sodium metabisulphite solution (0.1 to 0.5 w/v) was carried out. Experiments were designed according to Box-Behnken Design with these three factors and a total of 15 runs experimental variables of were analyzed. At linear level, the concentration of sodium metabisulphite had significant positive influence on percentage yield and whiteness index at p<0.05. At quadratic level, sodium metabisulphite concentration and sodium metabisulphite concentration2 had a significant negative influence on starch yield; sodium metabisulphite concentration and steeping time*temperature had significant (p<0.05) positive influence on whiteness index. The adjusted R2 above 0.8 for starch yield (0.906465) and whiteness index (0.909268) showed a good fit of the model with the experimental data. The optimum sodium metabisulphite concentration, steeping hours, and temperature for starch isolation with maximum starch yield (66.428%) and whiteness index (85%) as set goals for optimization with the desirability of 0.91939 was 0.255w/v concentration, 2hrs and 50 °C respectively. The determined experimental value of each response based on optimal condition was statistically in accordance with predicted levels at p<0.05. The Mango seeds are the by-products obtained during mango processing and possess disposal problem if not handled properly. The substitution of food based sizing agents with mango seed starch can contribute as pertinent resource deployment for value-added product manufacturing and waste utilization which might play significance role of food security in Ethiopia.

Keywords: mango, synthetic sizing agent, starch, extraction, textile, sizing

Procedia PDF Downloads 236
493 Generating 3D Battery Cathode Microstructures using Gaussian Mixture Models and Pix2Pix

Authors: Wesley Teskey, Vedran Glavas, Julian Wegener

Abstract:

Generating battery cathode microstructures is an important area of research, given the proliferation of the use of automotive batteries. Currently, finite element analysis (FEA) is often used for simulations of battery cathode microstructures before physical batteries can be manufactured and tested to verify the simulation results. Unfortunately, a key drawback of using FEA is that this method of simulation is very slow in terms of computational runtime. Generative AI offers the key advantage of speed when compared to FEA, and because of this, generative AI is capable of evaluating very large numbers of candidate microstructures. Given AI generated candidate microstructures, a subset of the promising microstructures can be selected for further validation using FEA. Leveraging the speed advantage of AI allows for a better final microstructural selection because high speed allows for the evaluation of many more candidate microstructures. For the approach presented, battery cathode 3D candidate microstructures are generated using Gaussian Mixture Models (GMMs) and pix2pix. This approach first uses GMMs to generate a population of spheres (representing the “active material” of the cathode). Once spheres have been sampled from the GMM, they are placed within a microstructure. Subsequently, the pix2pix sweeps over the 3D microstructure (iteratively) slice by slice and adds details to the microstructure to determine what portions of the microstructure will become electrolyte and what part of the microstructure will become binder. In this manner, each subsequent slice of the microstructure is evaluated using pix2pix, where the inputs into pix2pix are the previously processed layers of the microstructure. By feeding into pix2pix previously fully processed layers of the microstructure, pix2pix can be used to ensure candidate microstructures represent a realistic physical reality. More specifically, in order for the microstructure to represent a realistic physical reality, the locations of electrolyte and binder in each layer of the microstructure must reasonably match the locations of electrolyte and binder in previous layers to ensure geometric continuity. Using the above outlined approach, a 10x to 100x speed increase was possible when generating candidate microstructures using AI when compared to using a FEA only approach for this task. A key metric for evaluating microstructures was the battery specific power value that the microstructures would be able to produce. The best generative AI result obtained was a 12% increase in specific power for a candidate microstructure when compared to what a FEA only approach was capable of producing. This 12% increase in specific power was verified by FEA simulation.

Keywords: finite element analysis, gaussian mixture models, generative design, Pix2Pix, structural design

Procedia PDF Downloads 112
492 Investigating the Effects of Cylinder Disablement on Diesel Engine Fuel Economy and Exhaust Temperature Management

Authors: Hasan Ustun Basaran

Abstract:

Diesel engines are widely used in transportation sector due to their high thermal efficiency. However, they also release high rates of NOₓ and PM (particulate matter) emissions into the environment which have hazardous effects on human health. Therefore, environmental protection agencies have issued strict emission regulations on automotive diesel engines. Recently, these regulations are even increasingly strengthened. Engine producers search novel on-engine methods such as advanced combustion techniques, utilization of renewable fuels, exhaust gas recirculation, advanced fuel injection methods or use exhaust after-treatment (EAT) systems in order to reduce emission rates on diesel engines. Although those aforementioned on-engine methods are effective to curb emission rates, they result in inefficiency or cannot decrease emission rates satisfactorily at all operating conditions. Therefore, engine manufacturers apply both on-engine techniques and EAT systems to meet the stringent emission norms. EAT systems are highly effective to diminish emission rates, however, they perform inefficiently at low loads due to low exhaust gas temperatures (below 250°C). Therefore, the objective of this study is to demonstrate that engine-out temperatures can be elevated above 250°C at low-loaded cases via cylinder disablement. The engine studied and modeled via Lotus Engine Simulation (LES) software is a six-cylinder turbocharged and intercooled diesel engine. Exhaust temperatures and mass flow rates are predicted at 1200 rpm engine speed and several low loaded conditions using LES program. It is seen that cylinder deactivation results in a considerable exhaust temperature rise (up to 100°C) at low loads which ensures effective EAT management. The method also improves fuel efficiency through reduced total pumping loss. Decreased total air induction due to inactive cylinders is thought to be responsible for improved engine pumping loss. The technique reduces exhaust gas flow rate as air flow is cut off on disabled cylinders. Still, heat transfer rates to the after-treatment catalyst bed do not decrease that much since exhaust temperatures are increased sufficiently. Simulation results are promising; however, further experimental studies are needed to identify the true potential of the method on fuel consumption and EAT improvement.

