Search results for: stress effect
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 17344

Search results for: stress effect

11164 Novel Emulgel of Piroxicam for Topical Application with Mentha and Clove Oil

Authors: S. V. Patil, P. S. Dounde, S. S. Patil

Abstract:

Emulgels have emerged as one of the most interesting topical delivery system as it has dual release control system that is gel and emulsion. The major objective behind this formulation is delivery of hydrophobic drugs to systemic circulation via skin. In fact presence of a gelling agent in water phase converts a classical emulsion in to emulgel. The emulgel for dermatological use has several favorable properties such as being thixotropic, greaseless, easily spreadable, easily removable, emollient, non-staining, water-soluble, longer shelf life, bio-friendly, transparent and pleasing appearance. Various penetration enhancers can potentiate the effect. So this can be used as better topical drug delivery systems over present conventional systems available in market. Piroxicam is a non-steroidal anti-inflammatory drug that has major problems when administered orally; it is an insoluble drug and has irritant effect on gastro intestinal tract lead to ulceration and bleeding. The aim of this study was to overcoming these problems through preparation of topical emulgel of this drug. Emulgel of Piroxicam was prepared using Carbopol 940 along with mentha oil and clove oil as permeation enhancer. The prepared emulgel were evaluated for their physical appearance, pH determination, viscosity, spreadability, in vitro drug release, ex vivo permeation studies. All the prepared formulations showed acceptable physical properties, homogeneity, consistency, spreadability, viscosity and pH value. The emulgel was found to be stable with respect to physical appearance, pH, rheological properties and drug content at all temperature and conditions for three month.

Keywords: emulgel, piroxicam, menthe oil, clove oil

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11163 Effect of 10 Weeks of Aerobic Exercise Training on Serum Concentrations of Surfactant Protein D and Insulin Resistance in Women with Type 2 Diabetes

Authors: Sajjad Rezaei, Mahdieh Molanouri Shamsi, Azadeh Jamali

Abstract:

Background and purpose: Surfactant protein D (SP-D) is a lung-specific protein that is detectable in human plasma. Effect of exercise training on SP-D levels as well as its relation to metabolic indices is not known. The present study then aimed to investigate the effects of 10 weeks of aerobic training on serum levels of SP-D and insulin resistance in women with type 2 diabetes. Materials and methods: Twenty-two overweight women with type 2 diabetes mellitus were recruited through deliberate sampling and randomly assigned to intervention and control groups (11 in each group). The intervention group underwent a progressive aerobic training program for 10 weeks, 3 days per week, 30-55 min/day at 50-75% heart rate reserve (HRR). Control group continued with its everyday routine. Blood samples were obtained before and after training for biochemical analysis. Within-group and between-group differences were analyzed with paired and independent t-tests in spss software, respectively, and the relation between variables was analyzed with Pearson’s correlation coefficient (all at P = 0.05). Results: Significant differences were observed between groups in leptin, glucose, waist circumference and VO2 max after training. SP-D was decreased and VO2 max was increased significantly in intervention group. However, no significant correlation was observed between SP-D and other variables. Conclusion: Since there was no corresponding decrease in insulin resistance with decreased levels of SP-D, it seems unlikely for SP-D to mediate the association between obesity and insulin resistance in type 2 diabetics.

Keywords: exercise training, SP-D, insulin resistance, type 2 diabetes

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11162 Design and Control of a Knee Rehabilitation Device Using an MR-Fluid Brake

Authors: Mina Beheshti, Vida Shams, Mojtaba Esfandiari, Farzaneh Abdollahi, Abdolreza Ohadi

Abstract:

Most of the people who survive a stroke need rehabilitation tools to regain their mobility. The core function of these devices is a brake actuator. The goal of this study is to design and control a magnetorheological brake which can be used as a rehabilitation tool. In fact, the fluid used in this brake is called magnetorheological fluid or MR that properties can change by variation of the magnetic field. The braking properties can be set as control by using this feature of the fluid. In this research, different MR brake designs are first introduced in each design, and the dimensions of the brake have been determined based on the required torque for foot movement. To calculate the brake dimensions, it is assumed that the shear stress distribution in the fluid is uniform and the fluid is in its saturated state. After designing the rehabilitation brake, the mathematical model of the healthy movement of a healthy person is extracted. Due to the nonlinear nature of the system and its variability, various adaptive controllers, neural networks, and robust have been implemented to estimate the parameters and control the system. After calculating torque and control current, the best type of controller in terms of error and control current has been selected. Finally, this controller is implemented on the experimental data of the patient's movements, and the control current is calculated to achieve the desired torque and motion.

Keywords: rehabilitation, magnetorheological fluid, knee, brake, adaptive control, robust control, neural network control, torque control

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11161 A Study on the Effect of Mg and Ag Additions and Age Hardening Treatment on the Properties of As-Cast Al-Cu-Mg-Ag Alloys

Authors: Ahmed. S. Alasmari, M. S. Soliman, Magdy M. El-Rayes

Abstract:

This study focuses on the effect of the addition of magnesium (Mg) and silver (Ag) on the mechanical properties of aluminum based alloys. The alloying elements will be added at different levels using the factorial design of experiments of 22; the two factors are Mg and Ag at two levels of concentration. The superior mechanical properties of the produced Al-Cu-Mg-Ag alloys after aging will be resulted from a unique type of precipitation named as Ω-phase. The formed precipitate enhanced the tensile strength and thermal stability. This paper further investigated the microstructure and mechanical properties of as cast Al–Cu–Mg–Ag alloys after being complete homogenized treatment at 520 °C for 8 hours followed by isothermally age hardening process at 190 °C for different periods of time. The homogenization at 520 °C for 8 hours was selected based on homogenization study at various temperatures and times. The alloys’ microstructures were studied by using optical microscopy (OM). In addition to that, the fracture surface investigation was performed using a scanning electronic microscope (SEM). Studying the microstructure of aged Al-Cu-Mg-Ag alloys reveal that the grains are equiaxed with an average grain size of about 50 µm. A detailed fractography study for fractured surface of the aged alloys exhibited a mixed fracture whereby the random fracture suggested crack propagation along the grain boundaries while the dimples indicated that the fracture was ductile. The present result has shown that alloy 5 has the highest hardness values and the best mechanical behaviors.

