Search results for: acute toxicity tests
Commenced in January 2007
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Edition: International
Paper Count: 6227

Search results for: acute toxicity tests

4367 A Combination of Filtration and Coagulation Processes for Tannery Effluent Treatment

Authors: M. G. Mostafa, Manjushree Chowdhury, Tapan Kumar Biswas, , Ananda Kumar Saha

Abstract:

This study focused on effluents characterization and treatment process to reduce of toxicity from tannery effluents. Tanning industry is one of the oldest industries in the world. It is typically characterized as pollutants generated industries which produce wide varieties of high strength toxic chemicals. The study was conducted during the year 2008 to 2009 and the tannery effluents were collected three times in a year from the outlet of some selected leather industries located in Hagaribagh industrial zone Dhaka, Bangladesh. The analysis results of the raw effluents reveal that the effluents were yellowish-brown color, having basic pH, very high value of BOD5¬¬, COD, TDS, TSS, TS, and high concentrations of Cr, Na, SO42-, Cl- and other organic and inorganic constituents. The tannery effluents were treated with various doses of FeCl3 after settling and a subsequent filtration through sand-stone. The study observed that coagulant (FeCl3) 150 mg/L dose around neutral pH showed the best removal efficiency for major physico-chemical parameters. The analysis results of illustrate that the most of the physical and chemical parameters were found well below the prescribed permissible limits for effluent discharged. The study suggests that tannery effluents could be treated by a combined process consisting of settling, filtering and coagulating with FeCl3.

Keywords: characterization, effluent, tannery, treatment

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4366 Preventive Effects of Silymarin in Retinal Intoxication with Methanol in Rat: Transmission Electron Microscope Study

Authors: A. Zarenezhad, A. Esfandiari, E. Zarenezhad, M. Mardkhoshnood

Abstract:

The aim of this study was to investigate the ultra-structure of the photoreceptor layer of male rats under the effect of methanol intoxication and protective effect of silymarin against the methanol toxicity. Fifteen adult male rats were divided into three groups: Control group, Experimental group I (received 4g/kg methanol by intraperitoneal injection for five days), Experimental group II (received 4 g/kg methanol by intraperitoneal injection for five days and received 250 mg/kg silymarin orally for three months). At the end of the experiment, the eyes were removed; retina was separated near the optic disc and studied by transmission electron microscope. Results showed that the retina in the experimental group I exhibited loss of outer segments and disorganization in inner segment. Increased extra cellular space, disappearance of outer limiting membrane and pyknotic nuclei were seen in this group. But normal outer segment, organized inner segment and normal outer limiting membrane were obvious after treatment with silymarin in experimental group II. These findings show that methanol causes damage in the photoreceptor layer of the rat retina and silymarin can protect the damage to retina against the methanol intoxication.

Keywords: ultra-structure, photoreceptor layer, methanol intoxication, silymarin, rat

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4365 The Possible Interaction between Bisphenol A, Caffeine and Epigallocatechin-3-Gallate on Neurotoxicity Induced by Manganese in Rats

Authors: Azza A. Ali, Hebatalla I. Ahmed, Asmaa Abdelaty

Abstract:

Background: Manganese (Mn) is a naturally occurring element. Exposure to high levels of Mn causes neurotoxic effects and represents an environmental risk factor. Mn neurotoxicity is poorly understood but changing of AChE activity, monoamines and oxidative stress has been established. Bisphenol A (BPA) is a synthetic compound widely used in the production of polycarbonate plastics. There is considerable debate about whether its exposure represents an environmental risk. Caffeine is one of the major contributors to the dietary antioxidants which prevent oxidative damage and may reduce the risk of chronic neurodegenerative diseases. Epigallocatechin-3-gallate is another major component of green tea and has known interactions with caffeine. It also has health-promoting effects in CNS. Objective: To evaluate the potential protective effects of Caffeine and/or EGCG against Mn-induced neurotoxicity either alone or in the presence of BPA in rats. Methods: Seven groups of rats were used and received daily for 5 weeks MnCl2.4H2O (10 mg/kg, IP) except the control group which received saline, corn oil and distilled H2O. Mn was injected either alone or in combination with each of the following: BPA (50 mg/kg, PO), caffeine (10 mg/kg, PO), EGCG (5 mg/kg, IP), caffeine + EGCG and BPA +caffeine +EGCG. All rats were examined in five behavioral tests (grid, bar, swimming, open field and Y- maze tests). Biochemical changes in monoamines, caspase-3, PGE2, GSK-3B, glutamate, acetyl cholinesterase and oxidative parameters, as well as histopathological changes in the brain, were also evaluated for all groups. Results: Mn significantly increased MDA and nitrite content as well as caspase-3, GSK-3B, PGE2 and glutamate levels while significantly decreased TAC and SOD as well as cholinesterase in the striatum. It also decreased DA, NE and 5-HT levels in the striatum and frontal cortex. BPA together with Mn enhanced oxidative stress generation induced by Mn while increased monoamine content that was decreased by Mn in rat striatum. BPA abolished neuronal degeneration induced by Mn in the hippocampus but not in the substantia nigra, striatum and cerebral cortex. Behavioral examinations showed that caffeine and EGCG co-administration had more pronounced protective effect against Mn-induced neurotoxicity than each one alone. EGCG alone or in combination with caffeine prevented neuronal degeneration in the substantia nigra, striatum, hippocampus and cerebral cortex induced by Mn while caffeine alone prevented neuronal degeneration in the substantia nigra and striatum but still showed some nuclear pyknosis in cerebral cortex and hippocampus. The marked protection of caffeine and EGCG co-administration also confirmed by the significant increase in TAC, SOD, ACHE, DA, NE and 5-HT as well as the decrease in MDA, nitrite, caspase-3, PGE2, GSK-3B, the glutamic acid in the striatum. Conclusion: Neuronal degeneration induced by Mn showed some inhibition with BPA exposure despite the enhancement in oxidative stress generation. Co-administration of EGCG and caffeine can protect against neuronal degeneration induced by Mn and improve behavioral deficits associated with its neurotoxicity. The protective effect of EGCG was more pronounced than that of caffeine even with BPA co-exposure.

Keywords: manganese, bisphenol a, caffeine, epigallocatechin-3-gallate, neurotoxicity, behavioral tests, rats

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4364 Experimental Lead Toxicity in Lohi Sheep: Risks and Impact on Edible Tissues

Authors: Muhammad Younus, Muhammad Sajid, Muti-ur-Rehman Khan, Aftab Ahmad Anjum, Muhammad Asif Idrees, Iahtasham Khan, Aman Ullah Khan, Sajid Umar, Raheela Akhtar

Abstract:

The present study was conducted to investigate the hazardous effects of lead on health and edible organs of Lohi sheep. The adult Lohi sheep (n=48) were randomly divided into two equal groups. The first group was administered lead acetate at dose of 70 mg/kg live body weight daily as 10% solution by oral route for a period of 90 days and the second group served as a negative control. Blood and tissue samples were collected at day 0, 30, 60 and 90 and analyzed for lead concentration by atomic absorption spectrophotometry. The kidney showed the highest lead concentration (p < 0.05) followed by liver and then muscle. Lead acetate treated sheep showed structural and behavioral changes during the last month of trial. Liver showed necrosis, hemorrhages and hyperactivation of macrophages. Kidney showed degenerative and necrotic changes in glomeruli and tubules and the characteristic intranuclear inclusion bodies in tubular epithelial cells on H and E staining. It was concluded that Lohi sheep is affected by lead intoxication at low dose for longer period and hence exhibits lead accumulation in edible tissues.