Keywords: cylinder disablement, diesel engines, exhaust after-treatment, exhaust temperature, fuel efficiency

Procedia PDF Downloads 181
491 (In)Visibility of Afghan Migrants in Turkey's Informal Labour Market

Authors: Rezzan Alagoz, Seda Gonul

Abstract:

This study examines the migration, work, and social life experiences of undocumented Afghan migrants employed as shepherds in Igdır. Despite their high visibility in informal labor markets, their undocumented status renders them invisible in everyday life. Their invisibility in both official status and social life, coupled with their vulnerability to exploitation in the labor market, renders them particularly susceptible to marginalization. This research employs the concept of the subaltern to examine the characteristics of Afghan migrants as unrepresented, unheard, and invisible. It also analyzes their experiences in the labor market based on the concept of biopolitics. Undocumented Afghan migrants are engaged in labor-intensive occupations such as shepherding, thereby addressing an essential gap in the workforce that local workers are reluctant to undertake. The reliance of employers on the labor of these employees is significant; however, the undocumented status of these workers leaves them vulnerable to exploitation. In addition to serving as a critical source of low-cost labor, these individuals are susceptible to exploitation in the form of non-payment for their work, extended and intensive work schedules, and, on some occasions, physical violence. In the event of a conflict between shepherds and their employers, undocumented workers are unable to seek legal recourse, which serves to reinforce their marginalized status further. The predominant practice among Afghan shepherds is to utilize the workplace as a place of residence. In the context of shepherding work, the prevailing conditions at the workplace frequently pose a significant threat to the health and well-being of the individuals engaged in such activities. As a result of their lack of official status, these individuals lack access to basic services such as healthcare, which has the consequence of rendering them invisible in public and institutional spaces. Attempts to engage with public systems carry the risk of deportation, reinforcing the already fragile and precarious nature of their existence. This study examines the socio-political implications of undocumented status and addresses these experiences in the context of national and international migration policies. In line with Agamben's concept of the "state of exception" undocumented migrants exist in a state where fundamental rights are effectively nullified, and they are rendered outside the protection of the law. This exclusion is further exacerbated by the intersection of economic exploitation, political and physical invisibility, and limited access to basic services, which collectively contribute to a cycle of vulnerability. This research is based on in-depth interviews with 18 Afghan shepherds in Igdir province in August 2024. The research contributes to the ongoing critical debates on migration, labor exploitation, and biopolitics by focusing on the experiences of Afghan shepherds. The article examines how undocumented migrants maneuver between visibility and invisibility within the context of a system that relies on exploitation in the labor market and migration policies. The research findings demonstrate the necessity for policy intervention to address the structural exclusion of undocumented Afghan migrants from national and international protection systems, as well as their indispensable role in local economies.

Keywords: Afghan migrants, biopolitics, border economy, informal labour market, migration policy, sheepherding, Subaltern

Procedia PDF Downloads 22
490 Anti-Parasite Targeting with Amino Acid-Capped Nanoparticles Modulates Multiple Cellular Processes in Host

Authors: Oluyomi Stephen Adeyemi, Kentaro Kato

Abstract:

Toxoplasma gondii is the etiological agent of toxoplasmosis, a common parasitic disease capable of infecting a range of hosts, including nearly one-third of the human population. Current treatment options for toxoplasmosis patients are limited. In consequence, toxoplasmosis represents a large global burden that is further enhanced by the shortcomings of the current therapeutic options. These factors underscore the need for better anti-T. gondii agents and/or new treatment approach. In the present study, we sought to find out whether preparing and capping nanoparticles (NPs) in amino acids, would enhance specificity toward the parasite versus the host cell. The selection of amino acids was premised on the fact that T. gondii is auxotrophic for some amino acids. The amino acid-nanoparticles (amino-NPs) were synthesized, purified and characterized following established protocols. Next, we tested to determine the anti-T. gondii activity of the amino-NPs using in vitro experimental model of infection. Overall, our data show evidence that supports enhanced and excellent selective action against the parasite versus the host cells by amino-NPs. The findings are promising and provide additional support that warrants exploring the prospects of NPs as alternative anti-parasite agents. In addition, the anti-parasite action by amino-NPs indicates that nutritional requirement of parasite may represent a viable target in the development of better alternative anti-parasite agents. Furthermore, data suggest the anti-parasite mechanism of the amino-NPs involves multiple cellular processes including the production of reactive oxygen species (ROS), modulation of hypoxia-inducing factor-1 alpha (HIF-1α) as well as the activation of kynurenine pathway. Taken together, findings highlight further, the prospects of NPs as alternative source of anti-parasite agents.

Keywords: drug discovery, infectious diseases, mode of action, nanomedicine

Procedia PDF Downloads 113
489 Spinochromes: Kairomones Involved in the Symbiosis between the Shrimp Tuleariocaris holthuisi and Echinometra mathaei

Authors: Lola Brasseur, Guillaume Caulier, Marie Demeyer, Pascal Gerbaux, Igor Eeckhaut

Abstract:

Seawater being an ideal dispersing agent, chemical communication stays predominant in marine ecosystems. However, if many molecules acting in chemical heterospecific communication have already been well described in terrestrial ecosystems, only three of these molecules were identified in marine ecosystems. Echinoderms and their symbiotic organisms constitute very good models to study heterospecific chemical communication because each class synthesizes a specific type of molecules and symbioses with echinoderms as hosts are very usual. In this study, the chemical communication that allows the commensal shrimps Tuleariocaris holthuisi Hipeau-Jacquotte, 1965 to live with their host Echinometra mathaei (Blainville, 1825) was investigated. The chemoreception of the shrimp was characterized using olfactometers and it was demonstrated that hosts and synthetic hydroxynaphthoquinones are attractive to the symbiotic shrimps. Hydroxynaphthoquinonic pigments also known as spinochromes are by the way synthesized by sea urchin and involved in all probability in a lot of mechanisms. To our knowledge, this study is the first highlighting the ecological function of naphthoquinones as kairomones. Chemical extractions were also performed on sea urchins in order to analyze and identify their specific hydroxynaphthoquinones using HPLC-ESI-MS. Accurate mass identification and elemental composition have been performed on various organs (gonads, coelomic liquid, digestive system and test) in different morphotypes of Echinometra mathaei for a better understanding of the molecular diversity of these semiochemicals. Moreover, some experiments were performed to investigate the dependence of T. holthuisi for their host. First, the analyses showed that the molecules involved in shrimp pigmentation are the same that the ones involved in E. mathaei, suggesting a potential feeding on the host. Secondly, a substantial shrimp depigmentation and an increase of the mortality rate were demonstrated after the symbionts-host separation which could mean a potential implication of spinochromes in the shrimp metabolism.

