Search results for: negative binomial death rate

Authors: Yubo Bi, Xiao Chen, Shouxiang Lu

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A kind of gas-fueled burner, named Burning Rate Emulator, was proposed for the purpose of the emulation of condensed fuel recently. The gaseous fuel can be pure combustible fuel gas or blends of gaseous fuel or inert gas. However, this concept was recently proposed without detailed study on the combustion characteristic of fuel blends. In this study, two kinds of common gaseous fuels were selected, propane and acetylene, to provide the combustion heat as well as a large amount of smoke, which widely exists in liquid and solid fuel burning process. A set of experiments were carried out using a gas-fueled burner with a diameter of 8 cm. The total volume flow rate of propane and acetylene was kept at 3 liters per minute. The volume fraction of propane varied from 0% to 100% at interval of 10%. It is found that the flame height increases with propane volume fraction, which may be caused by the increase of heat release rate, as the energy density of propane is larger than that of acetylene. The dimensionless flame height is correlated against dimensionless heat release rate, which shows a power function relationship. The radiation fraction of the flame does not show a monotonic relationship with propane volume fraction. With the increase of propane volume fraction from 0% to 100%, the value of radiation fraction increases first and reach a maximum value around 0.46 at a propane volume fraction of 10%, and then decreases continuously to a value of 0.25 at the propane volume fraction of 100%. The flame radiation is related to the soot in the flame. The trend of the radiation fraction reflects that there may be a synergistic effect of soot formation between propane and acetylene which can be guessed from the significantly high radiation fraction at a propane volume fraction of 10%. This work provides data for combustion of gaseous fuel blends pool fire and also give reference on the design of Burning Rate Emulator.

Keywords: Burning Rate Emulator, fuel blends pool fire, flame height, radiation fraction

Procedia PDF Downloads 228

Authors: Auliya Adzillatin Uzhma, Ismu Rini Dwi Ari, I. Nyoman Suluh Wijaya

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Corporate Social Responsibility (CSR) programme in Pantai Harapan Jaya village is cultivation of mangrove and fishery capital distribution, to achieve the goal the CSR programme needed participation from the society in it. Moeliono in Fahrudin (2011) mentioned that participation from society is based by intrinsic reason from inside people it self and extrinsic reason from the other who related to him or from connection with other people. The fundamental connection who caused more boundaries from action which the organization can do called the social structure. The purpose of this research is to know the form of public participation and the density of the villager and people who is participated in CSR programme. This research use Social Network Analysis method by knew the Rate of Participation and Density. The result of the research is people who is involved in the programme is lived in Dusun Pondok Dua and they work in fisheries field. Rate of Participation is 11,61 and that means people involved in 11 or 12 activites of CSR Programme. The rate of participation of CSR Programme is categorized as high rate participation. The density value from the participant is 0.516 it’s mean that 51.6% of the people that participated is involved in the same step of CSR programme.

Keywords: community participation, social network analysis, corporate social responsibility, urban and regional studies

Procedia PDF Downloads 516

Authors: Azim Khodadadi, Sahar Sadaat Vakili, Ebrahim Babaei

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This study presents a numerical method to optimize the failure rate and repair time of a typical radial distribution system. Failure rate and repair time are effective parameters in customer and energy based indices of reliability. Decrease of these parameters improves reliability indices. Thus, system stability will be boost. The penalty functions indirectly reflect the cost of investment which spent to improve these indices. Constraints on customer and energy based indices, i.e. SAIFI, SAIDI, CAIDI and AENS have been considered by using a new method which reduces optimization algorithm controlling parameters. Imperialist Competitive Algorithm (ICA) used as main optimization technique and particle swarm optimization (PSO), simulated annealing (SA) and differential evolution (DE) has been applied for further investigation. These algorithms have been implemented on a test system by MATLAB. Obtained results have been compared with each other. The optimized values of repair time and failure rate are much lower than current values which this achievement reduced investment cost and also ICA gives better answer than the other used algorithms.

Keywords: imperialist competitive algorithm, failure rate, repair time, radial distribution network

Procedia PDF Downloads 668

Authors: R. Simutis, V. Galvanauskas, D. Levisauskas, J. Repsyte, V. Grincas

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This paper deals with advanced state estimation algorithms for estimation of biomass concentration and specific growth rate in a typical fed-batch biotechnological process. This biotechnological process was represented by a nonlinear mass-balance based process model. Extended Kalman Filter (EKF) and Particle Filter (PF) was used to estimate the unmeasured state variables from oxygen uptake rate (OUR) and base consumption (BC) measurements. To obtain more general results, a simplified process model was involved in EKF and PF estimation algorithms. This model doesn’t require any special growth kinetic equations and could be applied for state estimation in various bioprocesses. The focus of this investigation was concentrated on the comparison of the estimation quality of the EKF and PF estimators by applying different measurement noises. The simulation results show that Particle Filter algorithm requires significantly more computation time for state estimation but gives lower estimation errors both for biomass concentration and specific growth rate. Also the tuning procedure for Particle Filter is simpler than for EKF. Consequently, Particle Filter should be preferred in real applications, especially for monitoring of industrial bioprocesses where the simplified implementation procedures are always desirable.

