Search results for: landfill leachate treatment

Authors: Xuan Li, Xiaobing Cui, Nan Meng, Shuangshuang Guo, Lingling Wang

Abstract:

Objective: To investigate the influence of Paeonol on diabetic nephropathy progression in streptozocin (STZ) -induced diabetic rats. Method Male Wistar rats were injected STZ 30mg.kg-1 combined with Freund's complete adjuvant (CFA) 0.1mL/rat once a week for three weeks. The diabetic rats were treated with Paenol for 13 weeks. At the end of the experiments, the rats were anesthetized. Serum and the kidney were collected. Serum superoxide dismutase (SOD) activity, malondialdehyde (MDA), blood urea nitrogen (BUN), creatinine (Cr) and total cholesterol (Chol) level were detected; kidney paraffin sections were prepared and HE and PAS staining sections were used to evaluate the pathology changes of the kidney. Immunohistochemical analysis was used to observe the expression of VEGF and fibernectin expression in the kidney. Result The blood glucose level remained over 16mmol. L-1 for 13 weeks and the ECM accumulated in the diabetic kidney apparently. Paeonol treatment increased serum SOD activity, however, MDA, BUN, Cr, and Chol level was decreased by paeonol treatment. VEGF and fibernectin expression were increased significantly in the DN rats and paeonol treatment ameliorated the overexpression. Conclusion: paeonol prevented the progression of DN.

Keywords: paeonol, STZ, diabetic nephropathy, fibernectin expression, kidney paraffin sections

Procedia PDF Downloads 463

Authors: K. Digheche, K. Saadi, Z. Boumerzoug

Abstract:

Welding is one of the most important technological processes used in many branches of industry such as industrial engineering, shipbuilding, pipeline fabrication among others. Generally, welding is the preferred joining method and most common steels are weldable. This investigation is a contribution to scientific work of welding of low carbon steel. This work presents the results of the isothermal heat treatment effect at 200, 400 and 600 °C on microstructural evolution in weld region of X70 pipeline steel. The welding process has been realized in three passes by industrial arc welding. We have found that the heat treatments cause grain growth reaction.

Keywords: heat treatments, low carbon steel, microstructures, welding

Procedia PDF Downloads 462

Authors: Batoul Mohamed Abdullatif, Nouf Ali Asiri

Abstract:

O. basilicum plant was subjected to deficit irrigation using four treatments viz. control, irrigated with 70% of soil water capacity (SWC), Treatment 1, irrigated with 50% SWC, Treatment 2, irrigated with 30% SWC and Treatment 3, irrigated with 10 % SWC. Photosynthesis pigments viz. chlorophyll a, b, and the carotenoids, proline accumulation, and oil quantity were investigated under these irrigation treatments. The results indicate that photosynthesis pigments and oil content of deficit irrigation treatments did not significantly reduced than that of the full irrigation control. Photosynthesis pigments were affected by the stage of growth and not by irrigation treatments. They were high during flowering stage and low during seed formation stage for all treatments. The lowest irrigation plants (10 % SWC) achieved, during flowering stage, 0.72 mg\g\fresh weight of chlorophyll a, compared to 0.43 mg\g\fresh weight in control plant, 0.40 mg\g\fresh weight of chlorophyll b, compared to 0.19 mg\g\fresh weight in control plants and 0.29 mg\g\fresh weight of carotenoids, compared to 0.21 mg\g\fresh weight in control plants. It has been shown that reduced irrigation rates tend to enhance O. basilicum to have high oil quantity reaching a value of 63.37 % in a very low irrigation rate (10 % SWC) compared to 45.38 of control in seeds. Proline was shown to be accumulated in roots to almost double the amount in shoot during flowering stage in treatment 3. This accumulation seems to have a pronounce effect on O. basilicum acclimation to deficit irrigation.

Keywords: deficit irrigation, photosynthesis pigments, proline accumulation, oil quantity, sweet basil flowering formation, seed formation

Procedia PDF Downloads 425

Authors: William G. "Gus" Simmons

Abstract:

Municipal and industrial wastewater plants across our country utilize anaerobic digestion as either primary treatment or as a means of waste sludge treatment and reduction. The emphasis on renewable energy and clean energy over the past several years, coupled with increasing electricity costs and increasing consumer demands for efficient utility operations has led to closer examination of the potential for harvesting the energy value of the biogas produced by anaerobic digestion. Although some facilities may have already come to the belief that harvesting this energy value is not practical or a top priority as compared to other capital needs and initiatives at the wastewater plant, we see that many are seeing biogas, and an opportunity for additional revenues, go up in flames as they continue to flare. Conversely, few wastewater plants under progressive and visionary leadership have demonstrated that harvesting the energy value from anaerobic digestion is more than “smoke and hot air”. From providing thermal energy to adjacent or on-campus operations to generating electricity and/or transportation fuels, these facilities are proving that energy harvesting can not only be profitable, but sustainable. This paper explores ways in which wastewater treatment plants can increase their value and import to the communities they serve through the generation of clean, renewable energy; also presented the processes in which these facilities moved from energy and cost sinks to sparks of innovation and pride in the communities in which they operate.

Keywords: anaerobic digestion, harvesting energy, biogas, renewable energy, sustainability

Procedia PDF Downloads 317

Authors: Jin-Hui Lee, Myung-Min Oh

Abstract:

The application of temporary abiotic stresses before crop harvest is a potential strategy to enhance phytochemical content. The objective of this study was to determine the effect of various UV-A LED lights on the growth and content of bioactive compounds in kale (Brassica oleracea var. acephala). Fourteen-day-old kale seedlings were cultivated in a plant factory with artificial lighting (air temperature of 20℃, relative humidity of 60%, photosynthesis photon flux density (PPFD) of 125 µmol·m⁻²·s⁻¹) for 3 weeks. Kale plants were irradiated by four types of UV-A LEDs (peak wavelength; 365, 375, 385, and 395 nm) with 30 W/m² for 7 days. As a result, image chlorophyll fluorescence (Fv/Fm) value of kale leaves was lower as the UV-A LEDs peak wavelength was shorter. Fresh and dry weights of shoots and roots of kale plants were significantly higher in the plants under UV-A than the control at 7 days of treatment. In particular, the growth was significantly increased with a longer peak wavelength of the UV-A LEDs. The results of leaf area and specific leaf weight showed a similar pattern with those of growth characteristics. Chlorophyll content was highest in kale leaves subjected to UV-A LEDs with the peak wavelength of 395 nm at 3 days of treatment compared with the control. Total phenolic contents of UV-A LEDs with the peak wavelength of 395 nm at 5 and 6 days of treatment were 44% and 47% higher than those of the control, respectively. Antioxidant capacity showed almost the same pattern as the results of total phenol content. The activity of phenylalanine ammonia-lyase was approximately 11% and 8% higher in the UV-A LEDs with the peak wavelength of 395 nm compared to the control at 5 and 6 days of treatment, respectively. Our results imply that the UV-A LEDs with relative longer peak wavelength were effective to improve growth as well as the content of bioactive compounds of kale plants.

