Search results for: type IV pressure vessels

Authors: S. C. Gupta

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The wind flow over several buildings lying in close vicinity in urban areas generates flow interference effects causing problems related to pedestrian comfort and ventilation within the buildings. This promoted a lot of research interest in the recent years. Airflow over a building creates a positive pressure zone on the upstream side and negative pressure zones (cavities or eddy zones) on the roof and all other sides. Large eddy simulation model is used along with sub-grid-scale model to numerically simulate turbulence for this purpose. The basis of flow outside the building is the pressure difference (between the wind and building interior). Wind Tunnel models are fabricated and tested in the subsonic wind tunnel. Theoretical results are compared with the experimental data. Newer configuration is tried for favorable effects in recovering static pressure values. Results obtained are seen very encouraging. The proposed exhaustive research investigation through numerical simulations and the experimental work are described and some interesting findings are brought out.

Keywords: wind flow, buildings, static pressure wind tunnel testing, CFD

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Authors: Shehret Tilvaldyev, Jorge Flores-Garay, Alfredo Villanueva, Erwin Martinez, Lazaro Rico

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The efficiency of modern transportation is severely compromised by the prevalence of turbulent drag. The high level of turbulent skin-friction occurring, e.g., on the surface of an aircraft, automobiles or the carriage of a high-speed train, is responsible for excess fuel consumption and increased carbon emissions. The environmental, political, and economic pressure to improve fuel efficiency and reduce carbon emissions associated with transportation means that reducing turbulent skin-friction drag is a pressing engineering problem. The dynamic pressure of subsonic airflow around solid objects creates lift, but also induces drag force. This paper is presenting the results of laboratory experiments, investigating appearance and magnitude of dynamic pressure in micro scale of subsonic air flow around right cylinder and symmetrical airfoil.

Keywords: airflow, dynamic pressure, micro scale, symmetric object

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Authors: Hashaam Akhtar

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IFNλR1 and IL10R2 collectively construct a heterodimer, which is an acknowledged functional receptor for all type III interferons (IFNs). Expression of IFNλR1 is highly tissue specific, which can help in making type III IFNs a drug of choice as comparable to its analogue, type I IFNs, for treating hepatitis C in the near future. Although, expression of IFNλR1 also varies with the concentration of type I IFNs, but in this study it was shown that the expression of IFNλR1 varies with the protein titers of IFN-α, IFN-λ3 and the newly discovered IFN-λ4. High dosage of IFN-α reduces the expression of IFNλR1 in HepG2 cells, which can affect the antiviral activity of type III IFNs in vivo. We premeditated an experimental strategy to differentiate monocytes into dendritic cells (DCs), type I and type II macrophages in vitro and quantified the expression of the IFNλR1 by qPCR. The exposure of newly discovered IFN-λ4 to macrophages and DCs also raised the expression of its own receptor, which shows that expression of IFN-λ4 protein in hepatitis C patient may augment type I treatment and help ease off viral titers. The results of this study may contribute in some understanding towards the mechanisms involved in the selective expression of IFNLR1 and exceptionalities associated with the receptor.

Keywords: IFNLR1, Interferon Lambda 4 (IFN-λ4), Mononuclear Phagocyte Cells (MPCs), expression

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Authors: Todor Bačkalić, Marinko Maslarić, Milosav Georgijević, Sanja Bojić

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Water transport could be the backbone of the future European combined transport system. The future transport policy in landlocked countries from the Danube Region has to be based on inland waterway transport (IWT). The development of the container transport on inland waterways depends directly on technical-exploitative characteristics of the network of inland waterways. Research of navigational abilities of inland waterways is the basic step in transport planning. The size of the vessel’s draught (T) is the limiting value in project tasks and it depends on the depth of the waterway. Navigation characteristics of rivers have to be determined as precise as possible, especially from the aspect of determination of the possible draught of vessels. This article outlines a rationale, why it is necessary to develop competence about infrastructure risk in water transport. Climate changes are evident and require special attention and global monitoring. Current risk assessment methods for Inland waterway transport just consider some dramatic events. We present a new method for the assessment of risk and vulnerability of inland waterway transport where river depth represents a crucial part. The analysis of water level changes in the lower Danube was done for two significant periods (1965-1979 and 1998-2012).

Keywords: container vessel, draught, probability, the Danube

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Authors: B. Farahani, R. Fadil, A. Aboonabi, B. Hoffmann, J. Loscheider, K. Tavakolian, S. Arzanpour

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Wheelchair users spend long hours in a sitting position, and selecting the right cushion is highly critical in preventing pressure ulcers in that demographic. Pressure mapping systems (PMS) are typically used in clinical settings by therapists to identify the sitting profile and pressure points in the sitting area to select the cushion that fits the best for the users. A PMS is a flexible mat composed of arrays of distributed networks of flexible sensors. The output of the PMS systems is a color-coded image that shows the intensity of the pressure concentration. Therapists use the PMS images to compare different cushions fit for each user. This process is highly subjective and requires good visual memory for the best outcome. This paper aims to develop an image processing technique to analyze the images of PMS and provide an objective measure to assess the cushions based on their pressure distribution mappings. In this paper, we first reviewed the skeletal anatomy of the human sitting area and its relation to the PMS image. This knowledge is then used to identify the important features that must be considered in image processing. We then developed an algorithm based on those features to analyze the images and rank them according to their fit to the users' needs.

