Search results for: mechanical heart valve

Authors: Rhodine Hickman, Craig Wylie, Michael G. McCaul

Abstract:

Introduction: The World Health Organisation has called on governments around the world to recognise emergency conditions as a global public health problem and respond with appropriate steps for effective preventative strategies. However, to understand the magnitude of the problem, good quality epidemiological data is required. This is especially challenging in low and middle-income countries, where routine data is scarce, specifically within the prehospital setting. Methods: We conducted a retrospective cross-sectional study of a national prehospital private sector EMS database. The database being the property of ER24 (private Emergency Medical Services (EMS) company in South Africa) contains claims submitted by the majority of ambulance services in South Africa during the period between 1 January 2008 to 28 March 2017. We used descriptive statistics and control charts to describe the data using STATA 14. Results: 299,257 calls were included in the analysis. The top clinical conditions requiring ambulance transport were transport accidents (10% of total call volume) and ischaemic heart disease (4.4%). The number of transport accidents consistently increased between 2009 and 2014 and reached beyond the limit for normal variation in 2015. Victims of transport accidents required basic life support services 60% of the time with 80% of injuries being minor to moderate. The frequency of ischaemic heart disease had a steady incline from 2011 to 2016. Advanced life support services were required about 50% of the time, with 60% of patients needing urgent care. Conclusion: Transport accidents, followed by ischaemic heart disease, are the most prevalent conditions in South African private EMS. There is a potential to address these conditions by developing the capacity of low and mid-level providers in trauma and advanced EMS providers in ischaemic heart disease.

Keywords: emergency care, emergency medicine, prehospital providers, South Africa

Procedia PDF Downloads 148

Authors: Gehan Hussein, Hams Ahmad, Baher Matta, Yasmeen Mansi, Mohamad Fawzi

Abstract:

Background: Congenital heart disease (CHD) is a common problem worldwide with variable incidence in different countries. The exact etiology is unknown, suggested to be multifactorial. We aimed to study the incidence of various CHD in a neonatal intensive care unit (NICU) in a tertiary care hospital in Egypt and the possible associations with variable risk factors. Methods: Prospective study was conducted over a period of one year (2013 /2014) at NICU KasrAlAini School of Medicine, Cairo University. Questionnaire about possible maternal and/or paternal risk factors for CHD, clinical examination, bedside echocardiography were done. Cases were classified into groups: group 1 without CHD and group 2 with CHD. Results: from 723 neonates admitted to NICU, 180 cases were proved to have CHD, 58 % of them were males. patent ductus arteriosus(PDA) was the most common CHD (70%), followed by an atrial septal defect (ASD8%), while Fallot tetralogy and single ventricle were the least common (0.45 %) for each. CHD was found in 30 % of consanguineous parents Maternal age ≥ 35 years at the time of conception was associated with increased incidence of PDA (p= 0.45 %). Maternal diabetes and insulin intake were significantly associated with cases of CHD (p=0.02 &0.001 respectively), maternal hypertension and hypothyroidism were both associated with VSD, but the difference did not reach statistical significance (P=0.36 &0.44respectively). Maternal passive smoking was significantly associated with PDA (p=0.03). Conclusion: The most frequent CHD in the studied population was PDA, followed by ASD. Maternal conditions as diabetes was associated with VSD occurrence.

Keywords: NICU, risk factors, congenital heart disease, echocardiography

Procedia PDF Downloads 154

Authors: Magdy Abouzeid

Abstract:

Objectives: The aim of this study was to examine the influence of Monofin training, 36 weeks, 6 times per week, 90 min/unit on left ventricular performance in elite Egyptian Monofin athletes. Background: The elite athletes are one who has superior athletic talent. Monofin swimming already provide the most efficient way of swimming for human being, it is an aquatics sport practice on the surface or under water. Methods :To study these effects,14 elite Monofin children(3 girls and 11boys) aged(11.95± 1.09yr) HT (153.07± 4.2 cm) , WT(52.4 ± 3.7 kg ) , body surface area (BSA.m2 1.48 ± 5.6 m2 ) took part in long-term Monofin Training(LTMT).All subjects underwent two-dimension and M-mode Echordiography at rest before and after(LTMT). Results: There was significant difference (P < 0.01) and percentage improvement for all echocardiography parameter after (LTMT). Inter ventricular septal thickness in diastole and in systole increased by 27.9 % and 42.75 %. Left ventricular end systolic dimension and diastole increased by 16.81 % and 42.7 % respectively. Posterior wall thickness in systole was very highly increased by 283.3 % and in diastole increased by 51.78 %. Left ventricular mass in diastole and in systole increased by 44.8 % and 40.1 % respectively. Stroke volume and resting heart rate (HR) significant changed (sv) 25 %, (HR) 14.7 %. Conclusion: Monofin training is an effective sport to enhance ‘Heart athlete's’ for children, because the unique swim fin tool and create propulsion and overcome resistance. Further researches are needed to determine the effects of Monofin training on right ventricular in child athletes.

Keywords: prepubertal, monofin training, heart athlete's, elite child athlete, echocardiography

Procedia PDF Downloads 291

Authors: Priyashri Kamlesh Sridhar, Suranga Nanayakkara

Abstract:

Current frameworks in assessment follow lesson delivery and rely heavily on test performance or teacher’s observations. This, however, neglects the underlying cognitive load during the learning process. Identifying the pivotal points when the load occurs helps design effective pedagogies and tools that respond to learners’ cognitive state. There has been limited research on quantifying cognitive load in preschoolers, real-time. In this study, we recorded electrodermal activity and heart rate variability (HRV) from 10 kindergarteners performing executive function tasks and Johnson Woodcock test of cognitive abilities. Preliminary findings suggest that there are indeed sensitive task-dependent markers in skin conductance (number of SCRs and average amplitude of SCRs) and HRV (mean heart rate and low frequency component) captured during the learning process.