Keywords: Lohi sheep, lead acetate, edible tissue, histopathology

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4363 Ameliorating Effects of Rosemary and Costus on Blood-Associated Toxicity in Ehrlich-Bearing Mice Treated with Cisplatin

Authors: Yousry El-Sayed Elbolkiny, Mohamed Labib Salem

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Background: Rosemary (ROLE) and costus (SLRE) have been established to show antioxidant effects. Aim: This study aimed to evaluate the ameliorating effects of ROLE and SLRE on the side effects induced by cisplatin (CIS) in tumor-bearing mice. Materials and Methods: Extracts of ROLE and SLRE were examined for their phytochemical activities. To evaluate their anti-tumor effects, mice were inoculated intraperitoneally (i.p.) with 2.5x105 Ehrlich ascites carcinoma (EAC) and then treated i.p. with CIS at days 3-7 and with ROLE (dose) or SLRE (dose) at days 3-14. Mice were sacrificed on day 14 for CBC and T-cell analyses. Results: Phytochemical analysis revealed that both ROLE and SLRE showed similar antioxidant activities. Treatment of EAC-bearing mice with CIS-induced antitumor efficacy of about 90%. Treatment with CIS in combination with ROLE or SLRE did not further enhance the antitumor activity of CIS. However, co-administration of ROLE or SLRE with CIS significantly increased the antitumor efficacy of CIS. Flow cytometric analysis showed that the numbers of CD4+ and CD8+ T cells were decreased in EAC-bearing mice after treatment with CIS. Treatment with both ROLE and SLRE improved the number of these cells. Conclusion: Combinatorial treatment with rosemary and costus can enhance the antitumor activity of CIS

Keywords: CBC, cisplantin, costus, rosemary

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4362 Analyzing the Effects of Bio-fibers on the Stiffness and Strength of Adhesively Bonded Thermoplastic Bio-fiber Reinforced Composites by a Mixed Experimental-Numerical Approach

Authors: Sofie Verstraete, Stijn Debruyne, Frederik Desplentere

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Considering environmental issues, the interest to apply sustainable materials in industry increases. Specifically for composites, there is an emerging need for suitable materials and bonding techniques. As an alternative to traditional composites, short bio-fiber (cellulose-based flax) reinforced Polylactic Acid (PLA) is gaining popularity. However, these thermoplastic based composites show issues in adhesive bonding. This research focusses on analyzing the effects of the fibers near the bonding interphase. The research applies injection molded plate structures. A first important parameter concerns the fiber volume fraction, which directly affects adhesion characteristics of the surface. This parameter is varied between 0 (pure PLA) and 30%. Next to fiber volume fraction, the orientation of fibers near the bonding surface governs the adhesion characteristics of the injection molded parts. This parameter is not directly controlled in this work, but its effects are analyzed. Surface roughness also greatly determines surface wettability, thus adhesion. Therefore, this research work considers three different roughness conditions. Different mechanical treatments yield values up to 0.5 mm. In this preliminary research, only one adhesive type is considered. This is a two-part epoxy which is cured at 23 °C for 48 hours. In order to assure a dedicated parametric study, simple and reproduceable adhesive bonds are manufactured. Both single lap (substrate width 25 mm, thickness 3 mm, overlap length 10 mm) and double lap tests are considered since these are well documented and quite straightforward to conduct. These tests are conducted for the different substrate and surface conditions. Dog bone tensile testing is applied to retrieve the stiffness and strength characteristics of the substrates (with different fiber volume fractions). Numerical modelling (non-linear FEA) relates the effects of the considered parameters on the stiffness and strength of the different joints, obtained through the abovementioned tests. Ongoing work deals with developing dedicated numerical models, incorporating the different considered adhesion parameters. Although this work is the start of an extensive research project on the bonding characteristics of thermoplastic bio-fiber reinforced composites, some interesting results are already prominent. Firstly, a clear correlation between the surface roughness and the wettability of the substrates is observed. Given the adhesive type (and viscosity), it is noticed that an increase in surface energy is proportional to the surface roughness, to some extent. This becomes more pronounced when fiber volume fraction increases. Secondly, ultimate bond strength (single lap) also increases with increasing fiber volume fraction. On a macroscopic level, this confirms the positive effect of fibers near the adhesive bond line.

Keywords: adhesive bonding, bio-fiber reinforced composite, flax fibers, lap joint

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4361 Enhancing Self-Assessment and Management Potentials by Modifying Option Selections on Hartman’s Personality Test

Authors: Daniel L. Clinciu, IkromAbdulaev, Brian D. Oscar

Abstract:

Various personality profile tests are used to identify personality strengths and limits in individuals, helping both individuals and managers to optimize work and team effort in organizations. One such test, Hartman’s personality profile emphasizes four driving "core motives" influenced or affected by both strengths and limitations. The driving core motives are classified into four colors: Red-motivated by power; Blue-discipline and loyalty; White-peace; and Yellow–fun loving. Two shortcomings of Hartman’s personality test are noted; 1) only one choice for every item/situation allowed and 2) selection of a choice even if not applicable. A test taker may be as much nurturing as he is opinionated but since “opinionated” seems less attractive the individual would likely select nurturing, causing a misidentification in personality strengths and limits. Since few individuals have a "strong" personality, it is difficult to assess their true personality strengths and limits allowing either only one choice or requiring unwanted choices, undermining the potential of the test. We modified Hartman’s personality profile allowing test takers to make either multiple choices for any item/situation or leave them blank when not applying. Sixty-eight participants (38 males and 30 females), 17-49 years old, from countries in Asia, Europe, N. America, CIS, Africa, Latin America, and Oceania were included. 58 participants (85.3%) reported the modified test, allowing either multiple or no choices better identified their personality strengths and limits, while 10 participants (14.7%) expressed the original (one choice version) is sufficient. The overall results show our modified test enhanced the identification and balance of personality strengths and limits, aiding test takers, managers, and firms to better understand personality strengths and limits, particularly useful in making task-related, teamwork, and management decisions.