Keywords: crustacean, sea urchin, spinochrome, symbiosis

Procedia PDF Downloads 197
488 Evaluation of the Cytotoxicity and Genotoxicity of Chemical Material in Filters PM2.5 of the Monitoring Stations of the Network of Air Quality in the Valle De Aburrá, Colombia

Authors: Alejandra Betancur Sánchez, Carmen Elena Zapata Sánchez, Juan Bautista López Ortiz

Abstract:

Adverse effects and increased air pollution has raised concerns about regulatory policies and has fostered the development of new air quality standards; this is due to the complexity of the composition and the poorly understood reactions in the atmospheric environment. Toxic compounds act as environmental agents having various effects, from irritation to death of cells and tissues. A toxic agent is defined an adverse response in a biological system. There is a particular class that produces some kind of alteration in the genetic material or associated components, so they are recognized as genotoxic agents. Within cells, they interact directly or indirectly with DNA, causing mutations or interfere with some enzymatic repair processes or in the genesis or polymerization of proteinaceous material involved in chromosome segregation. An air pollutant may cause or contribute to increased mortality or serious illness and even pose a potential danger to human health. The aim of this study was to evaluate the effect on the viability and the genotoxic potential on the cell lines CHO-K1 and Jurkat and peripheral blood of particulate matter PM T lymphocytes 2.5 obtained from filters collected three monitoring stations network air quality Aburrá Valley. Tests, reduction of MTT, trypan blue, NRU, comet assay, sister chromatid exchange (SCE) and chromosomal aberrations allowed evidence reduction in cell viability in cell lines CHO-K1 and Jurkat and damage to the DNA from cell line CHOK1, however, no significant effects were observed in the number of SCEs and chromosomal aberrations. The results suggest that PM2.5 material has genotoxic potential and can induce cancer development, as has been suggested in other studies.

Keywords: PM2.5, cell line Jurkat, cell line CHO-K1, cytotoxicity, genotoxicity

Procedia PDF Downloads 267
487 Aspirin Loaded Poly-L-Lactic Acid Nanofibers and Their Potentials as Small Diameter Vascular Grafts

Authors: Mahboubeh Kabiri, Saba Aslani

Abstract:

Among various approaches used for the treatment of cardiovascular diseases, the occlusion of the small-diameter vascular graft (SDVG) is still an unresolved problem which seeks further research to address them. Though autografts are now the gold standards to be replaced for blocked coronary arteries, they suffer from inadequate quality and quantity. On the other hand, the major problems of the tissue engineered grafts are thrombosis and intimal hyperplasia. Provision of a suitable spatiotemporal release pattern of anticoagulant agents such as heparin and aspirin can be a step forward to overcome such issues . Herein, we fabricated electrospun scaffolds from FDA (Food and Drug Administration) approved poly-L-lactic acid (PLLA) with aspirin loaded into the nanofibers. Also, we surface coated the scaffolds with Amniotic Membrane lysate as a source for natural elastic polymers and a mimic of endothelial basement membrane. The scaffolds were characterized thoroughly structurally and mechanically for their morphology, fiber orientation, tensile strength, hydrophilicity, cytotoxicity, aspirin release and cell attachment support. According to the scanning electron microscopy (SEM) images, the size of fibers ranged from 250 to 500 nm. The scaffolds showed appropriate tensile strength expected for vascular grafts. Cellular attachment, growth, and infiltration were proved using SEM and MTT (3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide) assay. Drug-loaded scaffolds showed a sustained release profile of aspirin in 7 days. An enhanced cytocompatibility was observed in AM-coated electrospun PLLA fibers compared to uncoated scaffolds. Our results together indicated that AM lysate coated ASA releasing scaffolds have promising potentials for development of a biocompatible SDVG.

Keywords: vascular tissue engineering, vascular grafts, anticoagulant agent, aspirin, amniotic membrane

Procedia PDF Downloads 170
486 Education Management and Planning with Manual Based

Authors: Purna Bahadur Lamichhane

Abstract:

Education planning and management are foundational pillars for developing effective educational systems. However, in many educational contexts, especially in developing nations, technology-enabled management is still emerging. In such settings, manual-based systems, where instructions and guidelines are physically documented, remain central to educational planning and management. This paper examines the effectiveness, challenges, and potential of manual-based education planning systems in fostering structured, reliable, and adaptable management frameworks. The objective of this study is to explore how a manual-based approach can successfully guide administrators, educators, and policymakers in delivering high-quality education. By using structured, accessible instructions, this approach serves as a blueprint for educational governance, offering clear, actionable steps to achieve institutional goals. Through an analysis of case studies from various regions, the paper identifies key strategies for planning school schedules, managing resources, and monitoring academic and administrative performance without relying on automated systems. The findings underscore the significance of organized documentation, standard operating procedures, and comprehensive manuals that establish uniformity and maintain educational standards across institutions. With a manual-based approach, management can remain flexible, responsive, and user-friendly, especially in environments where internet access and digital literacy are limited. Moreover, it allows for localization, where instructions can be tailored to the unique cultural and socio-economic contexts of the community, thereby increasing relevancy and ownership among local stakeholders. This paper also highlights several challenges associated with manual-based education management. Manual systems often require significant time and human resources for maintenance and updating, potentially leading to inefficiencies and inconsistencies over time. Furthermore, manual records can be susceptible to loss, damage, and limited accessibility, which may affect decision-making and institutional memory. There is also the risk of siloed information, where crucial data resides with specific individuals rather than being accessible across the organization. However, with proper training and regular oversight, many of these limitations can be mitigated. The study further explores the potential for hybrid approaches, combining manual planning with selected digital tools for record-keeping, reporting, and analytics. This transitional strategy can enable schools and educational institutions to gradually embrace digital solutions without discarding the familiarity and reliability of manual instructions. In conclusion, this paper advocates for a balanced, context-sensitive approach to education planning and management. While digital systems hold the potential to streamline processes, manual-based systems offer resilience, inclusivity, and adaptability for institutions where technology adoption may be constrained. Ultimately, by reinforcing the importance of structured, detailed manuals and instructional guides, educational institutions can build robust management frameworks that facilitate both short-term successes and long-term growth in their educational mission. This research aims to provide a reference for policymakers, educators, and administrators seeking practical, low-cost, and adaptable solutions for sustainable educational planning and management.