Keywords: biomass concentration, extended Kalman filter, particle filter, state estimation, specific growth rate

Procedia PDF Downloads 428

Authors: Pawthawala Nancy Manish, Syed Alay Hashim

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A hybrid rocket is a rocket engine which uses propellants in two different states of matter- one is in solid and the other either gas or liquid. A hybrid rocket exhibit advantages over both liquid rockets and solid rockets especially in terms of simplicity, stop-start-restart capabilities, safety and cost. This paper deals the design and development of a hybrid rocket having paraffin wax as solid fuel and liquid oxygen as oxidizer. Due to variation of pressure in combustion chamber there is significantly change in mass flow rate, burning rate and uneven regression along the length of the grain. This project describes the working model of a hybrid propellant rocket motor. We have designed a hybrid rocket thrust chamber based on the predetermined combustion chamber pressure and the properties of hybrid propellant. This project is all ready in working condition with normal oxygen injector. Now we have planned to modify the injector design to improve the combustion property. We will use spray type injector for injecting the oxidizer. This idea will increase the performance followed by the regression rate of the solid fuel. By employing mass conservation law, oxygen mass flux, oxidizer/fuel ratio and regression rate the thrust coefficient can be obtained for our current design. CATIA V5 R20 is our design software for the complete setup. This project is fully based on experimental evaluation and the collection of combustion and flow parameters. The thrust chamber is made of stainless steel and the duration of test is around 15-20 seconds (Maximum). These experiments indicates that paraffin based fuel provides the opportunity to satisfy a broad range of mission requirements for the next generation of the hybrid rocket system.

Keywords: burning rate, liquid oxygen, mass flow rate, paraffin wax and sugar

Procedia PDF Downloads 335

Authors: Hansraj Riteesh Bookun, Emily Maree Stevens, Jarryd Leigh Solomon, Anthony Chan

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Objective: This was a retrospective cross-sectional study evaluating the safety and efficacy of femoral endarterectomy using the eversion technique with transection as opposed to the conventional endarterectomy technique with either vein or synthetic patch arterioplasty. Methods: Between 2010 to mid 2017, 19 patients with mean age of 75.4 years, underwent eversion femoral endarterectomy with transection by a single surgeon. There were 13 males (68.4%), and the comorbid burden was as follows: ischaemic heart disease (53.3%), diabetes (43.8%), stage 4 kidney impairment (13.3%) and current or ex-smoking (73.3%). The indications were claudication (45.5%), rest pain (18.2%) and tissue loss (36.3%). Results: The technical success rate was 100%. One patient required a blood transfusion following bleeding from intraoperative losses. Two patients required blood transfusions from low post operative haemogloblin concentrations – one of them in the context of myelodysplastic syndrome. There were no unexpected returns to theatre. The mean length of stay was 11.5 days with two patients having inpatient stays of 36 and 50 days respectively due to the need for rehabilitation. There was one death unrelated to the operation. Conclusion: The eversion technique with transection is safe and effective with low complication rates and a normally expected length of stay. It poses the advantage of not requiring a synthetic patch. This technique features minimal extraneous dissection as there is no need to harvest vein for a patch. Additionally, future endovascular interventions can be performed by puncturing the native vessel. There is no change to the femoral bifurcation anatomy after this technique. We posit that this is a useful adjunct to the surgeon’s panoply of vascular surgical techniques.

Keywords: endarterectomy, eversion, femoral, vascular

Procedia PDF Downloads 199

Authors: Zatovska T. V., Nesterova N. V., Baranova G. V., Zagorodnya S. D.

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In recent years, biosensor technologies based on the phenomenon of surface plasmon resonance (SPR) are becoming increasingly used in biology and medicine. Their application facilitates exploration in real time progress of binding of biomolecules and identification of agents that specifically interact with biologically active substances immobilized on the biosensor surface (biochips). Special attention is paid to the use of Biosensor analysis in determining the antibody-antigen interaction in the diagnostics of diseases caused by viruses and bacteria. According to WHO, the diseases that are caused by the herpes simplex virus (HSV), take second place (15.8%) after influenza as a cause of death from viral infections. Current diagnostics of HSV infection include PCR and ELISA assays. The latter allows determination the degree of immune response to viral infection and respective stages of its progress. In this regard, the searches for new and available diagnostic methods are very important. This work was aimed to develop Biosensor chip for detection of specific antibodies to HSV-1 in the human blood serum. The proteins of HSV1 (strain US) were used as antigens. The viral particles were accumulated in cell culture MDBK and purified by differential centrifugation in cesium chloride density gradient. Analysis of the HSV1 proteins was performed by polyacrylamide gel electrophoresis and ELISA. The protein concentration was measured using De Novix DS-11 spectrophotometer. The device for detection of antigen-antibody interactions was an optoelectronic two-channel spectrometer ‘Plasmon-6’, using the SPR phenomenon in the Krechman optical configuration. It was developed at the Lashkarev Institute of Semiconductor Physics of NASU. The used carrier was a glass plate covered with 45 nm gold film. Screening of human blood serums was performed using the test system ‘HSV-1 IgG ELISA’ (GenWay, USA). Development of Biosensor chip included optimization of conditions of viral antigen sorption and analysis steps. For immobilization of viral proteins 0.2% solution of Dextran 17, 200 (Sigma, USA) was used. Sorption of antigen took place at 4-8°C within 18-24 hours. After washing of chip, three times with citrate buffer (pH 5,0) 1% solution of BSA was applied to block the sites not occupied by viral antigen. It was found direct dependence between the amount of immobilized HSV1 antigen and SPR response. Using obtained biochips, panels of 25 positive and 10 negative for the content of antibodies to HSV-1 human sera were analyzed. The average value of SPR response was 185 a.s. for negative sera and from 312 to. 1264 a.s. for positive sera. It was shown that SPR data were agreed with ELISA results in 96% of samples proving the great potential of SPR in such researches. It was investigated the possibility of biochip regeneration and it was shown that application of 10 mM NaOH solution leads to rupture of intermolecular bonds. This allows reuse the chip several times. Thus, in this study biosensor chip for detection of specific antibodies to HSV1 was successfully developed expanding a range of diagnostic methods for this pathogen.