Keywords: precipitation hardening, aluminum alloys, aging, design of experiments, analysis of variance, heat treatments

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11160 Effect of Fines on Liquefaction Susceptibility of Sandy Soil

Authors: Ayad Salih Sabbar, Amin Chegenizadeh, Hamid Nikraz

Abstract:

Investigation of liquefaction susceptibility of materials that have been used in embankments, slopes, dams, and foundations is very essential. Many catastrophic geo-hazards such as flow slides, declination of foundations, and damage to earth structure are associated with static liquefaction that may occur during abrupt shearing of these materials. Many artificial backfill materials are mixtures of sand with fines and other composition. In order to provide some clarifications and evaluations on the role of fines in static liquefaction behaviour of sand sandy soils, the effect of fines on the liquefaction susceptibility of sand was experimentally examined in the present work over a range of fines content, relative density, and initial confining pressure. The results of an experimental study on various sand-fines mixtures are presented. Undrained static triaxial compression tests were conducted on saturated Perth sand containing 5% bentonite at three different relative densities (10, 50, and 90%), and saturated Perth sand containing both 5% bentonite and slag (2%, 4%, and 6%) at single relative density 10%. Undrained static triaxial tests were performed at three different initial confining pressures (100, 150, and 200 kPa). The brittleness index was used to quantify the liquefaction potential of sand-bentonite-slag mixtures. The results demonstrated that the liquefaction susceptibility of sand-5% bentonite mixture was more than liquefaction susceptibility of clean sandy soil. However, liquefaction potential decreased when both of two fines (bentonite and slag) were used. Liquefaction susceptibility of all mixtures decreased with increasing relative density and initial confining pressure.  

Keywords: liquefaction, bentonite, slag, brittleness index

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11159 Using Plant Oils in Total Mixed Ration on Voluntary Feed Intake and Blood Metabolize of Crossbred Thai Native X American Brahman Cattle

Authors: Wantanee Polviset, N. Prakobsaeng, N. Wetchakama, C. Yuangklang

Abstract:

The aim of this study was to evaluate the effect of soybean oil, palm oil and sunflower oil supplementations in total mixed ration on voluntary feed intake, dry matter (DM) digestibility and blood metabolize in crossbred Thai native x American Brahman Cattle. Three Thai native x American Brahman cattle, one-year-old with liveweight of 116±22.59 kg, were randomly assigned according to a 3 x 3 latin square design. Each period of feeding lasted for 21 days to receive three dietary treatments were soybean oil, palm oil and sunflower oil supplementation at 5%. During the experimental periods, all cattle were fed a diet with total mixed ration containing roughage to concentrate ratio of 40:60 and rice straw was used as a roughage source. Based on the present study, the results revealed that voluntary feed intake (kgDM/head/day) and %BW DM intake were not affected (P>0.05), whereas percentage of dry matter digestibility was greater with the soybean oil supplementation (P<0.01). It was also found that blood glucose, blood urea nitrogen, cholesterol, triglyceride, high density lipoprotein and low density lipoprotein in plasma were similar among treatments. Based on this study, supplementing 5% soybean oil in total mixed ration (TMR) diets was suitable in beef cattle without any effect dry matter digestibility and blood metabolites.

Keywords: plant oils, feed intake, blood metabolize, crossbred Thai native x Brahman cattle

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11158 Activation of Mitophagy and Autophagy in Familial Forms of Parkinson's Disease, as a Potential Strategy for Cell Protection

Authors: Nafisa Komilova, Plamena Angelova, Andrey Abramov, Ulugbek Mirkhodjaev

Abstract:

Parkinson’s disease (PD) is a progressive neurodegenerative disorder which is induced by the loss of dopaminergic neurons in the midbrain. The mechanism of neurodegeneration is associated with the aggregation of misfolded proteins, oxidative stress, and mitochondrial disfunction. Considering this, the process of removal of unwanted organelles or proteins by autophagy is vitally important in neurons, and activation of these processes could be protective in PD. Short-time acidification of cytosol can activate mitophagy and autophagy, and here we used sodium pyruvate and sodium lactate in human fibroblasts with PD mutations (Pink1, Pink1/Park2, α-syn triplication, A53T) to induce changes in intracellular pH. We have found that both lactate and pyruvate in millimolar concentrations can induce short-time acidification of cytosol in these cells. It induced activation of mitophagy and autophagy in control and PD fibroblasts and protected against cell death. Importantly, the application of lactate to acute brain slices of control and Pink1 knockout mice also induced a reduction of pH in neurons and astrocytes that increase the level of mitophagy. Thus, acidification of cytosol by compounds which play important role in cell metabolism also can activate mitophagy and autophagy and protect cells in the familial form of PD.

Keywords: Parkinson's disease, mutations, mitophagy, autophagy

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11157 Identification of Potential Predictive Biomarkers for Early Diagnosis of Preeclampsia Growth Factors to microRNAs

Authors: Sadia Munir

Abstract:

Preeclampsia is the contributor to the worldwide maternal mortality of approximately 100,000 deaths a year. It complicates about 10% of all pregnancies and is the first cause of maternal admission to intensive care units. Predicting preeclampsia is a major challenge in obstetrics. More importantly, no major progress has been achieved in the treatment of preeclampsia. As placenta is the main cause of the disease, the only way to treat the disease is to extract placental and deliver the baby. In developed countries, the cost of an average case of preeclampsia is estimated at £9000. Interestingly, preeclampsia may have an impact on the health of mother or infant, beyond the pregnancy. We performed a systematic search of PubMed including the combination of terms such as preeclampsia, biomarkers, treatment, hypoxia, inflammation, oxidative stress, vascular endothelial growth factor A, activin A, inhibin A, placental growth factor, transforming growth factor β-1, Nodal, placenta, trophoblast cells, microRNAs. In this review, we have summarized current knowledge on the identification of potential biomarkers for the diagnosis of preeclampsia. Although these studies show promising data in early diagnosis of preeclampsia, the current value of these factors as biomarkers, for the precise prediction of preeclampsia, has its limitation. Therefore, future studies need to be done to support some of the very promising and interesting data to develop affordable and widely available tests for early detection and treatment of preeclampsia.

Keywords: activin, biomarkers, growth factors, miroRNA

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11156 Android-Based Edugame Application for Earthquakes Disaster Mitigation Education

Authors: Endina P. Purwandari, Yolanda Hervianti, Feri Noperman, Endang W. Winarni

Abstract:

The earthquakes disaster is an event that can threaten at any moment and cause damage and loss of life. Game earthquake disaster mitigation is a useful educational game to enhance children insight, knowledge, and understanding in the response to the impact of the earthquake. This study aims to build an educational games application on the Android platform as a learning media for earthquake mitigation education and to determine the effect of the application toward children understanding of the earthquake disaster mitigation. The methods were research and development. The development was to develop edugame application for earthquakes mitigation education. The research involved elementary students as a research sample to test the developed application. The research results were valid android-based edugame application, and its the effect of application toward children understanding. The application contains an earthquake simulation video, an earthquake mitigation video, and a game consisting three stages, namely before the earthquake, when the earthquake occur, and after the earthquake. The results of the feasibility test application showed that this application was included in the category of 'Excellent' which the average percentage of the operation of applications by 76%, view application by 67% and contents of application by 74%. The test results of students' responses were 80% that showed that a positive their responses toward the application. The student understanding test results show that the average score of children understanding pretest was 71,33, and post-test was 97,00. T-test result showed that t value by 8,02 more than table t by 2,001. This indicated that the earthquakes disaster mitigation edugame application based on Android platform affects the children understanding about disaster earthquake mitigation.