Keywords: educatoin, planning, management, manual

Procedia PDF Downloads 24
485 Environmental and Toxicological Impacts of Glyphosate with Its Formulating Adjuvant

Authors: I. Székács, Á. Fejes, S. Klátyik, E. Takács, D. Patkó, J. Pomóthy, M. Mörtl, R. Horváth, E. Madarász, B. Darvas, A. Székács

Abstract:

Environmental and toxicological characteristics of formulated pesticides may substantially differ from those of their active ingredients or other components alone. This phenomenon is demonstrated in the case of the herbicide active ingredient glyphosate. Due to its extensive application, this active ingredient was found in surface and ground water samples collected in Békés County, Hungary, in the concentration range of 0.54–0.98 ng/ml. The occurrence of glyphosate appeared to be somewhat higher at areas under intensive agriculture, industrial activities and public road services, but the compound was detected at areas under organic (ecological) farming or natural grasslands, indicating environmental mobility. Increased toxicity of the formulated herbicide product Roundup, compared to that of glyphosate was observed on the indicator aquatic organism Daphnia magna Straus. Acute LC50 values of Roundup and its formulating adjuvant Polyethoxylated Tallowamine (POEA) exceeded 20 and 3.1 mg/ml, respectively, while that of glyphosate (as isopropyl salt) was found to be substantially lower (690-900 mg/ml) showing good agreement with literature data. Cytotoxicity of Roundup, POEA and glyphosate has been determined on the neuroectodermal cell line, NE-4C measured both by cell viability test and holographic microscopy. Acute toxicity (LC50) of Roundup, POEA and glyphosate on NE-4C cells was found to be 0.013±0.002%, 0.017±0.009% and 6.46±2.25%, respectively (in equivalents of diluted Roundup solution), corresponding to 0.022±0.003 and 53.1±18.5 mg/ml for POEA and glyphosate, respectively, indicating no statistical difference between Roundup and POEA and 2.5 orders of magnitude difference between these and glyphosate. The same order of cellular toxicity seen in average cell area has been indicated under quantitative cell visualization. The results indicate that toxicity of the formulated herbicide is caused by the formulating agent, but in some parameters toxicological synergy occurs between POEA and glyphosate.

Keywords: glyphosate, polyethoxylated tallowamine, Roundup, combined aquatic and cellular toxicity, synergy

Procedia PDF Downloads 323
484 Board Nomination and Selection Process in Indonesian State-Owned Enterprises

Authors: Synthia A. Sari

Abstract:

The transparent nomination and selection process is the first step to obtaining qualified members of board. It is believed as the representative (agent) of the owners, members of the board must consist of competent and professional people. However, the development of transparent and ideal nomination and selection process in Indonesian State-owned enterprises (SOEs) has been based on relatively little research. Considering the relative importance attached by boards to conduct their roles in their principal’s interest in a variety of governance tasks in state-owned enterprises, the primary aim of this paper is to shed light on the extent of nomination and selection process impact performance of the board in implementing good corporate governance in Indonesian SOEs. The exploratory nature of this study led to the adoption of a qualitative research methodology which uses semi-structured interviews and publically available documents to collect a range of data pertaining board nomination and selection and the work of boards. Interviews were conducted with four informants from three Indonesian SOEs and Ministry of SOEs. Findings in this study demonstrate unclear job description and expectations board members as a result of unclear functions of the board in Indonesian SOEs make transparent and accountable nomination and selection process hard to conduct. This situation is vulnerable to the influences from political interest and that even the process itself can degenerate into situations of political interference. In the end, it leads to choosing the wrong person for membership of the board. This study makes a significant contribution to several fields; the human resource management, corporate governance, and Southeast studies by addressing the basic research gaps of board selection process issues in Indonesian SOEs. The gap is addressed by providing a more coherent framework for effective nomination and selection system which reflects more clearly the real experiences of those actually involved at board level.

Keywords: board selection and nomination process, Indonesian stated-owned enterprises, good corporate governance, political influence

Procedia PDF Downloads 270
483 Gender Discrimination and Wellbeing in Family Sphere Due to Male Migration and Remittances: A Study of Doaba Region of Punjab

Authors: Atinder Pal Kaur

Abstract:

A central characteristic of people is their apparent movement from one station to other for their sustenance. Human migration has become one of the most challenging issues faced by the world today. Migration represents an important dimension in world-wide setting; and remittances received by families constitute a major agent in integrating societies in the all over the world, both economically and socially. This paper is an attempt to explore the impact of male migration and remittances upon the family system. This paper brings out how the women play the role of head of the household and take all the economic decisions, but still faces discrimination in the family, that bring loneliness and emotional breakdown on their personal front. For the purpose of this study, data was collected using 30 interviews and 10 case studies in the Doaba region of Punjab. The respondents were classified into two age groups 20-35 years and above 40 years aged women whose husbands migrated abroad. The findings of this study revealed that even though the women were taking some of the economic decisions, but in majority of the cases the patriarchal structure still existed and power remained in the hands of their husbands or in-laws. It was found that women of different age groups reported differently in terms of authority that they have regarding remittances and its consequences in their emotional well-being. The distinction related to their participation in public and private spheres still exists and public spheres are mostly dominated by male members of the family. It can be concluded that freedom of women to take decision on their own is still restricted and they are subjugated to follow their husband or in-law’s opinion in matters related to both public and private spheres. However, old age group women enjoyed more independence and freedom to take decision in comparison to young age women. Loneliness and depression were more common in the young age respondent’s group than in old age women.