Keywords: early childhood, learning, methodologies, pedagogies

Procedia PDF Downloads 296

Authors: Feng Ji Mervin Goh, Edmund Chee Jian Pua, Stuart Alexander Cook

Abstract:

Dilated cardiomyopathy (DCM) is a common cause of heart failure. Genetic mutations account for 50% of DCM cases with TTN mutations being the most common, accounting for up to 25% of DCM cases. However, the genetic architecture underlying Asian DCM patients is unknown. We evaluated 68 patients (female= 17) with DCM who underwent follow-up at the National Heart Centre, Singapore from 2013 through 2014. Clinical data were obtained and analyzed retrospectively. Genomic DNA was subjected to next-generation targeted sequencing. Nextera Rapid Capture Enrichment was used to capture the exons of a panel of 169 cardiac genes. DNA libraries were sequenced as paired-end 150-bp reads on Illumina MiSeq. Raw sequence reads were processed and analysed using standard bioinformatics techniques. The average age of onset of DCM was 46.1±10.21 years old. The average left ventricular ejection fraction (LVEF), left ventricular diastolic internal diameter (LVIDd), left ventricular systolic internal diameter (LVIDs) were 26.1±11.2%, 6.20±0.83cm, and 5.23±0.92cm respectively. The frequencies of mutations in major DCM-associated genes were as follows TTN (5.88% vs published frequency of 20%), LMNA (4.41% vs 6%), MYH7 (5.88% vs 4%), MYH6 (5.88% vs 4%), and SCN5a (4.41% vs 3%). The average callability at 10 times coverage of each major gene were: TTN (99.7%), LMNA (87.1%), MYH7 (94.8%), MYH6 (95.5%), and SCN5a (94.3%). In conclusion, TTN mutations are not common in Singaporean DCM patients. The frequencies of other major DCM-associated genes are comparable to frequencies published in the current literature.

Keywords: heart failure, dilated cardiomyopathy, genetics, next-generation sequencing

Procedia PDF Downloads 220

Authors: Reza Behmanesh, Mohammad Nasrolahzadeh-Masouleh, Ehsan Khaksar, Saeed Bokaie

Abstract:

Domestic rabbits (Oryctolagus cuniculus) are an excellent model for cardiovascular research because the size of these animals is more suitable for study and experimentation than smaller animals. One of the most important diagnostic imaging methods is echocardiography, which is used today to evaluate the anatomical and functional cardiovascular system and is one of the most accurate and sensitive non-invasive methods for examining heart disease. Ventricular function indices can be assessed with cardiac imaging techniques. One of these important cardiac parameters is the ejection fraction (EF), which has a valuable place along with other involved parameters. EF is a measure of the percentage of blood that comes out of the heart with each contraction. For this study, 100 adult and young standard domestic rabbits, six months to one year old and of both sexes (50 female and 50 male rabbits) without anesthesia and sedation were used. In this study, the mean EF in domestic rabbits studied in males was 58.753 ± 6.889 and in females, 61.397 ± 6.530, which are comparable to the items mentioned in the valid books and the average size of EF measured in this study; there is no significant difference between this research and other research. There was no significant difference in the percentage of EF between most weight groups, but there was a significant difference (p < 0.05) in weight groups (2161–2320 g and 2481–2640 g). Echocardiographic EF reference values for domestic rabbits (Oryctolagus cuniculus) non-anesthetized are presented, providing reference values for future studies.

Keywords: echocardiography, ejection fraction, rabbit, heart

Procedia PDF Downloads 68

Authors: Aysan Esgandanian, Sabalan Daneshvar

Abstract:

The study is done to determine the comparison between proportional-integral-derivative controller (PID controller) and tilt-integral-derivative (TID controller) for cardiac pacemaker systems, which can automatically control the heart rate to accurately track a desired preset profile. The controller offers good adaption of heart to the physiological needs of the patient. The parameters of the both controllers are tuned by particle swarm optimization (PSO) algorithm which uses the integral of time square error as a fitness function to be minimized. Simulation results are performed on the developed cardiovascular system of humans and results demonstrate that the TID controller produces superior control performance than PID controllers. In this paper, all simulations were performed in Matlab.

Keywords: integral of time square error, pacemaker systems, proportional-integral-derivative controller, PSO algorithm, tilt-integral-derivative controller

Procedia PDF Downloads 434

Authors: Munir Tasdemir

Abstract:

Polymer/clay composites have received great attention in the past three decades owing to their light weight coupled with significantly better mechanical and barrier properties than the corresponding neat polymer resins. An investigation was carried out on the effects of red mud powder size and ratio on the mechanical and thermal properties of polypropylene /red mud polymer composites. Red mud, in four different concentrations (0, 10, 20 and 30 wt %) and three different powder size (180, 63 and 38 micron) were added to PP to produce composites. The mechanical properties, including the elasticity modulus, tensile & yield strength, % elongation, hardness, Izod impact strength and the thermal properties including the melt flow index, heat deflection temperature and vicat softening point of the composites were investigated. The structures of the composites were investigated by scanning electron microscopy and compared to mechanical and thermal properties as a function of red mud powder content and size.