Keywords: bioactive compounds, growth, Kale, UV-A LEDs

Procedia PDF Downloads 144

Authors: M. Yadegari, M. Nourbakhsh, N. Arbabzadeh

Abstract:

The skeletal system injuries are of major importance. In addition, it is recommended to use materials for hard tissue repair in open or closed fractures. It is important to use complex minerals with a beneficial effect on hard tissue repair, stimulating cell growth in the bone. Materials that could help avoid bone fracture inflammatory reaction and speed up bone fracture repair are of utmost importance in the treatment of bone fractures. Similar to minerals, the inner eggshell membrane consists of carbohydrates, lipids, proteins with the high pH, high calcium absorptive capacity and with faster bone fracture repair ability. In the present radiographic survey, eggshell-derived bone graft substitutes were used for bone defect repair in 8 dog tibia, measuring bone density on the day of implant placement and 30 and 60 days after placement. In fact, the result of this study shows the difference in bone growth and misshapen bones between treatment and control sites. Cell growth was adequate in treatment sites and misshapen bones were less frequent here than in control sites.

Keywords: bone repair, eggshell powder, implant, radiography

Procedia PDF Downloads 322

Authors: Justina I. Reamen

Abstract:

The study examined the influence of rational emotive therapy on the treatment of substance abuse among Senior Secondary School Students in Makurdi metropolis Benue State Nigeria. This research adopted youth self report scale which was distributed to 1,690 SSS Students drawn from Government day Secondary School Makurdi and Government Model College Makurdi. Afterwards, 200 who were identified to indulge in substance abuse were selected for the study, 100 each from the two schools. 100 were taken as the control group and 100 as the experimental group, (50 of each group from each school). The Rational Emotive Behavior Therapy (REBT) intervention program was presented to the experimental group for seven (7) weeks. The students were taught how to apply REBT’s cognitive, Emotive and Behavioral techniques on their problems. After which post test was conducted to find out the impact of REBT on the treatment of adolescent students with substance abuse problem. GLM repeated measures of ANOVA were used to analyze the data from the study. The study reveals that REBT has positive impact on the treatment of adolescent students that abuse substances in the study area. Between pretest to post-test scores, a significant difference was observed (F=26.939; P=000) in substance abuse where a decrease of 1.12 (pre-10.91, post-9.79) scores was noticed irrespective of the groups. However, when the decrease in substance abuse were analyzed group wise, (experimental control) again significant F value (F=38.782; P=000) was obtained. From the mean scores it is evident that experimental group decreased it means by 2.56 (Pre-10.04 - Post-8.83) scores compared to control group, which changed its scores by only 0.32 scores (pre 11.04 - Post 11.36). Recommendations were made based on the findings of the research.

Keywords: abuse, influence, substance, therapy, treatment

Procedia PDF Downloads 234

Authors: Mateusz Bilski, Jakub Klas, Emilia Kowalczyk, Sylwia Koziej, Katarzyna Kulszo, Ludmiła Grzybowska- Szatkowska

Abstract:

Background: Liver metastases are a common complication of primary solid tumors and sig-nificantly reduce patient survival. In the era of increasing diagnosis of oligometastatic disease and oligoprogression, methods of local treatment of metastases, i.e. MDT, are becoming more important. Implementation of such treatment can be considered for liver metastases, which are a common complication of primary solid tumors and significantly reduce patient survival. To date, the mainstay of treatment for oligometastatic disease has been surgical resection, but not all patients qualify for the procedure. As an alternative to surgical resection, radiotherapy techniques have become available, including stereotactic body radiation therapy (SBRT) or high-dose interstitial brachytherapy (iBT). iBT is an invasive method that emits very high doses of radiation from the inside of the tumor to the outside. This technique provides better tumor coverage than SBRT while having little impact on surrounding healthy tissue and elim-inates some concerns involving respiratory motion. Methods: We conducted a systematic re-view of the scientific literature on the use of brachytherapy in the treatment of liver metasta-ses from 2018 - 2023 using PubMed and ResearchGate browsers according to PRISMA rules. Results: From 111 articles, 18 publications containing information on 729 patients with liver metastases were selected. iBT has been shown to provide high rates of tumor control. Among 14 patients with 54 unresectable RCC liver metastases, after iBT LTC was 92.6% during a median follow-up of 10.2 months, PFS was 3.4 months. In analysis of 167 patients after treatment with a single fractional dose of 15-25 Gy with brachytherapy at 6- and 12-month follow-up, LRFS rates of 88,4-88.7% and 70.7 - 71,5%, PFS of 78.1 and 53.8%, and OS of 92.3 - 96.7% and 76,3% - 79.6%, respectively, were achieved. No serious complications were observed in all patients. Distant intrahepatic progression occurred later in patients with unre-sectable liver metastases after brachytherapy (PFS: 19.80 months) than in HCC patients (PFS: 13.50 months). A significant difference in LRFS between CRC patients (84.1% vs. 50.6%) and other histologies (92.4% vs. 92.4%) was noted, suggesting a higher treatment dose is necessary for CRC patients. The average target dose for metastatic colorectal cancer was 40 - 60 Gy (compared to 100 - 250 Gy for HCC). To better assess sensitivity to therapy and pre-dict side effects, it has been suggested that humoral mediators be evaluated. It was also shown that baseline levels of TNF-α, MCP-1 and VEGF, as well as NGF and CX3CL corre-lated with both tumor volume and radiation-induced liver damage, one of the most serious complications of iBT, indicating their potential role as biomarkers of therapy outcome. Con-clusions: The use of brachytherapy methods in the treatment of liver metastases of various cancers appears to be an interesting and relatively safe therapeutic method alternative to sur-gery. An important challenge remains the selection of an appropriate brachytherapy method and radiation dose for the corresponding initial tumor type from which the metastasis origi-nated.