Keywords: android, edugame, mitigation, earthquakes

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11155 Biomass Enhancement of Stevia (Stevia rebaudiana Bertoni) Shoot Culture in Temporary Immersion System (TIS) RITA® Bioreactor Optimized in Two Different Immersion Periods

Authors: Agustine Melviana, Rizkita Esyanti

Abstract:

Stevia plant contains steviol glycosides which is estimated to be 300 times sweeter than sucrose. However in Indonesia, conventional (in vivo) propagation of Stevia rebaudiana was not effective due to a poor result. Therefore, alternative methods to propagate S. rebaudiana plants is needed, one of it is using in vitro method. Multiplication with a large quantity of stevia biomass in relatively short period can be conducted by using TIS RITA® (Recipient for Automated Temporary Immersion System). The objective of this study was to evaluate the effect of immersion period of the medium on growth and the medium bioconversion into the production of shoot biomass. The study was conducted to determine the effect of different intensity period of medium to enhance biomass of stevia shoots. Shoot culture of S. rebaudiana was grown in full strength MS medium supplemented with 1 ppm Kinetin. RITA® bioreactors were set up with two different immersion periods, 15 min (RITA® 15) and 30 min (RITA® 30), scheduled every 6 hours and incubated for 21 days. The result indicated that immersion period affected the biomass and growth rate (µ). Thirty-minutes immersion showed greater percentage of shoot multiplication (93.44 ± 0.83%), percentage of leaf growth (85.24 ± 5.99%), growth rate (0.042 ± 0.001 g/day), and productivity (0.066 g/L medium/day) compared to that immersed in RITA® 15 min (76.90 ± 4.85%; 79.73 ± 7.76; 0.045 ± 0.004 g/day, and 0.045 g/L medium/day respectively). Enhancement of biomass in RITA® 30 reached 1,702 ± 0,114 gr, whereas in RITA® 15 only 0,953 ± 0,093 gr. Additionally, the pattern of sucrose, mineral, and inorganic compounds consumption followed the growth of plant biomass for both systems. In conclusion, the bioconversion efficiency from medium to biomass in RITA® 30 is better than RITA® 15.

Keywords: intensity period, shoot culture, Stevia rebaudiana, TIS RITA®

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11154 Evaluation of Drilling Performance through Bit-Rock Interaction Using Passive Vibration Assisted Rotation Drilling (PVARD) Tool

Authors: Md. Shaheen Shah, Abdelsalam Abugharara, Dipesh Maharjan, Syed Imtiaz, Stephen Butt

Abstract:

Drilling performance is an essential goal in petroleum and mining industry. Drilling rate of penetration (ROP), which is inversely proportional to the mechanical specific energy (MSE) is influenced by numerous factors among which are the applied parameter: torque (T), weight on bit (WOB), fluid flow rate, revolution per minute (rpm), rock related parameters: rock type, rock homogeneousness, rock anisotropy orientation, and mechanical parameters: bit type, configuration of the bottom hole assembly (BHA). This paper is focused on studying the drilling performance by implementing a passive vibration assisted rotary drilling tool (pVARD) as part of the BHA through using different bit types: coring bit, roller cone bit, and PDC bit and various rock types: rock-like material, granite, sandstone, etc. The results of this study aim to produce a pVARD index for optimal drilling performance considering the recommendations of the pVARD’s spring compression tests and stress-strain analysis of rock samples conducted prior to drilling experiments, analyzing the cutting size distribution, and evaluating the applied drilling parameters as a function of WOB. These results are compared with those obtained from drilling without pVARD, which represents the typical rigid BHA of the conventional drilling.

Keywords: BHA, drilling performance, MSE, pVARD, rate of penetration, ROP, tensile and shear fractures, unconfined compressive strength

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11153 Emotion Expression of the Leader and Collective Efficacy: Pride and Guilt

Authors: Hsiu-Tsu Cho

Abstract:

Collective efficacy refers to a group’s sense of its capacity to complete a task successfully or to reach objectives. Little effort has been expended on investigating the relationship between the emotion expression of a leader and collective efficacy. In this study, we examined the impact of the different emotions and emotion expression of a group leader on collective efficacy and explored whether the emotion–expressive effects differed under conditions of negative and positive emotions. A total of 240 undergraduate and graduate students recruited using Facebook and posters at a university participated in this research. The participants were separated randomly into 80 groups of four persons consisting of three participants and a confederate. They were randomly assigned to one of five conditions in a 2 (pride vs. guilt) × 2 (emotion expression of group leader vs. no emotion expression of group leader) factorial design and a control condition. Each four-person group was instructed to get the reward in a group competition of solving the five-disk Tower of Hanoi puzzle and making decisions on an investment case. We surveyed the participants by employing the emotional measure revised from previous researchers and collective efficacy questionnaire on a 5-point scale. To induce an emotion of pride (or guilt), the experimenter announced whether the group performance was good enough to have a chance of getting the reward (ranking the top or bottom 20% among all groups) after group task. The leader (confederate) could either express or not express a feeling of pride (or guilt) following the instruction according to the assigned condition. To check manipulation of emotion, we added a control condition under which the experimenter revealed no results regarding group performance in maintaining a neutral emotion. One-way ANOVAs and post hoc pairwise comparisons among the three emotion conditions (pride, guilt, and control condition) involved assigning pride and guilt scores (pride: F(1,75) = 32.41, p < .001; guilt: F(1,75) = 6.75, p < .05). The results indicated that manipulations of emotion were successful. A two-way between-measures ANOVA was conducted to examine the predictions of the main effects of emotion types and emotion expression as well as the interaction effect of these two variables on collective efficacy. The experimental findings suggest that pride did not affect collective efficacy (F(1,60) = 1.90, ns.) more than guilt did and that the group leader did not motivate collective efficacy regardless of whether he or she expressed emotion (F(1,60) = .89, ns.). However, the interaction effect of emotion types and emotion expression was statistically significant (F(1,60) = 4.27, p < .05, ω2 = .066); the effects accounted for 6.6% of the variance. Additional results revealed that, under the pride condition, the leader enhanced group efficacy when expressing emotion, whereas, under the guilt condition, an expression of emotion could reduce collective efficacy. Overall, these findings challenge the assumption that the effect of expression emotion are the same on all emotions and suggest that a leader should be cautious when expressing negative emotions toward a group to avoid reducing group effectiveness.