Keywords: dynamic cushion, image processing, pressure mapping system, wheelchair

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Authors: Ahmed El-Banbi, Ahmed El-Maraghi

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PVT properties are needed as input data in all reservoir, production, and surface facilities engineering calculations. In the absence of PVT reports on valid reservoir fluid samples, engineers rely on PVT correlations to generate the required PVT data. The accuracy of PVT correlations varies, and no correlation group has been found to provide accurate results for all oil types. The effect of inaccurate PVT data can be significant in engineering calculations and is well documented in the literature. Bubble point pressure can sometimes be obtained from external sources. In this paper, we show how to utilize the known bubble point pressure to improve the accuracy of calculated PVT properties from correlations. We conducted a systematic study using around 250 reservoir oil samples to quantify the effect of pre-knowledge of bubble point pressure. The samples spanned a wide range of oils, from very volatile oils to black oils and all the way to low-GOR oils. A method for shifting both undersaturated and saturated sections of the PVT properties curves to the correct bubble point is explained. Seven PVT correlation families were used in this study. All PVT properties (e.g., solution gas-oil ratio, formation volume factor, density, viscosity, and compressibility) were calculated using the correct bubble point pressure and the correlation estimated bubble point pressure. Comparisons between the calculated PVT properties and actual laboratory-measured values were made. It was found that pre-knowledge of bubble point pressure and using the shifting technique presented in the paper improved the correlation-estimated values by 10% to more than 30%. The most improvement was seen in the solution gas-oil ratio and formation volume factor.

Keywords: PVT data, PVT properties, PVT correlations, bubble point pressure

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Authors: Jacqueline Miller, Dongyuan Y. Wang, F. Dan Richard

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Before trying to make an ethical machine that holds a higher ethical standard than humans, a better understanding of human moral standards that could be used as a guide is crucial. How humans make decisions in dangerous driving situations like moral dilemmas can contribute to developing acceptable ethical principles for autonomous vehicles (AVs). This study uses a driving simulator to investigate whether drivers make utilitarian choices (choices that maximize lives saved and minimize harm) in unavoidable automobile accidents (moral dilemmas) with time pressure manipulated. This study also investigates how impulsiveness influences drivers’ behavior in moral dilemmas. Manipulating time pressure results in collisions that occur at varying time intervals (4 s, 5 s, 7s). Manipulating time pressure helps investigate how time pressure may influence drivers’ response behavior. Thirty-one undergraduates participated in this study using a STISM driving simulator to respond to driving moral dilemmas. The results indicated that the percentage of utilitarian choices generally increased when given more time to respond (from 4 s to 7 s). Additionally, participants in vehicle scenarios preferred responding right over responding left. Impulsiveness did not influence utilitarian choices. However, as time pressure decreased, response time increased. Findings have potential implications and applications on the regulation of driver assistance technologies and AVs.

Keywords: time pressure, automobile moral dilemmas, impulsiveness, reaction time

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Authors: Varun K, Pramod B. Balareddy

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Estimation of wind forces plays a significant role in the in the design of large antenna parabolic reflectors. Reflector surface accuracies are very sensitive to the gain of the antenna system at higher frequencies. Hence accurate estimation of wind forces becomes important, which is primary input for design and analysis of the reflector system. In the present work, numerical simulation of wind flow using Computational Fluid Dynamics (CFD) software is used to investigate the external pressure coefficients. An extensive comparative study has been made between the CFD results and the published wind tunnel data for different wind angle of attacks (α) acting over concave to convex surfaces respectively. Flow simulations using CFD are carried out to estimate the coefficients of Drag, Lift and Moment for the parabolic reflector. Coefficients of pressures (Cp) over the front and the rear face of the reflector are extracted over surface of the reflector to study the net pressure variations. These resultant pressure variations are compared with the published wind tunnel data for different angle of attacks. It was observed from the CFD simulations, both convex and concave face of reflector system experience a band of pressure variations for the positive and negative angle of attacks respectively. In the published wind tunnel data, Pressure variations over convex surfaces are assumed to be uniform and vice versa. Chordwise and spanwise pressure variations were calculated and compared with the published experimental data. In the present work, it was observed that the maximum pressure coefficients for α ranging from +30° to -90° and α=+90° was lower. For α ranging from +45° to +75°, maximum pressure coefficients were higher as compared to wind tunnel data. This variation is due to non-uniform pressure distribution observed over front and back faces of reflector. Variations in Cd, Cl and Cm over α=+90° to α=-90° was in close resemblance with the experimental data.