Keywords: organizational behavior, personality tests, personality limitations, personality strengths, task management, team work

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4360 Cellulose Containing Metal Organic Frameworks in Environmental Applications

Authors: Hossam El-Sayed Emam

Abstract:

As an essential issue for life, water while it’s important for all living organisms. However, the world is dangerously facing the serious problem for the deficiency of the sources of drinking water. Within the aquatic systems, there are various gases, microbes, and other toxic ingredients (chemical compounds and heavy metals) occurred owing to the draining of agricultural and industrial wastewater, resulting in water pollution. On the other hand, fuel (gaseous, liquid, or in solid phase) is one of the extensively consumable energy sources, and owing to its origin from fossil, it contains some sulfur-, nitrogen- and oxygen-based compounds that cause serious problems (toxicity, catalyst poisoning, corrosion, and gum formation andcarcinogenic effects), to be ascribed as undesirable pollutants.MOFs as porous coordinating polymers are superiorly exploited in the adsorption and separationof contaminants for wastewater treatment and fuel purification. The inclusion of highly adsorbent materials like MOFs to be immobilized within cellulosic materialscould be investigated as a new challenge for the separation of contaminants with high efficiency and opportunity for recyclability. Therefore, the current approach ascribes the exploitation of different MOFsimmobilized within cellulose (powder, films, and fabrics)for applications in environmental. Herein, using cellulose containing MOFs in dye removal (degradation and adsorption), pharmaceutical intermediates removal, and fuel purification were summarized.

Keywords: cellulose, MOFs, dye removal, pharmaceutical intermediates, fuel purification

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4359 Study of Petroleum Hydrocarbons Biodegradation and the Role of Biosurfactants Produced by Bacteria Isolated from the Lagoon of Mar Chica in This Process

Authors: Ikram Kamal, Mohamed Blaghen

Abstract:

Petroleum hydrocarbons are serious problems and global pollutants in the environment due to their toxicity, carcinogenicity and persistent organic pollutant properties. One of the approaches to enhance biodegradation of petroleum hydrocarbons is to use biosurfactant. Biosurfactants are amphiphilic biomolecules produced as metabolic by-products from microorganisms they received considerable attention in the field of environmental remediation processes such as bioremediation. Biosurfactants have been considered as a desirable alternative to synthetic surfactants in various applications particularly in the environmental field. In comparison with their synthetic counterparts, biosurfactants have been reported to be less toxic, biodegradable and persistent. In this study we have investigated the potential of bacterial strains collected aseptically from the lagoon Marchika (water and soil) in Nador, Morocco; for the production of biosurfactants. This study also aimed to optimize the biosurfactant production process by changing the variables that influence the type and amount of biosurfactant produced by these microorganisms such as: carbon sources and also other physical and chemical parameters such as temperature and pH. Emulsification index, methylene blue test and thin layer chromatography (TLC) revealed the ability of strains used in this study to produce compounds that could emulsify gasoline. In addition, a HPLC/MS was used to separate and identify different biosurfactants purified.

Keywords: petroleum hydrocarbons, biosurfactants, biodegradation, lagoon marchika, emulsification index

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4358 Decisional Regret in Men with Localized Prostate Cancer among Various Treatment Options and the Association with Erectile Functioning and Depressive Symptoms: A Moderation Analysis

Authors: Caren Hilger, Silke Burkert, Friederike Kendel

Abstract:

Men with localized prostate cancer (PCa) have to choose among different treatment options, such as active surveillance (AS) and radical prostatectomy (RP). All available treatment options may be accompanied by specific psychological or physiological side effects. Depending on the nature and extent of these side effects, patients are more or less likely to be satisfied or to struggle with their treatment decision in the long term. Therefore, the aim of this study was to assess and explain decisional regret in men with localized PCa. The role of erectile functioning as one of the main physiological side effects of invasive PCa treatment, depressive symptoms as a common psychological side effect, and the association of erectile functioning and depressive symptoms with decisional regret were investigated. Men with localized PCa initially managed with AS or RP (N=292) were matched according to length of therapy (mean 47.9±15.4 months). Subjects completed mailed questionnaires assessing decisional regret, changes in erectile functioning, depressive symptoms, and sociodemographic variables. Clinical data were obtained from case report forms. Differences among the two treatment groups (AS and RP) were calculated using t-tests and χ²-tests, relationships of decisional regret with erectile functioning and depressive symptoms were computed using multiple regression. Men were on average 70±7.2 years old. The two treatment groups differed markedly regarding decisional regret (p<.001, d=.50), changes in erectile functioning (p<.001, d=1.2), and depressive symptoms (p=.01, d=.30), with men after RP reporting higher values, respectively. Regression analyses showed that after adjustment for age, tumor risk category, and changes in erectile functioning, depressive symptoms were still significantly associated with decisional regret (B=0.52, p<.001). Additionally, when predicting decisional regret, the interaction of changes in erectile functioning and depressive symptoms reached significance for men after RP (B=0.52, p<.001), but not for men under AS (B=-0.16, p=.14). With increased changes in erectile functioning, the association of depressive symptoms with decisional regret became stronger in men after RP. Decisional regret is a phenomenon more prominent in men after RP than in men under AS. Erectile functioning and depressive symptoms interact in their prediction of decisional regret. Screening and treating depressive symptoms might constitute a starting point for interventions aiming to reduce decisional regret in this target group.

Keywords: active surveillance, decisional regret, depressive symptoms, erectile functioning, prostate cancer, radical prostatectomy

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4357 Initial Resistance Training Status Influences Upper Body Strength and Power Development

Authors: Stacey Herzog, Mitchell McCleary, Istvan Kovacs

Abstract:

Purpose: Maximal strength and maximal power are key athletic abilities in many sports disciplines. In recent years, velocity-based training (VBT) with a relatively high 75-85% 1RM resistance has been popularized in preparation for powerlifting and various other sports. The purpose of this study was to discover differences between beginner/intermediate and advanced lifters’ push/press performances after a heavy resistance-based BP training program. Methods: A six-week, three-workouts per week program was administered to 52 young, physically active adults (age: 22.4±5.1; 12 female). The majority of the participants (84.6%) had prior experience in bench pressing. Typical workouts began with BP using 75-95% 1RM in the 1-5 repetition range. The sets in the lower part of the range (75-80% 1RM) were performed with velocity-focus as well. The BP sets were followed by seated dumbbell presses and six additional upper-body assistance exercises. Pre- and post-tests were conducted on five test exercises: one-repetition maximum BP (1RM), calculated relative strength index: BP/BW (RSI), four-repetition maximal-effort dynamic BP for peak concentric velocity with 80% 1RM (4RV), 4-repetition ballistic pushups (BPU) for height (4PU), and seated medicine ball toss for distance (MBT). For analytic purposes, the participant group was divided into two subgroups: self-indicated beginner or intermediate initial resistance training status (BITS) [n=21, age: 21.9±3.6; 10 female] and advanced initial resistance training status (ATS) [n=31, age: 22.7±5.9; 2 female]. Pre- and post-test results were compared within subgroups. Results: Paired-sample t-tests indicated significant within-group improvements in all five test exercises in both groups (p < 0.05). BITS improved 18.1 lbs. (13.0%) in 1RM, 0.099 (12.8%) in RSI, 0.133 m/s (23.3%) in 4RV, 1.55 in. (27.1%) in BPU, and 1.00 ft. (5.8%) in MBT, while the ATS group improved 13.2 lbs. (5.7%) in 1RM, 0.071 (5.8%) in RSI, 0.051 m/s (9.1%) in 4RV, 1.20 in. (13.7%) in BPU, and 1.15 ft. (5.5%) in MBT. Conclusion: While the two training groups had different initial resistance training backgrounds, both showed significant improvements in all test exercises. As expected, the beginner/intermediate group displayed better relative improvements in four of the five test exercises. However, the medicine ball toss, which had the lightest resistance among the tests, showed similar relative improvements between the two groups. These findings relate to two important training principles: specificity and transfer. The ATS group had more specific experiences with heavy-resistance BP. Therefore, fewer improvements were detected in their test performances with heavy resistances. On the other hand, while the heavy resistance-based training transferred to increased power outcomes in light-resistance power exercises, the difference in the rate of improvement between the two groups disappeared. Practical applications: Based on initial training status, S&C coaches should expect different performance gains in maximal strength training-specific test exercises. However, the transfer from maximal strength to a non-training-specific performance category along the F-v curve continuum (i.e., light resistance and high velocity) might not depend on initial training status.