Keywords: collective efficacy, group leader, emotion expression, pride, guilty

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11152 Effect of Acid-Basic Treatments of Lingocellulosic Material Forest Wastes Wild Carob on Ethyl Violet Dye Adsorption

Authors: Abdallah Bouguettoucha, Derradji Chebli, Tariq Yahyaoui, Hichem Attout

Abstract:

The effect of acid -basic treatment of lingocellulosic material (forest wastes wild carob) on Ethyl violet adsorption was investigated. It was found that surface chemistry plays an important role in Ethyl violet (EV) adsorption. HCl treatment produces more active acidic surface groups such as carboxylic and lactone, resulting in an increase in the adsorption of EV dye. The adsorption efficiency was higher for treated of lingocellulosic material with HCl than for treated with KOH. Maximum biosorption capacity was 170 and 130 mg/g, for treated of lingocellulosic material with HCl than for treated with KOH at pH 6 respectively. It was also found that the time to reach equilibrium takes less than 25 min for both treated materials. The adsorption of basic dye (i.e., ethyl violet or basic violet 4) was carried out by varying some process parameters, such as initial concentration, pH and temperature. The adsorption process can be well described by means of a pseudo-second-order reaction model showing that boundary layer resistance was not the rate-limiting step, as confirmed by intraparticle diffusion since the linear plot of Qt versus t^0.5 did not pass through the origin. In addition, experimental data were accurately expressed by the Sips equation if compared with the Langmuir and Freundlich isotherms. The values of ΔG° and ΔH° confirmed that the adsorption of EV on acid-basic treated forest wast wild carob was spontaneous and endothermic in nature. The positive values of ΔS° suggested an irregular increase of the randomness at the treated lingocellulosic material -solution interface during the adsorption process.

Keywords: adsorption, isotherm models, thermodynamic parameters, wild carob

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11151 Effects of the Food Colour Erythrosine on Thyroid Gland Function in Experimental Rats

Authors: Maha M.Saber, Eitedal Daoud, Moetazza M. Alshafei, Lobna M. Abd El-Latif

Abstract:

Children in the third world consumes many food products colored red like sweets and soft drink without knowing its effect on health or the type of color used in these products Erythrosine (ER,FD & C Red No.3) is one of the most common coloring agent used in these products and in coloring cherry in compotes. The possible adverse effect of erythrosine ER on the thyroid gland function is investigated in albino rats. Forty-five adult male albino rats were divided to three groups two groups will receive ER orally in doses 68 and I36mg/kg respectively. Third group will receive distilled water for three months Sections of thyroid glands were examined for histopathological, morphometric analysis and MIB-I Ki67 (proliferative marker). Serum concentration of triiodothyronine (T3), Thyroxin (T4) and thyrotrophin (TSH) were determined, results showed histological changes in the two treatment groups versus control group in the group with 68mg/kg dose show vaculation of the cytoplasm of follicular cells and pleomorphism of their nuclei. While the other treated group {136mg /kg} showed congestion of blood vessels, hyperplasia of the interstitial cells and increased multilayer of the follicular cells. Highly significant increase in the mean area of the thyroid follicles in both treated groups compared to control group.Erythrosine treated groups showed a very highly significant decrease (P < 0.001) in serum concentration of T3 and T 4 while TSH showed a very highly significant increase versus control.

Keywords: erythrosine, thyroid, morphometrics, proliferative marker

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11150 High Temperature Properties of Diffusion Brazed Joints of in 939 Ni-Base Superalloy

Authors: Hyunki Kang, Hi Won Jeong

Abstract:

The gas turbine operates for a long period of time under harsh, cyclic conditions of high temperature and pressure, where high turbine inlet temperature (TIT) can range from 1273 to 1873K. Therefore, Ni-base superalloys such as IN738, IN939, Rene 45, Rene 71, Rene 80, Mar M 247, CM 247, and CMSX-4 with excellent mechanical properties and resistance to creep, corrosion and oxidation at high temperatures are indeed used. Among the alloying additions for these alloys, aluminum (Al) and titanium (Ti) form gamma prime and enhance the high-temperature properties. However, when crack-damaged high-temperature turbine components such as blade and vane are repaired by fusion welding, they cause cracks. For example, when arc welding is applied to certain superalloys that contain Al and Ti with more than 3 wt.% and T3.5 wt%, respectively, such as IN738, IN939, Rene 80, Mar M 247, and CM 247, aging cracks occur. Therefore, repair technologies using diffusion brazing, which has less heat input into the base material, are being developed. Analysis of microstructural evolution of the brazed joints with a base metal of IN 939 Ni-base superalloy using brazing different filler metals was also carried out using X-ray diffraction, OEM, SEM-EDS, and EPMA. Stress rupture and high-temperature tensile strength properties were also measured to analyze the effects of different brazing heat cycles. The boron amount in the diffusion-affected zone (DAZ) was decreased towards the base metal and the formation of borides at grain boundaries was detected through EPMA.

Keywords: gas turbine, diffusion brazing, superalloy, gas turbine repair

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11149 Thermo-Mechanical Behavior of Steel-Wood Connections of Wooden Structures Under the Effect of a Fire

Authors: Ahmed Alagha, Belkacem Lamri, Abdelhak Kada.

Abstract:

Steel-wood assemblies often have complex geometric configurations whose overall behavior under the effect of a fire is conditioned by the thermal response, by combining the two materials steel and wood, whose thermal characteristics are greatly influenced by high temperatures. The objective of this work is to study the thermal behavior of a steel-wood connection, with or without insulating material, subjected to an ISO834 standard fire model. The analysis is developed by the analytical approach using the Eurocode, and numerically, by the finite element method, through the ANSYS calculation code. The design of the connections is evaluated at room temperature taking the cases of single shear and double shear. The thermal behavior of the connections is simulated in transient state while taking into account the modes of heat transfer by convection and by radiation. The variation of temperature as a function of time is evaluated in different positions of the connections while talking about the heat produced and the formation of the carbon layer. The results relate to the temperature distributions in the connection elements as a function of the duration of the fire. The results of the thermal analysis show that the temperature increases rapidly and reaches more than 260 °C in the steel material for an hour of exposure to fire. The temperature development in wood material is different from that in steel because of its thermal properties. Wood heats up on the outside and burns, its surface can reach very high temperatures in points on the surface.