Keywords: polypropylene, powder, red mud, mechanical properties

Procedia PDF Downloads 299

Authors: Yi Jen Wang, Yu Ju Chen

Abstract:

Background: Heart rate variability (HRV) biofeedback can promote autonomic nervous function, sleep quality and reduce psychological stress. In HRV biofeedback training, it is hoped that through the guidance of machine video or audio, the patient can breathe slowly according to his own heart rate changes so that the heart and lungs can achieve resonance, thereby promoting the related effects of autonomic nerve function; while, it is also pointed out that if slow breathing of 6 times per minute can also guide the case to achieve the effect of cardiopulmonary resonance. However, there is no relevant research to explore the comparison of the effectiveness of cardiopulmonary resonance by using video or audio HRV biofeedback training and metronome-guided slow breathing. Purpose: To compare the promotion of autonomic nervous function performance between using HRV biofeedback and slow breathing guided by a metronome. Method: This research is a kind of experimental design with convenient sampling; the cases are randomly divided into the heart rate variability biofeedback training group and the slow breathing training group. The HRV biofeedback training group will conduct HRV biofeedback training in a four-week laboratory and use the home training device for autonomous training; while the slow breathing training group will conduct slow breathing training in the four-week laboratory using the mobile phone APP breathing metronome to guide the slow breathing training, and use the mobile phone APP for autonomous training at home. After two groups were enrolled and four weeks after the intervention, the autonomic nervous function-related performance was repeatedly measured. Using the chi-square test, student’s t-test and other statistical methods to analyze the results, and use p <0.05 as the basis for statistical significance. Results: A total of 27 subjects were included in the analysis. After four weeks of training, the HRV biofeedback training group showed significant improvement in the HRV indexes (SDNN, RMSSD, HF, TP) and sleep quality. Although the stress index also decreased, it did not reach statistical significance; the slow breathing training group was not statistically significant after four weeks of training, only sleep quality improved significantly, while the HRV indexes (SDNN, RMSSD, TP) all increased. Although HF and stress indexes decreased, they were not statistically significant. Comparing the difference between the two groups after training, it was found that the HF index improved significantly and reached statistical significance in the HRV biofeedback training group. Although the sleep quality of the two groups improved, it did not reach that level in a statistically significant difference. Conclusion: HRV biofeedback training is more effective in promoting autonomic nervous function than slow breathing training, but the effects of reducing stress and promoting sleep quality need to be explored after increasing the number of samples. The results of this study can provide a reference for clinical or community health promotion. In the future, it can also be further designed to integrate heart rate variability biological feedback training into the development of AI artificial intelligence wearable devices, which can make it more convenient for people to train independently and get effective feedback in time.

Keywords: autonomic nervous function, HRV biofeedback, heart rate variability, slow breathing

Procedia PDF Downloads 145

Authors: Belalia Douma Mohammed

Abstract:

The translator must have a wide knowledge of all fields, especially cultural and literary, so that he can enjoy smoothly translating scientific, literary, political, or any oral or written translation without distorting the meaning. so to be a transfer of the entire content, a correct and identical translation that expresses the culture and literature of the mother country. But this has always been an obstacle for any translator, as, for example, a person who translates from Spanish to another language may face the problem of different in speech speed, a difference that appears clearly considering the pronunciation of the Spanish language is more rapid than other languages, and this certrainly will effect the translator’s performance, as also the word “ snowed my heart” in the Arabic language is common and known to the Arabs as it means to make me happy and delight me, but translating it without transferring its culture, for example, to a country like Russia, may mean the cold that causes freezing of the heart, so in this research paper, we aim to research such difficulties and its impacts on translation and interpretation and on translator's performance.

Keywords: interpretation, translation, performance, difficulties, differences

Procedia PDF Downloads 70

Authors: C. H. Jeon, Y. H. Kim, G. A. Lee

Abstract:

Reducing resource consumption and carbon dioxide emission are recognized as urgent issues. One way of resolving these issues is to reduce product weight. Magnesium alloys are considered promising candidates because of their lightness. Various studies have been conducted on using magnesium alloy instead of conventional iron or aluminum in mechanical parts, due to the light weight and superior specific strength of magnesium alloy. However, even stronger magnesium alloys are needed for mechanical parts. One common way to enhance the strength of magnesium alloy is by extruding the ingot. In order to enhance the mechanical properties, magnesium alloy ingot were extruded at various extrusion ratios. Relationship between extrusion ratio and mechanical properties was examined on extruded material of magnesium alloy. And Textures and microstructures of the extruded materials were investigated.

Keywords: extrusion, extrusion ratio, magnesium, mechanical property, lightweight material

Procedia PDF Downloads 470

Authors: Hyun-Kyung Lee, Jehyung Oh, Young Eun Jeong, Hyun-Shik Lee

Abstract:

Perfluoroalkyl compounds (PFCs) are environmental toxicants that persistently accumulate in the human blood. Their widespread detection and accumulation in the environment raise concerns about whether these chemicals might be developmental toxicants and teratogens in the ecosystem. We evaluated and compared the toxicity of PFCs of containing various numbers of carbon atoms (C8-11 carbons) on vertebrate embryogenesis. We assessed the developmental toxicity and teratogenicity of various PFCs. The toxic effects on Xenopus embryos were evaluated using different methods. We measured teratogenic indices (TIs) and investigated the mechanisms underlying developmental toxicity and teratogenicity by measuring the expression of organ-specific biomarkers such as xPTB (liver), Nkx2.5 (heart), and Cyl18 (intestine). All PFCs that we tested were found to be developmental toxicants and teratogens. Their toxic effects were strengthened with increasing length of the fluorinated carbon chain. Furthermore, we produced evidence showing that perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFuDA) are more potent developmental toxicants and teratogens in an animal model compared to the other PFCs we evaluated [perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA)]. In particular, severe defects resulting from PFDA and PFuDA exposure were observed in the liver and heart, respectively, using the whole mount in situ hybridization, real-time PCR, pathologic analysis of the heart, and dissection of the liver. Our studies suggest that most PFCs are developmental toxicants and teratogens, however, compounds that have higher numbers of carbons (i.e., PFDA and PFuDA) exert more potent effects.

Keywords: PFC, xenopus, fetax, development

Procedia PDF Downloads 321

Authors: B. Padmaja, V. V. Rama Prasad, K. V. N. Sunitha, E. Krishna Rao Patro

Abstract:

Stress is a psychological condition that reduces the quality of sleep and affects every facet of life. Constant exposure to stress is detrimental not only for mind but also body. Nevertheless, to cope with stress, one should first identify it. This paper provides an effective method for the cognitive stress level detection by using data provided from a physical activity tracker device Fitbit. This device gathers people’s daily activities of food, weight, sleep, heart rate, and physical activities. In this paper, four major stressors like physical activities, sleep patterns, working hours and change in heart rate are used to assess the stress levels of individuals. The main motive of this system is to use machine learning approach in stress detection with the help of Smartphone sensor technology. Individually, the effect of each stressor is evaluated using logistic regression and then combined model is built and assessed using variants of ordinal logistic regression models like logit, probit and complementary log-log. Then the quality of each model is evaluated using Akaike Information Criterion (AIC) and probit is assessed as the more suitable model for our dataset. This system is experimented and evaluated in a real time environment by taking data from adults working in IT and other sectors in India. The novelty of this work lies in the fact that stress detection system should be less invasive as possible for the users.

Keywords: physical activity tracker, sleep pattern, working hours, heart rate, smartphone sensor

Procedia PDF Downloads 211

Authors: Roshani S. Golhar, Neerajkumar S. Sathawane, Snehal Dongre

Abstract:

Background and objectives: As the, cardiovascular illnesses increasing and becoming cause of mortality worldwide, killing around lot of people each year. Arrhythmia is a type of cardiac illness characterized by a change in the linearity of the heartbeat. The goal of this study is to develop novel deep learning algorithms for successfully interpreting arrhythmia using a single second segment. Because the ECG signal indicates unique electrical heart activity across time, considerable changes between time intervals are detected. Such variances, as well as the limited number of learning data available for each arrhythmia, make standard learning methods difficult, and so impede its exaggeration. Conclusions: The proposed method was able to outperform several state-of-the-art methods. Also proposed technique is an effective and convenient approach to deep learning for heartbeat interpretation, that could be probably used in real-time healthcare monitoring systems

Keywords: electrocardiogram, ECG classification, neural networks, convolutional neural networks, portable document format

Procedia PDF Downloads 42

Authors: Lu Zhao, Yanrong Kang, Lili Guo, Yuan Long, Guidong Xing

Abstract:

Smart watches, as a handy device with rich functionality, has become one of the most popular wearable devices all over the world. Among the various function, the most basic is health monitoring. The monitoring data can be provided as an effective evidence or a clue for the detection of crime cases. For instance, the step counting data can help to determine whether the watch wearer was quiet or moving during the given time period. There is, however, still quite few research on the analysis of human character based on these data. The purpose of this research is to analyze the health monitoring data to distinguish the drinking state from normal state. The analysis result may play a role in cases involving drinking, such as drunk driving. The experiment mainly focused on finding the figures of smart watch health monitoring data that change with drinking and figuring up the change scope. The chosen subjects are mostly in their 20s, each of whom had been wearing the same smart watch for a week. Each subject drank for several times during the week, and noted down the begin and end time point of the drinking. The researcher, then, extracted and analyzed the health monitoring data from the watch. According to the descriptive statistics analysis, it can be found that the heart rate change when drinking. The average heart rate is about 10% higher than normal, the coefficient of variation is less than about 30% of the normal state. Though more research is needed to be carried out, this experiment and analysis provide a thought of the application of the data from smart watches.

Keywords: character analysis, descriptive statistics analysis, drink state, heart rate, smart watch

Procedia PDF Downloads 133

Authors: Saurabh Sharma, Yong Sun, Bruce Vernham

Abstract:

Accurate prediction of NOx emission is a continuous challenge in the field of diesel engine-out emission modeling. Performing experiments for each conditions and scenario cost significant amount of money and man hours, therefore model-based development strategy has been implemented in order to solve that issue. NOx formation is highly dependent on the burn gas temperature and the O₂ concentration inside the cylinder. The current empirical models are developed by calibrating the parameters representing the engine operating conditions with respect to the measured NOx. This makes the prediction of purely empirical models limited to the region where it has been calibrated. An alternative solution to that is presented in this paper, which focus on the utilization of in-cylinder combustion parameters to form a predictive semi-empirical NOx model. The result of this work is shown by developing a fast and predictive NOx model by using the physical parameters and empirical correlation. The model is developed based on the steady state data collected at entire operating region of the engine and the predictive combustion model, which is developed in Gamma Technology (GT)-Power by using Direct Injected (DI)-Pulse combustion object. In this approach, temperature in both burned and unburnt zone is considered during the combustion period i.e. from Intake Valve Closing (IVC) to Exhaust Valve Opening (EVO). Also, the oxygen concentration consumed in burnt zone and trapped fuel mass is also considered while developing the reported model.  Several statistical methods are used to construct the model, including individual machine learning methods and ensemble machine learning methods. A detailed validation of the model on multiple diesel engines is reported in this work. Substantial numbers of cases are tested for different engine configurations over a large span of speed and load points. Different sweeps of operating conditions such as Exhaust Gas Recirculation (EGR), injection timing and Variable Valve Timing (VVT) are also considered for the validation. Model shows a very good predictability and robustness at both sea level and altitude condition with different ambient conditions. The various advantages such as high accuracy and robustness at different operating conditions, low computational time and lower number of data points requires for the calibration establishes the platform where the model-based approach can be used for the engine calibration and development process. Moreover, the focus of this work is towards establishing a framework for the future model development for other various targets such as soot, Combustion Noise Level (CNL), NO₂/NOx ratio etc.

Keywords: diesel engine, machine learning, NOₓ emission, semi-empirical

Procedia PDF Downloads 87

Authors: Huseyin A. Yavasoglu, Yusuf Ziya Tengiz, Ali Göksenli

Abstract:

In this study, an automatic feeding machine for different type and class of bovine animals is designed. Daily nutrition of a bovine consists of grass, corn, straw, silage, oat, wheat and different vitamins and minerals. The amount and mixture amount of each of the nutrition depends on different parameters of the bovine. These parameters are; age, sex, weight and maternity of the bovine, also outside temperature. The problem in a farm is to constitute the correct mixture and amount of nutrition for each animal. Faulty nutrition will cause an insufficient feeding of the animal concluding in an unhealthy bovine. To solve this problem, a new automatic feeding machine is designed. Travelling of the machine is performed by four tires, which is pulled by a tractor. The carrier consists of eight bins, which each of them carries a nutrition type. Capacity of each unit is 250 kg. At the bottom of each chamber is a sensor measuring the weight of the food inside. A funnel is at the bottom of each chamber by which open/close function is controlled by a valve. Each animal will carry a RFID tag including ID on its ear. A receiver on the feeding machine will read this ID and by given previous information by the operator (veterinarian), the system will detect the amount of each nutrition unit which will be given to the selected animal for feeding. In the system, each bin will open its exit gate by the help of the valve under the control of PLC (Programmable Logic Controller). The amount of each nutrition type will be controlled by measuring the open/close time. The exit canals of the bins are collected in a reservoir. To achieve a homogenous nitration, the collected feed will be mixed by a worm gear. Further the mixture will be transported by a help of a funnel to the feeding unit of the animal. The feeding process can be performed in 100 seconds. After feeding of the animal, the tractor pulls the travelling machine to the next animal. By the help of this system animals can be feeded by right amount and mixture of nutrition

Keywords: bovine, feeding, nutrition, transportation, automatic

Procedia PDF Downloads 313

Authors: Lokvendra S. Budania, Yogesh K Gaude, Vamsidhar Chamala

Abstract:

Introduction: Congenitally corrected transposition of great arteries (CCTGA) is a complex congenital heart disease where there are both atrioventricular and ventriculoarterial discordances, usually accompanied by other cardiovascular malformations. Case Report: A 24-year-old primigravida known case of CCTGA at 37 weeks of gestation was referred to our hospital for safe delivery. Her electrocardiogram showed HR-40/pm, echocardiography showed Ejection Fraction of 65% and CCTGA. Temporary pacemaker was inserted by cardiologist in catheterization laboratory, before giving trial of labour in view of complete heart block. She was planned for normal delivery, but emergency Caesarean section was planned due to non-reassuring foetal Cardiotocography Pre-op vitals showed PR-50 bpm with temporary pacemaker, Blood pressure-110/70 mmHg, SpO2-99% on room air. Nil per oral was inadequate. Patency of two peripheral IV cannula checked and left radial arterial line secured. Epidural Anaesthesia was planned, and catheter was placed at L2-L3. Test dose was given, Anaesthesia was provided with 5ml + 5ml of 2% Lignocaine with 25 mcg Fentanyl and further 2.5Ml of 0.5% Bupivacaine was given to achieve a sensory level of T6. Cesarean section was performed and baby was delivered. Cautery was avoided during this procedure. IV Oxytocin (15U) was added to 500 mL of ringer’s lactate. Hypotension was treated with phenylephrine boluses. Patient was shifted to post-operative care unit and later to high dependency unit for monitoring. Post op vitals remained stable. Temporary pacemaker was removed after 24 hours of surgery. Her post-operative period was uneventful and discharged from hospital. Conclusion: Rare congenital cardiac disorders require detail knowledge of pathophysiology and associated comorbidities with the disease. Meticulously planned and carefully titrated neuraxial techniques will be beneficial for such cases.

Keywords: congenitally corrected transposition of great arteries, complete heart block, emergency LSCS, epidural anaesthesia

Procedia PDF Downloads 95

Authors: G. B. Lim, C. H. Jeon, K. H. Jung

Abstract:

General light metal alloys are often developed in the material of transportation equipment such as automobiles and aircraft. Among the light metal alloys, magnesium is the lightest structural material with superior specific strength and many attractive physical and mechanical properties. However, magnesium alloys were difficult to obtain the mechanical properties at warm temperature. The aims of present work were to establish an analytical relation between mechanical properties and plastic flow induced by local indentation. An experimental investigation of the local strain distribution was carried out using a specially designed local indentation equipment in conjunction with ARAMIS based on digital image correlation method.