Keywords: biochip, herpes virus, SPR

Procedia PDF Downloads 417

Authors: Dawid Przystupski, Agata Gorska, Paulina Rozborska, Weronika Bartosik, Olga Michel, Joanna Rossowska, Anna Szewczyk, Malgorzata Drag-Zalesinska, Jedrzej Gorski, Julita Kulbacka

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Researchers are still looking for an answer to the question which has been fascinating the mankind for generations, specifically – is there life beyond Earth? As long as routine flights to other planets remain beyond our reach, there is a need to find alternative ways to conduct the astrobiological research. It is worth noticing that the part of the Earth’s atmosphere, stratosphere, has been found to show subcosmic environmental conditions, namely temperatures around -50°C, very rarefied air, increased cosmic radiation and the Sun’s ultraviolet radiation. This phenomenon gives rise to the opportunity for the use of stratospheric environment as a research model for the space conditions. Therefore the idea of conducting astrobiological experiments during the stratospheric flights arose. Up to now, the preliminary work in this field included launching balloons containing solely microbiological samples into the stratosphere to figure out if they would be able to survive under the stratospheric conditions. In our study, we take this concept further, sending the human healthy and cancerous cells treated with various compounds to investigate whether these medicines are capable to protect the cells against stratospheric stress. Due to oxidative stress caused by ionizing radiation and temperature shock, we used natural compounds which display antioxidant properties. In this way, we were able to reduce the reactive oxygen species production affecting cells, which results in their death. After-flight laboratory tests of biological samples from the stratosphere have been performed and indicated the most active antioxidants as potential agents which can minimize the harmful impacts of stratospheric conditions, especially radiation and temperature.

Keywords: antioxidants, stratosphere, balloon flight, oxidative stress, cell death, radiation

Procedia PDF Downloads 138

Authors: Stanley Ibuchukwu Onwukwe

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Most reservoir in mature oil fields are vulnerable to challenges of water and/or gas coning as the size of their oil column reduces due to long period of oil production. These often result to low oil production and excessive water and/or gas production. Since over 50 years of oil production in the Niger delta, it is apparent that most of the oil fields in the region have reached their mature stages, thereby susceptible to coning tendencies. As a result of these, a good number of wells have been shut-in and abandoned, with significant amount of oil left unproduced. Analysis of the movement of fluid contacts in the reservoir is a significant aspect of reservoir studies and can assist in the management of coning tendencies and production performance of reservoirs in a mature field. This study, therefore, seeks to evaluate the occurrence of coning through the movement of fluid contacts (GOC and OWC) and determine the critical rate for controlling coning tendencies in mature oil field. This study applies the principle of Nodal analysis to calibrate the thin oil column of a reservoir of a mature field, and was graphically evaluated using the Joshi’s equation of critical rate for gas-oil system and oil-water system respectively. A representative Proxy equation was developed and sensitivity analysis carried out to determine the trend of critical rate as the oil column is been depleted. The result shows the trend in the movement of the GOC and OWC, and the critical rate, beyond which will result in excessive water and gas production, resulting to decreasing oil production from the reservoir. This result of this study can be used as a first pass assessment in the development of mature oil field reservoirs anticipated to experience water and/or gas coning during production.

Keywords: coning, fluid contact movement, mature oil field, oil production

Procedia PDF Downloads 242

Authors: Xingyu Gao, Qiang Wu, Yuanyuan Liu, Yue Yang

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In the era of the knowledge economy, the relationship between scientific knowledge and patents has garnered significant attention. Understanding the intricate interplay between the foundations of science and technological innovation has emerged as a pivotal challenge for both researchers and policymakers. This study establishes a coupled network of artificial intelligence patents based on co-cited scientific papers. Leveraging centrality metrics from network analysis offers a fresh perspective on understanding the influence of information flow and knowledge sharing within the network on patent impact. The study initially obtained patent numbers for 446,890 granted US AI patents from the United States Patent and Trademark Office’s artificial intelligence patent database for the years 2002-2020. Subsequently, specific information regarding these patents was acquired using the Lens patent retrieval platform. Additionally, a search and deduplication process was performed on scientific non-patent references (SNPRs) using the Web of Science database, resulting in the selection of 184,603 patents that cited 37,467 unique SNPRs. Finally, this study constructs a coupled network comprising 59,379 artificial intelligence patents by utilizing scientific papers co-cited in patent backward citations. In this network, nodes represent patents, and if patents reference the same scientific papers, connections are established between them, serving as edges within the network. Nodes and edges collectively constitute the patent coupling network. Structural characteristics such as node degree centrality, betweenness centrality, and closeness centrality are employed to assess the scientific connections between patents, while citation count is utilized as a quantitative metric for patent influence. Finally, a negative binomial model is employed to test the nonlinear relationship between these network structural features and patent influence. The research findings indicate that network structural features such as node degree centrality, betweenness centrality, and closeness centrality exhibit inverted U-shaped relationships with patent influence. Specifically, as these centrality metrics increase, patent influence initially shows an upward trend, but once these features reach a certain threshold, patent influence starts to decline. This discovery suggests that moderate network centrality is beneficial for enhancing patent influence, while excessively high centrality may have a detrimental effect on patent influence. This finding offers crucial insights for policymakers, emphasizing the importance of encouraging moderate knowledge flow and sharing to promote innovation when formulating technology policies. It suggests that in certain situations, data sharing and integration can contribute to innovation. Consequently, policymakers can take measures to promote data-sharing policies, such as open data initiatives, to facilitate the flow of knowledge and the generation of innovation. Additionally, governments and relevant agencies can achieve broader knowledge dissemination by supporting collaborative research projects, adjusting intellectual property policies to enhance flexibility, or nurturing technology entrepreneurship ecosystems.

Keywords: centrality, patent coupling network, patent influence, social network analysis

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Authors: Changyin Zhou

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Ba constructions are a special type of constructions in Chinese. Their syntactic behaviors are closely related to their event structural properties. The existing study which treats the semantic function of Ba as causative meets difficulty in treating the discrepancy between Ba constructions and their corresponding constructions without Ba in expressing causativity. This paper holds that Ba in Ba constructions is a functional category expressing affectedness. The affectedness expressed by Ba can be positive or negative. The functional category Ba expressing negative affectedness has the semantic property of being 'expected'. The precondition of Ba construction is the boundedness of the event concerned. This paper, holding the parallelism between motion events and change-of-state events, proposes a syntactic model based on the notions of boundedness and affectedness, discusses the transformations between Ba constructions and the related resultative constructions, and derivates the various Ba constructions concerned.