Keywords: Eurocode 5, finite elements, ISO834, simple shear, thermal behaviour, wood-steel connection

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11148 Evaluating and Prioritizing the Effective Management Factors of Human Resources Empowerment and Efficiency in Manufacturing Companies: A Case Study on Fars’ Livestock and Poultry Manufacturing Companies

Authors: Mohsen Yaghmor, Sima Radmanesh

Abstract:

Rapid environmental changes have been threatening the life of many organizations. Enabling and productivity of human resource should be considered as the most important issue in order to increase performance and ensure survival of the organizations. In this research, the effectiveness of management factory in productivity and inability of human resource have been identified and reviewed at glance. Afterwards, answers were sought to questions "What are the factors effecting productivity and enabling of human resource?" and "What are the priority order based on effective management of human resource in Fars Poultry Complex?". A specified questionnaire has been designed regarding the priorities and effectiveness of the identified factors. Six factors were specified consisting of: individual characteristics, teaching, motivation, partnership management, authority or power submission and job development that have most effect on organization. Then a questionnaire was specified for priority and effect measurement of specified factors that were reached after collecting information and using statistical tests of Keronchbakh alpha coefficient r = 0.792, so that we can say the questionnaire has sufficient reliability. After information analysis of specified six factors by Friedman test their effects were categorized. Measurement on organization respectively consists of individual characteristics, job development or enrichment, authority submission, partnership management, teaching and motivation. Lastly, approaches has been introduced to increase productivity of manpower.

Keywords: productivity, empowerment, enrichment, authority submission, partnership management, teaching, motivation

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11147 Effect of Genotype and Sex on Morphometric Traits of Turkey

Authors: I. O. Dudusola, I. Ogunjimi

Abstract:

This study was carried out to determine the effect of sex and genotype on morphometric traits of turkey (Meleagris gallopavo) in a turkey population. Linear body measurements were taken on 150 turkeys. 70 exotic turkeys which include both males (20) and Females (50) and 80 locally adapted turkeys which include males (30) and females (50). The study was conducted at the Turkey Unit of the Teaching and Research Farm, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria. The linear body measurements taken and recorded were the beak length, head length, neck length, body length, keel length, wingspan, wing length, drumstick, Shank length, toe length, tail length and body girth all taken in centimetres (cm). The recorded variables were analyzed with SAS (2008). Duncan multiple range test was used to detect differences among means. Variation was noted between male and female turkeys in favour of the male turkeys as an expression of sexual dimorphism for all studied traits. The male is found to be significantly higher (p <0.05) than the females for all the morphometric traits measured both for the local and exotic type. The exotic type is found to be significantly higher (p <0.05) than the local type for all the morphometric traits measured. The interaction is higher significantly (p <0.05) in the exotic genotype and in the male sex in relation with the morphometric trait especially in the beak length, neck length, body length, keel length, drumstick, shank length and the toe length.

Keywords: exotic type, linear measurement, local type, morphometric traits, Meleagris gallopavo

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11146 Insufficiency Fracture of Femoral Head in Patients Treated With Intramedullary Nailing for Proximal Femur Fracture

Authors: Jai Hyung Park, Eugene Kim, Jin Hun Park, Min Joon Oh

Abstract:

Introduction: Subchondral insufficiency fracture of the femoral head (SIF) is a rare complication; however, it has been recognized to cause femoral head collapse. Subchondral insufficiency fracture (SIF) is caused by normal or physiological stress without any trauma. It has been reported in osteoporotic patients after the fixation of the proximal femur with an Intramedullary nail. Case presentation: We reported 5 cases with SIF of the femoral head after proximal femur fracture fixation with Intra-medullary nail. All patients had osteoporosis as an underlying disease. Good reduction was achieved in all 5 patients. SIF was found from about 3 months to 4 years after the initial operation, and all the fractures were solidly united at the final diagnosis. We investigated retrospectively the feature of those cases and several factors that affected the occurrence of SIF. Discussion: There are a few discussions regarding the SIF of the femoral head. These discussions may include the predisposing risk factors, how to diagnose the SIF in osteoporotic patients, and the peri-operative factors to prevent SIF. Conclusion: Subchondral insufficiency fracture of the femoral head is a considerable complication after the internal fixation of the proximal femur. There are several factors that can be modified. If they could be controlled in the peri-operative period, SIF could be prevented or handled in advance. Other options related to arthroplasty can be considered in old osteoporotic patients.

Keywords: insufficiency fracture of femoral head, intra-medullary nail, osteoporosis, proximal femur fracture

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11145 Biological Activities of Flaxseed Peptides (Linusorbs)

Authors: Youn Young Shim, Ji Hye Kim, Jae Youl Cho, Martin J. T. Reaney

Abstract:

Flaxseed (Linum usitatissimum L.) is gaining popularity in the food industry as a superfood due to its health-promoting properties. The flax plant synthesizes an array of biologically active cyclic peptides or linusorbs (LOs, a.k.a. cyclolinopeptides) from three or more ribosome-derived precursors. [1–9-NαC]-linusorb B3 and [1–9-NαC]-linusorb B2, suppress immunity, induce apoptosis in human epithelial cancer cell line (Calu-3) cells, and inhibit T-cell proliferation, but the mechanism of LOs action is unknown. Using gene expression analysis in nematode cultures and human cancer cell lines, we have observed that LOs exert their activity, in part, through induction of apoptosis. Specific LOs’ properties include: 1) distribution throughout the body after flaxseed consumption; 2) induce heat shock protein (HSP) 70A production as an indicator of stress and address the issue in Caenorhabditis elegans (exposure of nematode cultures to [1–9-NαC]-linusorb B3 induced a 30% increase in production of the HSP 70A protein); 3) induce apoptosis in Calu-3 cells; and 4) modulate regulatory genes in microarray analysis. These diverse activities indicate that LOs might induce apoptosis in cancer cells or act as versatile platforms to deliver a variety of biologically active molecules for cancer therapy.

Keywords: flaxseed, linusorb, cyclic peptide, orbitides, heat shock protein, apoptosis, anti-cancer

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11144 Numerical Study of Homogeneous Nanodroplet Growth

Authors: S. B. Q. Tran

Abstract:

Drop condensation is the phenomenon that the tiny drops form when the oversaturated vapour present in the environment condenses on a substrate and makes the droplet growth. Recently, this subject has received much attention due to its applications in many fields such as thin film growth, heat transfer, recovery of atmospheric water and polymer templating. In literature, many papers investigated theoretically and experimentally in macro droplet growth with the size of millimeter scale of radius. However few papers about nanodroplet condensation are found in the literature especially theoretical work. In order to understand the droplet growth in nanoscale, we perform the numerical simulation work to study nanodroplet growth. We investigate and discuss the role of the droplet shape and monomer diffusion on drop growth and their effect on growth law. The effect of droplet shape is studied by doing parametric studies of contact angle and disjoining pressure magnitude. Besides, the effect of pinning and de-pinning behaviours is also studied. We investigate the axisymmetric homogeneous growth of 10–100 nm single water nanodroplet on a substrate surface. The main mechanism of droplet growth is attributed to the accumulation of laterally diffusing water monomers, formed by the absorption of water vapour in the environment onto the substrate. Under assumptions of quasi-steady thermodynamic equilibrium, the nanodroplet evolves according to the augmented Young–Laplace equation. Using continuum theory, we model the dynamics of nanodroplet growth including the coupled effects of disjoining pressure, contact angle and monomer diffusion with the assumption of constant flux of water monomers at the far field. The simulation result is validated by comparing with the published experimental result. For the case of nanodroplet growth with constant contact angle, our numerical results show that the initial droplet growth is transient by monomer diffusion. When the flux at the far field is small, at the beginning, the droplet grows by the diffusion of initially available water monomers on the substrate and after that by the flux at the far field. In the steady late growth rate of droplet radius and droplet height follow a power law of 1/3, which is unaffected by the substrate disjoining pressure and contact angle. However, it is found that the droplet grows faster in radial direction than high direction when disjoining pressure and contact angle increase. The simulation also shows the information of computational domain effect in the transient growth period. When the computational domain size is larger, the mass coming in the free substrate domain is higher. So the mass coming in the droplet is also higher. The droplet grows and reaches the steady state faster. For the case of pinning and de-pinning droplet growth, the simulation shows that the disjoining pressure does not affect the droplet radius growth law 1/3 in steady state. However the disjoining pressure modifies the growth rate of the droplet height, which then follows a power law of 1/4. We demonstrate how spatial depletion of monomers could lead to a growth arrest of the nanodroplet, as observed experimentally.

Keywords: augmented young-laplace equation, contact angle, disjoining pressure, nanodroplet growth

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11143 Effect of Friction Pressure on the Properties of Friction Welded Aluminum–Ceramic Dissimilar Joints

Authors: Fares Khalfallah, Zakaria Boumerzoug, Selvarajan Rajakumar, Elhadj Raouache

Abstract:

The ceramic-aluminum bond is strongly present in industrial tools, due to the need to combine the properties of metals, such as ductility, thermal and electrical conductivity, with ceramic properties like high hardness, corrosion and wear resistance. In recent years, some joining techniques have been developed to achieve a good bonding between these materials such as brazing, diffusion bonding, ultrasonic joining and friction welding. In this work, AA1100 aluminum alloy rods were welded with Alumina 99.9 wt% ceramic rods, by friction welding. The effect of friction pressure on mechanical and structural properties of welded joints was studied. The welding was performed by direct friction welding machine. The welding samples were rotated at a constant rotational speed of 900 rpm, friction time of 4 sec, forging strength of 18 MPa, and forging time of 3 sec. Three different friction pressures were applied to 20, 34 and 45 MPa. The three-point bending test and Vickers microhardness measurements were used to evaluate the strength of the joints and investigate the mechanical properties of the welding area. The microstructure of joints was examined by optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that bending strength increased, and then decreased after reaching a maximum value, with increasing friction pressure. The SEM observation shows that the increase in friction pressure led to the appearance of cracks in the microstructure of the interface area, which is decreasing the bending strength of joints.

Keywords: welding of ceramic to aluminum, friction welding, alumina, AA1100 aluminum alloy

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11142 Influence of the Molar Concentration and Substrate Temperature on Fluorine-Doped Zinc Oxide Thin Films Chemically Sprayed

Authors: J. Ramirez, A. Maldonado, M. de la L. Olvera

Abstract:

The effect of both the molar concentration of the starting solution and the substrate temperature on the electrical, morphological, structural and optical properties of chemically sprayed fluorine-doped zinc oxide (ZnO:F) thin films deposited on glass substrates, is analyzed in this work. All the starting solutions employed were aged for ten days before the deposition. The results show that as the molar concentration increases, a decrease in the electrical resistivity values is obtained, reaching the minimum in films deposited from a 0.4 M solution at 500°C. A further increase in the molar concentration leads to a very slight increase in the resistivity. On the other hand, as the substrate temperature is increased, the resistivity decreases and a tendency towards to minimum value is evidenced; taking the molar concentration as parameter, minimum values are reached at 500°C. The attain of ZnO:F thin films, with a resistivity as low as 7.8×10-3 Ώcm (sheet resistance of 130 Ώ/☐ and film thickness of 600 nm) measured in as-deposited films is reported here for the first time. The concurrent effect of the high molar concentration of the starting solution, the substrate temperature values used, and the ageing of the starting solution, which might cause polymerization of the zinc ions with the fluorine species, enhance the electrical properties. The structure of the films is polycrystalline, with a (002) preferential growth. Molar concentration rules the surface morphology as at low concentration an hexagonal and porous structure is developed changing to a uniform compact and small grain size surface in the films deposited with the high molar concentrations.

Keywords: zinc oxide, chemical spray, thin films, TCO

Procedia PDF Downloads 495
11141 Comparison of Different Techniques to Estimate Surface Soil Moisture

Authors: S. Farid F. Mojtahedi, Ali Khosravi, Behnaz Naeimian, S. Adel A. Hosseini

Abstract:

Land subsidence is a gradual settling or sudden sinking of the land surface from changes that take place underground. There are different causes of land subsidence; most notably, ground-water overdraft and severe weather conditions. Subsidence of the land surface due to ground water overdraft is caused by an increase in the intergranular pressure in unconsolidated aquifers, which results in a loss of buoyancy of solid particles in the zone dewatered by the falling water table and accordingly compaction of the aquifer. On the other hand, exploitation of underground water may result in significant changes in degree of saturation of soil layers above the water table, increasing the effective stress in these layers, and considerable soil settlements. This study focuses on estimation of soil moisture at surface using different methods. Specifically, different methods for the estimation of moisture content at the soil surface, as an important term to solve Richard’s equation and estimate soil moisture profile are presented, and their results are discussed through comparison with field measurements obtained from Yanco1 station in south-eastern Australia. Surface soil moisture is not easy to measure at the spatial scale of a catchment. Due to the heterogeneity of soil type, land use, and topography, surface soil moisture may change considerably in space and time.