Keywords: liver metastases, brachytherapy, CT-HDRBT, iBT

Procedia PDF Downloads 115

Authors: Kadir Mokrane, Souag Doudja

Abstract:

In Algeria, one of the Mediterranean countries, water resources are limited and unevenly distributed in space and in time. Boumerdes, coastal town of Algeria, known for its farming and fishing activities. The region is also known for its semi-arid climate and a large water deficit. In order to preserve the quality of water bodies and to reduce withdrawals in the natural environment, it is necessary to seek alternative supplies. The reuse of treated wastewater seems to be a good alternative, especially for irrigation. In the framework of sustainable development, it is imperative to rationalize the use of water resources conventional and unconventional. That is why the re-use agricultural of by-products of the treatment is an alternative expected to preserve the environment and promotion of the agricultural sector. The present work aims, to search for the possibility of reuse of treated wastewater, and sludge resulting from treatment plant of the city of Boumerdes in agriculture, through the analysis of physical, chemical and bacteriological on the samples, and the continuous monitoring of the evolution of several elements during the period of study extended over 12 months, and then, the comparison of these test results to standards and guidelines established in the framework of irrigation and land application.

Keywords: treated water, sewage sludge, recycling, agriculture

Procedia PDF Downloads 249

Authors: Hanan Al-Khalaifah, Afaf Al-Nasser

Abstract:

Probiotics and prebiotics claimed to serve as effective alternatives to antibiotics in the poultry. This study aims to investigate the effect of different probiotics and prebiotics on the economic impact analysis of the use of probiotics and prebiotics in broiler feed. The study involved four broiler cycles, two during winter and two during summer. In the first two cycles (summer and winter), different types of prebiotics and probiotics were used. The probiotics were Bacillus coagulans (1 g/kg dried culture) and Lactobacillus (1 g/kg dried culture of 12 commercial strains), and prebiotics included fructo-oligosaccharides (FOS) (5 g/kg) and mannan-oligosaccharide (MOS) derived from Saccharomyces cerevisiae (5 g/kg). Based on the results obtained, the best treatment was chosen to be FOS, from which different ratios were used in the last two cycles during winter and summer. The levels of FOS chosen were 0.3, 0.5, and 0.7% of the diet. From an economic point of view, it was generally concluded that in all dietary treatments, food was consumed less in cycle 1 than in cycle 2, the total body weight gain was more in cycle 1 than cycle 2, and the average feed efficiency was less in cycle l than cycle 2. This indicates that the weather condition affected better in cycle 1. Also, there were very small differences between the dietary treatments in each cycle. In cycle 1, the best total feed consumption was for the FOS treatment, the highest total body weight gain and average feed efficiency were for B. coagulans. In cycle 2, all performance was better in FOS treatment. FOS significantly reduced the Salmonella sp. counts in the intestine, where the environment was driven towards acidity. FOS was the best on the average taste panel study of the produced meat. Accordingly, FOS prebiotic was chosen to be the best treatment to be used in cycles 3 and 4. The economic impact analysis generally revealed that there were no big differences between the treatments in all of the studied indicators, but there was a difference between the cycles.

Keywords: antibiotic, economic impact, prebiotic, probiotic, broiler

Procedia PDF Downloads 152

Authors: E. A. Kiridi, A. O. Ogunlela

Abstract:

The control of ammonia build-up and its by-product is a limiting factor for a successful commercial aquaculture in a developing country like Nigeria. The technology for an advanced treatment of fish tank effluent is uneconomical to local fish farmers which have led to indiscriminate disposal of aquaculture wastewater, thereby increasing the concentrations of these nitrogenous compound and other contaminants in surface and groundwater above the permissible level. Phytoremediation using water lettuce could offer cheaper and sustainable alternative. On the first day of experimentation, approximately 100 g of water lettuce were replicated in four hydroponic units containing aquaculture effluents. The water quality parameters measured were concentration of ammonium–nitrogen (NH₄⁺-N), nitrite-nitrogen (NO₂^--N), nitrate-nitrogen (NO₃^--N), and phosphate–phosphorus (PO₄^3--P). Others were total suspended solids (TSS), pH, electrical conductivity (EC), and biomass value. At phytoremediation intervals of 7, 14, 21 and 28 days, the biomass recorded were 361.2 g, 498.7 g, 561.2 g, and 623.7 g. Water lettuce was able to reduce the pollutant concentration of all the selected parameter. The percentage reduction of pH ranged from 3.9% to 14.4%, EC from 49.8% to 96.2%, TDS from 50.4% to 96.2%, TSS from 38.3% to 81.7%, NH₄⁺-N from 38.9% to 90.7%, NO₂^--N from 0% to 74.9%, NO₃^--N from 63.2% to 95.9% and PO₄^3--P from 0% to 76.3%. At 95% confidence level, the analysis of variance shows that F(critical) is less than F(cal) and p < 0.05; therefore, it can be concluded statistically that the inequality between the pre-treatment and post-treatment values are significant. This suggests the potency of water lettuce for remediation of aquaculture effluent.

Keywords: aquaculture effluent, nitrification, phytoremediation, water lettuce

Procedia PDF Downloads 212

Authors: Deirdre Mc Grath, Joanne Reid

Abstract:

Background: Ovarian cancer is the leading cause of mortality among gynaecologic cancers in developed countries and the seventh most common cancer worldwide, with nearly 240,000 women diagnosed each year. Although it is recognized engaging in exercise results in positive health care outcomes, women with ovarian cancer are reluctant to participate. No evidence currently exists focusing on how to successfully implement an exercise intervention program for patients with ovarian cancer, using a realist approach. There is a requirement for the implementation of exercise programmes within the oncology health care setting as engagement in such interventions has positive health care outcomes for women with ovarian cancer both during and following treatment. Aim: To co-design the implementation of an exercise intervention for women following treatment for ovarian cancer. Methods: This study is a realist evaluation using quantitative and qualitative methods of data collection and analysis. Realist evaluation is well-established within the health and social care setting and has, in relation to this study, enabled a flexible approach to investigate how to optimise implementation of an exercise intervention for this patient population. This single centre study incorporates three stages in order to identify the underlying contexts and mechanisms which lead to the successful implementation of an exercise intervention for women who have had treatment for ovarian cancer. Stage 1 - A realist literature review. Stage 2 -Co-design of the implementation of an exercise intervention with women following treatment for ovarian cancer, their carer’s, and health care professionals. Stage 3 –Implementation of an exercise intervention with women following treatment for ovarian cancer. Evaluation of the implementation of the intervention from the perspectives of the women who participated in the intervention, their informal carers, and health care professionals. The underlying programme theory initially conceptualised before and during the realist review was developed further during the co-design stage. The evolving programme theory in relation to how to successfully implement an exercise for these women is currently been refined and tested during the final stage of this realist evaluation which is the implementation and evaluation stage. Results: This realist evaluation highlights key issues in relation to the implementation of an exercise intervention within this patient population. The underlying contexts and mechanisms which influence recruitment, adherence, and retention rates of participants are identified. Conclusions: This study will inform future research on the implementation of exercise interventions for this patient population. It is anticipated that this intervention will be implemented into practice as part of standard care for this group of patients.

Keywords: exercise, ovarian cancer, co-design, implementation

Procedia PDF Downloads 120

Authors: Dalila Hammiche, Lisa Klaai, Amar Boukerrou

Abstract:

Following this trend, natural fiber reinforcements have been gaining importance in the composites sector. The effectiveness of natural fiber–reinforced PLA composite as an alternative material to substitute the non-renewable petroleum-based materials has been examined by researchers. In this study, we investigated the physicochemical, particle size and distribution, and thermal behavior of prickly pear seed flour (PPSF). Then, composites were manufactured with 20% in PPSF. Thermal, morphological, and mechanical properties have been studied, and water absorption tests as well. The characterization of this fiber has shown that cellulose is the majority constituent (30%), followed by hemicellulose (27%). To improve the fiber-matrix adhesion, the PPS was chemically treated with alkali treatment. The addition of PPSF decreases the thermal properties, and the study of the mechanical properties showed that the increase in the fiber content from 0 to 20% increased Young’s modulus. According to the results, the mechanical and thermal behaviors of composites are improved after fiber treatment. However, there is an increase in water absorption of composites compared to the PLA matrix. The moisture sensitivity of natural fiber composites limits their use in structural applications. Degradation of the fiber-matrix interface is likely to occur when the material is subjected to variable moisture conditions.

Keywords: biopolymer, composites, alcali treatment, mechanical properties

Procedia PDF Downloads 128

Authors: Chih-Rong Shyr, Chi-Ping Huang

Abstract:

Intravesical BCG is the gold-standard therapy for high risk non-muscle invasive bladder cancer (NMIBC) after TURBT, but if not responsive to BCG, these BCG unresponsive patients face cystectomy that causes morbidity and comes with a morality risk. To provide the bladder sparing options for patients with BCG-unresponsive NMIBC, several new treatments have been developed to salvage the bladders and prevent progression to muscle invasive or metastatic, but however, most approved or developed treatments still fail in a significant proportion of patients without long term success. Thus more treatment options and the combination of different therapeutic modalities are urgently needed to change the outcomes. Xenogeneic rejection has been proposed to a mechanism of action to induce anti-tumor immunity for the treatment of cancers due to the similarities between rejection mechanism to xenoantigens (proteins, glycans and lipids) and anti-tumor immunities to tumor specific antigens (neoantigens, tumor associated carbohydrates and lipids). Xenogeneic urothelial cells (XUC) of porcine origin have been shown to induce anti-tumor immune responses to inhibit bladder tumor progression in mouse bladder cancer models. To further demonstrate the efficacy of the distinct intravesical XUC treatment in NMIBC, and the combined effects with chemotherapy and immune checkpoint inhibitors (ICIs) as a alternate therapeutic option, this study investigated the therapeutic effects and mechanisms of intravesical XUC immunotherapy in an orthotopic mouse immune competent model of NMIBC, generated from a mouse bladder cancer cell line. We found that the tumor progression was inhibited by intravescial XUC treatment and there was a synergy between intravesical XUC with intravesical chemotherapeutic agent, gemcitabine or systemic ICI, anti-PD1 antibody treatment. The cancer cell proliferation was decreased but the cell death was increased by the intravecisal XUC treatment. Most importantly, the mechanisms of action of intravesical XUC immunotherapy were found to be linked to enhanced infiltration of CD4+ and CD8+ T-cell as well as NK cells, but decreased presence of myeloid immunosuppressive cells in XUC treated tumors. The increased stimulation of immune cells of XUC treated mice to xenogeneic urothelial cells and mouse bladder cancer cells in immune cell proliferation and cytokine secretion were observed both as a monotherapy and in combination with intravesical gemcitabine or systemic anti PD-L1 treatment. In sum, we identified the effects of intravesical XUC treatment in monotherapy and combined therapy on tumor progression and its cellular and molecular events related to immune activation to understand the anti-tumoral mechanisms behind intravesical XUC immunotherapy for NMIBC. These results contribute to the understanding of the mechanisms behind successful xenogeneic cell immunotherapy against NMIBC and characterize a novel therapeutic approach with a new xenogeneic cell modality for BCG-unresponsive NMIBC.

Keywords: xenoantigen, neoantigen, rejection, immunity

Procedia PDF Downloads 15

Authors: Moiseenko F. V., Volkov N. M., Zhabina A. S., Stepanova E. O., Kirillov A. V., Myslik A. V., Artemieva E. V., Agranov I. R., Oganesyan A. P., Egorenkov V. V., Abduloeva N. H., Aleksakhina S. Yu., Ivantsov A. O., Kuligina E. S., Imyanitov E. N., Moiseyenko V. M.

