Search results for: Pressure Ulcer
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4024

Search results for: Pressure Ulcer

3994 Outcomes of Combined Penetrating keratoplasty and Vitreo-Retinal Surgery in Management of Endophthalmitis with Obscured Corneal Clarity

Authors: Abhishek Dave, Manisha Singh

Abstract:

Purpose: The study aims to evaluate the outcomes of combined Penetrating keratoplasty (PKP) and Vitreo-Retinal (VR) surgery in patients having endophthalmitis with poor corneal clarity. Methods: PKP with VR Surgery was performed in 43 eyes. This is a retrospective analysis of their preoperative, intraoperative and microbiological characteristics and anatomical and functional outcomes. Results: Corneal opacification was due to corneal ulcer in 30 (69.7%), graft infection in 8 (18.6%), bullous keratopathy in 4 and corneal scar in 1 eye. Postoperative visual acuity improved in 20 (46.5%), not changed in 14 (32.5%) and deteriorated in 9 eyes (20.9%). Poor anatomic success was seen in 15 (34.88%) eyes (9-phthisis bulbi, 6-eviscerated). Graft remained clear in 24 eyes (1 year). Microbiology revealed bacteria in 26, fungus in 14 and no growth in 3 eyes. Six out of 11 patients having poor vision in the fellow eye, too, achieved functional success. Conclusion: PKP with VR surgery is a complex but globe-salvaging procedure for poor prognosis eyes, which otherwise would need evisceration.

Keywords: penetrating keratoplasty, VR surgery, endophthalmitis, corneal ulcer

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3993 Investigation and Analysis on Pore Pressure Variation by Sonic Impedance under Influence of Compressional, Shear, and Stonely Waves in High Pressure Zones

Authors: Nouri, K., Ghassem Alaskari, M., K., Amiri Hazaveh, A., Nabi Bidhendi, M.

Abstract:

Pore pressure is one on the key Petrophysical parameter in exploration discussion and survey on hydrocarbon reservoir. Determination of pore pressure in various levels of drilling and integrity of drilling mud and high pressure zones in order to restrict blow-out and following damages are significant. The pore pressure is obtained by seismic and well logging data. In this study the pore pressure and over burden pressure through the matrix stress and Tarzaqi equation and other related formulas are calculated. By making a comparison on variation of density log in over normal pressure zones with change of sonic impedance under influence of compressional, shear, and Stonely waves, the correlation level of sonic impedance with density log is studied. The level of correlation and variation trend is recorded in sonic impedance under influence Stonely wave with density log that key factor in recording of over burden pressure and pore pressure in Tarzaqi equation is high. The transition time is in divert relation with porosity and fluid type in the formation and as a consequence to the pore pressure. The density log is a key factor in determination of pore pressure therefore sonic impedance under Stonley wave is denotes well the identification of high pressure besides other used factors.

Keywords: pore pressure, stonely wave, density log, sonic impedance, high pressure zone

Procedia PDF Downloads 367
3992 Observation on Microbiological Profile of Type2 Diabetic Foot Ulcer and Its Antimicrobial Sensitivity Pattern in a Tertiary Care Hospital in Eastern India

Authors: Pampita Chakraborty, Sukumar Mukherjee

Abstract:

Diabetes Mellitus (DM) is commonly encountered metabolic disorder in clinical practice. An estimated 25 percent of DM patients develop foot problems. Foot ulceration and infection are one of the major causes of morbidity, hospitalization or even amputation. Objective: To isolate and identify bacterial pathogens in Diabetic Foot Ulcer (DFU) and to observe its antimicrobial sensitivity pattern. Methodology: A prospective study was conducted for a period of 9 months at the Department of Microbiology, GD Hospital & Diabetes Institute, Kolkata. 75 DFU patients were recruited in the study. Specimens for microbiological studies obtained from ulcer base were examined as gram stained smear and was cultured aerobically on Nutrient agar, Blood agar and MacConkey agar plates. Antimicrobial sensitivity test was performed by disc diffusion techniques according to CLSI guidelines. Result: In this study out of 75cases, 73% (55/75) were male and 27% (20/75) were females with mean (SD) age of 51.11(±10) years. Out of 75 pus cultures, 63(84%) showed growth of microorganism making total of 81 bacterial isolates with 71.42% of monomicrobial infection and 28.57% of polymicrobial infection. Out of 81 isolates 53(65.43%) were gram negative and 21(25.92%) were gram positive. E.coli was relatively common isolate 21(26%) followed by Staphylococcus aureus 15(18.5%), Klebsiella pneumonia 14(17.28%), Pseudomonas aeruginosa 12 (14.81%), Proteus spp. 3 (3.70%), and Enterococcus faecalis 6 (7.40%). 75% of Gram-negative microorganism were extended Beta-lactamase enzyme (ESBL) producer and around 20 % of Klebsiella and Proteus spp. were carbapenemase enzyme producer. Among Gram positive, around 50% of S.aureus was MRSA, sensitive only to Vancomycin, Teicoplanin & Linezolid. Conclusion: More prevalence of monomicrobial gram-negative bacteria than gram-positive bacteria in DFU was observed. This study emphasizes that Beta-Lactam group of antibiotics should not be the empirical treatment of choice for Gram-negative isolates; instead alternatives like Carbapenems, Amikacin could be a better option. On the other hand, Vancomycin and Linezolid are preferred for most of the infection with gram-positive aerobes. Continuous surveillance of resistant bacteria is required for empiric therapy.

Keywords: antibiotic resistant, antimicrobial susceptibility, diabetic foot ulcer, surveillance

Procedia PDF Downloads 341
3991 Evaluation of Carbon Dioxide Pressure through Radial Velocity Difference in Arterial Blood Modeled by Drift Flux Model

Authors: Aicha Rima Cheniti, Hatem Besbes, Joseph Haggege, Christophe Sintes

Abstract:

In this paper, we are interested to determine the carbon dioxide pressure in the arterial blood through radial velocity difference. The blood was modeled as a two phase mixture (an aqueous carbon dioxide solution with carbon dioxide gas) by Drift flux model and the Young-Laplace equation. The distributions of mixture velocities determined from the considered model permitted the calculation of the radial velocity distributions with different values of mean mixture pressure and the calculation of the mean carbon dioxide pressure knowing the mean mixture pressure. The radial velocity distributions are used to deduce a calculation method of the mean mixture pressure through the radial velocity difference between two positions which is measured by ultrasound. The mean carbon dioxide pressure is then deduced from the mean mixture pressure.

Keywords: mean carbon dioxide pressure, mean mixture pressure, mixture velocity, radial velocity difference

Procedia PDF Downloads 398
3990 Design of Saddle Support for Horizontal Pressure Vessel

Authors: Vinod Kumar, Navin Kumar, Surjit Angra, Prince Sharma

Abstract:

This paper presents the design analysis of saddle support of a horizontal pressure vessel. Since saddle have the vital role to support the pressure vessel and to maintain its stability, it should be designed in such a way that it can afford the vessel load and internal pressure of the vessel due to liquid contained in the vessel. A model of horizontal pressure vessel and saddle support is created in Ansys. Stresses are calculated using mathematical approach and Ansys software. The analysis reveals the zone of high localized stress at the junction part of the pressure vessel and saddle support due to operating conditions. The results obtained by both the methods are compared with allowable stress value for safe designing.

Keywords: ANSYS, pressure vessel, saddle, support

Procedia PDF Downloads 711
3989 Metal Berthelot Tubes with Windows for Observing Cavitation under Static Negative Pressure

Authors: K. Hiro, Y. Imai, T. Sasayama

Abstract:

Cavitation under static negative pressure is not revealed well. The Berthelot method to generate such negative pressure can be a means to study cavitation inception. In this study, metal Berthelot tubes built in observation windows are newly developed and are checked whether high static negative pressure is generated or not. Negative pressure in the tube with a pair of a corundum plate and an aluminum gasket increased with temperature cycles. The trend was similar to that as reported before.

Keywords: Berthelot method, cavitation, negative pressure, observation

Procedia PDF Downloads 303
3988 Feature Extraction Based on Contourlet Transform and Log Gabor Filter for Detection of Ulcers in Wireless Capsule Endoscopy

Authors: Nimisha Elsa Koshy, Varun P. Gopi, V. I. Thajudin Ahamed

Abstract:

The entire visualization of GastroIntestinal (GI) tract is not possible with conventional endoscopic exams. Wireless Capsule Endoscopy (WCE) is a low risk, painless, noninvasive procedure for diagnosing diseases such as bleeding, polyps, ulcers, and Crohns disease within the human digestive tract, especially the small intestine that was unreachable using the traditional endoscopic methods. However, analysis of massive images of WCE detection is tedious and time consuming to physicians. Hence, researchers have developed software methods to detect these diseases automatically. Thus, the effectiveness of WCE can be improved. In this paper, a novel textural feature extraction method is proposed based on Contourlet transform and Log Gabor filter to distinguish ulcer regions from normal regions. The results show that the proposed method performs well with a high accuracy rate of 94.16% using Support Vector Machine (SVM) classifier in HSV colour space.