Keywords: exercise, power, resistance training, strength

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4356 Risk Factors for Diabetic Foot: Upper Egypt Experience

Authors: Ali Kassem, Mohamed Alsenbasy, Ahmed Nagaah

Abstract:

Background: Diabetic foot is one of the often neglected complications of diabetes mellitus It was reported that patients of diabetic foot ulcer (DFU) have considerable morbidity and mortality. Due to arterial abnormalities, diabetic neuropathy, as well as the tendency to delayed wound healing, foot infection and or gangrene is relatively common in diabetic patients. Foot related problems are responsible for up to 50% of diabetic related hospital admissions. Aim of work: The aim of the present study is to assess the risk factors for DFU in diabetic patients attending Sohag University Hospitals (Upper Egypt) Material and methods: The present study includes 100 diabetic foot patients attending the diabetic outpatient clinic of Sohag University Hospitals. For all of the studied patients the following were done: Full medical history and clinical examination; thorough foot examination; Laboratory tests including: Blood glucose level, HBA1c, serum lipids and renal function tests, ECG and Echocardiography, Doppler study on the lower limbs. Results: Sixty eight percent of the affected patients were males versus 32 % female patients. All male patients and none of the female were smoker. Seventy nine percent of patients were living in rural areas versus 14 % in urban areas. Duration of diabetes was more than 12 years in 74%, less than 12 years in 26% of patients. Fifty percent of patients have associated hypertension, 46% have dyslipidemia, 18% have ischemic heart disease or old myocardial infarction and 8% have impaired renal function. History of previous foot ulcers was reported in 11 % and foot amputation in 2% of patients. Conclusion: Male gender, low socioeconomic status, smoking, long duration of diabetes, other cardiovascular risk factors particularly hypertension and previous history of foot ulceration are the major risk factors for diabetic foot in our locality.

Keywords: diabetic foot, diabetic neuropathy, foot gangrene, risk factors for diabetic complications

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4355 Effect of Volcanic Ash and Recycled Aggregates in Concrete

Authors: Viviana Letelier, Ester Tarela, Giacomo Moriconi

Abstract:

The cement industry is responsible for around a 5% of the CO2 emissions worldwide and considering that concrete is one of the most used materials in construction its total effect is important. An alternative to reduce the environmental impact of concrete production is to incorporate certain amount of residuals in the dosing, limiting the replacement percentages to avoid significant losses in the mechanical properties of the final material. This study analyses the variation in the mechanical properties of structural concretes with recycled aggregates and volcanic ash as cement replacement to test the effect of the simultaneous use of different residuals in the same material. Analyzed concretes are dosed for a compressive strength of 30MPa. The recycled aggregates are obtained from prefabricated pipe debris with a compressive strength of 20MPa. The volcanic ash was obtained from the Ensenada (Chile) area after the Calbuco eruption in April 2015. The percentages of natural course aggregates that are replaced by recycled aggregates are of 0% and 30% and the percentages of cement replaced by volcanic ash are of 0%, 5%, 10% and 15%. The combined effect of both residuals in the mechanical properties of the concrete is evaluated through compressive strength tests after, 28 curing days, flexural strength tests after 28 days, and the elasticity modulus after 28 curing days. Results show that increasing the amount of volcanic ash used increases the losses in compressive strength. However, the use of up to a 5% of volcanic ash allows obtaining concretes with similar compressive strength to the control concrete, whether recycled aggregates are used or not. Furthermore, the pozzolanic reaction that occurs between the amorphous silica and the calcium hydroxide (Ca(OH)2) provokes an increase of a 10% in the compressive strength when a 5% of volcanic ash is combined with a 30% of recycled aggregates. Flexural strength does not show significant changes with neither of the residues. On the other hand, decreases between a 14% and a 25% in the elasticity modulus have been found. Concretes with up to a 30% of recycled aggregates and a 5% of volcanic ash as cement replacement can be produced without significant losses in their mechanical properties, reducing considerably the environmental impact of the final material.

Keywords: compressive strength of recycled concrete, mechanical properties of recycled concrete, recycled aggregates, volcanic ash as cement replacement

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4354 Prospects of Acellular Organ Scaffolds for Drug Discovery

Authors: Inna Kornienko, Svetlana Guryeva, Natalia Danilova, Elena Petersen

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Drug toxicity often goes undetected until clinical trials, the most expensive and dangerous phase of drug development. Both human cell culture and animal studies have limitations that cannot be overcome by improvements in drug testing protocols. Tissue engineering is an emerging alternative approach to creating models of human malignant tumors for experimental oncology, personalized medicine, and drug discovery studies. This new generation of bioengineered tumors provides an opportunity to control and explore the role of every component of the model system including cell populations, supportive scaffolds, and signaling molecules. An area that could greatly benefit from these models is cancer research. Recent advances in tissue engineering demonstrated that decellularized tissue is an excellent scaffold for tissue engineering. Decellularization of donor organs such as heart, liver, and lung can provide an acellular, naturally occurring three-dimensional biologic scaffold material that can then be seeded with selected cell populations. Preliminary studies in animal models have provided encouraging results for the proof of concept. Decellularized Organs preserve organ microenvironment, which is critical for cancer metastasis. Utilizing 3D tumor models results greater proximity of cell culture morphological characteristics in a model to its in vivo counterpart, allows more accurate simulation of the processes within a functioning tumor and its pathogenesis. 3D models allow study of migration processes and cell proliferation with higher reliability as well. Moreover, cancer cells in a 3D model bear closer resemblance to living conditions in terms of gene expression, cell surface receptor expression, and signaling. 2D cell monolayers do not provide the geometrical and mechanical cues of tissues in vivo and are, therefore, not suitable to accurately predict the responses of living organisms. 3D models can provide several levels of complexity from simple monocultures of cancer cell lines in liquid environment comprised of oxygen and nutrient gradients and cell-cell interaction to more advanced models, which include co-culturing with other cell types, such as endothelial and immune cells. Following this reasoning, spheroids cultivated from one or multiple patient-derived cell lines can be utilized to seed the matrix rather than monolayer cells. This approach furthers the progress towards personalized medicine. As an initial step to create a new ex vivo tissue engineered model of a cancer tumor, optimized protocols have been designed to obtain organ-specific acellular matrices and evaluate their potential as tissue engineered scaffolds for cultures of normal and tumor cells. Decellularized biomatrix was prepared from animals’ kidneys, urethra, lungs, heart, and liver by two decellularization methods: perfusion in a bioreactor system and immersion-agitation on an orbital shaker with the use of various detergents (SDS, Triton X-100) in different concentrations and freezing. Acellular scaffolds and tissue engineered constructs have been characterized and compared using morphological methods. Models using decellularized matrix have certain advantages, such as maintaining native extracellular matrix properties and biomimetic microenvironment for cancer cells; compatibility with multiple cell types for cell culture and drug screening; utilization to culture patient-derived cells in vitro to evaluate different anticancer therapeutics for developing personalized medicines.