Abstract:

Analysis of ctDNA in patients with NSCLC is an emerging biomarker. Multiple research efforts of quantitative or at least qualitative analysis before and during the first periods of treatment with TKI showed the prognostic value of ctDNA clearance. Still, these important results are not incorporated in clinical standards. We evaluated the role of ctDNA in EGFR-mutated NSCLC receiving first-line TKI. Firstly, we analyzed sequential plasma samples from 30 patients that were collected before intake of the first tablet (at baseline) and at 6, 12, 24, 36, and 48 hours after the “starting point.” EGFR-M+ allele was measured by ddPCR. Afterward, we included sequential qualitative analysis of ctDNA with cobas® EGFR Mutation Test v2 from 99 NSCLC patients before the first dose, after 2 and 4 months of treatment, and on progression. Early response analysis showed the decline of EGFR-M+ level in plasma within the first 48 hours of treatment in 11 subjects. All these patients showed objective tumor response. 10 patients showed either elevation of EGFR-M+ plasma concentration (n = 5) or stable content of circulating EGFR-M+ after the start of the therapy (n = 5); only 3 of these patients achieved an objective response (p = 0.026) when compared to the former group). The rapid decline of plasma EGFR-M+ DNA concentration also predicted for longer PFS (13.7 vs. 11.4 months, p = 0.030). Long-term ctDNA monitoring showed clinically significant heterogeneity of EGFR-mutated NSCLC treated with 1st line TKIs in terms of progression-free and overall survival. Patients without detectable ctDNA at baseline (N = 32) possess the best prognosis on the duration of treatment (PFS: 24.07 [16.8-31.3] and OS: 56.2 [21.8-90.7] months). Those who achieve clearance after two months of TKI (N = 42) have indistinguishably good PFS (19.0 [13.7 – 24.2]). Individuals who retain ctDNA after 2 months (N = 25) have the worst prognosis (PFS: 10.3 [7.0 – 13.5], p = 0.000). 9/25 patients did not develop ctDNA clearance at 4 months with no statistical difference in PFS from those without clearance at 2 months. Prognostic heterogeneity of EGFR-mutated NSCLC should be taken into consideration in planning further clinical trials and optimizing the outcomes of patients.

Keywords: NSCLC, EGFR, targeted therapy, ctDNA, prognosis

Procedia PDF Downloads 55

Authors: Mike Yaw Osei-Atweneboana, John Asiedu Larbi, Edward Jenner Tettevi

Abstract:

Background: The lymphatic filariasis (LF) control programme has been on-going in Ghana since 2000. This community-wide approach involves the use of ivermectin (IVM) and albendazole (ALB). Soil-transmitted helminth (STH) infections control is augmented within this programme; however, in areas where LF is not prevalent, albendazole alone is administered to school children. The purpose of this study was therefore, to determine the efficacy of albendazole against soils transmitted helminths and the impact of mass drug administration of albendazole and ivermectin on the health status of children of school going age and pregnant women. Material/Methods: This was a twelve months longitudinal study. A total of 412 subjects including school children (between the ages of 2-17 years) and pregnant women were randomly selected from four endemic communities in Kpandai district of the Northern region. Coprological assessment for parasites was based on the Kato–Katz technique in both dry and rainy seasons at baseline, 21 days and 3 months post-treatment. Single-dose albendazole treatment was administered to all patients at baseline. Preserved samples are currently under molecular studies to identify possible single nucleotide polymorphism (SNP) within the beta tubulin gene which is associated with benzimidazole resistance. Results: Of all the parasites found (hookworm, Trichuris trichiura, Hymenolepis nana, and Taenia sp.); hookworm was the most prevalent. In the dry season, the overall STHs prevalence at pre-treatment was 29%, while 9% and 13% prevalence was recorded at 21 days, and three months after treatment respectively. However, in the rainy season, the overall STHs prevalence was 8%, while 4% and 12% was recorded at 21 days and three months respectively after ALB treatment. In general, ALB treatment resulted in an overall hookworm egg count reduction rate of 89% in the dry season and 93% in the rainy season, while the T. trichiura egg count reduction rate was 100% in both seasons. Conclusions: STH infections still remains a significant public health burden in Ghana. Hookworm infection seems to respond poorly or sub-optimally to ALB, raising concerns of possible emergence of resistance which may lead to a major setback for the control and elimination of STH infections, especially hookworm infections.

Keywords: hookworm, sub-optimal response, albendazole, trichuriasis, soil-transmitted helminths

Procedia PDF Downloads 291

Authors: Yasemin Seki, Aysun Akşit

Abstract:

The goal of this research is to modify the surface characterization of jute yarns with different chemical agents to improve the compatibility with a non-polar polymer, polypropylene, when used as reinforcement. A literature review provided no knowledge on surface treatment of jute fibers with sodium perborate trihydrate. This study also aims to compare the efficiency of sodium perborate trihydrate on jute fiber treatment with other commonly used chemical agents. Accordingly, jute yarns were treated with 0.02% potassium dichromate (PD), potassium permanganate (PM) and sodium perborate trihydrate (SP) aqueous solutions in order to enhance interfacial compatibility with polypropylene in this study. The effect of treatments on surface topography, surface chemistry and interfacial shear strength of jute yarns with polypropylene were investigated. XPS results revealed that surface treatments enhanced surface hydrophobicity by increasing C/O ratios of fiber surface. Surface roughness values increased with the treatments. The highest interfacial adhesion with polypropylene was achieved after SP treatment by providing the highest surface roughness values and hydrophobic character of jute fiber.

Keywords: jute, chemical modification, sodium perborate, polypropylene

Procedia PDF Downloads 509

Authors: Nagendra P. Luitel, Mark J. D. Jordans

Abstract:

Globally, there is a significant gap between the number of individuals in need of mental health care and those who actually receive treatment. The evidence is accumulating that mental health services can be delivered effectively by primary health care workers through community-based programs and task-sharing approaches. Changing the role of specialist mental health workers from service delivery to building clinical capacity of the primary health care (PHC) workers could help in reducing treatment gap in low and middle-income countries (LMICs). We developed a comprehensive mental health care plan in 2012 and evaluated its feasibility and effectiveness over the past three years. Initially, a mixed method formative study was conducted for the development of mental health care plan (MHCP). Routine monitoring and evaluation data, including client flow and reports of satisfaction, were obtained from beneficiaries (n=135) during the pilot-testing phase. Repeated community survey (N=2040); facility detection survey (N=4704) and the cohort study (N=576) were conducted for evaluation of the MHCP. The resulting MHCP consists of twelve packages divided over the community, health facility, and healthcare organization platforms. Detection of mental health problems increased significantly after introducing MHCP. Service implementation data support the real-life applicability of the MHCP, with reasonable treatment uptake. Currently, MHCP has been implemented in the entire Chitwan district where over 1400 people (438 people with depression, 406 people with psychosis, 181 people with epilepsy, 360 people with alcohol use disorder and 51 others) have received mental health services from trained health workers. Key barriers were identified and addressed, namely dissatisfaction with privacy, perceived burden among health workers, high drop-out rates and continue the supply of medicines. The results indicated that involvement of PHC workers in detection and management of mental health problems is an effective strategy to minimize treatment gap on mental health care in Nepal.