Keywords: indentation, magnesium, mechanical property, lightweight material, ARAMIS

Procedia PDF Downloads 449

Authors: Wameed Alghazali, Shawn Kenny, Paul J. Van Geel

Abstract:

Settlement of municipal solid waste (MSW) in landfills can be represented by mechanical settlement, which is instantaneous and time-dependent creep components, and biodegradation-induced settlement. Mechanical settlement is governed by the physical characteristics of MSW and the applied overburden pressure. Several research studies used oedometers and different size compression cells to evaluate the primary and mechanical creep compression indices/ratios. However, MSW is known for its heterogeneity, which means data obtained from laboratory testing are not necessary to be a good representation of the mechanical response observed in the field. Furthermore, most of the laboratory tests found in the literature were conducted on shredded samples of MSW to obtain specimens that are suitable for the testing setup. It is believed that shredding MSW samples changes the physical and mechanical properties of the waste. In this study, settlement field data was collected during the filling stage of Ste. Sophie landfill was used to estimate the primary and mechanical creep compression ratios. The field results from Ste. Sophie landfill indicated that both the primary and mechanical creep compression ratios of MSW are not constants but decrease with the increase in the applied vertical stress.

Keywords: mechanical creep compression ratio, municipal solid waste, primary compression ratio, stress level

Procedia PDF Downloads 61

Authors: Jeffri Ramli, Brabha Nagaratnam, Keerthan Poologanathan, Wai Ming Cheung, Thadshajini Suntharalingham

Abstract:

Fiber-reinforced self-compacting concrete (FRSCC) combines the benefits of SCC of high flowability and randomly dispersed short fibres together in one single concrete. Fibres prevent brittle behaviour and improve several mechanical properties of SCC. In this paper, an experimental investigation of the effect of three-dimensional (3D) fibres on the mechanical properties of SCC has been conducted. Seven SCC mixtures, namely SCC with no fibres as a reference mix, and six 3D steel fibre reinforced SCC mixes were prepared. Two different sizes of 3D steel fibres with perimeters of 115 mm and 220 mm at different fibre contents of 1%, 2%, and 3% (by cement weight) were considered. The mechanical characteristics were obtained through compressive, splitting tensile, and flexural strength tests. The test results revealed that the addition of 3D fibres improves the mechanical properties of SCC.

Keywords: self-compacting concrete, three-dimensional steel fibres, mechanical properties, compressive strength, splitting tensile strength, flexural strength

Procedia PDF Downloads 116

Authors: M. Esmailian, M. Shakouri, A. Mottahedi, S. G. Shabestari

Abstract:

Heat treatable aluminium alloys such as 7075 and 7055, because of high strength and low density, are used widely in aircraft industry. For best mechanical properties, T6 heat treatment has recommended for this regards, but this temper treatment is sensitive to corrosion induced and Stress Corrosion Cracking (SCC) damage. For improving this property, the over-aging treatment (T7) applies to this alloy, but it decreases the mechanical properties up to 30 percent. Hence, to increase the mechanical properties, without any remarkable decrease in SCC resistant, Retrogression and Re-Aging (RRA) heat treatment is used. This treatment performs in a relatively short time. In this paper, the RRA heat treatment was applied to 7055 aluminum alloy and then effect of RRA time on the mechanical properties of 7055 has been investigated. The results show that the 40 minute time is suitable time for retrogression of 7055 aluminum alloy and ultimate strength increases up to 625MPa.

Keywords: 7055 Aluminum alloy, mechanical properties, SCC resistance, heat Treatment

Procedia PDF Downloads 401

Authors: Mark P. Mayala, Henry Mayala, Khuzeima Khanbhai

Abstract:

Background: Heart failure has been a rising concern in Tanzania. New drugs have been introduced, including the group of drugs called Angiotensin receptor Neprilysin Inhibitor (ARNI), but due to their high cost, angiotensin-converting enzymes inhibitors (ACEIs) and Angiotensin receptor blockers (ARBs) have been mostly used in Tanzania. However, according to our knowledge, the efficacy comparison of the two groups is yet to be studied in Tanzania. The aim of this study was to compare the efficacy of ACEIs and ARBs among patients with heart failure. Methodology: This was a hospital-based prospective cohort study done at Jakaya Kikwete Cardiac Institution (JKCI), Tanzania, from June to December 2020. Consecutive enrollment was done until fulfilling the inclusion criteria. Clinical details were measured at baseline. We assessed the relationship between ARBs and ACEIs users with N-terminal pro-brain natriuretic peptide (NT pro-BNP) levels at admission and at 1-month follow-up using a chi-square test. A Kaplan-Meier curve was used to estimate the survival time of the two groups. Results: 155 HF patients were enrolled, with a mean age of 48 years, whereby 52.3% were male, and their mean left ventricular ejection fraction (LVEF) was 37.3%. 52 (33.5%) heart failure patients were on ACEIs, 57 (36.8%) on ARBs, and 46 (29.7%) were neither using ACEIs nor ARBs. At least half of the patients did not receive a guideline-directed medical therapy (GDMT), with only 82 (52.9%) receiving a GDMT. A drop in NT pro-BNP levels was observed during admission and at 1-month follow-up on both groups, from 6389.2 pg/ml to 4000.1 pg/ml for ARB users and 5877.7 pg/ml to 1328.2 pg/ml for the ACEIs users. There was no statistical difference between the two groups when estimated by the Kaplan-Meier curve, though more deaths were observed in those who were neither on ACEIs nor ARBs, with a calculated P value of 0.01. Conclusion: This study demonstrates that ACEIs have more efficacy and overall better clinical outcome than ARBs, but this should be taken under the patient-based case, considering the side effects of ACEIs and patients’ adherence.