Keywords: gender discrimination, migration, patriarchal structure, remittances

Procedia PDF Downloads 267
482 A Systematic Review on Prevalence, Serotypes and Antibiotic Resistance of Salmonella in Ethiopia

Authors: Atsebaha Gebrekidan Kahsay, Tsehaye Asmelash, Enquebaher Kassaye

Abstract:

Background: Salmonella remains a global public health problem with a significant burden in sub-Saharan African countries. Human restricted cause of typhoid and paratyphoid fever are S. Typhi and S. Paratyphi, whereas S. Enteritidis and S. Typhimurium is the causative agent of invasive nontyphoidal diseases among humans and animals are their reservoir. The antibiotic resistance of Salmonella is another public health threat around the globe. To come up with full information about human and animal salmonellosis, we made a systematic review of the prevalence, serotypes, and antibiotic resistance of Salmonella in Ethiopia. Methods: This systematic review used Google Scholar and PubMed search engines to search articles from Ethiopia that were published in English in peer-reviewed international journals from 2010 to 2022. We used keywords to identify the intended research articles and used a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the inclusion and exclusion criteria. Frequencies and percentages were analyzed using Microsoft Excel. Results: Two hundred seven published articles were searched, and 43 were selected for a systematic review, human (28) and animals (15). The prevalence of Salmonella in humans and animals was 434 (5.2%) and 641(10.1%), respectively. Fourteen serotypes were identified from animals, and S. Typhimurium was among the top five. Among the ciprofloxacin-resistant isolates in human studies, 16.7% was the highest, whereas, for ceftriaxone, 100% resistance was reported. Conclusions: The prevalence of Salmonella among diarrheic patients and food handlers (5.2%) was lower than the prevalence in food animals (10.1%). We did not find serotypes of Salmonella in human studies, although fourteen serotypes were included in food-animal studies, and S. Typhimurium was among the top five. Salmonella species from some human studies revealed a non-susceptibility to ceftriaxone. We recommend further study about invasive nontyphoidal Salmonella and predisposing factors among humans and animals in Ethiopia.

Keywords: antibiotic resistance, prevalence, systematic review, serotypes, Salmonella, Ethiopia

Procedia PDF Downloads 88
481 Potentialities of Onopordum Tauricum (Willd.) as Milk Clotting Agent

Authors: Massimo Mozzon, Nadia Raffaelli

Abstract:

Proteases from herbs, woody plants, and trees are exploited for cheesemaking in several countries, especially in South Europe and West Africa. Particularly, “thistles” belonging to several genera within the Asteraceae family (Cynara, Silybum, Centaurea, Carlina, Cirsium, Onopordum) are traditionally used in Mediterranean countries for clotting raw ewe’s and goat’s milk. For the first time, the clotting performance of an aqueous extract from flowers of Onopordum tauricum Willd. (Taurian thistle, bull cottonthistle) were tested in milk of different origin (cow, goat, ewe). The vegetable material was collected in the Central Apennines range, between the Marche and Umbria regions. A response surface methodology (RSM) approach was used to study the effect of the curdling variables (temperature, pH, amount of enzymatic extract) on the technological performance of the thistle extract. A three-step procedure for the purification of the enzyme (ammonium sulphate precipitation, gel filtration and ion-exchange chromatography) was also carried out. The milk clotting activity (MCA) of O. tauricum crude extracts was strongly affected by temperature, pH and by the interaction between these two variables, according to a second-order response surface model, while the milk/coagulant ratio did not affect in a significant way the clotting properties. Experimental data showed that the addition of 10 mM CaCl2 reduced the clotting time of ewe’s, goat’s, and cow’s milk by about 3-fold, 8-fold, and 14-fold, respectively, at 35°C and pH 6.7-6.8. After purification, an enzymatic preparation very close to homogeneity was obtained, which showed a major band at about 30 kDa when analyzed by SDS-PAGE. The identity of the enzyme as an aspartic protease was confirmed by inhibition studies. Cheese-making trials were carried out to check the scale-up (1 to 5 L of milk; 37 °C; 10 mM CaCl2 fortification) and set the recipe: 35-45% of curd yields were recorded, according to curd cutting and pressing.

Keywords: milk clotting activity, Onopordum tauricum, plant proteases, vegetable rennet

Procedia PDF Downloads 162
480 Effect of Oxidative Stress on Glutathione Reductase Activity of Escherichia coli Clinical Isolates from Patients with Urinary Tract Infection

Authors: Fariha Akhter Chowdhury, Sabrina Mahboob, Anamika Saha, Afrin Jahan, Mohammad Nurul Islam

Abstract:

Urinary tract infection (UTI) is frequently experienced by the female population where the prevalence increases with aging. Escherichia coli, one of the most common UTI causing organisms, retains glutathione defense mechanism that aids the organism to withstand the harsh physiological environment of urinary tract, host oxidative immune response and even to affect antibiotic-mediated cell death and the emergence of resistance. In this study, we aimed to investigate the glutathione reductase activity of uropathogenic E. coli (UPEC) by observing the reduced glutathione (GSH) level alteration under stressful condition. Urine samples of 58 patients with UTI were collected. Upon isolation and identification, 88% of the samples presented E. coli as UTI causing organism among which randomly selected isolates (n=9), obtained from urine samples of female patients, were considered for this study. E. coli isolates were grown under normal and stressful conditions where H₂O₂ was used as the stress-inducing agent. GSH level estimation of the isolates in both conditions was carried out based on the colorimetric measurement of 5,5'-dithio-bis (2-nitrobenzoic acid) (DTNB) and GSH reaction product using microplate reader assay. The GSH level of isolated E. coli sampled from adult patients decreased under stress compared to normal condition (p = 0.011). On the other hand, GSH production increased markedly in samples that were collected from elderly subjects (p = 0.024). A significant partial correlation between age and change of GSH level was found as well (p = 0.007). This study may help to reveal ways for better understanding of E. coli pathogenesis of UTI prevalence in elderly patients.