Keywords: angle of attack, drag coefficient, lift coefficient, pressure coefficient

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Authors: D. R. Masvodza, G. Coetzer, E. van der Watt

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Microorganisms usually have a prolific growth nature and may cause major problems on in-vitro cultures. For in vitro propagation to be successful explants need to be sterile. In order to determine the best sterilization method for potato explants cv. Amerthyst, five sterilization methods were applied separately to 24 shoots. The first sterilization method was the use of 20% sodium hypochlorite with 1 ml Tween 20 for 15 minutes. The second, third and fourth sterilization methods were the immersion of explants in 70% ethanol in a beaker for either 30 seconds, 1 minute or 2 minutes, followed by 1% sodium hypochlorite with 1 ml Tween 20 for 5 minutes. For the control treatment, no chemicals were used. Finally, all the explants were rinsed three times with autoclaved distilled water and trimmed to 1-2 cm. Explants were then cultured on MS medium with 0.01 mg L-1 NAA and 0.1 mg L-1 GA3 and supplemented with 2 mg L-1 D-calcium pentothenate. The trial was laid out as a complete randomized design, and each treatment combination was replicated 24 times. At 7, 14 and 21 days after culture, data on explant color, survival, and presence or absence of contamination was recorded. Best results were obtained when 20% sodium hypochlorite was used with 1 ml Tween 20 for 15 minutes which is sterilization method 1. Method 2 was comparable to method 1 when explants were cultured in glass vessels. Explants in glass vessels were significantly less contaminated than explants in polypropylene vessel. Therefore at times, ideal methods for sterilization should be coupled with ideal culture conditions such as good quality culture vessel, rather than the addition of more stringent sterilants.

Keywords: culture containers, explants, sodium hypochlororite, sterilization

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Authors: Kornanong Yuenyongchaiwat, Duangnate Pepatsitipong, Panthip Sangprasert

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High blood pressure and diabetes have been suggested as being non-communicable disease (NCDs), and there is one of the components of the definition of metabolic syndrome. Therefore, the purpose of this study was to evaluate the effect of a 12-week pedometer based community walking intervention on change in resting blood pressure and blood glucose in participants with overweight in the community setting. Method: Participants were recruited both males and females who had a sedentary lifestyle aged 35-59 years (mean aged 49.67 years). A longitudinal quasi-experimental study was designed with 35 overweight participants who had body mass index ≥ 25 kg/m2. These volunteers were assigned to the 12-week pedometer-based walking program (an accumulated at least 10,000 steps a day). Blood pressure and blood glucose were measured initially before and after 12-week intervention. Results: Systolic blood pressure and heart rate were significantly lower in 30 individuals who had accumulated 10,000 steps d-1 in the intervention group at 12 week follow-up (-13.74 mmHg and 5.3 bpm, respectively). In addition, reduction in blood glucose (-14.89 mmol) in the intervention participants was statistically significant (p < .001). A regression analysis indicated that reductions in systolic blood pressure were significantly related to the increase in steps per day. Conclusion: The accumulation of least 10,000 steps d-1 resulted in decreased resting systolic blood pressure and blood glucose in overweight participants. This has also shown that an increase in physical activity in overweight participants with sedentary lifestyle by accumulating at least 10,000 steps a day can reduce the risk of cardiovascular disease (e.g., hypertension and diabetes).

Keywords: blood glucose, blood pressure, diabetes, hypertension, physical activity, walking

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Authors: Ekpon Oghenetega Philip, Tayire Okabare Favour, Boye Ejobowah Thomas

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The study evaluated the resting systolic blood pressure (RSBP) and resting diastolic blood pressure (RDBP) of staff of a multi-national petroleum company in Nigeria with the aim of helping the staff maintain optimal health which is necessary to carry out their secular work. Eleven healthy male (age 36.9±10.48 years, mean±S.D) and 38 healthy female (39.99±12.23 years, mean±S.D) staff of the multi-national petroleum company performed an incremental exercise on a treadmill and cycle ergometers to determine RSBP and RDBP. An assessment of the health status of the staff of the company was carried out using a physical activity readiness questionnaire (PAR-Q) to determine their suitability for the program. Analysis of the t-test for male staff of RSBP shows that it was statistically significant with a calculated t value of 2.19, α = 0.05 and t-calculated for RSBP of female staff was 1.897, α = 0.05 showing a significance. While the t-calculated RSBP for male staff of the multi-national company is 0.44 with α =0.05 and the female RDBP is 4.129, α = 0.05 and they are all significant. It was recommended that staff of the company should regularly visit the company gym during their leisure hours to maintain optimum health.

Keywords: systolic blood pressure, diastolic blood pressure, exercise, pressure staff

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Authors: Regina Maria M. Castilho, Isabela M. Morita, Ana Carolina T. Malavolta, Maximiliano K. Pagliarini

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An essential factor for flower production is solar radiation, which is part of plant vital processes. As excess as shortage of light can harm the development of the culture leading to loss in product quality, Unfeasible or decreasing their commercial value. The objective of this research was to evaluate different light levels and their influence on Amaryllis (Hippeastrum X hybridum Hort.) development and flowering. The experiment was conducted at UNESP, São Paulo State, Brazil from August to October 2014. The bulbs were placed in black vases of 1.2 L filled with commercial substrate and divided into 4 different lighting environments (treatments): T1–greenhouse, T2–greenhouse with shade cloth (50%), T3–low lights indoor (until 500 lx) and T4–medium lights indoor (between 500–1000 lx). The used design was completely randomized with ten repetitions and three vessels (bulbs), totalling 30 vessels (bulbs) per treatment. The evaluated characteristics were: Chlorophyll content, number of leaves, length of leaf, number of simultaneous rods, rod length, rod diameter, number of flowers, flowers diameter, beginning of flowering and flowering duration. The results showed that in greenhouse provided Amaryllis better quality plants.