Keywords: angiotensin converting enzymes inhibitors, angiotensin receptor blockers, guideline direct medical therapy, N-terminal pro-brain natriuretic peptide

Procedia PDF Downloads 53

Authors: G. Kloudova, S. Kozlova, M. Stehlik

Abstract:

Pilots are operating in a high-risk environment rich in potential stressors, which negatively affect aviation safety and the mental health of pilots. In the research conducted, the pilots were offered mental training biofeedback therapy. Biofeedback is an objective tool to measure physiological responses to stress. After only six sessions, all of the pilots tested showed significant differences between their initial condition and their condition after therapy. The biggest improvement was found in decreased heart rate (in 83.3% of tested pilots) and respiration rate (66.7%), which are the best indicators of anxiety states and panic attacks. To incorporate all of the variables, we correlated the measured physiological state of the pilots with their personality traits. Surprisingly, we found a high correlation with peripheral temperature and confidence (0.98) and with heart rate and aggressiveness (0.97). A retest made after a one-year interval showed that in majority of the subjects tested their acquired self-regulation ability had been internalized.

Keywords: aviation, biofeedback, mental workload, performance psychology

Procedia PDF Downloads 216

Authors: M. Zielinski, M. Debowski, P. Rusanowska, A. Glowacka-Gil, M. Zielinska, A. Cydzik-Kwiatkowska, J. Kazimierowicz

Abstract:

Technologies for the micro-biogas plant with heating and mixing systems are presented as a part of the Research Coordination for a Low-Cost Biomethane Production at Small and Medium Scale Applications (Record Biomap). The main objective of the Record Biomap project is to build a network of operators and scientific institutions interested in cooperation and the development of promising technologies in the sector of small and medium-sized biogas plants. The activities carried out in the project will bridge the gap between research and market and reduce the time of implementation of new, efficient technological and technical solutions. Reactor with simultaneously mixing and heating system is a concrete tank with a rectangular cross-section. In the reactor, heating is integrated with the mixing of substrate and anaerobic sludge. This reactor is solution dedicated for substrates with high solids content, which cannot be introduced to the reactor with pumps, even with positive displacement pumps. Substrates are poured to the reactor and then with a screw pump, they are mixed with anaerobic sludge. The pumped sludge, flowing through the screw pump, is simultaneously heated by a heat exchanger. The level of the fermentation sludge inside the reactor chamber is above the bottom edge of the cover. Cover of the reactor is equipped with the screw pump driver. Inside the reactor, an electric motor is installed that is driving a screw pump. The heated sludge circulates in the digester. The post-fermented sludge is collected using a drain well. The inlet to the drain well is below the level of the sludge in the digester. The biogas is discharged from the reactor by the biogas intake valve located on the cover. The technology is very useful for fermentation of lignocellulosic biomass and substrates with high content of dry mass (organic wastes). The other technology is a reactor for micro-biogas plant with a pressure mixing system. The reactor has a form of plastic or concrete tank with a circular cross-section. The effective mixing of sludge is ensured by profiled at 90° bottom of the tank. Substrates for fermentation are supplied by an inlet well. The inlet well is equipped with a cover that eliminates odour release. The introduction of a new portion of substrates is preceded by pumping of digestate to the disposal well. Optionally, digestate can gravitationally flow to digestate storage tank. The obtained biogas is discharged into the separator. The valve supplies biogas to the blower. The blower presses the biogas from the fermentation chamber in such a way as to facilitate the introduction of a new portion of substrates. Biogas is discharged from the reactor by valve that enables biogas removal but prevents suction from outside the reactor.

Keywords: biogas, digestion, heating system, mixing system

Procedia PDF Downloads 121

Authors: Mounir Gaci, Salim Meziani, Atmane Fouathia

Abstract:

The purpose of the present paper is to model the behavior of metal alloy, type TRIP steel (Transformation Induced Plasticity), during solid/solid phase transition. A two-dimensional micromechanical model is implemented in finite element software (ZEBULON) to simulate the martensitic transformation in Fe-Ni-C steel grain under mechanical tensile stress of 250 MPa. The effects of non-uniform grain boundary and the criterion of mechanical shear load on the transformation and on the TRIP value during martensitic transformation are studied. The suggested mechanical criterion is favourable to the influence of the shear phenomenon on the progression of the martensitic transformation (Magee’s mechanism). The obtained results are in satisfactory agreement with experimental ones and show the influence of the grain boundary shape and the chosen mechanical criterion (SMF) on the transformation parameters.