Keywords: Escherichia coli, glutathione reductase activity, oxidative stress, reduced glutathione (GSH), urinary tract infection (UTI)

Procedia PDF Downloads 334
479 Comparative Efficacy of Vasodilators on Internal Mammary Artery Flow in Coronary Artery Bypass Grafting (CABG): A Systematic Review and Network Meta-Analysis

Authors: Umm E. Aimen Minhas, Sameen Tahira, Haneen Kamran, Syed Saad Ul Hassan, Haris Bin Khalid, Hadia Nadeem, Ahmed Sanan

Abstract:

In coronary artery bypass grafting (CABG) patients, vasodilators play a key role in optimizing graft patency by preventing vasospasm and enhancing blood flow. Limited literature is available comparing the effectiveness of various vasodilators on IMA flow in CABG patients. Thus, the rationale for conducting this Network-meta-analysis is to identify the most efficacious vasodilator for increasing IMA flow in CABG patients. A systematic search of 3 databases yielded 357 studies, with 19 meeting inclusion criteria (18 RCTs, 1 observational study). The primary outcome was IMA flow, with secondary outcomes including central venous pressure (CVP) and mean arterial pressure (MAP). Analyses were conducted on an intention-to-treat basis using the net meta package in R. A frequentist random-effects model was employed, with consistency assessed via node-splitting and heterogeneity evaluated. The risk of bias was assessed using RoB 2 and ROBINS-I tools. Out of 92 possible pairwise comparisons, 11 were direct, and 3 included both direct and indirect evidence. Network ranking identified milrinone as the most effective vasodilator for improving IMA flow (SMD: 1.12; 95% CI: 0.36–1.87), followed by nitroglycerin (SMD: 0.51; 95% CI: 0.01–1.00). On the contrary, CO₂ insufflation significantly reduced IMA flow (SMD: -1.17; 95% CI: -2.28 to -0.06). Dobutamine significantly increased CVP, favoring placebo, with no notable differences in MAP across interventions. This analysis positions milrinone as a potentially superior agent for enhancing IMA flow in CABG, warranting its consideration as a first-line therapy. However, moderate to high heterogeneity and limited direct evidence highlight the need for more head-to-head trials.

Keywords: IMA flow, vasodilators, CABG, milrinone, cardiac outcomes

Procedia PDF Downloads 11
478 Experimental Quantification of the Intra-Tow Resin Storage Evolution during RTM Injection

Authors: Mathieu Imbert, Sebastien Comas-Cardona, Emmanuelle Abisset-Chavanne, David Prono

Abstract:

Short cycle time Resin Transfer Molding (RTM) applications appear to be of great interest for the mass production of automotive or aeronautical lightweight structural parts. During the RTM process, the two components of a resin are mixed on-line and injected into the cavity of a mold where a fibrous preform has been placed. Injection and polymerization occur simultaneously in the preform inducing evolutions of temperature, degree of cure and viscosity that furthermore affect flow and curing. In order to adjust the processing conditions to reduce the cycle time, it is, therefore, essential to understand and quantify the physical mechanisms occurring in the part during injection. In a previous study, a dual-scale simulation tool has been developed to help determining the optimum injection parameters. This tool allows tracking finely the repartition of the resin and the evolution of its properties during reactive injections with on-line mixing. Tows and channels of the fibrous material are considered separately to deal with the consequences of the dual-scale morphology of the continuous fiber textiles. The simulation tool reproduces the unsaturated area at the flow front, generated by the tow/channel difference of permeability. Resin “storage” in the tows after saturation is also taken into account as it may significantly affect the repartition and evolution of the temperature, degree of cure and viscosity in the part during reactive injections. The aim of the current study is, thanks to experiments, to understand and quantify the “storage” evolution in the tows to adjust and validate the numerical tool. The presented study is based on four experimental repeats conducted on three different types of textiles: a unidirectional Non Crimp Fabric (NCF), a triaxial NCF and a satin weave. Model fluids, dyes and image analysis, are used to study quantitatively, the resin flow in the saturated area of the samples. Also, textiles characteristics affecting the resin “storage” evolution in the tows are analyzed. Finally, fully coupled on-line mixing reactive injections are conducted to validate the numerical model.

Keywords: experimental, on-line mixing, high-speed RTM process, dual-scale flow

Procedia PDF Downloads 169
477 Efficient Field-Oriented Motor Control on Resource-Constrained Microcontrollers for Optimal Performance without Specialized Hardware

Authors: Nishita Jaiswal, Apoorv Mohan Satpute

Abstract:

The increasing demand for efficient, cost-effective motor control systems in the automotive industry has driven the need for advanced, highly optimized control algorithms. Field-Oriented Control (FOC) has established itself as the leading approach for motor control, offering precise and dynamic regulation of torque, speed, and position. However, as energy efficiency becomes more critical in modern applications, implementing FOC on low-power, cost-sensitive microcontrollers pose significant challenges due to the limited availability of computational and hardware resources. Currently, most solutions rely on high-performance 32-bit microcontrollers or Application-Specific Integrated Circuits (ASICs) equipped with Floating Point Units (FPUs) and Hardware Accelerated Units (HAUs). These advanced platforms enable rapid computation and simplify the execution of complex control algorithms like FOC. However, these benefits come at the expense of higher costs, increased power consumption, and added system complexity. These drawbacks limit their suitability for embedded systems with strict power and budget constraints, where achieving energy and execution efficiency without compromising performance is essential. In this paper, we present an alternative approach that utilizes optimized data representation and computation techniques on a 16-bit microcontroller without FPUs or HAUs. By carefully optimizing data point formats and employing fixed-point arithmetic, we demonstrate how the precision and computational efficiency required for FOC can be maintained in resource-constrained environments. This approach eliminates the overhead performance associated with floating-point operations and hardware acceleration, providing a more practical solution in terms of cost, scalability and improved execution time efficiency, allowing faster response in motor control applications. Furthermore, it enhances system design flexibility, making it particularly well-suited for applications that demand stringent control over power consumption and costs.