Keywords: 3D models, decellularization, drug discovery, drug toxicity, scaffolds, spheroids, tissue engineering

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4353 Bright Light Effects on the Concentration and Diffuse Attention Reaction Time, Tension, Angry, Fatigue and Alertness among Shift Workers

Authors: Mohammad Imani, JabraeilNasl Seraji, Abolfazl Zakerian

Abstract:

Background: Reaction time is the amount of time it takes to respond to a stimulus. In fact The time that passes between the introduction of a stimulus and the reaction by the subject to that stimulus. The aim of this interventional study is evaluation of bright light effects on concentration and diffuse attention reaction time, tension, angry, fatigue and alertness among shift workers. There are several incentives that can reduce the reaction time or added. Bright light as one of the environmental factors can reduce reaction time. Material &Method: This cross-sectional descriptive study was conducted in 1391, in 88 subjects (44 Fixed morning worker and 44 shift worker ) In a 24 h time (13-16-19-22-1-4-7-10) in an ordinary light situation after a randomly selected sample size calculation, concentration and diffuse attention test (reaction time) has been done. After intervention and using of bright light (4500lux), again reaction time test was done. After analyzing by ElISA method obtained data were analyzed by statistical software SPSS 19 and using T-test and ANOVA statistical analysis. Results: Between average of reaction time tests in ordinary light exposed to fixed morning workers and bright light exposed to shift worker, with 95% CI, (P>%5) there was no significant relationship. After the intervention and the use of bright light (4500 lux),between average of concentration and diffused attention reaction time tests in ordinary light exposure on the fixed morning workers and bright light exposure shift workers with 95% CI, (P<5%) there was significant relationship. Conclusion: In sometimes of 24 h during ordinary light exposure concentration and diffused attention reaction time has changed in shift workers. After intervention, during bright light (4500lux) exposure as a light shower, focused and diffuse attention reaction time, tension ,angry and fatigue decreased.

Keywords: bright light, reaction time, tension, angry, fatigue, alertness

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4352 Modelling, Simulation, and Experimental Validation of the Influence of Golf-Ball-Inspired Dimpled Design in Drag Reduction and Improved Fuel Efficiency of Super-Mileage Vehicle

Authors: Bibin Sagaram, Ronith Stanly, S. S. Suneesh

Abstract:

Due to the dwindling supply of fuel reserves, engineers and designers now focus on fuel efficient designs for the solution of any problem; the transportation industry is not new to this kind of approach. Though the aerodynamic benefits of the dimples on a Golf-ball are known, it has never been scientifically tested on how such a design philosophy can improve the fuel efficiency of a real-life vehicle by imparting better aerodynamic performance. The main purpose of the paper is to establish the aerodynamic benefits of the Golf-ball-Inspired Dimpled Design in improving the fuel efficiency of a Super-mileage vehicle, constructed by Team Go Viridis for ‘Shell Eco Marathon Asia 2015’, and to predict the extent to which the results can be held valid for a road car. The body design was modeled in Autodesk Inventor and the Computational Fluid Dynamics (CFD) simulations were carried out using Ansys Fluent software. The aerodynamic parameters of designs (with and without the Golf-ball-Inspired Dimples) have been studied and the results are experimentally validated against those obtained from wind tunnel tests carried out on a 1:10 scaled-down 3D printed model. Test drives of the Super-mileage vehicle were carried out, under various conditions, to compare the variation in fuel efficiency with and without the Golf-ball-Inspired design. Primary investigations reveal an aerodynamic advantage of 25% for the vehicle with the Golf Ball Inspired Dimpled Design as opposed to the normal design. Initial tests conducted by ‘Mythbusters’ on Discovery Network using a modified road car has shown positive results which has motivated us to conduct such a research work using a custom-built experimental Super-Mileage vehicle. The content of the paper becomes relevant to the present Automotive and Energy industry where improving the fuel efficiency is of the top most priority.

Keywords: aerodynamics, CFD, fuel efficiency, golf ball

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4351 Semi-pilot Biooxidation of Refractory Sulfide-Gold Ore Using Ferroplasma Acidophilum: D-(+)-Sucsore as a Booster and Columns Tests

Authors: Mohammad Hossein Karimi Darvanjooghi, Sara Magdouli, Satinder Kaur Brar

Abstract:

It has been reported that the microorganism’s attachment to the surfaces of ore samples is a key factor that influences the biooxidation in pretreatment for recovery of gold in sulfide-bearing ores. In this research, the implementation of D-(+)-Sucrose on the biooxidation of ore samples were studied in a semi-pilot experiment. The experiments were carried out in five separate jacketed columns (1 m height and 6 cm diameter) at a constant temperature of 37.5 ̊C and saturated humidity. The airflow rate and recycling solution flow rate were studied in the research and the optimum operating condition were reported. The ore sample (0.49 ppm gold grade) was obtained from the Hammond Reef mine site containing 15 wt.% of pyrite which included 98% of gold according to the results of micrograph images. The experiments were continued up to 100 days while air flow rates were chosen to be 0.5, 1, 1.5, 2, and 3 lit/min and the recycling solution (Containing 9K media and 0.4 wt.% D-(+)-Sucrose) flow rates were kept 5, 8, 15 ml/hr. The results indicated that the addition of D-(+)-Sucrose increased the bacterial activity due to the overproduction of extracellular polymeric substance (EPS) up to 95% and for the condition that the recycling solution and air flow rate were chosen to be 8 ml/hr and 2 lit/min, respectively, the maximum pyrite dissolution of 76% was obtained after 60 days. The results indicated that for the air flow rates of 0.5, 1, 1.5, 2, and 3 lit/min the ratio of daily pyrite dissolution per daily solution lost were found to be 0.025, 0.033, 0.031, 0.043, and 0.009 %-pyrite dissolution/ml-lost. The implementation of this microorganisms and the addition of D-(+)-Sucrose will enhance the efficiency of gold recovery through faster biooxidation process and leads to decrease in the time and energy of operation toward desired target; however, still other parameters including particle size distribution, agglomeration, aeration design, chemistry of recycling solution need to be controlled and monitored for reaching the optimum condition.