Keywords: martensitic transformation, non-uniform Grain Boundary, TRIP, shear Mechanical force (SMF)

Procedia PDF Downloads 223

Authors: I. Hua Chu, Hsiang-Chi Yu, Hsuan Su

Abstract:

Purpose: To examine the associations between self-determined motivation and physical activity in patients with coronary heart disease (CHD) in a longitudinal study. Methods: Patients with CHD were recruited for this study. Their motivations for exercise were measured by the Behavioral Regulation in Exercise Questionnaire-2 (BREQ-2). Physical activity was assessed using the 7-day physical activity recall questionnaire. Duration and energy expenditure of moderate to vigorous physical activity (MVPA) were used in data analysis. All outcome measures were assessed at baseline and 12 months follow up. Data were analyzed using Pearson correlation analysis and regression analysis. Results: The results of the 45 participants (mean age 60.24 yr; 90.2% male) revealed that there were significant negative correlations between amotivation at baseline and duration (r=-.295, p=.049) and energy expenditure (r=-.300, p=.045) of MVPA at 12 months. In contrast, there were significant positive correlations between calculated relative autonomy index (RAI) at baseline and duration (r=.377, p=.011) and energy expenditure (r=.382, p=.010) of MVPA at 12 months. There was no significant correlation between other subscales of the BREQ-2 and duration or energy expenditure of MVPA. Regression analyses revealed that RAI was a significant predictor of duration (p=.011) and energy expenditure (p=.010) of MVPA at 12 months follow-up. Conclusions: These results suggest that the relative degree of self-determined motivation could predict long-term MVPA behaviors in CHD patients. Physical activity interventions are recommended to target enhancing one’s identified and intrinsic motivation to increase the likelihood of physical activity participation in this population.

Keywords: self-determined motivation, physical activity, coronary heart disease, relative autonomy index (RAI)

Procedia PDF Downloads 403

Authors: Mohammad S. Rouhi, Magdalena Juntikka

Abstract:

Processing of polymer fiber composites has a remarkable influence on their mechanical performance. These mechanical properties are even more influenced when using recycled reinforcement. Therefore, we place particular attention on the evaluation of micromechanical models to estimate the mechanical properties and compare them against the experimental results of the manufactured composites. For the manufacturing process, an epoxy matrix and carbon fiber production cut-offs as reinforcing material are incorporated using a vacuum infusion process. In addition, continuous textile reinforcement in combination with the epoxy matrix is used as reference material to evaluate the kick-down in mechanical performance of the recycled composite. The experimental results show less degradation of the composite stiffness compared to the strength properties. Observations from the modeling also show the same trend as the error between the theoretical and experimental results is lower for stiffness comparisons than the strength calculations. Yet still, good mechanical performance for specific applications can be expected from these materials.

Keywords: composite recycling, carbon fibers, mechanical properties, micromechanics

Procedia PDF Downloads 119

Authors: Nihan Nugay, Nur Cicek Kekec, Kalman Toth, Turgut Nugay, Joseph P. Kennedy

Abstract:

In recent years, polyurethane structures are paving the way for elastomer usage in biology, human medicine, and biomedical application areas. Polyurethanes having a combination of high oxidative and hydrolytic stability and excellent mechanical properties are focused due to enhancing the usage of PUs especially for implantable medical device application such as cardiac-assist. Currently, unique polyurethanes consisting of polyisobutylenes as soft segments and conventional hard segments, named as PIB-based PUs, are developed with precise NCO/OH stoichiometry (∽1.05) for obtaining PIB-based PUs with enhanced properties (i.e., tensile stress increased from ∽11 to ∽26 MPa and elongation from ∽350 to ∽500%). Static and dynamic mechanical properties were optimized by examining stress-strain graphs, self-organization and crystallinity (XRD) traces, rheological (DMA, creep) profiles and thermal (TGA, DSC) responses. Annealing procedure was applied for PIB-based PUs. Annealed PIB-based PU shows ∽26 MPa tensile strength, ∽500% elongation, and ∽77 Microshore hardness with excellent hydrolytic and oxidative stability. The surface characters of them were examined with AFM and contact angle measurements. Annealed PIB-based PU exhibits the higher segregation of individual segments and surface hydrophobicity thus annealing significantly enhances hydrolytic and oxidative stability by shielding carbamate bonds by inert PIB chains. According to improved surface and microstructure characters, greater efforts are focused on analyzing protein adsorption and calcification profiles. In biomedical applications especially for cardiological implantations, protein adsorption inclination on polymeric heart valves is undesirable hence protein adsorption from blood serum is followed by platelet adhesion and subsequent thrombus formation. The protein adsorption character of PIB-based PU examines by applying Bradford assay in fibrinogen and bovine serum albumin solutions. Like protein adsorption, calcium deposition on heart valves is very harmful because vascular calcification has been proposed activation of osteogenic mechanism in the vascular wall, loss of inhibitory factors, enhance bone turnover and irregularities in mineral metabolism. The calcium deposition on films are characterized by incubating samples in simulated body fluid solution and examining SEM images and XPS profiles. PIB-based PUs are significantly more resistant to hydrolytic-oxidative degradation, protein adsorption and calcium deposition than ElastEonTM E2A, a commercially available PDMS-based PU, widely used for biomedical applications.

Keywords: biomedical application, calcification, polyisobutylene, polyurethane, protein adsorption

Procedia PDF Downloads 231

Authors: M. Khlifa, A. Youssef, A. F. Zaed, A. Kraft, V. Arrighi

Abstract:

A series of PS-nanoparticles were prepared by grafting PS from both aggregated silica and colloidally silica using atom-transfer radical polymerisation (ATRP). The mechanical behaviour of the nanocomposites have been examined by differential scanning calorimetry (DSC)and dynamic mechanical thermal analysis (DMTA).

Keywords: ATRP, nanocomposites, polystyrene, reinforcement

Procedia PDF Downloads 592