Keywords: açucena, bulbs, light, ornamental plants

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Authors: M. Kakavand, S. A. Naeini

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Dynamic properties of soil in small strains, especially for geotechnical engineers, are important for describing the behavior of soil and estimation of the earth structure deformations and structures, especially significant structures. This paper presents the effect of density on the shear modulus and damping ratio of saturated clean sand at various isotropic confining pressures. For this purpose, the specimens were compared with two different relative densities, loose Dr = 30% and dense Dr = 70%. Dynamic parameters were attained from a series of consolidated undrained fixed – free type torsional resonant column tests in small strain. Sand No. 161 is selected for this paper. The experiments show that by increasing sand density and confining pressure, the shear modulus increases and the damping ratio decreases.

Keywords: dynamic properties, shear modulus, damping ratio, clean sand, density, confining pressure, resonant column/torsional simple shear, TSS

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Authors: Yoftahe Nigussie Worku

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This report unveils a meticulous project focused on the design intricacies of a Fire Tube Boiler tailored for the efficient generation of saturated steam. The overarching objective is to produce 2000kg/h of saturated steam at 12-bar design pressure, achieved through the development of an advanced fire tube boiler. This design is meticulously crafted to harmonize cost-effectiveness and parameter refinement, with a keen emphasis on material selection for component parts, construction materials, and production methods throughout the analytical phases. The analytical process involves iterative calculations, utilizing pertinent formulas to optimize design parameters, including the selection of tube diameters and overall heat transfer coefficients. The boiler configuration incorporates two passes, a strategic choice influenced by tube and shell size considerations. The utilization of heavy oil fuel no. 6, with a higher heating value of 44000kJ/kg and a lower heating value of 41300kJ/kg, results in a fuel consumption of 140.37kg/hr. The boiler achieves an impressive heat output of 1610kW with an efficiency rating of 85.25%. The fluid flow pattern within the boiler adopts a cross-flow arrangement strategically chosen for inherent advantages. Internally, the welding of the tube sheet to the shell, secured by gaskets and welds, ensures structural integrity. The shell design adheres to European Standard code sections for pressure vessels, encompassing considerations for weight, supplementary accessories (lifting lugs, openings, ends, manhole), and detailed assembly drawings. This research represents a significant stride in optimizing fire tube boiler technology, balancing efficiency and safety considerations in the pursuit of enhanced saturated steam production.

Keywords: fire tube, saturated steam, material selection, efficiency

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Authors: Indira Kothalanka

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For individuals born with a cleft palate (CP), there is no separation between the nasal cavity and the oral cavity, due to which they cannot build up enough air pressure in the mouth for speech. Therefore, it is common for them to have speech problems. Common cleft type speech errors include abnormal articulation (compensatory or obligatory) and abnormal resonance (hyper, hypo and mixed nasality). These are generally resolved after palate repair. However, in some individuals, articulation problems do persist even after the palate repair. Such individuals develop variant articulations in an attempt to compensate for the inability to produce the target phonemes. A spectrographic analysis is used to investigate the compensatory articulatory behaviours of pressure consonants in the speech of 10 Telugu speaking individuals aged between 7-17 years with a history of cleft palate. Telugu is a Dravidian language which is spoken in Andhra Pradesh and Telangana states in India. It is a language with the third largest number of native speakers in India and the most spoken Dravidian language. The speech of the informants is analysed using single word list, sentences, passage and conversation. Spectrographic analysis is carried out using PRAAT, speech analysis software. The place and manner of articulation of consonant sounds is studied through spectrograms with the help of various acoustic cues. The types of compensatory articulation identified are glottal stops, palatal stops, uvular, velar stops and nasal fricatives which are non-native in Telugu.

Keywords: cleft palate, compensatory articulation, spectrographic analysis, PRAAT

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Authors: Ji-Hoon Byeon, Kwon-Hee Lee

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Strainer filter serves to block the inflow of impurities while mixed fluid is entering or exiting the piping. The filter of the strainer has a perforated structure, so that the pressure drop and the velocity change necessarily occur when the mixed fluid passes through the filter. It is possible to predict the pressure drop and velocity change of the strainer by numerical analysis by implementing all the perforated plates. However, if the size of the perforated plate exceeds a certain size, it is difficult to perform the numerical analysis, and sometimes we cannot guarantee its accuracy. In this study, we tried to predict the pressure drop and velocity change by using the porous media technique to obtain the equivalent resistance without actual implementation of the perforation shape of the strainer. Ansys-CFX, a commercial software, is used to perform the numerical analysis. The analysis procedure is as follows. Firstly, the unit pattern of the perforated plate is modeled, and the pressure drop is analyzed by varying the velocity by symmetry of the wall surface. Secondly, since the equation for obtaining resistance is a quadratic equation of pressure having unknown velocity, the viscous resistance and the inertia resistance of the perforated plate are obtained from the relationship between pressure and speed. Thirdly, by using the calculated resistance values, the values are substituted into the flat plate implemented as a two-dimensional porous media, and the accuracy is verified by comparing the pressure drop and the velocity change. Fourthly, the pressure drop and velocity change in the whole strainer are analyzed by using the resistance values obtained on the perforated plate in the actual whole strainer model. Using the porous media technique, it is found that pressure drop and velocity change can be predicted in relatively short time without modeling the overall shape of the filter. Acknowledgements: This work was supported by the Valve Center from the Regional Innovation Center(RIC) Program of Ministry of Trade, Industry & Energy (MOTIE).