Keywords: artificial neural network, empirical method, remote sensing, surface soil moisture, unsaturated soil

Procedia PDF Downloads 357
11140 Fabrication of a New Electrochemical Sensor Based on New Nanostructured Molecularly Imprinted Polypyrrole for Selective and Sensitive Determination of Morphine

Authors: Samaneh Nabavi, Hadi Shirzad, Arash Ghoorchian, Maryam Shanesaz, Reza Naderi

Abstract:

Morphine (MO), the most effective painkiller, is considered the reference by which analgesics are assessed. It is very necessary for the biomedical applications to detect and maintain the MO concentrations in the blood and urine with in safe ranges. To date, there are many expensive techniques for detecting MO. Recently, many electrochemical sensors for direct determination of MO were constructed. The molecularly imprinted polymer (MIP) is a polymeric material, which has a built-in functionality for the recognition of a particular chemical substance with its complementary cavity.This paper reports a sensor for MO using a combination of a molecularly imprinted polymer (MIP) and differential-pulse voltammetry (DPV). Electropolymerization of MO doped polypyrrole yielded poor quality, but a well-doped, nanostructure and increased impregnation has been obtained in the pH=12. Above a pH of 11, MO is in the anionic forms. The effect of various experimental parameters including pH, scan rate and accumulation time on the voltammetric response of MO was investigated. At the optimum conditions, the concentration of MO was determined using DPV in a linear range of 7.07 × 10−6 to 2.1 × 10−4 mol L−1 with a correlation coefficient of 0.999, and a detection limit of 13.3 × 10-8 mol L−1, respectively. The effect of common interferences on the current response of MO namely ascorbic acid (AA) and uric acid (UA) is studied. The modified electrode can be used for the determination of MO spiked into urine samples, and excellent recovery results were obtained. The nanostructured polypyrrole films were characterized by field emission scanning electron microscopy (FESEM) and furrier transforms infrared (FTIR).

Keywords: morphine detection, sensor, polypyrrole, nanostructure, molecularly imprinted polymer

Procedia PDF Downloads 419
11139 Cycleloop Personal Rapid Transit: An Exploratory Study for Last Mile Connectivity in Urban Transport

Authors: Suresh Salla

Abstract:

In this paper, author explores for most sustainable last mile transport mode addressing present problems of traffic congestion, jams, pollution and travel stress. Development of energy-efficient sustainable integrated transport system(s) is/are must to make our cities more livable. Emphasis on autonomous, connected, electric, sharing system for effective utilization of systems (vehicles and public infrastructure) is on the rise. Many surface mobility innovations like PBS, Ride hailing, ride sharing, etc. are, although workable but if we analyze holistically, add to the already congested roads, difficult to ride in hostile weather, causes pollution and poses commuter stress. Sustainability of transportation is evaluated with respect to public adoption, average speed, energy consumption, and pollution. Why public prefer certain mode over others? How commute time plays a role in mode selection or shift? What are the factors play-ing role in energy consumption and pollution? Based on the study, it is clear that public prefer a transport mode which is exhaustive (i.e., less need for interchange – network is widespread) and intensive (i.e., less waiting time - vehicles are available at frequent intervals) and convenient with latest technologies. Average speed is dependent on stops, number of intersections, signals, clear route availability, etc. It is clear from Physics that higher the kerb weight of a vehicle; higher is the operational energy consumption. Higher kerb weight also demands heavier infrastructure. Pollution is dependent on source of energy, efficiency of vehicle, average speed. Mode can be made exhaustive when the unit infrastructure cost is less and can be offered intensively when the vehicle cost is less. Reliable and seamless integrated mobility till last ¼ mile (Five Minute Walk-FMW) is a must to encourage sustainable public transportation. Study shows that average speed and reliability of dedicated modes (like Metro, PRT, BRT, etc.) is high compared to road vehicles. Electric vehicles and more so battery-less or 3rd rail vehicles reduce pollution. One potential mode can be Cycleloop PRT, where commuter rides e-cycle in a dedicated path – elevated, at grade or underground. e-Bike with kerb weight per rider at 15 kg being 1/50th of car or 1/10th of other PRT systems makes it sustainable mode. Cycleloop tube will be light, sleek and scalable and can be modular erected, either on modified street lamp-posts or can be hanged/suspended between the two stations. Embarking and dis-embarking points or offline stations can be at an interval which suits FMW to mass public transit. In terms of convenience, guided e-Bike can be made self-balancing thus encouraging driverless on-demand vehicles. e-Bike equipped with smart electronics and drive controls can intelligently respond to field sensors and autonomously move reacting to Central Controller. Smart switching allows travel from origin to destination without interchange of cycles. DC Powered Batteryless e-cycle with voluntary manual pedaling makes it sustainable and provides health benefits. Tandem e-bike, smart switching and Platoon operations algorithm options provide superior through-put of the Cycleloop. Thus Cycleloop PRT will be exhaustive, intensive, convenient, reliable, speedy, sustainable, safe, pollution-free and healthy alternative mode for last mile connectivity in cities.

Keywords: cycleloop PRT, five-minute walk, lean modular infrastructure, self-balanced intelligent e-cycle

Procedia PDF Downloads 127
11138 Schizosaccharomyces pombe, Saccharomyces cerevisiae Yeasts and Acetic Acid Bacteria in Alcoholic and Acetous Fermentations: Effect on Phenolic Acids of Kei-Apple (Dovyalis caffra L.) Vinegar

Authors: Phillip Minnaar, Neil Jolly, Louisa Beukes, Santiago Benito-Saez

Abstract:

Dovyalis caffra is a tree found on the African continent. Limited information exists on the effect of acetous fermentation on the phytochemicals of Kei-apple fruit. The phytochemical content of vinegars is derived from compounds present in the fruit the vinegar is made of. Kei-apple fruit juice was co-inoculated with Schizosaccharomyces pombe and Saccharomyces cerevisiae to induce alcoholic fermentation (AF). Acetous fermentation followed AF, using an acetic acid bacteria consortium as an inoculant. Juice had the lowest pH and highest total acidity (TA). The wine had the highest pH and vinegars lowest TA. Total soluble solids and L-malic acid decreased during AF and acetous fermentation. Volatile acidity concentration was not different among vinegars. Gallic, syringic, caffeic, p-coumaric, and chlorogenic acids increased during acetous fermentation, whereas ferulic, sinapic, and protocatechuic acids decreased. Chlorogenic acid was the most abundant phenolic acid in both wines and vinegars. It is evident from this investigation that Kei-apple vinegar is a source of plant-derived phenolics, which evolved through fermentation. However, the AAB selection showed minimal performance with respect to VA production. Acetic acid bacteria selection for acetous fermentation should be reconsidered, and the reasons for the decrease of certain phenolic acids during acetous fermentation needs to be investigated.

Keywords: acetic acid bacteria, acetous fermentation, liquid chromatography, phenolic acids

Procedia PDF Downloads 146
11137 Dielectric Properties in Frequency Domain of Main Insulation System of Printed Circuit Board

Authors: Xize Dai, Jian Hao, Claus Leth Bak, Gian Carlo Montanari, Huai Wang

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Printed Circuit Board (PCB) is a critical component applicable to power electronics systems, especially for high-voltage applications involving several high-voltage and high-frequency SiC/GaN devices. The insulation system of PCB is facing more challenges from high-voltage and high-frequency stress that can alter the dielectric properties. Dielectric properties of the PCB insulation system also determine the electrical field distribution that correlates with intrinsic and extrinsic aging mechanisms. Hence, investigating the dielectric properties in the frequency domain of the PCB insulation system is a must. The paper presents the frequency-dependent, temperature-dependent, and voltage-dependent dielectric properties, permittivity, conductivity, and dielectric loss tangents of PCB insulation systems. The dielectric properties mechanisms associated with frequency, temperature, and voltage are revealed from the design perspective. It can be concluded that the dielectric properties of PCB in the frequency domain show a strong dependence on voltage, frequency, and temperature. The voltage-, frequency-, and temperature-dependent dielectric properties are associated with intrinsic conduction behavior and polarization patterns from the perspective of dielectric theory. The results may provide some reference for the PCB insulation system design in high voltage, high frequency, and high-temperature power electronics applications.