Keywords: mental health, Nepal, primary care, treatment gap

Procedia PDF Downloads 295

Authors: Payman A. A. Zibari, Mosleh M. S. Duhoky

Abstract:

These experiments were conducted at Tissue Culture Laboratory/ Faculty of Agriculture / University of Duhok during the period from January 2011 to May 2013. The objectives of this study were to study the effects of interaction between colchcine concentrations and treatment time duration of Creps capilaris (with and without 2B chromosome) on chromosome polyploidy during fifteen passages until regeneration of plants from the callus. Data showed that high percentage of chromosome polyploidy approximately can be obtained from high concentration of colchicin and long time of duration.

Keywords: polyploidy, Crepis capilaris, colchicine, B chromosome

Procedia PDF Downloads 194

Authors: Ewa Mojs, Katarzyna Wiechec, Maia Kubiak, Wlodzimierz Samborski

Abstract:

Interactions between mother’s psychological condition and child’s health status are complex and derive from the nature of the mother-child relationship. The aim of the study was to analyze the issue of anxiety amongst mothers of short children in the aspect of growth hormone therapy. The study was based on a group of 101 mothers of originally short-statured children – 70 with growth hormone deficiency (GHD) treated with recombinant human growth hormone (rhGH) and 31 undergoing the diagnostic process, without any treatment. Collected medical data included child's gender, height and weight, chronological age, bone age delay, and rhGH therapy duration. For all children, the height SDS and BMI SDS were calculated. To evaluate anxiety in mothers, the Spielberger State-Trait Anxiety Inventory (STAI) was used. Obtained results revealed low trait anxiety levels, with no statistically significant differences between the groups. State anxiety levels were average when mothers of all children were analyzed together, but when divided into groups, statistical differences appeared. Mothers of children without diagnosis and treatment had significantly higher levels of state anxiety than mothers of children with GHD receiving appropriate therapy. These results show, that the occurrence of growth failure in children is not related to high maternal trait anxiety, but the lack of diagnosis and lack of appropriate treatment generates higher levels of maternal state anxiety than the process of rh GH therapy in the offspring. Commencement of growth hormone therapy induce a substantial reduction of the state anxiety in mothers, and the duration of treatment causes its further decrease.

Keywords: anxiety, development, growth hormone deficiency, motherhood

Procedia PDF Downloads 283

Authors: Vedansh Gupta, Allyson Lutz, Ameen Razavi, Fatemeh Shirazi

Abstract:

The agriculture industry is especially vulnerable to forecasted water shortages. In the fresh and fresh-cut produce sector, conventional flume-based washing with recirculation exhibits high water demand. This leads to a large water footprint and possible cross-contamination of pathogens. These can be alleviated through advanced water reuse processes, such as membrane technologies including reverse osmosis (RO). Water reuse technologies effectively remove dissolved constituents but can easily foul without pre-treatment. Biological treatment is effective for the removal of organic compounds responsible for fouling, but not at the low temperatures encountered at most produce processing facilities. This study showed that the Microvi MicroNiche Engineering (MNE) technology effectively removes organic compounds (> 80%) at low temperatures (6-8 °C) from wash water. The MNE technology uses synthetic microorganism-material composites with negligible solids production, making it advantageously situated as an effective bio-pretreatment for RO. A preliminary technoeconomic analysis showed 60-80% savings in operation and maintenance costs (OPEX) when using the Microvi MNE technology for organics removal. This study and the accompanying economic analysis indicated that the proposed technology process will substantially reduce the cost barrier for adopting water reuse practices, thereby contributing to increased food safety and furthering sustainable water reuse processes across the agricultural industry.

Keywords: biological pre-treatment, innovative technology, vegetable processing, water reuse, agriculture, reverse osmosis, MNE biocatalysts

Procedia PDF Downloads 129

Authors: Neeraj Vij, Amber Brennan, Jenni Winters, Hadi Salehi, Hamy Temkit, Emily Andrisevic, Mohan V. Belthur

Abstract:

Idiopathic clubfoot is a common lower extremity deformity with an incidence of 1:500. The Ponseti Method is well known as the gold standard of treatment. However, there is limited functional data demonstrating correction of the clubfoot after treatment with the Ponseti method. The purpose of this study was to study the clinical and functional outcomes after the Ponseti method with the Clubfoot Disease-Specific Instrument (CDS) and pedobarography. This IRB-approved prospective study included patients aged 3-18 who were treated for idiopathic clubfoot with the Ponseti method between January 2008 and December 2018. Age-matched controls were identified through siblings of clubfoot patients and other community members. Treatment details were collected through a chart review of the included patients. Laboratory assessment included a physical exam, gait analysis, and pedobarography. The Pediatric Outcomes Data Collection Instrument and the Clubfoot Disease-Specific Instrument were also obtained on clubfoot patients (CF). The Wilcoxson rank-sum test was used to study differences between the CF patients and the typically developing (TD) patients. Statistical significance was set at p < 0.05. There were a total of 37 enrolled patients in our study. 21 were priorly treated for CF and 16 were TD. 94% of the CF patients had bilateral involvement. The age at the start of treatment was 29 days, the average total number of casts was seven to eight, and the average total number of casts after Achilles tenotomy was one. The reoccurrence rate was 25%, tenotomy was required in 94% of patients, and ≥1 tenotomy was required in 25% of patients. There were no significant differences between step length, step width, stride length, force-time integral, maximum peak pressure, foot progression angles, stance phase time, single-limb support time, double limb support time, and gait cycle time between children treated with the Ponseti method and typically developing children. The average post-treatment Pirani and Dimeglio scores were 5.50±0.58 and 15.29±1.58, respectively. The average post-treatment PODCI subscores were: Upper Extremity: 90.28, Transfers: 94.6, Sports: 86.81, Pain: 86.20, Happiness: 89.52, Global: 88.6. The average post-treatment Clubfoot Disease-Specific Instrument scores subscores were: Satisfaction: 73.93, Function: 80.32, Overall: 78.41. The Ponseti Method has a very high success rate and remains to be the gold standard in the treatment of idiopathic clubfoot. Timely management leads to good outcomes and a low need for repeated Achilles tenotomy. Children treated with the Ponseti method demonstrate good functional outcomes as measured through pedobarography. Pedobarography may have clinical utility in studying congenital foot deformities. Objective measures for hours of brace wear could represent an improvement in clubfoot care.