Keywords: strainer, porous media, CFD, numerical analysis

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Authors: Faiz N. K. Yusufi, Aquil Ahmed, Jamal Ahmad

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Diabetes in India is growing at an alarming rate and the complications caused by it need to be controlled. Coronary heart disease (CHD) is one of the complications that will be discussed for prediction in this study. India has the second most number of diabetes patients in the world. To the best of our knowledge, there is no CHD risk score for Indian type 2 diabetes patients. Any form of CHD has been taken as the event of interest. A sample of 750 was determined and randomly collected from the Rajiv Gandhi Centre for Diabetes and Endocrinology, J.N.M.C., A.M.U., Aligarh, India. Collected variables include patients data such as sex, age, height, weight, body mass index (BMI), blood sugar fasting (BSF), post prandial sugar (PP), glycosylated haemoglobin (HbA1c), diastolic blood pressure (DBP), systolic blood pressure (SBP), smoking, alcohol habits, total cholesterol (TC), triglycerides (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), physical activity, duration of diabetes, diet control, history of antihypertensive drug treatment, family history of diabetes, waist circumference, hip circumference, medications, central obesity and history of CHD. Predictive risk scores of CHD events are designed by cox proportional hazard regression. Model calibration and discrimination is assessed from Hosmer Lemeshow and area under receiver operating characteristic (ROC) curve. Overfitting and underfitting of the model is checked by applying regularization techniques and best method is selected between ridge, lasso and elastic net regression. Youden’s index is used to choose the optimal cut off point from the scores. Five year probability of CHD is predicted by both survival function and Markov chain two state model and the better technique is concluded. The risk scores for CHD developed can be calculated by doctors and patients for self-control of diabetes. Furthermore, the five-year probabilities can be implemented as well to forecast and maintain the condition of patients.

Keywords: coronary heart disease, cox proportional hazard regression, ROC curve, type 2 diabetes Mellitus

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Authors: M. T. Ahn, J. H. Park, S. H. Park, S. H. Ha

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Diffusion bonding has been continuously studied. Temperature and pressure are the most important factors to increase the strength between diffusion bonded interfaces. Diffusion bonding is an important factor affecting the bonding strength of the lined pipe. The increase of the diffusion bonding force results in a high formability clad pipe. However, in the case of drawing, it is difficult to obtain a high pressure between materials due to a relatively small reduction in cross-section, and it is difficult to prevent elongation or to tear of material in hot drawing even if the reduction in the section is increased. In this paper, to increase the diffusion bonding force, we derive optimal temperature and pressure to suppress material stretching and realize precise thickness precision.

Keywords: diffusion bonding, temperature, pressure, drawing speed

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Authors: Ashok Kumar, Sarita Sahu, H. N. Bar

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Low cycle fatigue behavior of a ferritic, martensitic pressure vessel steel at dynamic strain ageing regime of 250°C to 280°C has been investigated. Dynamic strain ageing is a mechanism that has attracted interests of researchers due to its fascinating inexplicable repetitive nature for quite a long time. The interaction of dynamic strain ageing and cyclic plasticity has been studied from the mechanistic point of view. Dynamic strain ageing gives rise to identical serrated flow behavior in tensile and compressive halves of hysteresis loops and this has been found to gives rise to initial cyclic hardening followed by softening behavior, where as in non-DSA regime continuous cyclic softening has been found to be the dominant mechanism. An appreciable sensitivity towards nature of serrations has been observed due to degree of hardening of stable loop. The increase in degree of hardening with strain amplitude in the regime where only A type serrations are present and it decreases with strain amplitude where A+B type of serrations are present. Masing type of locus has been found in the behavior of metal at 280°C. Cyclic Stress Strain curve and Master curve has been constructed to decipher among the fatigue strength and ductility coefficients. Fractographic examinations have also shown a competition between progression of striations and secondary cracking.