Keywords: column tests, biooxidation, gold recovery, Ferroplasma acidophilum, optimization

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4350 Renovation of Pipeline in Residential Buildings by Polymeric Composites

Authors: Parastou Kharazmi

Abstract:

In this paper, rehabilitation methods for pipeline by advanced polymeric coating such as relining are reviewed. A number of diverse methods which are globally used are described and a brief summary of advances in technology, methods and materials is provided. The paper explains why it is claimed that sewerage rehabilitation with relining in residential buildings is environmentally friendly and economical, the importance of the quality control procedure is discussed and several quality tests are proposed.

Keywords: buildings, composite, material, renovation

Procedia PDF Downloads 269
4349 A Study of Mortars with Granulated Blast Furnace Slag as Fine Aggregate and Its Influence on Properties of Burnt Clay Brick Masonry

Authors: Vibha Venkataramu, B. V. Venkatarama Reddy

Abstract:

Natural river sand is the most preferred choice as fine aggregate in masonry mortars. Uncontrolled mining of sand from riverbeds for several decades has had detrimental effects on the environment. Several countries across the world have put strict restrictions on sand mining from riverbeds. However, in countries like India, the huge infrastructural boom has made the local construction industry to look for alternative materials to sand. This study aims at understanding the suitability of granulated blast furnace slag (GBS) as fine aggregates in masonry mortars. Apart from characterising the material properties of GBS, such as particle size distribution, pH, chemical composition, etc., of GBS, tests were performed on the mortars with GBS as fine aggregate. Additionally, the properties of five brick tall, stack bonded masonry prisms with various types of GBS mortars were studied. The mortars with mix proportions 1: 0: 6 (cement: lime: fine aggregate), 1: 1: 6, and 1: 0: 3 were considered for the study. Fresh and hardened properties of mortar, such as flow and compressive strength, were studied. To understand the behaviour of GBS mortars on masonry, tests such as compressive strength and flexure bond strength were performed on masonry prisms made with a different type of GBS mortars. Furthermore, the elastic properties of masonry with GBS mortars were also studied under compression. For comparison purposes, the properties of corresponding control mortars with natural sand as fine aggregate and masonry prisms with sand mortars were also studied under similar testing conditions. From the study, it was observed the addition of GBS negatively influenced the flow of mortars and positively influenced the compressive strength. The GBS mortars showed 20 to 25 % higher compressive strength at 28 days of age, compared to corresponding control mortars. Furthermore, masonry made with GBS mortars showed nearly 10 % higher compressive strengths compared to control specimens. But, the impact of GBS on the flexural strength of masonry was marginal.

Keywords: building materials, fine aggregate, granulated blast furnace slag in mortars, masonry properties

Procedia PDF Downloads 121
4348 Insecticidal Effects of Plant Extract-Based Formulations on the Cotton Bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

Authors: Reza Sadeghi, Maryam Nazarahari

Abstract:

Considering the effectiveness of botanical pesticides in pest management, these compounds have garnered attention as a sustainable approach to reducing pest-induced damage in agriculture while preserving the environment. Botanical pesticides enable farmers to cultivate higher-quality crops by minimizing the use of chemical pesticides. In this study, plant extracts obtained using n-hexane as a solvent from two botanical sources, thyme and eucalyptus, were evaluated under laboratory conditions for their effectiveness in controlling the cotton bollworm (Helicoverpa armigera). The mortality rate of bollworm larvae was assessed across various concentrations of the hexane-based formulations. The results revealed that the hexane-based formulations of thyme and eucalyptus extracts significantly reduced the population of bollworm larvae after 24 hours of exposure. Thyme extract, in particular, demonstrated high effectiveness as a botanical pesticide, suggesting its potential as an efficient alternative to chemical pesticides in pest management. These findings underscore that botanical pesticides can mitigate the environmental consequences of chemical pesticides and provide innovative solutions for sustainable agriculture by leveraging the active compounds present in plant extracts.

Keywords: cotton bollworm, thyme, eucalyptus, extract formulation, , toxicity

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4347 Inducible Trans-Encapsidation System for Temporal Separation of Hepatitis C Virus Life Cycle

Authors: Ovidiu Vlaicu, Leontina Banica, Dan Otelea, Andrei-Jose Petrescu, Costin-Ioan Popescu

Abstract:

Hepatitis C Virus (HCV) infects 170 million peoples worldwide. Major advances have been made recently in HCV standard of care with interferon-free therapy being already approved. Despite major progress in HCV therapy, the genotype associated treatment efficacy and toxicity still represent issues to address. To identify endogenous factors involved in different stages of HCV life cycle, we have developed a trans-packaging system for HCV subgenomic replicons lacking core protein gene. Huh7 cells were used to generate a packaging cell line expressing the core protein in an inducible manner. The core packaging cell line was able to trans-complemented various subgenomic replicons to secret infectious trans-complemented HCV particles (HCV-TCP). Further, we constructed subgenomic replicons with foreign epitopes suitable for immunoaffinity purification or fluorescence microscopy studies. We have shown that the insertion has not effects on the efficacy of trans-complementation yielding similar titers to the control subgenomic replicon. This system will be a valuable tool in studying pre- and post-assembly events in HCV life cycle and for the fast identification of HCV assembly inhibitors.

Keywords: assembly inhibitors, core protein, HCV, trans-complementation

Procedia PDF Downloads 292
4346 Evaluation of Heavy Metal Concentrations of Stem and Seed of Juncus acutus for Grazing Animals and Birds in Kızılırmak Delta

Authors: N. Cetinkaya, F. Erdem

Abstract:

Juncus acutus (Juncaceae) is a perennial wetland plant and it is commonly known as spiny rush or sharp rush. It is the most abundant plant in Kizilirmak grassland, Samsun, Turkey. Heavy metals are significant environmental contaminants in delta and their toxicity is an increasing problem for animals whose natural habitat is delta. The objective of this study was to evaluate heavy metal concentrations mainly As, Cd, Sb, Ba, Pb and Hg in stem and seed of Juncus acutus for grazing animals and birds in delta. The Juncus acutus stem and seed samples were collected from Kizilirmak Delta in July, August and September. Heavy metal concentrations of collected samples were analyzed by Inductively Coupled Plasma – Mass Spectrometer (ICP-MS). The obtained mean values of three months for As, Cd, Sb, Ba, Pb and Hg of stem and seed samples of Juncus acutus were 0.11 and 0.23 mg/kg; 0.07 and 0.11 mg/kg; 0.02 and 0.02 mg/kg; 5.26 and 1.75 mg/kg; 0.05 and not detectable in July respectively. Hg was not detected in both stem and seed of Juncus acutus, Pb concentration was determined only in stem of Juncus acutus but not in seed. There were no significant differences between the values of three months for As, Cd, Sb, Ba, Pb and Hg of stem and seed samples of Juncus acutus. The obtained As, Cd, Sb, Ba, Pb and Hg results of stem and seed of Juncus acutus show that seed and stem of Juncus acutus may be safely consumed for grazing animals and birds regarding to heavy metals contamination in Kizilirmak Delta.