Keywords: affectedness, Ba constructions, boundedness, event structure, resultative constructions

Procedia PDF Downloads 421

Authors: Vitaliy Petrov, Natalia Shusharina, Vitaliy Kasymov, Maksim Patrushev, Evgeny Bogdanov

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The leading worldwide death reasons are ischemic heart disease and other cardiovascular illnesses. Generally, the common symptom is high blood pressure. Long-time blood pressure control is very important for the prophylaxis, correct diagnosis and timely therapy. Non-invasive methods which are based on Korotkoff sounds are impossible to apply often and for a long time. Implantable devices can combine longtime monitoring with high accuracy of measurements. The main purpose of this work is to create a real-time monitoring system for decreasing the death rate from cardiovascular diseases. These days implantable electronic devices began to play an important role in medicine. Usually implantable devices consist of a transmitter, powering which could be wireless with a special made battery and measurement circuit. Common problems in making implantable devices are short lifetime of the battery, big size and biocompatibility. In these work, blood pressure measure will be the focus because it’s one of the main symptoms of cardiovascular diseases. Our device will consist of three parts: the implantable pressure sensor, external transmitter and automated workstation in a hospital. The Implantable part of pressure sensors could be based on piezoresistive or capacitive technologies. Both sensors have some advantages and some limitations. The Developed circuit is based on a small capacitive sensor which is made of the technology of microelectromechanical systems (MEMS). The Capacitive sensor can provide high sensitivity, low power consumption and minimum hysteresis compared to the piezoresistive sensor. For this device, it was selected the oscillator-based circuit where frequency depends from the capacitance of sensor hence from capacitance one can calculate pressure. The external device (transmitter) used for wireless charging and signal transmission. Some implant devices for these applications are passive, the external device sends radio wave signal on internal LC circuit device. The external device gets reflected the signal from the implant and from a change of frequency is possible to calculate changing of capacitance and then blood pressure. However, this method has some disadvantages, such as the patient position dependence and static using. Developed implantable device doesn’t have these disadvantages and sends blood pressure data to the external part in real-time. The external device continuously sends information about blood pressure to hospital cloud service for analysis by a physician. Doctor’s automated workstation at the hospital also acts as a dashboard, which displays actual medical data of patients (which require attention) and stores it in cloud service. Usually, critical heart conditions occur few hours before heart attack but the device is able to send an alarm signal to the hospital for an early action of medical service. The system was tested with wireless charging and data transmission. These results can be used for ASIC design for MEMS pressure sensor.

Keywords: MEMS sensor, RF power, wireless data, oscillator-based circuit

Procedia PDF Downloads 589

Authors: S. Benchelha, H. C. Aoudjehane, M. Hakdaoui, R. El Hamdouni, H. Mansouri, T. Benchelha, M. Layelmam, M. Alaoui

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The logistic regression (LR) and multivariate adaptive regression spline (MarSpline) are applied and verified for analysis of landslide susceptibility map in Oudka, Morocco, using geographical information system. From spatial database containing data such as landslide mapping, topography, soil, hydrology and lithology, the eight factors related to landslides such as elevation, slope, aspect, distance to streams, distance to road, distance to faults, lithology map and Normalized Difference Vegetation Index (NDVI) were calculated or extracted. Using these factors, landslide susceptibility indexes were calculated by the two mentioned methods. Before the calculation, this database was divided into two parts, the first for the formation of the model and the second for the validation. The results of the landslide susceptibility analysis were verified using success and prediction rates to evaluate the quality of these probabilistic models. The result of this verification was that the MarSpline model is the best model with a success rate (AUC = 0.963) and a prediction rate (AUC = 0.951) higher than the LR model (success rate AUC = 0.918, rate prediction AUC = 0.901).

Keywords: landslide susceptibility mapping, regression logistic, multivariate adaptive regression spline, Oudka, Taounate

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Authors: Mandlenkosi G. R. Mahlobo, Peter A. Olubambi, Philippe Refait

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The aim of this study was to use voltammetry as a method to understand the behaviour of steel in unsaturated soil in the presence of cathodic protection (CP). Three carbon steel coupons were buried in artificial soil wetted at 65-70% of saturation for 37 days. All three coupons were left at open circuit potential (OCP) for the first seven days in the unsaturated soil before CP, which was only applied on two of the three coupons at the protection potential -0.8 V vs Cu/CuSO₄ for the remaining 30 days of the experiment. Voltammetry was performed weekly on the coupon without CP, while electrochemical impedance spectroscopy (EIS) was performed daily to monitor and correct the applied CP potential from the ohmic drop. Voltammetry was finally performed on the last day on the coupons under CP. All the voltammograms were modeled with mathematical equations in order to compute the electrochemical parameters and subsequently deduced the corrosion rate of the steel coupons. For the coupon without CP, the corrosion rate was determined at 300 µm/y. For the coupons under CP, the residual corrosion rate under CP was estimated at 12 µm/y while the corrosion rate of the coupons, after interruption of CP, was estimated at 25 µm/y. This showed that CP was efficient due to two effects: a direct effect from the decreased potential and an induced effect associated with the increased interfacial pH that promoted the formation of a protective layer on the steel surface.