Keywords: dynamic strain ageing, hardening, low cycle fatigue, softening

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Authors: Hanaa M. M. El-Khayat, Hanan S. Gaber, Hoda Abdel-Hamid, Kadria M. A. Mahmoud, Hoda M. A. Abu Taleb

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This work aimed to examine Oreochromis niloticus fish from Lake Manzala in Port Said, Dakahlya and Damietta governorates, Egypt, as a bio-indicator for the lake water pollution through recording alterations in their hematological, physiological, and histopathological parameters. All fish samples showed a significant increase in levels of alkaline phosphatase (ALP), creatinine and glutathione-S-transferase (GST); only Dakahlya samples showed a significant increase (p<0.01) in aspartate aminotransferase (AST) level and most Dakahlya and Damietta samples showed reversed albumin and globulin ratio and a significant increase in γ-glutamyltransferase (GGT) level. Port-Said and Damietta samples showed a significant decrease of hemoglobin (Hb) while Dakahlya samples showed a significant decrease in white blood cell (WBC) count. Histopathological investigation for different fish organs showed that Port-Said and Dakahlya samples were more altered than Damietta. The muscle and gill followed by intestine were the most affected organs. The muscle sections showed severe edema, neoplasia, necrotic change, fat vacuoles and splitting of muscle fiber. The gill sections showed dilated blood vessels of the filaments, curling of gill lamellae, severe hyperplasia, edema and blood vessels congestion of filaments. The intestine sections revealed degeneration, atrophy, dilation in blood vessels and necrotic changes in sub-mucosa and mucosa with edema in between. The recorded significant alterations, in most of the physiological and histological parameters in O. niloticus samples from Lake Manzala, were alarming for water pollution impacts on lake fish community, which constitutes the main diet and the main source of income for the people inhabiting these areas, and were threatening their public health and economy. Also, results evaluate the use of O. niloticus fish as important bio-indicator for their habitat stressors.

Keywords: Lake Manzala, Oreochromis niloticus fish, water pollution, physiological, hematological and histopathological parameters

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Authors: Chih-Jer Lin, Chun-Ying Lee, Ying Liu, Chiang-Ho Cheng

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The main objective of this article is to present the semi-active vibration control using an electro-rheological fluid embedded sandwich structure for a cantilever beam. ER fluid is a smart material, which cause the suspended particles polarize and connect each other to form chain. The stiffness and damping coefficients of the ER fluid can be changed in 10 micro seconds; therefore, ERF is suitable to become the material embedded in the tunable vibration absorber to become a smart absorber. For the ERF smart material embedded structure, the fuzzy control law depends on the experimental expert database and the proposed self-tuning strategy. The electric field is controlled by a CRIO embedded system to implement the real application. This study investigates the different performances using the Type-1 fuzzy and interval Type-2 fuzzy controllers. The Interval type-2 fuzzy control is used to improve the modeling uncertainties for this ERF embedded shock absorber. The self-tuning vibration controllers using Type-1 and Interval Type-2 fuzzy law are implemented to the shock absorber system. Based on the resulting performance, Internal Type-2 fuzzy is better than the traditional Type-1 fuzzy control for this vibration control system.

Keywords: electro-rheological fluid, semi-active vibration control, shock absorber, type 2 fuzzy control

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Authors: Moiz S. Vohra, Nagalingam Arun Prasanth, Wei L. Tan, S. H. Yeo

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The understanding of generation and collapse of acoustic cavitation bubbles are prerequisites for application of cavitation erosion. Microbubbles generated due to rapid fluctuation of pressure induced by propagation of ultrasonic wave lead to formation of high velocity microjets and or shock waves upon collapse. Due to vast application of ultrasonic, it is important to characterize and understand cavitation collapse pressure under the radiating surface at different conditions. A comparative investigation is carried out to determine impact load and dynamic pressure distribution exerted upon bubble collapse using thin film pressure sensors. Measurements were recorded at different input conditions such as amplitude, stand-off distance, insertion depth of the horn inside the liquid and pulse on-off time of acoustic vibrations. Impact force of 2.97 N is recorded at amplitude of 108 μm and stand-off distance of 1 mm from the sensor film, whereas impulsive force as low as 0.4 N is recorded at amplitude of 12 μm and stand-off distance of 5 mm from the sensor film. The results drawn from the investigation indicated that variety of impact loads can be achieved by controlling generation and collapse of bubbles, making it suitable to use for numerous application.

Keywords: ultrasonic cavitation, bubble collapse, pressure mapping sensor, impact load

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Authors: M. Attom, F. Abed, M. Elemam, M. Nazal, N. ElMessalami

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—The main objective of this paper is to study the effect of treated waste-water (TWW) on the compaction and compressibility properties of fine soil. Two types of fine soils (clayey soils) were selected for this study and classified as CH soil and Cl type of soil. Compaction and compressibility properties such as optimum water content, maximum dry unit weight, consolidation index and swell index, maximum past pressure and volume change were evaluated using both tap and treated waste water. It was found that the use of treated waste water affects all of these properties. The maximum dry unit weight increased for both soils and the optimum water content decreased as much as 13.6% for highly plastic soil. The significant effect was observed in swell index and swelling pressure of the soils. The swell indexed decreased by as much as 42% and 33% for highly plastic and low plastic soils, respectively, when TWW is used. Additionally, the swelling pressure decreased by as much as 16% for both soil types. The result of this research pointed out that the use of treated waste water has a positive effect on compaction and compression properties of clay soil and promise for potential use of this water in engineering applications. Keywords—Consolidation, proctor compaction, swell index, treated waste-water, volume change.