Keywords: heavy metals, Juncus acutus, Kizilirmak Delta, wetland

Procedia PDF Downloads 139
4345 Functional Vision of Older People in Galician Nursing Homes

Authors: C. Vázquez, L. M. Gigirey, C. P. del Oro, S. Seoane

Abstract:

Early detection of visual problems plays a key role in the aging process. However, although vision problems are common among older people, the percentage of aging people who perform regular optometric exams is low. In fact, uncorrected refractive errors are one of the main causes of visual impairment in this group of the population. Purpose: To evaluate functional vision of older residents in order to show the urgent need of visual screening programs in Galician nursing homes. Methodology: We examined 364 older adults aged 65 years and over. To measure vision of the daily living, we tested distance and near presenting visual acuity (binocular visual acuity with habitual correction if warn, directional E-Snellen) Presenting near vision was tested at the usual working distance. We defined visual impairment (distance and near) as a presenting visual acuity less than 0.3. Exclusion criteria included immobilized residents unable to reach the USC Dual Sensory Loss Unit for visual screening. Association between categorical variables was performed using chi-square tests. We used Pearson and Spearman correlation tests and the variance analysis to determine differences between groups of interest. Results: 23,1% of participants have visual impairment for distance vision and 16,4% for near vision. The percentage of residents with far and near visual impairment reaches 8,2%. As expected, prevalence of visual impairment increases with age. No differences exist with regard to the level of functional vision between gender. Differences exist between age group respect to distance vision, but not in case of near vision. Conclusion: prevalence of visual impairment is high among the older people tested in this pilot study. This means a high percentage of older people with limitations in their daily life activities. It is necessary to develop an effective vision screening program for early detection of vision problems in Galician nursing homes.

Keywords: functional vision, elders, aging, nursing homes

Procedia PDF Downloads 408
4344 Using Deep Learning in Lyme Disease Diagnosis

Authors: Teja Koduru

Abstract:

Untreated Lyme disease can lead to neurological, cardiac, and dermatological complications. Rapid diagnosis of the erythema migrans (EM) rash, a characteristic symptom of Lyme disease is therefore crucial to early diagnosis and treatment. In this study, we aim to utilize deep learning frameworks including Tensorflow and Keras to create deep convolutional neural networks (DCNN) to detect images of acute Lyme Disease from images of erythema migrans. This study uses a custom database of erythema migrans images of varying quality to train a DCNN capable of classifying images of EM rashes vs. non-EM rashes. Images from publicly available sources were mined to create an initial database. Machine-based removal of duplicate images was then performed, followed by a thorough examination of all images by a clinician. The resulting database was combined with images of confounding rashes and regular skin, resulting in a total of 683 images. This database was then used to create a DCNN with an accuracy of 93% when classifying images of rashes as EM vs. non EM. Finally, this model was converted into a web and mobile application to allow for rapid diagnosis of EM rashes by both patients and clinicians. This tool could be used for patient prescreening prior to treatment and lead to a lower mortality rate from Lyme disease.

Keywords: Lyme, untreated Lyme, erythema migrans rash, EM rash

Procedia PDF Downloads 240
4343 Development of Carrageenan-Psyllium/Montmorillonite Clay Hybrid Hydrogels for Agriculture Purpose

Authors: D. Aydinoglu, N. Karaca, O. Ceylan

Abstract:

Limited water resources on the earth come first among the most alarming issues. In this respect, several solutions from treatment of waste water to water management have been proposed. Recently, use of hydrogels as soil additive, which is one of the water management ways in agriculture, has gained increasing interest. In traditional agriculture applications, water used with irrigation aim, rapidly flows down between the pore structures in soil, without enough useful for soil. To overcome this fact and increase the abovementioned limit values, recently, several natural based hydrogels have been suggested and tested to find out their efficiency in soil. However, most of these researches have dealt with grafting of synthetic acrylate based monomers on natural gelling agents, most probably due to reinforced of the natural gels. These results motivated us to search a natural based hydrogel formulations, not including any synthetic component, and strengthened with montmorillonite clay instead of any grafting polymerization with synthetic monomer and examine their potential in this field, as well as characterize of them. With this purpose, carrageenan-psyllium/ montmorillonite hybrid hydrogels have been successively prepared. Their swelling capacities were determined both in deionized and tap water and were found to be dependent on the carrageenan, psyllium and montmorillonite ratios, as well as the water type. On the other hand, mechanical tests revealed that especially carrageenan and montmorillonite contents have a great effect on gel strength, which is one of the essential features, preventing the gels from cracking resulted in readily outflow of all the water in the gel without beneficial for soil. They found to reach 0.23 MPa. The experiments carried out with soil indicated that hydrogels significantly improved the water uptake capacities and water retention degrees of the soil from 49 g to 85 g per g of soil and from 32 to 67%, respectively, depending on the ingredient ratios. Also, biodegradation tests demonstrated that all the hydrogels undergo biodegradation, as expected from their natural origin. The overall results suggested that these hybrid hydrogels have a potential for use as soil additive and can be safely used owing to their totally natural structure.

Keywords: carrageenan, hydrogel, montmorillonite, psyllium

Procedia PDF Downloads 115
4342 Clinical Outcomes of Neonates Born to COVID-19 Positive Mothers in a Tertiary Level Private Hospital

Authors: Patricia Abigail B. Miranda, Imelda A. Luna

Abstract:

Introduction: COVID-19 infection is a novel viral illness that began as a local epidemic in December 2019 in Wuhan, China which quickly emerged into a pandemic by February 2020. The virus causes a spectrum of signs and symptoms, ranging from mild upper respiratory symptoms to acute respiratory distress syndrome, which may lead to death. Among children and neonates, those afflicted with the disease may present asymptomatically or with mild symptoms. To date, there has been limited local data that describes the outcomes of the growing number of COVID-19 cases, specifically in neonates. Methods: A cross-sectional study was conducted to determine the outcomes of neonates born to COVID-19 Positive Mothers from March 2020 until June 2022. The prevalence of COVID-19 among these neonates was also determined. Results: COVID-positive prevalence after 24 hours of life is at 8%, while prevalence after 48 hours among those who still underwent testing was at 13.51%. Moreover, among those COVID-19-negative neonates who had symptoms, they mostly presented with tachypnea (5.7%). The prevalence of complications among COVID-19-negative neonates delivered to COVID-19-positive mothers is 22.7%. Conclusion: Neonates born to COVID-19-positive mothers who yielded positive COVID-19 results are generally asymptomatic. Moreover, there are no associated mortalities among those who yielded positive results.