Keywords: contourlet transform, log gabor filter, ulcer, wireless capsule endoscopy

Procedia PDF Downloads 518
3987 Gastroprotective Effect of Copper Complex On Indomethacin-Induced Gastric Ulcer In Rats. Histological and Immunohistochemical Study

Authors: Heba M. Saad Eldien, Ola Abdel-Tawab Hussein, Ahmed Yassein Nassar

Abstract:

Background: Indomethacin is a non-steroidal anti inflammatory drug. Indomethacin induces an injury to gastrointestinal mucosa in experimental animals and humans and their use is associated with a significant risk of hemorrhage, erosions and perforation of both gastric and intestinal ulcers. The anti-inflammatory action of copper complexes is an important activity of their anti-ulcer effect achieved by their intermediary role as a transport form of copper that allow activation of the several copper-dependent enzymes. Therefore, several copper complexes were synthesized and investigated as promising alternative anti-ulcer therapy. Aim of the work: The purpose of this study was to evaluate a copper chelating complex consisting of egg albumin and copper as one of the copper peptides that can be used as anti-inflammatory agent and effective in ameliorates the hazards of the indomethacin on the histological structure of the fundus of the stomach that could be added to raise the efficacy of the currently used simple and cheap gastric anti-inflammatory drug mucogel. Material &methods: This study was carried out on 40 adult male albino rats,divided equally into 4 groups;Group I(control group) received distilled water,Group II(indomethacin treated group) received (25 mg/kg body weight, oral intubation) once, Group III (mucogel treated group)2 mL/rat once daily, oral incubation, Group IV(copper complex group) 1 mL /rat of 30 gm of copper albumin complex was mixed uniformly with mucogel to 100 mL. Treatment has been started six hour after Induction of Ulcers and continued till the 3rd day. The animals sacrificed and was processed for light, transmission electron microscopy(TEM) and immunostaining for inducible nitric oxide synthase(iNOS). Results: Fundic mucosa of group II, showed exfoliation of epithelial cells lining the gland, discontinuity of surface epithelial cells (ulcer formation), vacuolation and detachment of cells, eosinophilic infiltration and congestion of blood vessels in the lamina propria and submucosa. There was thickening and disarrangement of mucosa, weak positive reaction for PAS and marked increase in the collagen fibers lamina propria and the submucosa of the fundus. TEM revealed degeneration of cheif and parietal cells.Marked increase positive reactive of iNOS in all cells of the fundic gland. Group III showed reconstruction of gastric gland with cystic dilatation and vacuolation, moderate decrease of collagen fibers, reduced the intensity of iNOS while in Group IV healthy mucosa with normal surface lining epithelium and fundic glands, strong positive reaction for PAS, marked decrease of collagen fibers and positive reaction for iNOS. TEM revealed regeneration of cheif and parietal cells. Conclusion: Co treatment of copper-albumin complex seems to be useful for gastric ulcer treatment and ameliorates most of hazards of indomethacin.

Keywords: copper complex, gastric ulcer, indomethacin, rat

Procedia PDF Downloads 313
3986 Design of Impedance Box to Study Fluid Parameters

Authors: K. AlJimaz, A. Abdullah, A. Abdulsalam, K. Ebdah, A. Abdalrasheed

Abstract:

Understanding flow distribution and head losses is essential to design and calculate Thermo fluid parameters in order to reduce the pressure to a certain required pressure. This paper discusses the ways acquired in design and simulation to create and design an impedance box that reduces pressure. It's controlled by specific scientific principles such as Bernoulli’s principle and conservation of mass. In this paper, the design is made using SOLIDWORKS, and the simulation is done using ANSYS software to solve differential equations and study the parameters in the 3D model, also to understand how the design of this box reduced the pressure. The design was made so that fluid enters at a certain pressure of 3000 Pa in a single inlet; then, it exits from six outlets at a pressure of 300 Pa with respect to the conservation of mass principle. The effect of the distribution of flow and the head losses has been noticed that it has an impact on reducing the pressure since other factors, such as friction, were neglected and also the temperature, which was constant. The design showed that the increase in length and diameter of the pipe helped to reduce the pressure, and the head losses contributed significantly to reduce the pressure to 10% of the original pressure (from 3000 Pa to 300 Pa) at the outlets.