Keywords: consolidation, proctor compaction, swell index, treated waste-water, volume change

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Authors: Mohammad Hossain Validad, Maryam Nakhaei-Moghadam, Monire Mahjoob

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Introduction: The prevalence of type 1 diabetes is increasing worldwide, and given the role of ethnicity and race in complications of diabetes, this study was designed to evaluate the ocular complications of type 1 diabetes mellitus in Zahedan. Methods: This prospective cross-sectional study was conducted on Type 1 diabetic children that referred to Alzahra Eye Hospital. All patients had a dilated binocular indirect ophthalmoscopy using a +90 D condensing lens and slit-lamp biomicroscopy. Age, gender, onset, duration of diabetes, and HbA1c level were recorded. Results: 76 type 1 diabetes patients with an age of 11.93 ± 3.76 years participated in this study. Out of 76 patients with diabetes, 19 people (25%) had ocular complications. There was a significant difference in age (P=0.01) and disease duration (P=0.07) between the two groups with and without ocular complications. Odd ratios for ocular complications with age and duration of diabetes were 1.32 and 1.32, respectively. Conclusion: Cataract was the most common ocular complication in type 1 diabetes in Zahedan, a tropical region that was significantly related to the duration of the disease and the age of the patients.

Keywords: diabet mellitus type one, cataract, ocular complication, hemoglobin A1C

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Authors: H. Emari, Z. Emari

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The purpose of this paper is to design an applied framework for strategic thinking which can be applied in all managerial levels and all types of organizational environments. No special applied frame has been presented for this thinking. This paper presents a theoretical framework for the thinking type of a manager by making a historical research and studying the scientific documents about thinking of a strategist. In the new theoretical framework it has been tried to suggest the best type of thinking for a strategist after analyzing the environment of his decisions. So, in this framework, the traditional viewpoint about strategic thinking, which has considered it as a special type of right-brain thinking against other types of right-brain thinking and suggested it for a strategist, was put aside and suggests that the strategist should use a suitable type of thinking under different conditions.

Keywords: strategic thinking, systemic thinking, lateral thinking, intuitive thinking, hybrid thinking

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Authors: Fahad Aljasass, Hamza Abu-Tarboush, Salah Aleid, Siddig Hamad

Abstract:

The effects of different high hydrostatic pressure treatments on the shelf life of camel’s milk were studied. Treatments at 300 to 350 MPa for 5 minutes at 40°C reduced microbial contamination to levels that prolonged the shelf life of refrigerated (3° C) milk up to 28 days. The treatment resulted in a decrease in the proteolytic activity of the milk. The content of proteolytic enzymes in the untreated milk sample was 4.23 µM/ml. This content decreased significantly to 3.61 µM/ml when the sample was treated at 250 MPa. Treatment at 300 MPa decreased the content to 3.90 which was not significantly different from the content of the untreated sample. The content of the sample treated at 350 MPa dropped to 2.98 µM/ml which was significantly lower than the contents of all other treated and untreated samples. High pressure treatment caused a slight but statistically significant increase in the pH of camel’s milk. The pH of the untreated sample was 6.63, which increased significantly to 6.70, in the samples treated at 250 and 350 MPa, but insignificantly in the sample treated at 300 MPa. High pressure treatment resulted in some degree of milk fat oxidation. The thiobarbituric acid (TBA) value of the untreated sample was 0.86 mg malonaldehyde/kg milk. This value remained unchanged in the sample treated at 250 MPa, but then it increased significantly to 1.25 and 1.33 mg/kg in the samples treated at 300 and 350 MPa, respectively. High pressure treatment caused a small increase in the greenness (a* value) of camel’s milk. The value of a* was reduced from -1.17 for the untreated sample to -1.26, -1.21 and -1.30 for the samples treated at 250, 300 and 350 MPa, respectively. Δa* at the 250 MPa treatment was -0.09, which then decreased to -0.04 at the 300 MPa treatment to increase again to -0.13 at the 350 MPa treatment. The yellowness (b* value) of camel’s milk increased significantly as a result of high pressure treatment. The b* value of the untreated sample was 1.40, this value increased to 2.73, 2.31 and 2.18 after treatments at 250, 300 and 350 MPa, respectively. The Δb* value was +1.33 at the treatment 250 MPa, decreased to +0.91 at 300 MPa and further to +0.78 at 350 MPa. The pressure treatment caused slight effect on color, slight decrease in protease activity and a slight increase in the oxidation products of lipids.

Keywords: high hydrostatic pressure, camel’s milk, mesophilic aerobic bacteria, clotting, protease

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Authors: Raphael M. Ritti-Dias, Marilia A. Correia, Wagner J. R. Domingues, Aline C. Palmeira, Paulo Longano, Nelson Wolosker, Lauro C. Vianna, Gabriel G. Cucato

Abstract:

Patients with peripheral arterial disease (PAD) have a high prevalence of hypertension, which contributes to a high risk of acute cardiovascular events and cardiovascular mortality. Strategies to reduce cardiovascular risk of these patients are needed. Meta-analysis studies have shown that isometric handgrip training promotes reductions in clinical blood pressure in normotensive, pre-hypertensive and hypertensive individuals. However, the effect of this exercise training on other cardiovascular function indicators in PAD patients remains unknown. Thus, the aim of this study was to analyze the effects of isometric handgrip training on blood pressure in patients with PAD. In this clinical trial, 28 patients were randomly allocated into two groups: isometric handgrip training (HG) and control (CG). The HG conducted the unilateral handgrip training three days per week (four sets of two minutes, with 30% of maximum voluntary contraction with an interval of four minutes between sets). CG was encouraged to increase their physical activity levels. At baseline and after eight weeks blood pressure and heart rate were obtained. ANOVA two-way for repeated measures with the group (GH and GC) and time (pre- and post-intervention) as factors was performed. After 8 weeks of training there were no significant changes in systolic blood pressure (HG pre 141 ± 24.0 mmHg vs. HG post 142 ± 22.0 mmHg; CG pre 140 ± 22.1 mmHg vs. CG post 146 ± 16.2 mmHg; P=0.18), diastolic blood pressure (HG pre 74 ± 10.4 mmHg vs. HG post 74 ± 11.9 mmHg; CG pre 72 ± 6.9 mmHg vs. CG post 74 ± 8.0 mmHg; P=0.22) and heart rate (HG pre 61 ± 10.5 bpm vs. HG post 62 ± 8.0 bpm; CG pre 64 ± 11.8 bpm vs. CG post 65 ± 13.6 bpm; P=0.81). In conclusion, our preliminary data indicate that isometric handgrip training did not modify blood pressure and heart rate in patients with PAD.

Keywords: blood pressure, exercise, isometric, peripheral artery disease

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Authors: Tarannom Parhizkar, Halle Bakhteeyar

Abstract:

This paper presents a feasibility assessment of an expansion system applied to the natural gas transportation process in Iran. Power can be generated from the pressure energy of natural gas along its supply chain at various pressure reduction points by using turboexpanders. This technology is being applied in different countries around the world. The system consists of a turboexpander reducing the natural gas pressure and providing mechanical energy to drive electric generator. Moreover, gas pre-heating, required to prevent hydrate formation, is performed upstream of expansion stage using burner. The city gate station (CGS) has a nominal flow rate in range of 45000 to 270000 cubic meters per hour and a pressure reduction from maximum 62 bar at the upstream to 6 bar. Due to variable feed pressure and temperature in this station sensitivity analysis of generated electricity and required heat is performed. Results show that plant gain is more sensible to pressure variation than temperature changes. Furthermore, using turboexpander to reduce the pressure result in an electrical generation of 2757 to 17574 kW with the value of approximately 4 million US$ per year. Moreover, the required heat range to prevent a hydrate formation is almost 2189 to 14157 kW. To provide this heat, a burner is used with a maximum annual cost of 268,640 $ burner fuel. Therefore, the actual annual benefit of proposed plant modification is approximately over 6,5 million US$.

Keywords: feasibility study, simulation, turboexpander, feed characteristic

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Authors: Rukia Yosuf

Abstract:

Diabetes is a national healthcare crisis related to both macrovascular and microvascular complications. We hypothesized that higher levels of physical activity are associated with lower total and visceral fat mass, lower systolic blood pressure, and increased insulin sensitivity. Participant inclusion criteria: 21-50 years old, BMI ≥ 30 kg/m2, hemoglobin A1C 5.7-6.4, fasting glucose 100-125 mg/dL, and HOMA IR ≥ 2.5. Exclusion criteria: history of diabetes, hypertension, HIV, renal disease, hearing loss, alcoholic intake over four drinks daily, use of organic nitrates or PDE5 inhibitors, and decreased cardiac function. Total physical activity was measured using accelerometers, body composition using DXA, and insulin resistance via fsIVGTT. Clinical and biochemical cardiometabolic risk factors, blood pressure and heart rate were obtained using a calibrated sphygmomanometer. Anthropometric measures, fasting glucose, insulin, lipid profile, C-reactive protein, and BMP were analyzed using standard procedures. Within our study, we found correlations between levels of physical activity in a heterogeneous group of prediabetic adults. Patients with more physical activity had a higher degree of insulin sensitivity, lower blood pressure, total visceral adipose tissue, and overall lower total mass. Total physical activity levels showed small, but significant correlations with systolic blood pressure, visceral fat, lean mass and insulin sensitivity. After normalizing for the race, age, and gender using multiple regression, these associations were no longer significant considering our small sample size. More research into prediabetes will decrease the population of diabetics overall. In the future, we could increase sample size and conduct cross sectional and longitudinal studies in various populations with prediabetes.

Keywords: diabetes, kidney disease, nephrology, prediabetes

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Authors: Barenten Suciu

Abstract:

In this paper, a theoretical study on the forced vibration of one degree of freedom system equipped with inerter, working under load-type or displacement-type excitation, is presented. Differential equations of movement are solved under cosinusoidal excitation, and explicit relations for the magnitude, resonant magnitude, phase angle, resonant frequency, and critical frequency are obtained. Influence of the inertance and damping on these dynamic characteristics is clarified. From the obtained results, one concludes that the inerter increases the magnitude of vibration and the phase angle of the damped mechanical system. Moreover, the magnitude ratio and difference of phase angles are not depending on the actual type of excitation. Consequently, such kind of similitude allows for the comparison of various theoretical and experimental results, which can be broadly found in the literature.

Keywords: displacement-type excitation, inerter, load-type excitation, one degree of freedom vibration, parallel connection

Procedia PDF Downloads 187