Keywords: functional outcomes, pediatric deformity, patient-reported outcomes, talipes equinovarus

Procedia PDF Downloads 80

Authors: Pilar Giffenig, Avanna Kotlarz, Taylor Dehring

Abstract:

Anxiety and depression are common mental illnesses in the U.S today. While there are various treatments for these mental health disorders, many of the medications come with a large variety of side effects that decrease medication compliance. Recent studies have looked at the impact of probiotics on anxiety and depression. Our goal was to determine whether probiotics could help relieve symptoms of anxiety and or depression. We conducted a literature search of three databases focusing on systematic reviews and RTC and found 25 articles, 8 of which were used for our analysis. Seven out of the eight articles showed that probiotics have the potential to significantly reduce symptoms of anxiety and depression. However, larger study sample sizes, type of probiotic, and correct dosage are required in future research to determine the role of probiotics in the treatment of anxiety and depression.

Keywords: probiotics, anxiety, depression, treatment, psychology, nutrition

Procedia PDF Downloads 271

Authors: Nootchanat Mairuae, Walaiporn Tongjaroenbuangam, Chalisa Louicharoen Cheepsunthorn, Poonlarp Cheepsunthorn

Abstract:

The aim of this study was to investigate the anti-oxidative effect, the anti-inflammatory effects, and the molecular mechanisms of okra (Abelmoschus esculentus Linn.) on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. The BV2 cells were treated with LPS in the presence or absence of okra. Reactive oxygen species (ROS) and nitric oxide (NO) production were measured using the ROS detection reagent DCF-DA and the Griess reaction, respectively. The phosphorylation levels of nuclear factor-kappa B (NF-kB) p65 was detected by Western blot assay. Treatment of BV2 microglia cells with okra was found to significantly suppress the LPS-induced inflammatory mediator NO as well as ROS compared to untreated cells. The levels of LPS-induced NF-kB p65 phosphorylation were significantly decreased following okra treatment too. These results show that okra exerts anti-oxidative and anti-inflammatory effects in LPS-stimulated BV2 microglial cells by suppressing the NF-κB pathway. This suggests okra might be a valuable agent for treatment of anti-neuroinflammatory diseases mediated by microglial cells.

Keywords: Abelmoschus esculentus Linn, microglia, neuroinflammation, reactive oxygen spicy

Procedia PDF Downloads 287

Authors: R. Berglund, T. Backström, M. Bellgran

Abstract:

This study explores how management addresses psychosocial risks in seven teams of engineers and technicians in the midst of the fourth industrial revolution. The sample is from an ongoing quasi-experiment about psychosocial risk management in a manufacturing company in Sweden. Each of the seven teams belongs to one of two clusters: a positive cluster or a negative cluster. The positive cluster reports a significantly positive change in psychosocial risk levels between two time-points and the negative cluster reports a significantly negative change. The data are collected using semi-structured interviews. The results of the computer aided thematic analysis show that there are more differences than similarities when comparing the risk treatment actions taken between the two clusters. Findings show that the managers in the positive cluster use more enabling actions that foster and support formal and informal relationship building. In contrast, managers that use less enabling actions hinder the development of positive group processes and contribute negative changes in psychosocial risk levels. This exploratory study sheds some light on how management can influence significant positive and negative changes in psychosocial risk levels during a risk management process.

Keywords: group process model, risk treatment, risk management, psychosocial

Procedia PDF Downloads 162

Authors: Abhishek Kumar, Nilam

Abstract:

As we know that, time delay exists almost in every biological phenomenon. Therefore, in the present study, we propose a susceptible–infected–recovered (SIR) epidemic model along with time delay, modulated incidence rate of infection, and Holling Type II nonlinear treatment rate. The present model aims to provide a strategy to control the spread of epidemics. In the mathematical study of the model, it has been shown that the model has two equilibriums which are named as disease-free equilibrium (DFE) and endemic equilibrium (EE). Further, stability analysis of the model is discussed. To prove the stability of the model at DFE, we derived basic reproduction number, denoted by (R₀). With the help of basic reproduction number (R₀), we showed that the model is locally asymptotically stable at DFE when the basic reproduction number (R₀) less than unity and unstable when the basic reproduction number (R₀) is greater than unity. Furthermore, stability analysis of the model at endemic equilibrium has also been discussed. Finally, numerical simulations have been done using MATLAB 2012b to exemplify the theoretical results.

Keywords: time delayed SIR epidemic model, modulated incidence rate, Holling type II nonlinear treatment rate, stability

Procedia PDF Downloads 158

Authors: Abdalla Mansour, Dan Brown, Adel Helmy, Rikin Trivedi, Mathew Guilfoyle

Abstract:

Introduction: Diagnosing delayed cerebral ischaemia (DCI) following aneurysmal subarachnoid haemorrhage (SAH) can be challenging, particularly in poor-grade patients. Objectives: This study sought to assess the value of routine CTP in identifying (or excluding) DCI and in guiding management. Methods: Eight-year retrospective neuroimaging study at a large UK neurosurgical centre. Subjects included a random sample of adult patients with confirmed aneurysmal SAH that had a CTP scan during their inpatient stay, over a 8-year period (May 2014 - May 2022). Data collected through electronic patient record and PACS. Variables included age, WFNS scale, aneurysm site, treatment, the timing of CTP, radiologist report, and DCI management. Results: Over eight years, 916 patients were treated for aneurysmal SAH; this study focused on 466 patients that were randomly selected. Of this sample, 181 (38.84%) had one or more CTP scans following brain aneurysm treatment (Total 318). The first CTP scan in each patient was performed at 1-20 days following ictus (median 4 days). There was radiological evidence of DCI in 83, and no reversible ischaemia was found in 80. Findings were equivocal in the remaining 18. Of the 103 patients treated with clipping, 49 had DCI radiological evidence, in comparison to 31 of 69 patients treated with endovascular embolization. The remaining 9 patients are either unsecured aneurysms or non-aneurysmal SAH. Of the patients with radiological evidence of DCI, 65 had a treatment change following the CTP directed at improving cerebral perfusion. In contrast, treatment was not changed for (61) patients without radiological evidence of DCI. Conclusion: CTP is a useful adjunct to clinical assessment in the diagnosis of DCI and is helpful in identifying patients that may benefit from intensive therapy and those in whom it is unlikely to be effective.