Keywords: box, pressure, thermodynamics, 3D

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3985 Measurement of Reverse Flow Generated at Cold Exit of Vortex Tube

Authors: Mohd Hazwan bin Yusof, Hiroshi Katanoda

Abstract:

In order to clarify the structure of the cold flow discharged from the vortex tube (VT), the pressure of the cold flow was measured, and a simple flow visualization technique using a 0.75 mm-diameter needle and an oily paint is made to study the reverse flow at the cold exit. It is clear that a negative pressure and positive pressure region exist at a certain pressure and cold fraction area, and that a reverse flow is observed in the negative pressure region.

Keywords: flow visualization, pressure measurement, reverse flow, vortex tube

Procedia PDF Downloads 489
3984 Design and Simulation of MEMS-Based Capacitive Pressure Sensors

Authors: Kirankumar B. Balavalad, Bhagyashree Mudhol, B. G. Sheeparamatti

Abstract:

MEMS sensor have gained popularity in automotive, biomedical, and industrial applications. In this paper, the design and simulation of conventional, slotted, and perforated MEMS capacitive pressure sensor is proposed. Polysilicon material is used as diaphragm material that deflects due to applied pressure. Better sensitivity is the main advantage of conventional pressure sensor as compared with other two sensors and perforated pressure sensor achieves large operating pressure range. The proposed MEMS sensor demonstrated with diaphragm length 50um, gap depth 3um is being modelled. The simulation is carried out for different types of MEMS capacitive pressure sensor using COMSOL Multiphysics and Coventor ware.

Keywords: MEMS, conventional pressure sensor, slotted and perforated diaphragm, COMSOL multiphysics, coventor ware

Procedia PDF Downloads 476
3983 The Universal Theory: Role of Imaginary Pressure on Different Relative Motions

Authors: Sahib Dino Naseerani

Abstract:

The presented scientific text discusses the concept of imaginary pressure and its role in different relative motions. It explores how imaginary pressure, which is the combined effect of external atmospheric pressure and real pressure, affects various substances and their physical properties. The study aims to understand the impact of imaginary pressure and its potential applications in different contexts, such as spaceflight. The main objective of this study is to investigate the role of imaginary pressure on different relative motions. Specifically, the researchers aim to examine how imaginary pressure affects the contraction and mass variation of a body when it is in motion at the speed of light. The study seeks to provide insights into the behavior and consequences of imaginary pressure in various scenarios. The data was collected using three research papers. This research contributes to a better understanding of the theoretical implications of imaginary pressure. It elucidates how imaginary pressure is responsible for the contraction and mass variation of a body in motion, particularly at the speed of light. The findings shed light on the behavior of substances under the influence of imaginary pressure, providing valuable insights for future scientific studies. The study addresses the question of how imaginary pressure influences various relative motions and their associated physical properties. It aims to understand the role of imaginary pressure in the contraction and mass variation of a body, particularly at high speeds. By examining different substances in liquid and solid forms, the research explores the consequences of imaginary pressure on their volume, length, and mass.

Keywords: imaginary pressure, contraction, variation, relative motion

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3982 Evaluation of Longitudinal and Hoop Stresses and a Critical Study of Factor of Safety (FoS) in Design of a Glass-Fiber Pressure Vessel

Authors: Zainul Huda, Mohammed Hani Ajani

Abstract:

The design, manufacture, and operation of thin-walled pressure vessels must be based on maximum safe operating pressure and an adequate factor of safety (FoS). This research paper first reports experimental evaluation of longitudinal and hoops stresses based on working pressure as well as maximum pressure; and then includes a critical study of factor of safety (FoS) in the design of a glass fiber pressure vessel. Experimental work involved the use of measuring instruments and the readings from pressure gauges. Design calculations involved the computations of design stress and FoS; the latter was based on breaking strength of 55 MPa for the glass fiber (pressure-vessel material). The experimentally determined FoS value has been critically compared with the general FoS allowed in the design of glass fiber pressure vessels.