Keywords: carbon steel, cathodic protection, voltammetry, unsaturated soil, Raman spectroscopy

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Authors: Tobias Schramm, Günther Prokop

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In Germany, the number of road fatalities has been falling since 2010 at a more moderate rate than before. At the same time, the average age of all registered passenger cars in Germany is rising continuously. Studies show that there is a correlation between the age and mileage of passenger cars and the degradation of their chassis components. Various studies show that degraded shock absorbers increase the braking distance of passenger cars and have a negative impact on driving stability. The exact effect of degraded vehicle shock absorbers on road safety is still the subject of research. A shock absorber examination as part of the periodic technical inspection is only mandatory in very few countries. In Germany, there is as yet no requirement for such a shock absorber examination. More comprehensive findings on the effect of degraded shock absorbers on the safety-critical driving dynamics of passenger cars can provide further arguments for the introduction of mandatory shock absorber testing as part of the periodic technical inspection. The specific effect chains of untripped rollover accidents are also still the subject of research. However, current research results show that the high proportion of sport utility vehicles in the vehicle field significantly increases the probability of untripped rollover accidents. The aim of this work is to estimate the effect of degraded twin-tube shock absorbers on the safety-critical tipping and rolling behaviour of passenger cars, which can lead to untripped rollover accidents. A characteristic curve-based five-mass full vehicle model and a semi-physical phenomenological shock absorber model were set up, parameterized and validated. The shock absorber model is able to reproduce the damping characteristics of vehicle twin-tube shock absorbers with oil and gas loss for various excitations. The full vehicle model was validated with steering wheel angle sinus sweep driving maneuvers. The model was then used to simulate steering wheel angle sine and fishhook maneuvers, which investigate the safety-critical tipping and rolling behavior of passenger cars. The simulations were carried out in a realistic parameter space in order to demonstrate the effect of various vehicle characteristics on the effect of degraded shock absorbers. As a result, it was shown that degraded shock absorbers have a negative effect on the tipping and rolling behavior of all passenger cars. Shock absorber degradation leads to a significant increase in the observed roll angles, particularly in the range of the roll natural frequency. This superelevation has a negative effect on the wheel load distribution during the driving maneuvers investigated. In particular, the height of the vehicle's center of gravity and the stabilizer stiffness of the vehicles has a major influence on the effect of degraded shock absorbers on the overturning and rolling behaviour of passenger cars.

Keywords: numerical simulation, safety-critical driving dynamics, suspension degradation, tipping and rolling behavior of passenger cars, vehicle shock absorber

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Authors: Katarína Čurová, Leonard Siegfried, Radka Vargová, Marta Kmeťová, Vladimír Hrabovský

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Introduction: Cytolethal distending toxins (CDTs) represent intracellular acting proteins which interfere with cell cycle of eukaryotic cells. They are produced by Gram-negative bacteria with afinity to mucocutaneous surfaces and could play a role in the pathogenesis of various diseases. CDTs induce DNA damage probably through DNAse activity, which causes cell cycle arrest and leads to further changes (cell distension and death, apoptosis) depending on the cell type. Five subtypes of CDT (I to V) were reported in E. coli. Methods: We examined 252 E. coli strains belonging to four different groups. Of these strains, 57 were isolated from patients with diarrhea, 65 from patients with urinary tract infections (UTI), 65 from patients with sepsis and 65 from patients with other extraintestinal infections (mostly surgical wounds, decubitus ulcers and respiratory tract infections). Identification of these strains was performed by MALDI-TOF analysis and detection of genes encoding CDTs and determination of the phylogenetic group was performed by PCR. Results: In this study, we detected presence of cdt genes in 11 of 252 E. coli strains tested (4,4 %). Four cdt positive E. coli strains were confirmed in group of UTI (6,15 %), three cdt positive E. coli strains in groups of diarrhea (5,3 %) and other extraintestinal infections (4,6 %). The lowest incidence, one cdt positive E. coli strain, was observed in group of sepsis (1,5 %). All cdt positive E. coli strains belonged to phylogenetic group B2. Conclusion: CDT-producing E. coli are isolated in a low percentage from patients with intestinal and extraintestinal infections, including sepsis and our results correspond with these studies. A weak prevalence of cdt genes suggests that CDTs are not major virulence factors but in combination with other virulence factors may increase virulence potential of E. coli. We suppose that all 11 cdt positive E. coli strains represent real pathogens because they belong to the phylogenetic group B2 which is pathogenic lineage for bacteria E. coli.

Keywords: cytolethal distending toxin, E. coli, phylogenetic group, extraintestinal infection, diarrhea

Procedia PDF Downloads 350

Authors: N. Masoudnia, M. Fatahi

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An experimental study of saturated pool boiling on a single artificial nucleation site without and with the application of an electric field on the boiling surface has been conducted. N-pentane is boiling on a copper surface and is recorded with a high speed camera providing high quality pictures and movies. The accuracy of the visualization allowed establishing an experimental bubble growth law from a large number of experiments. This law shows that the evaporation rate is decreasing during the bubble growth, and underlines the importance of liquid motion induced by the preceding bubble. Bubble rise is therefore studied: once detached, bubbles accelerate vertically until reaching a maximum velocity in good agreement with a correlation from literature. The bubbles then turn to another direction. The effect of applying an electric field on the boiling surface in finally studied. In addition to changes of the bubble shape, changes are also shown in the liquid plume and the convective structures above the surface. Lower maximum rising velocities were measured in the presence of electric fields, especially with a negative polarity.

Keywords: single bubbles, electric field, boiling, effect

Procedia PDF Downloads 270

Authors: Xuelin Zhang, Shouxiang Lu, Changhai Li

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The commercial retardant flame polycarbonate samples as the main high speed train interior carriage material with different thicknesses were investigated in Fire Propagation Apparatus with different external heat fluxes under different oxygen concentration from 12% to 40% to study the fire characteristics and quantitatively analyze the ignition time, mass loss rate and heat blockage. The additives of commercial retardant flame polycarbonate were intumescent and maintained a steady height before ignition when heated. The results showed the transformed ignition time (1/t_ig)ⁿ increased linearly with external flux under different oxygen concentration after deducting the heat blockage due to pyrolysis products, the mass loss rate was taken on linearly with external heat fluxes and the slop of the fitting line for mass loss rate and external heat fluxes decreased with the enhanced oxygen concentration and the heat blockage independent on external heat fluxes rose with oxygen concentration increasing. The inquired data as the input of the fire simulation model was the most important to be used to evaluate the fire risk of commercial retardant flame polycarbonate.