Keywords: field-oriented control, fixed-point arithmetic, floating point unit, hardware accelerator unit, motor control systems

Procedia PDF Downloads 26
476 Cucurbita pepo L. Attenuates Diabetic Neuropathy by Targeting Oxidative Stress in STZ-Nicotinamide Induced Diabetic Rats

Authors: Navpreet Kaur, Randhir Singh

Abstract:

Diabetic neuropathy is one of the most common microvascular complications of diabetes mellitus which affects more than 50% of diabetic patients. The present study targeted oxidative stress mediated nerve damage in diabetic rats using a hydro-alcohol extract of Cucurbita pepo L. (Family: Cucurbitaceae) and its potential in treatment of diabetic neuropathy. Diabetes neuropathy was induced in Wistar rats by injection of streptozotocin (65 mg/kg, i.p.) 15 min after Nicotinamide (230 mg/kg, i.p.) administration. Hydro-alcohol extract of C. pepo seeds was assessed by oral administration at 100, 200 and 400 mg/kg in STZ-nicotinamide induced diabetic rats. Thermal hyperalgesia (Eddy's hot plate and tail immersion), mechanical hyperalgesia (Randall-Selitto) and tactile allodynia (Von Frey hair tests) were evaluated in all groups of streptozotocin diabetic rats to assess the extent of neuropathy. Tissue (sciatic nerve) antioxidant enzymes (SOD, CAT, GSH and LPO) levels were measured along with the formation of AGEs in serum to assess the effect of hydro-alcohol extract of C. pepo in ameliorating oxidative stress. Diabetic rats exhibited significantly decreased tail-flick latency in the tail-immersion test and decreased paw withdrawal threshold in both Randall-Selitto and von-Frey hair test. A decrease in the nociceptive threshold was accompanied by significantly increased oxidative stress in sciatic nerve of diabetic rats. Treatment with the C. pepo hydro-alcohol extract significantly attenuated all the behavioral and biochemical alterations in a dose-dependent manner. C. pepo attenuated the diabetic condition and also reversed neuropathic pain through modulation of oxidative stress and thus it may find application as a possible therapeutic agent against diabetic neuropathy.

Keywords: advanced glycation end products, antioxidant enzymes, cucurbita pepo, hyperglycemia

Procedia PDF Downloads 301
475 Innovation Eco-Systems and Cities: Sustainable Innovation and Urban Form

Authors: Claudia Trillo

Abstract:

Regional innovation eco-ecosystems are composed of a variety of interconnected urban innovation eco-systems, mutually reinforcing each other and making the whole territorial system successful. Combining principles drawn from the new economic growth theory and from the socio-constructivist approach to the economic growth, with the new geography of innovation emerging from the networked nature of innovation districts, this paper explores the spatial configuration of urban innovation districts, with the aim of unveiling replicable spatial patterns and transferable portfolios of urban policies. While some authors suggest that cities should be considered ideal natural clusters, supporting cross-fertilization and innovation thanks to the physical setting they provide to the construction of collective knowledge, still a considerable distance persists between regional development strategies and urban policies. Moreover, while public and private policies supporting entrepreneurship normally consider innovation as the cornerstone of any action aimed at uplifting the competitiveness and economic success of a certain area, a growing body of literature suggests that innovation is non-neutral, hence, it should be constantly assessed against equity and social inclusion. This paper draws from a robust qualitative empirical dataset gathered through 4-years research conducted in Boston to provide readers with an evidence-based set of recommendations drawn from the lessons learned through the investigation of the chosen innovation districts in the Boston area. The evaluative framework used for assessing the overall performance of the chosen case studies stems from the Habitat III Sustainable Development Goals rationale. The concept of inclusive growth has been considered essential to assess the social innovation domain in each of the chosen cases. The key success factors for the development of the Boston innovation ecosystem can be generalized as follows: 1) a quadruple helix model embedded in the physical structure of the two cities (Boston and Cambridge), in which anchor Higher Education (HE) institutions continuously nurture the Entrepreneurial Environment. 2) an entrepreneurial approach emerging from the local governments, eliciting risk-taking and bottom-up civic participation in tackling key issues in the city. 3) a networking structure of some intermediary actors supporting entrepreneurial collaboration, cross-fertilization and co-creation, which collaborate at multiple-scales thus enabling positive spillovers from the stronger to the weaker contexts. 4) awareness of the socio-economic value of the built environment as enabler of cognitive networks allowing activation of the collective intelligence. 5) creation of civic-led spaces enabling grassroot collaboration and cooperation. Evidence shows that there is not a single magic recipe for the successful implementation of place-based and social innovation-driven strategies. On the contrary, the variety of place-grounded combinations of micro and macro initiatives, embedded in the social and spatial fine grain of places and encompassing a diversity of actors, can create the conditions enabling places to thrive and local economic activities to grow in a sustainable way.

Keywords: innovation-driven sustainable Eco-systems , place-based sustainable urban development, sustainable innovation districts, social innovation, urban policie

Procedia PDF Downloads 110
474 Investigating the Potential Use of Unsaturated Fatty Acids as Antifungal Crop Protective Agents

Authors: Azadeh Yasari, Michael Ganzle, Stephen Strelkov, Nuanyi Liang, Jonathan Curtis, Nat N. V. Kav

Abstract:

Pathogenic fungi cause significant yield losses and quality reductions to major crops including wheat, canola, and barley. Toxic metabolites produced by phytopathogenic fungi also pose significant risks to animal and human health. Extensive application of synthetic fungicides is not a sustainable solution since it poses risks to human, animal and environmental health. Unsaturated fatty acids may provide an environmentally friendly alternative because of their direct antifungal activity against phytopathogens as well as through the stimulation of plant defense pathways. The present study assessed the in vitro and in vivo efficacy of two hydroxy fatty acids, coriolic acid and ricinoleic acid, against the phytopathogens Fusarium graminearum, Pyrenophora tritici-repentis, Pyrenophora teres f. teres, Sclerotinia sclerotiorum, and Leptosphaeria maculans. Antifungal activity of coriolic acid and ricinoleic acid was evaluated using broth micro-dilution method to determine the minimum inhibitory concentration (MIC). Results indicated that both ricinoleic acid and coriolic acid showed antifungal activity against phytopathogens, with the strongest inhibitory activity against L. maculans, but the MIC varied greatly between species. An antifungal effect was observed for coriolic acid in vivo against pathogenic fungi of wheat and barley. This effect was not correlated to the in vitro activity because ricinoleic acid with equivalent in vitro antifungal activity showed no protective effect in vivo. Moreover, neither coriolic acid nor ricinoleic acid controlled fungal pathogens of canola. In conclusion, coriolic acid inhibits some phytopathogens in vivo and may have the potential to be an effective crop protection agent.