Keywords: thin-walled pressure vessel, hoop stress, longitudinal stress, factor of safety (FoS), fiberglass

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3981 Evaluation of Longitudinal and Hoops Stresses and a Critical Study of Factor of Safety (Fos) in the Design of a Glass-Fiber Pressure Vessel

Authors: Zainul Huda, Mohammad Hani Ajani

Abstract:

The design, manufacture, and operation of thin-walled pressure vessels must be based on maximum safe operating pressure and an adequate factor of safety (FoS). This research paper first reports experimental evaluation of longitudinal and hoops stresses based on working pressure as well as maximum pressure; and then includes a critical study of factor of safety (FoS) in the design of a glass fiber pressure vessel. Experimental work involved the use of measuring instruments and the readings from pressure gauges. Design calculations involved the computations of design stress and FoS; the latter was based on breaking strength of 55 MPa for the glass fiber (pressure-vessel material). The experimentally determined FoS value has been critically compared with the general FoS allowed in the design of glass fiber pressure vessels.

Keywords: thin-walled pressure vessel, hoop stress, longitudinal stress, factor of safety (FoS), fiberglass

Procedia PDF Downloads 471
3980 Fracture Pressure Predict Based on Well Logs of Depleted Reservoir in Southern Iraqi Oilfield

Authors: Raed H. Allawi

Abstract:

Formation pressure is the most critical parameter in hydrocarbon exploration and exploitation. Specifically, predicting abnormal pressures (high formation pressures) and subnormal pressure zones can provide valuable information to minimize uncertainty for anticipated drilling challenges and risks. This study aims to interpret and delineate the pore and fracture pressure of the Mishrif reservoir in the southern Iraq Oilfield. The data required to implement this study included acoustic compression wave, gamma-ray, bulk density, and drilling events. Furthermore, supporting these models needs the pore pressure measurement from the Modular Formation Dynamics Tester (MDT). Many measured values of pore pressure were used to validate the accurate model. Using sonic velocity approaches, the mean absolute percentage error (MAPE) was about 4%. The fracture pressure results were consistent with the measurement data, actual drilling report, and events. The model's results will be a guide for successful drilling in future wells in the same oilfield.

Keywords: pore pressure, fracture pressure, overburden pressure, effective stress, drilling events

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3979 Significant Stressed Zone of Highway Embankment

Authors: Sharifullah Ahmed, P. Eng

Abstract:

The Axle Pressure and the Consolidation Pressure decrease with the height of the highway embankment and the depth of subsoil. This reduction of pressure depends on the height and width of the embankment. The depth is defined as the significantly stressed zone at which the pressure is reduced to 0.2 or 20%. The axle pressure is reduced to 7% for embankment height 1-3m and to 0.7% for embankment height 4-12m at the bottom level of Highway Embankment. This observation implies that, the portion of axle pressure transferred to subsoil underlying the embankment is not significant for ESAL factor 4.8. The 70% consolidation to have occurred after the construction of the surface layer of pavement. Considering this ratio of post construction settlement, 70% consolidation pressure (Δσ70) is used in this analysis. The magnitude of influence depth or Significant Stressed Zone (Ds) had been obtained for the range of crest width (at the top level of the embankment) is kept between 5m and 50m and for the range of embankment height from 1.0m to 12.0m considering 70% of consolidation pressure (Δσ70). Significantly stressed zones (Ds) for 70% embankment pressure are found as 2-6.2He for embankment top width 5-50m.

Keywords: consolidation pressure, consolidation settlement, ESAL, highway embankment, HS 20-44, significant stressed zone, stress distribution

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3978 A CFD Analysis of Flow through a High-Pressure Natural Gas Pipeline with an Undeformed and Deformed Orifice Plate

Authors: R. Kiš, M. Malcho, M. Janovcová

Abstract:

This work aims to present a numerical analysis of the natural gas which flows through a high-pressure pipeline and an orifice plate, through the use of CFD methods. The paper contains CFD calculations for the flow of natural gas in a pipe with different geometry used for the orifice plates. One of them has a standard geometry and a shape without any deformation and the other is deformed by the action of the pressure differential. It shows the behaviour of natural gas in a pipeline using the velocity profiles and pressure fields of the gas in both models with their differences. The entire research is based on the elimination of any inaccuracy which should appear in the flow of the natural gas measured in the high-pressure pipelines of the gas industry and which is currently not given in the relevant standard.