Keywords: ignition time, mass loss rate, heat blockage, fire characteristic

Procedia PDF Downloads 282

Authors: Mansur Agzamov, Valery Bersnev, Natalia Ivanova, Istam Agzamov, Timur Khayrullaev, Yulduz Agzamova

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Objectives. Treatment of hypertensive intracerebral hematoma (ICH) is controversial. Advantage of one surgical method on other has not been established. Recent reports suggest a favorable effect of minimally invasive surgery. We conducted a small comparative study of different surgical methods. Methods. We analyzed the result of surgical treatment of 176 patients with intracerebral hematomas at the age from 41 to 78 years. Men were been113 (64.2%), women - 63 (35.8%). Level of consciousness: conscious -18, lethargy -63, stupor –55, moderate coma - 40. All patients on admission and in the dynamics underwent computer tomography (CT) of the brain. ICH was located in the putamen in 87 cases, thalamus in 19, in the mix area in 50, in the lobar area in 20. Ninety seven patients of them had an intraventricular hemorrhage component. The baseline volume of the ICH was measured according to a bedside method of measuring CT intracerebral hematomas volume. Depending on the intervention of the patients were divided into three groups. Group 1 patients, 90 patients, operated open craniotomy. Level of consciousness: conscious-11, lethargy-33, stupor–18, moderate coma -18. The hemorrhage was located in the putamen in 51, thalamus in 3, in the mix area in 25, in the lobar area in 11. Group 2 patients, 22 patients, underwent smaller craniotomy with endoscopic-assisted evacuation. Level of consciousness: conscious-4, lethargy-9, stupor–5, moderate coma -4. The hemorrhage was located in the putamen in 5, thalamus in 15, in the mix area in 2. Group 3 patients, 64 patients, was conducted minimally invasive removal of intracerebral hematomas using the original device (patent of Russian Federation № 65382). The device - funnel cannula - which after the special markings introduced into the hematoma cavity. Level of consciousness: conscious-3, lethargy-21, stupor–22, moderate coma -18. The hemorrhage was located in the putamen in 31, in the mix area in 23, thalamus in 1, in the lobar area in 9. Results of treatment were evaluated by Glasgow outcome scale. Results. The study showed that the results of surgical treatment in three groups depending on the degree of consciousness, the volume and localization of hematoma. In group 1, good recovery observed in 8 cases (8.9%), moderate disability in 22 (24.4%), severe disability - 17 (18.9%), death-43 (47.8%). In group 2, good recovery observed in 7 cases (31.8%), moderate disability in 7 (31.8%), severe disability - 5 (29.7%), death-7 (31.8%). In group 3, good recovery was observed in 9 cases (14.1%), moderate disability-17 (26.5%), severe disability-19 (29.7%), death-19 (29.7%). Conclusions. The method of using cannulae allowed to abandon from open craniotomy of the majority of patients with putaminal hematomas. Minimally invasive technique reduced the postoperative mortality and improves treatment outcomes of these patients.

Keywords: nontraumatic intracerebral hematoma, minimal invasive surgical technique, funnel canula, differentiated surcical treatment

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Authors: Adil Kaval, Digdem Muge Siyez

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With the negative effects of internet use in a person's life, the use of the Internet has become an issue. This subject was mostly considered as internet addiction, and it was investigated. In literature, it is noteworthy that some theoretical models have been proposed to explain the reasons for internet addiction. In addition to these theoretical models, it may be thought that the coping style for stressing events can be a predictor of internet addiction. It was aimed to test with logistic regression the effect of high school students' coping styles on internet addiction levels. Sample of the study consisted of 770 Turkish adolescents (471 girls, 299 boys) selected from high schools in the 2017-2018 academic year in İzmir province. Internet Addiction Test, Coping Scale for Child and Adolescents and a demographic information form were used in this study. The results of the logistic regression analysis indicated that the model of coping styles predicted internet addiction provides a statistically significant prediction of internet addiction. Gender does not predict whether or not to be addicted to the internet. The active coping style is not effective on internet addiction levels, while the avoiding and negative coping style are effective on internet addiction levels. With this model, % 79.1 of internet addiction in high school is estimated. The Negelkerke pseudo R2 indicated that the model accounted for %35 of the total variance. The results of this study on Turkish adolescents are similar to the results of other studies in the literature. It can be argued that avoiding and negative coping styles are important risk factors in the development of internet addiction.

Keywords: adolescents, coping, internet addiction, regression analysis

Procedia PDF Downloads 173

Authors: Louise Bernier

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Under some jurisdictions (including Canada), eligible patients can request and receive medical assistance in dying (MAiD) through lethal injections, inducing their cardiocirculatory death. Those same patients can also wish to donate their organs in the process. If they qualify as organ donors, a clinical and ethical rule called the 'dead donor rule' (DDR) requires the transplant teams to wait after cardiocirculatory death is confirmed, followed by a 'no touch' period (5 minutes in Canada) before they can proceed with organ removal. The medical procedures (lethal injections) as well as the delays associated with the DDR can damage organs (mostly thoracic organs) due to prolonged anoxia. Yet, strong scientific evidences demonstrate that operating differently and reconsidering the DDR would result in more organs of better quality available for transplant. This idea generates discomfort and resistance, but it is also worth considering, especially in a context of chronic shortage of available organs. One option that could be examined for MAiD’ patients who wish and can be organ donors would be to remove vital organs while patients are still alive (and under sedation). This would imply accepting that patient’s death would occur through organ donation instead of lethal injections required under MAiD’ legal rules. It would also mean that patients requesting MAiD and wishing to be organ donors could aspire to donate better quality organs, including their heart, an altruistic gesture that carries important symbolic value for many donors and their families. Following a patient centered approach, our hypothesis is that preventing vital organ donation from a living donor in all circumstance is neither perfectly coherent with how legal mentalities have evolved lately in the field of fundamental rights nor compatible with the clinical and ethical frameworks that shape the landscape in which those complex medical decisions unfold. Through a study of the legal, ethical, and clinical rules in place, both at the national and international levels, this analysis raises questions on the numerous inconsistencies associated with respecting the DDR with patients who have chosen to die through MAiD. We will begin with an assessment of the erosion of certain national legal frameworks that pertain to the sacred nature of the right to life which now also includes the right to choose how one wishes to die. We will then study recent innovative clinical protocols tested in different countries to help address acute organ shortage problems in creative ways. We will conclude this analysis with an ethical assessment of the situation, referring to principles such as justice, autonomy, altruism, beneficence, and non-malfeasance. This study will build a strong argument in favor of starting to allow vital organ donations from living donors in countries where MAiD is already permitted.