Keywords: electrical insulation system, dielectric properties, high voltage and frequency, printed circuit board

Procedia PDF Downloads 83
11136 Characterization of Bio-Inspired Thermoelastoplastic Composites Filled with Modified Cellulose Fibers

Authors: S. Cichosz, A. Masek

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A new cellulose hybrid modification approach, which is undoubtedly a scientific novelty, is introduced. The study reports the properties of cellulose (Arbocel UFC100 – Ultra Fine Cellulose) and characterizes cellulose filled polymer composites based on an ethylene-norbornene copolymer (TOPAS Elastomer E-140). Moreover, the approach of physicochemical two-stage cellulose treatment is introduced: solvent exchange (to ethanol or hexane) and further chemical modification with maleic anhydride (MA). Furthermore, the impact of the drying process on cellulose properties was investigated. Suitable measurements were carried out to characterize cellulose fibers: spectroscopic investigation (Fourier Transform Infrared Spektrofotometer-FTIR, Near InfraRed spectroscopy-NIR), thermal analysis (Differential scanning calorimetry, Thermal gravimetric analysis ) and Karl Fischer titration. It should be emphasized that for all UFC100 treatments carried out, a decrease in moisture content was evidenced. FT-IR reveals a drop in absorption band intensity at 3334 cm-1, the peak is associated with both –OH moieties and water. Similar results were obtained with Karl Fischer titration. Based on the results obtained, it may be claimed that the employment of ethanol contributes greatly to the lowering of cellulose water absorption ability (decrease of moisture content to approximately 1.65%). Additionally, regarding polymer composite properties, crucial data has been obtained from the mechanical and thermal analysis. The highest material performance was noted in the case of the composite sample that contained cellulose modified with MA after a solvent exchange with ethanol. This specimen exhibited sufficient tensile strength, which is almost the same as that of the neat polymer matrix – in the region of 40 MPa. Moreover, both the Payne effect and filler efficiency factor, calculated based on dynamic mechanical analysis (DMA), reveal the possibility of the filler having a reinforcing nature. What is also interesting is that, according to the Payne effect results, fibers dried before the further chemical modification are assumed to allow more regular filler structure development in the polymer matrix (Payne effect maximum at 1.60 MPa), compared with those not dried (Payne effect in the range 0.84-1.26 MPa). Furthermore, taking into consideration the data gathered from DSC and TGA, higher thermal stability is obtained in case of the materials filled with fibers that were dried before the carried out treatments (degradation activation energy in the region of 195 kJ/mol) in comparison with the polymer composite samples filled with unmodified cellulose (degradation activation energy of approximately 180 kJ/mol). To author’s best knowledge this work results in the introduction of a novel, new filler hybrid treatment approach. Moreover, valuable data regarding the properties of composites filled with cellulose fibers of various moisture contents have been provided. It should be emphasized that plant fiber-based polymer bio-materials described in this research might contribute significantly to polymer waste minimization because they are more readily degraded.

Keywords: cellulose fibers, solvent exchange, moisture content, ethylene-norbornene copolymer

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11135 Is Brain Death Reversal Possible in Near Future: Intrathecal Sodium Nitroprusside (SNP) Superfusion in Brain Death Patients=The 10,000 Fold Effect

Authors: Vinod Kumar Tewari, Mazhar Husain, Hari Kishan Das Gupta

Abstract:

Background: Primary or secondary brain death is also accompanied with vasospasm of the perforators other than tissue disruption & further exaggerates the anoxic damage, in the form of neuropraxia. In normal conditions the excitatory impulse propagates as anterograde neurotransmission (ANT) and at the level of synapse, glutamate activates NMDA receptors on postsynaptic membrane. Nitric oxide (NO) is produced by Nitric oxide Synthetase (NOS) in postsynaptic dendride or cell body and travels backwards across a chemical synapse to bind to the axon terminal of a presynaptic neuron for regulation of ANT this process is called as the retrograde neurotransmission (RNT). Thus the primary function of NO is RNT and the purpose of RNT is regulation of chemical neurotransmission at synapse. For this reason, RNT allows neural circuits to create feedback loops. The haem is the ligand binding site of NO receptor (sGC) at presynaptic membrane. The affinity of haem exhibits > 10,000-fold excess for NO than Oxygen (THE 10,000 FOLD EFFECT). In pathological conditions ANT, normal synaptic activity including RNT is absent. NO donors like sodium nitroprusside (SNP) releases NO by activating NOS at the level of postsynaptic area. NO now travels backwards across a chemical synapse to bind to the haem of NO receptor at axon terminal of a presynaptic neuron as in normal condition. NO now acts as impulse generator (at presynaptic membrane) thus bypasses the normal ANT. Also the arteriolar perforators are having Nitric Oxide Synthetase (NOS) at the adventitial side (outer border) on which sodium nitroprusside (SNP) acts; causing release of Nitric Oxide (NO) which vasodilates the perforators causing gush of blood in brain’s tissue and reversal of brain death. Objective: In brain death cases we only think for various transplantations but this study being a pilot study reverses some criteria of brain death by vasodilating the arteriolar perforators. To study the effect of intrathecal sodium nitroprusside (IT SNP) in cases of brain death in which: 1. Retrograde transmission = assessed by the hyperacute timings of reversal 2. The arteriolar perforator vasodilatation caused by NO and the maintenance of reversal of brain death reversal. Methods: 35 year old male, who became brain death after head injury and has not shown any signs of improvement after every maneuver for 6 hours, a single superfusion done by SNP via transoptic canal route for quadrigeminal cistern and cisternal puncture for IV ventricular with SNP done. Results: He showed spontaneous respiration (7 bouts) with TCD studies showing start of pulsations of various branches of common carotid arteries. Conclusions: In future we can give this SNP via transoptic canal route and in IV ventricle before declaring the body to be utilized for transplantations or dead or in broader way we can say that in near future it is possible to revert back from brain death or we have to modify our criterion.

Keywords: brain death, intrathecal sodium nitroprusside, TCD studies, perforators, vasodilatations, retrograde transmission, 10, 000 fold effect

Procedia PDF Downloads 399