Keywords: coriolic acid, minimum inhibitory concentration, pathogenic fungi, ricinoleic acid

Procedia PDF Downloads 181
473 Biological Methods to Control Parasitic Weed Phelipanche ramosa L. Pomel in the Field Tomato Crop

Authors: F. Lops, G. Disciglio, A. Carlucci, G. Gatta, L. Frabboni, A. Tarantino, E. Tarantino

Abstract:

Phelipanche ramosa L. Pomel is a root holoparasitic weed plant of many cultivations, particularly of tomato (Lycopersicum esculentum L.) crop. In Italy, Phelipanche problem is increasing, both in density and in acreage. The biological control of this parasitic weed involves the use of living organisms as numerous fungi and bacteria that can infect the parasitic weed, while it may improve the crop growth. This paper deals with the biocontrol with microorganism, including Arbuscular mycorrhizal (AM) fungi and fungal pathogens as Fusarium oxisporum spp. Colonization of crop roots by AM fungi can provide protection of crops against parasitic weeds because of a reduction in their seed germination and attachment, while F. oxisporum, isolated from diseased broomrape tubercles, proved to be highly virulent on P. ramosa. The experimental trial was carried out in open field at Foggia province (Apulia Region, Southern Italy), during the spring-summer season 2016, in order to evaluate the effect of four biological treatments: AM fungi and Fusarium oxisporum applied in the soil alone or combined together, and Rizosum Max® product, compared with the untreated control, to reduce the P. ramosa infestation in processing tomato crop. The principal results to be drawn from this study under field condition, in contrast of those reported previously under laboratory and greenhouse conditions, show that both AM fungi and F. oxisporum do not provide the reduction of the number of emerged shoots of P. ramosa. This can arise probably from the low efficacy seedling of the agent pathogens for the control of this parasite in the field. On the contrary, the Rizosum Max® product, containing AM fungi and some rizophere bacteria combined with several minerals and organic substances, appears to be most effective for the reduction of P. ramosa infestation.

Keywords: Arbuscular mycorrhized fungi, biocontrol methods, Phelipanche ramosa, tomato crop

Procedia PDF Downloads 464
472 Optimum Method to Reduce the Natural Frequency for Steel Cantilever Beam

Authors: Eqqab Maree, Habil Jurgen Bast, Zana K. Shakir

Abstract:

Passive damping, once properly characterized and incorporated into the structure design is an autonomous mechanism. Passive damping can be achieved by applying layers of a polymeric material, called viscoelastic layers (VEM), to the base structure. This type of configuration is known as free or unconstrained layer damping treatment. A shear or constrained damping treatment uses the idea of adding a constraining layer, typically a metal, on top of the polymeric layer. Constrained treatment is a more efficient form of damping than the unconstrained damping treatment. In constrained damping treatment a sandwich is formed with the viscoelastic layer as the core. When the two outer layers experience bending, as they would if the structure was oscillating, they shear the viscoelastic layer and energy is dissipated in the form of heat. This form of energy dissipation allows the structural oscillations to attenuate much faster. The purpose behind this study is to predict damping effects by using two methods of passive viscoelastic constrained layer damping. First method is Euler-Bernoulli beam theory; it is commonly used for predicting the vibratory response of beams. Second method is Finite Element software packages provided in this research were obtained by using two-dimensional solid structural elements in ANSYS14 specifically eight nodded (SOLID183) and the output results from ANSYS 14 (SOLID183) its damped natural frequency values and mode shape for first five modes. This method of passive damping treatment is widely used for structural application in many industries like aerospace, automobile, etc. In this paper, take a steel cantilever sandwich beam with viscoelastic core type 3M-468 by using methods of passive viscoelastic constrained layer damping. Also can proved that, the percentage reduction of modal frequency between undamped and damped steel sandwich cantilever beam 8mm thickness for each mode is very high, this is due to the effect of viscoelastic layer on damped beams. Finally this types of damped sandwich steel cantilever beam with viscoelastic materials core type (3M468) is very appropriate to use in automotive industry and in many mechanical application, because has very high capability to reduce the modal vibration of structures.

Keywords: steel cantilever, sandwich beam, viscoelastic materials core type (3M468), ANSYS14, Euler-Bernoulli beam theory

Procedia PDF Downloads 323
471 The Family as an Agent for Change in Aerobic Activity and Obesity in Grade 2-3 Schoolchildren

Authors: T. Goldstein, E. Serok, J. D. Kark

Abstract:

Background and Aim: The prevalence of obesity is increasing worldwide and in Israel. To meet this challenge, our study tests a new educational approach through a controlled school-based trial to achieve an improvement in eating habits, aerobic activity, and reduced obesity in Grades 2-3. Methods and Design: A cluster randomized controlled trial allocated 4 elementary schools (3rd and 2nd-grade classes each) to intervention or control groups. This allocation was switched with the next cohort of children. Recruitment was in first grade, randomization at the beginning of second grade, evaluation of results at the end of second grade and the beginning of third grade — intervention: 5 joint parent-children classroom activities on health topics and 5 educational workshops for parents only. Alfred Adler's concepts were guiding principles. Subjects: Of 743 children in 23-second grade classes, parents provided informed consent for 508 (68%). Information of retention health habits continued for third grade. Additional parental approvals were required. Parents provided informed consent for third-grade follow-up for 432. Results: At the end of 2nd grade, the amount of aerobic activity increased in the intervention group in comparison with the control group, the difference being marginally statistically significant (p=0.061). There is a significant difference between the groups in the percentage of "no activity being done" reported at the end of second grade when in the experimental group, the percentage is lower than the control. There are differences between genders in the percentage of aerobic activity at the end of second grade (p=0.044) and in the third grade (p < 0.0001). Height increased significantly (p=0.030 ), and waist circumference declined significantly (p=0.021) in the intervention compared with the control group. There were no significant between-group differences in BMI and weight. Conclusion: There were encouraging changes in aerobic activity and in anthropometric measurements. To maintain changes over longer periods, refreshing these nutrition and activity themes annually in school using the model is required.

Keywords: aerobic activity, child obesity, Alfred Adler, schoolchildren

Procedia PDF Downloads 152