Keywords: altruism, autonomy, dead donor rule, medical assistance in dying, non-malfeasance, organ donation

Procedia PDF Downloads 178

Authors: Naveed Ahmad Fazili

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More than 20 human diseases involve the fibrillation of a specific protein/peptide which forms pathological deposits at various sites. Hereditary lysozyme amyloidosis is a systemic disorder which mostly affects liver, spleen and kidney. This conformational disorder is featured by lysozyme fibril formation. In vivo lysozyme fibrillation was simulated under in vitro conditions using a strong denaturant GdHCl at 3M concentration. Sharp decline in the ANS fluorescence intensity compared to the partially unfolded states, almost 20 fold increase in ThT fluorescence intensity, increase in absorbance at 450 nm suggesting turbidity, negative ellipticity peak in the far-UVCD at 217 nm, red shift of 50 nm compared to the native state in congo red assay and appearance of a network of long rope like fibrils in TEM analysis suggested HEWL fibrillation. Anti-fibrillation potency of baicalein against the preformed fibrils of HEWL was investigated following ThT assay in which there was a dose dependent decrease in ThT fluorescence intensity compared to the fibrillar state of HEWL with the maximum effect observed at 150 μM baicalein concentration, loss of negative ellipticity peak in the far-UVCD region, dip in the Rayleigh scattering intensity and absorbance at 350 nm and 450 nm respectively together with a reduction in the density of fibrillar structure in TEM imaging. Thus, it could be suggested that baicalein could prove to be a positive therapeutics for hereditary human lysozyme amyloidosis.

Keywords: amyloid fibrils, baicalein, congo red, negative ellipticity, therapeutics

Procedia PDF Downloads 294

Authors: Kwak, Hyo-Gyung, Gang, Han Gul

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In the context of an increasing need for reliability and safety in concrete structures under blast and impact loading condition, the behavior of concrete under high strain rate condition has been an important issue. Since concrete subjected to impact loading associated with high strain rate shows quite different material behavior from that in the static state, several material models are proposed and used to describe the high strain rate behavior under blast and impact loading. In the process of modelling, in advance, mesh dependency in the used finite element (FE) is the key problem because simulation results under high strain-rate condition are quite sensitive to applied FE mesh size. It means that the accuracy of simulation results may deeply be dependent on FE mesh size in simulations. This paper introduces an improved criterion which can minimize the mesh-dependency of simulation results on the basis of the fracture energy concept, and HJC (Holmquist Johnson Cook), CSC (Continuous Surface Cap) and K&C (Karagozian & Case) models are examined to trace their relative sensitivity to the used FE mesh size. To coincide with the purpose of the penetration test with a concrete plate under a projectile (bullet), the residual velocities of projectile after penetration are compared. The correlation studies between analytical results and the parametric studies associated with them show that the variation of residual velocity with the used FE mesh size is quite reduced by applying a unique failure strain value determined according to the proposed criterion.

Keywords: high strain rate concrete, penetration simulation, failure strain, mesh-dependency, fracture energy

Procedia PDF Downloads 520

Authors: Waqar Ahmad Butt, Gholamreza Vakili Nezhaad, Ali Soud Al Bemani, Yahya Al Wahaibi

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Miscible gas injection processes as secondary recovery methods can be applied to a huge number of mature reservoirs to improve the trapped oil displacement. Successful miscible gas injection processes require an accurate estimation of the minimum miscibility pressure (MMP) to make injection process feasible, economical, and effective. There are several methods of MMP determination like slim tube approach, vanishing interfacial tension and rising bubble apparatus but slim tube is the deployed experimental technique in this study. Slim tube method is assumed to be non-standardized for MMP determination with respect to both operating procedure and design. Therefore, 25 slim tube runs were being conducted with three different coil lengths (12, 18 and 24 m) of constant diameter using three different injection rates (0.08, 0.1 and 0.15 cc/min) to evaluate uniqueness and repeatability of determined MMP. A trend of decrease in MMP with increase in coil length was found. No unique trend was found between MMP and injection rate. Lowest MMP and highest recovery were observed with highest coil length and lowest injection rate. It shows that slim tube measured MMP does not depend solely on interacting fluids characteristics but also affected by used coil selection and injection rate choice. Therefore, both slim tube design and procedure need to be standardized. It is recommended to use lowest possible injection rate and estimated coil length depending upon the distance between injections and producing wells for accurate and reliable MMP determination.

Keywords: coil length, injection rate, minimum miscibility pressure, multiple contacts miscibility

Procedia PDF Downloads 253

Authors: Ghada S. Ellithy, John. W. Murphy, Maureen K. Corcoran

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Erosion rate of soils during a levee or dam overtopping event is a major component in risk assessment evaluation of breach time and downstream consequences. The mechanism and evolution of dam or levee breach caused by overtopping erosion is a complicated process and difficult to measure during overflow due to accessibility and quickly changing conditions. In this paper, the results of a flume erosion tests are presented and discussed. The tests are conducted on a coarse-grained material with a median grain size D50 of 5 mm in a 1-m (3-ft) wide flume under varying flow rates. Each test is performed by compacting the soil mix r to its near optimum moisture and dry density as determined from standard Proctor test in a box embedded in the flume floor. The box measures 0.45 m wide x 1.2 m long x 0.25 m deep. The material is tested several times at varying hydraulic loading to determine the erosion rate after equal time intervals. The water depth, velocity are measured at each hydraulic loading, and the acting bed shear is calculated. A shallow water lidar (SWL) system was utilized to record the progress of soil erodibility and water depth along the scanned profiles of the tested box. SWL is a non-contact system that transmits laser pulses from above the water and records the time-delay between top and bottom reflections. Results from the SWL scans are compared with before and after manual measurements to determine the erosion rate of the soil mix and other erosion parameters.