Keywords: SAH, vasospasm, aneurysm, delayed cerebral ischemia

Procedia PDF Downloads 69

Authors: Laura Helena Caicedo Lopez, Luis Miguel Contreras Medina, Ramon Gerardo Guevara Gonzales, Juan E. Andrade

Abstract:

In this study, we evaluated the effect of three different hydric stress conditions: Low (LHS), medium (MHS), and high (HHS) on capsaicinoid content and enzyme regulation of C. annuum plants. Five main peaks were detected using a 2 Hz resolution vibrometer laser (Polytec-B&K). These peaks or “characteristic frequencies” were used as acoustic emissions (AEs) treatment, transforming these signals into audible sound with the frequency (Hz) content of each hydric stress. Capsaicinoids (CAPs) are the main, secondary metabolites of chili pepper plants and are known to increase during hydric stress conditions or short drought-periods. The AEs treatments were applied in two plant stages: the first one was in the pre-anthesis stage to evaluate the genes that encode the transcription of enzymes responsible for diverse metabolic activities of C. annuum plants. For example, the antioxidant responses such as peroxidase (POD), superoxide dismutase (Mn-SOD). Also, phenyl-alanine ammonia-lyase (PAL) involved in the biosynthesis of the phenylpropanoid compounds. The chalcone synthase (CHS) related to the natural defense mechanisms and species-specific aquaporin (CAPIP-1) that regulate the flow of water into and out of cells. The second stage was at 40 days after flowering (DAF) to evaluate the biochemical effect of AEs related to hydric stress on capsaicinoids production. These two experiments were conducted to identify the molecular responses of C. annuum plants to AE. Moreover, to define AEs could elicit any increase in the capsaicinoids content after a one-week exposition to AEs treatments. The results show that all AEs treatment signals (LHS, MHS, and HHS) were significantly different compared to the non-acoustic emission control (NAE). Also, the AEs induced the up-regulation of POD (~2.8, 2.9, and 3.6, respectively). The gene expression of another antioxidant response was particularly treatment-dependent. The HHS induced and overexpression of Mn-SOD (~0.23) and PAL (~0.33). As well, the MHS only induced an up-regulation of the CHs gene (~0.63). On the other hand, CAPIP-1 gene gas down-regulated by all AEs treatments LHS, MHS, and HHS ~ (-2.4, -0.43 and -6.4, respectively). Likewise, the down-regulation showed particularities depending on the treatment. LHS and MHS induced downregulation of the SOD gene ~ (-1.26 and -1.20 respectively) and PAL (-4.36 and 2.05, respectively). Correspondingly, the LHS and HHS showed the same tendency in the CHs gene, respectively ~ (-1.12 and -1.02, respectively). Regarding the elicitation effect of AE on the capsaicinoids content, additional treatment controls were included. A white noise treatment (WN) to prove the frequency-selectiveness of signals and a hydric stressed group (HS) to compare the CAPs content. Our findings suggest that WN and NAE did not present differences statically. Conversely, HS and all AEs treatments induced a significant increase of capsaicin (Cap) and dihydrocapsaicin (Dcap) after one-week of a treatment. Specifically, the HS plants showed an increase of 8.33 times compared to the NAE and WN treatments and 1.4 times higher than the MHS, which was the AEs treatment with a larger induction of Capsaicinoids among treatments (5.88) and compared to the controls.

Keywords: acoustic emission, capsaicinoids, elicitors, hydric stress, plant signaling

Procedia PDF Downloads 172

Authors: Evelyn Marie Richmond, Andrew McBride, Chris Johnston, John Marley

Abstract:

Background: Good quality patient information resources for orthognathic treatment help to reinforce information delivered during the initial consultation and help patients make informed decisions about their care. The Consultant Orthodontists and a Dental Core Trainee noted limited patient engagement with the British Orthodontic Society (BOS) 'Your Jaw Surgery' online resources and that the existing BOS patient information leaflet (PIL) could be customised and developed to meet local requirements. Aim: The quality improvement project (QIP) aimed to improve patients' understanding of orthognathic treatment by ensuring at least 90% of patients had read the new in-house patient information leaflet (PIL) and a minimum of 50% of patients had accessed the British Orthodontic Society (BOS) 'Your Jaw Surgery' online resources before attending the joint orthognathic multidisciplinary clinic by June 2023. Methods: The QIP was undertaken in the orthodontic department of the School of Dentistry, Belfast. Data was collected prospectively during a 6-month period from January 2023 to June 2023 over 3 Plan, Do, Study, Act (PDSA) cycles. Suitable patients were identified at consultant orthodontic new patient clinics. Following initial consultation for orthognathic treatment, patients were contacted to complete a patient questionnaire. Design: The change ideas were a poster with a QR code directing patients to the BOS 'Your Jaw Surgery' website in consultation areas and a new in-house PIL with a QR code directing patients to the BOS 'Your Jaw Surgery' website. Results: In PDSA cycle 1, 86.7% of patients were verbally directed to the BOS 'Your Jaw Surgery' website, and 53.3% accessed the online resources after their initial consultation. Although 100% of patients reported reading the existing PIL, only 64.3% felt it discussed the risks of orthognathic treatment in sufficient detail. By PDSA cycle 3, 100% of patients reported being directed to the BOS 'Your Jaw Surgery' website, however, only 58.3% engaged with the website. 100% of patients who read the new PIL felt that it discussed the risks of orthognathic treatment in sufficient detail. Conclusion: The slight improvement in access to the BOS 'Your Jaw Surgery' website shows that patients do not necessarily choose to access information online despite its availability. The uptake of the new PIL was greater than reported patient engagement with the BOS 'Your Jaw Surgery' website, which indicates patients still value written information despite the availability of online resources.

Keywords: orthognathic surgery, patient information resources, quality improvement project, risks

Procedia PDF Downloads 62

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 320