Keywords: COVID-19, neonates, outcomes, clinical profile

Procedia PDF Downloads 82
4341 Effect of Impact Angle on Erosive Abrasive Wear of Ductile and Brittle Materials

Authors: Ergin Kosa, Ali Göksenli

Abstract:

Erosion and abrasion are wear mechanisms reducing the lifetime of machine elements like valves, pump and pipe systems. Both wear mechanisms are acting at the same time, causing a “Synergy” effect, which leads to a rapid damage of the surface. Different parameters are effective on erosive abrasive wear rate. In this study effect of particle impact angle on wear rate and wear mechanism of ductile and brittle materials was investigated. A new slurry pot was designed for experimental investigation. As abrasive particle, silica sand was used. Particle size was ranking between 200-500 µm. All tests were carried out in a sand-water mixture of 20% concentration for four hours. Impact velocities of the particles were 4,76 m/s. As ductile material steel St 37 with Brinell Hardness Number (BHN) of 245 and quenched St 37 with 510 BHN was used as brittle material. After wear tests, morphology of the eroded surfaces were investigated for better understanding of the wear mechanisms acting at different impact angles by using optical microscopy and Scanning Electron Microscope. The results indicated that wear rate of ductile material was higher than brittle material. Maximum wear was observed by ductile material at a particle impact angle of 300. On the contrary wear rate increased by brittle materials by an increase in impact angle and reached maximum value at 450. High amount of craters were detected after observation on ductile material surface Also plastic deformation zones were detected, which are typical failure modes for ductile materials. Craters formed by particles were deeper according to brittle material worn surface. Amount of craters decreased on brittle material surface. Microcracks around craters were detected which are typical failure modes of brittle materials. Deformation wear was the dominant wear mechanism on brittle material. At the end it is concluded that wear rate could not be directly related to impact angle of the hard particle due to the different responses of ductile and brittle materials.

Keywords: erosive wear, particle impact angle, silica sand, wear rate, ductile-brittle material

Procedia PDF Downloads 401
4340 Viscoelastic Characterization of Gelatin/Cellulose Nanocrystals Aqueous Bionanocomposites

Authors: Liliane Samara Ferreira Leite, Francys Kley Vieira Moreira, Luiz Henrique Capparelli Mattoso

Abstract:

The increasing environmental concern regarding the plastic pollution worldwide has stimulated the development of low-cost biodegradable materials. Proteins are renewable feedstocks that could be used to produce biodegradable plastics. Gelatin, for example, is a cheap film-forming protein extracted from animal skin and connective tissues of Brazilian Livestock residues; thus it has a good potential in low-cost biodegradable plastic production. However, gelatin plastics are limited in terms of mechanical and barrier properties. Cellulose nanocrystals (CNC) are efficient nanofillers that have been used to extend physical properties of polymers. This work was aimed at evaluating the reinforcing efficiency of CNC on gelatin films. Specifically, we have employed the continuous casting as the processing method for obtaining the gelatin/CNC bionanocomposites. This required a first rheological study for assessing the effect of gelatin-CNC and CNC-CNC interactions on the colloidal state of the aqueous bionanocomposite formulations. CNC were isolated from eucalyptus pulp by sulfuric acid hydrolysis (65 wt%) at 55 °C for 30 min. Gelatin was solubilized in ultra-pure water at 85°C for 20 min and then mixed with glycerol at 20 wt.% and CNC at 0.5 wt%, 1.0 wt% and 2.5 wt%. Rotational measurements were performed to determine linear viscosity (η) of bionanocomposite solutions, which increased with increasing CNC content. At 2.5 wt% CNC, η increased by 118% regarding the neat gelatin solution, which was ascribed to percolation CNC network formation. Storage modulus (G’) and loss modulus (G″) further determined by oscillatory tests revealed that a gel-like behavior was dominant in the bionanocomposite solutions (G’ > G’’) over a broad range of temperature (20 – 85 °C), particularly at 2.5 wt% CNC. These results confirm effective interactions in the aqueous gelatin-CNC bionanocomposites that could substantially increase the physical properties of the gelatin plastics. Tensile tests are underway to confirm this hypothesis. The authors would like to thank the Fapesp (process n 2016/03080-3) for support.

Keywords: bionanocomposites, cellulose nanocrystals, gelatin, viscoelastic characterization

Procedia PDF Downloads 150
4339 Assessment of Water Resources and Inculcation of Controlled Water Consumption System

Authors: Vakhtang Geladze, Nana Bolashvili, Tamazi Karalashvili, Nino Machavariani, Vajha Neidze, Nana Kvirkvelia, Tamar Chichinadze

Abstract:

Deficiency of fresh water is a vital global problem today. It must be taken into consideration that in the nearest future fresh water crisis will become even more acute owing to the global climate warming and fast desertification processes in the world. Georgia has signed the association agreement with Euro Union last year where the priority spheres of cooperation are the management of water resources, development of trans-boundary approach to the problem and active participation in the “Euro Union water initiative” component of “the East Europe, Caucasus and the Central Asia”. Fresh water resources are the main natural wealth of Georgia. According to the average water layer height, Georgia is behind such European countries only as Norway, Switzerland and Austria. The annual average water provision of Georgia is 4-8 times higher than in its neighbor countries Armenia and Azerbaijan. Despite abundant water resources in Georgia, there is considerable discrepancy between their volume and use in some regions because of the uneven territorial distribution. In the East Georgia, water supply of the territory and population is four times less than in the West Georgia.

Keywords: GIS, water consumption, water management, water resources

Procedia PDF Downloads 419
4338 Functional Vision of Older People with Cognitive Impairment Living in Galician Nursing Homes

Authors: C. Vázquez, L. M. Gigirey, C. P. del Oro, S. Seoane

Abstract:

Poor vision is common among older people, and several studies show connections between visual impairment and cognitive function. 15 older adult live in Galician Government nursing homes, and cognitive decline is one of the main reasons of admission. Objectives: (1) To evaluate functional far and near vision of older people with cognitive impairment. (2) To determine connections between visual and cognitive state of “our” residents. Methodology: A total of 364 older adults (aged 65 years or more) underwent a visual and cognitive screening. We tested presenting visual acuity (binocular visual acuity with habitual correction if warn) for distance and near vision (E-Snellen, usual working distance for near vision). Binocular presenting visual acuity less than 0.3 was used as cut point for diagnosis of visual impairment. Exclusion criteria included immobilized residents unable to reach the USC Dual Sensory Loss Unit for visual screening. To screen cognition we employed the mini-mental examination test (Spanish version). Analysis of categorical variables was performed using chi-square tests. We utilized Pearson and Spearman correlation tests and the variance analysis to determine differences between groups of interest (SPSS 19.0 version). Results: the percentage of residents with cognitive decline reaches 32.2% Prevalence of visual impairment for distance and near vision increases among those subjects with cognitive impairment respect those with normal cognition. Shift correlation exists between distance visual acuity and mini-mental test (age and sex controlled), and moderate association was found in case of near vision (p<0.01). Conclusion: First results shows that people with cognitive impairment have poor functional distance and near vision than those with normal cognition. Next step will be to analyse the individual contribution of distance and near vision loss on cognition.

Keywords: visual impairment, cognition, aging, nursing homes

Procedia PDF Downloads 428