Keywords: coarse-grained materials, erosion rate, LIDAR system, soil erosion

Procedia PDF Downloads 112

Authors: Tatheer Zahra

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Auxetic materials have counteractive properties due to re-entrant geometry that enables them to possess Negative Poisson’s Ratio (NPR). These materials have better energy absorbing and shock resistance capabilities as compared to conventional positive Poisson’s ratio materials. The re-entrant geometry can be created through 3D printing for convenient application of these materials. This paper investigates the mechanical properties of 3D printed chiral auxetic geometries of various sizes. Small scale samples were printed using an ordinary 3D printer and were tested under compression and tension to ascertain their strength and deformation characteristics. A maximum NPR of -9 was obtained under compression and tension. The re-entrant chiral cell size has been shown to affect the mechanical properties of the re-entrant chiral auxetics.

Keywords: auxetic materials, 3D printing, Negative Poisson’s Ratio, re-entrant chiral auxetics

Procedia PDF Downloads 122

Authors: D. Srinivasacharya, G. Madhava Rao

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In this article, the pulsatile flow of blood flow in bifurcated artery with mild stenosis is investigated. Blood is treated to be a micropolar fluid with constant density. The arteries forming bifurcation are assumed to be symmetric about its axes and straight cylinders of restricted length. As the geometry of the stenosed bifurcated artery is irregular, it is changed to regular geometry utilizing the appropriate transformations. The numerical solutions, using the finite difference method, are computed for the flow rate, the shear stress, and the impedance. The influence of time, coupling number, half of the bifurcated angle and Womersley number on shear stress, flow rate and impedance (resistance to the flow) on both sides of the flow divider is shown graphically. It has been observed that the shear stress and flow rate are increasing with increase in the values of Womersley number and bifurcation angle on both sides of the apex. The shear stress is increasing along the inner wall and decreasing along the outer wall of the daughter artery with an increase in the value of coupling number. Further, it has been noticed that the shear stress, flow rate, and impedance are perturbed largely near to the apex in the parent artery due to the presence of backflow near the apex.

Keywords: micropolar fluid, bifurcated artery, stenosis, back flow, secondary flow, pulsatile flow, Womersley number

Procedia PDF Downloads 192

Authors: Francisco M. Silva

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Technology is evolving, creating an impact on our everyday lives and the telehealth industry. Telehealth encapsulates the provision of healthcare services and information via a technological approach. There are several benefits of using web-based methods to provide healthcare help. Nonetheless, few health and psychological help approaches combine this method with wearable sensors. This paper aims to create an online platform for users to receive self-care help and information using wearable sensors. In addition, researchers developing a similar project obtain a solid foundation as a reference. This study provides descriptions and analyses of the software and hardware architecture. Exhibits and explains a heart rate dynamic and efficient algorithm that continuously calculates the desired sensors' values. Presents diagrams that illustrate the website deployment process and the webserver means of handling the sensors' data. The goal is to create a working project using Arduino compatible hardware. Heart rate sensors send their data values to an online platform. A microcontroller board uses an algorithm to calculate the sensor heart rate values and outputs it to a web server. The platform visualizes the sensor's data, summarizes it in a report, and creates alerts for the user. Results showed a solid project structure and communication from the hardware and software. The web server displays the conveyed heart rate sensor's data on the online platform, presenting observations and evaluations.

Keywords: Arduino, heart rate BPM, microcontroller board, telehealth, wearable sensors, web-based healthcare

Procedia PDF Downloads 126

Authors: T. Bouchabchoub, A. Bendahmane, A. Haouriqui, N. Attou

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This paper presents simulation results of Forex predicting model equations in order to give approximately a prevision of interest rates. First, Hall-Taylor (HT) equations have been used with Taylor rule (TR) to adapt them to European and American Forex Markets. Indeed, initial Taylor Rule equation is conceived for all Forex transactions in every States: It includes only one equation and six parameters. Here, the model has been used with Hall-Taylor equations, initially including twelve equations which have been reduced to only three equations. Analysis has been developed on the following base macroeconomic variables: Real change rate, investment wages, anticipated inflation, realized inflation, real production, interest rates, gap production and potential production. This model has been used to specifically study the impact of an inflation shock on macroeconomic director interest rates.

Keywords: interest rate, Forex, Taylor rule, production, European Central Bank (ECB), Federal Reserve System (FED).

Procedia PDF Downloads 527

Authors: Blessing Igbadumhe

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The continuous long- and short-term delivery of value to customers continues to be the overarching objective of software organizations. Software engineering professionals and organizations face challenges in the maintenance and evolution of software as a result of architectural, technical debt. The issues of architectural, technical debt continue to receive a significant amount of attention because of its important impact on successful system implementation. The cost of doing nothing as far as architectural, technical debt is concerned can be significant both in financial terms and impacts on customers. Different architectural, technical debt issues exist, and this qualitative research design reviewed existing literature on the subject to identify and categorize them. This research intends to contribute to the existing bludgeoning body of knowledge on categorizations and descriptive model of technical debt related issues related to system architecture. The results identify the most common characteristics of architectural and technical debt categories. Raising awareness of the intricacies of architectural and technical debt helps technology stakeholders reduce negative consequences and increase the system success rate.

Keywords: architecture, categorizing TD, system design, technical debt

Procedia PDF Downloads 91