Keywords: orifice plate, high-pressure pipeline, natural gas, CFD analysis

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3977 Development and Characterization of Double Liposomes Based Dual Drug Delivery System for H. Pylori Targeting

Authors: Ashish Kumar Jain, Deepak Mishra

Abstract:

The objective of the present investigation was to prepare and evaluate a vesicular dual drug delivery system for effective management of mucosal ulcer. Inner encapsulating and Double liposomes were prepared by glass bead and reverse phase evaporation method respectively. The formulation consisted of inner liposomes bearing Ranitidine Bismuth Citrate (RBC) and outer liposomes encapsulating Amoxicillin trihydrate (AMOX). The optimized inner liposomes and double liposomes were extensively characterized for vesicle size, morphology, zeta potential, vesicles count, entrapment efficiency and in vitro drug release. In vitro, the double liposomes demonstrated a sustained release of AMOX and RBC viz 91.4±1.8% and 77.2±2.1% respectively at the end of 72 hr. Furthermore binding specificity and targeting propensity toward H. pylori (SKP-56) was confirmed by agglutination and in situ adherence assay. Reduction of the absolute alcohol induced ulcerogenic index from 3.01 ± 0.25 to 0.31 ± 0.09 and 100% H. pylori clearance rate was observed. These results suggested that double liposomes are potential vector for the development of dual drug delivery for effective treatment of H. pylori-associated peptic ulcer.

Keywords: double liposomes, H. pylori targeting, PE liposomes, glass-beads method, peptic ulcers

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3976 Stomach Perforation, due to Chronic External Pressure

Authors: Angelis P. Barlampas

Abstract:

PURPOSE: The purpose of this paper is to demonstrate the important role of taking an appropriate and detailed history, in order to reach the best possible diagnostic conclusion. MATERIAL: A patient presented to the emergency department due to the sudden onset of continuous abdominal pain, during the last hour and with the clinical symptoms of an acute abdomen. During the clinical examination, signs of peritoneal irritation and diffuse abdominal tenderness were found. The rest of the clinical and laboratory tests did not reveal anything important. From the reported medical history, nothing of note was found, except for the report of a large liver cyst, for which he was advised not to take any further action, except from regular ultrasound examination . METHOD: A computed tomography examination was performed after per os administration of gastrografin, which revealed a hyperdense ascitic effusion, similar in density to that of gastrografin within the intestinal tract. The presence of a large cyst of the left hepatic lobe was confirmed, contacting and pushing against the stomach. In the area of the contact between the liver cyst and the pylorus, there were extraluminal air bubbles and local opacity of the peritoneal fat, with a small hyperdense effusion. Result : The above, as well as the absence of a history of stomach ulcer or recent trauma, or other pathology, argue in favor of acute pyloric perforation, due to mural necrosis, in response to chronic external pressure from the pre-existing large liver cyst.

Keywords: perforation, stomach, large liver cyst, CT abdomen, acute abdominal pain, intraperitoneal leakage, constrast leakage

Procedia PDF Downloads 64
3975 On the Numerical and Experimental Analysis of Internal Pressure in Air Bearings

Authors: Abdurrahim Dal, Tuncay Karaçay

Abstract:

Dynamics of a rotor supported by air bearings is strongly depends on the pressure distribution between the rotor and the bearing. In this study, internal pressure in air bearings is numerical and experimental analyzed for different radial clearances. Firstly the pressure distribution between rotor and bearing is modeled using Reynold's equation and this model is solved numerically. The rotor-bearing system is also modeled in four degree of freedom and it is simulated for different radial clearances. Then, in order to validate numerical results, a test rig is designed and the rotor bearing system is run under the same operational conditions. Pressure signals of left and right bearings are recorded. Internal pressure variations are compared for numerical and experimental results for different radial clearances.

Keywords: air bearing, internal pressure, Reynold’s equation, rotor

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3974 Pressure Regulator Optimization in LPG Fuel Injection Systems

Authors: M. Akif Ceviz, Alirıza Kaleli, Erdoğan Güner

Abstract:

LPG pressure regulator is a device which is used to change the phase of LPG from liquid to gas by decreasing the pressure. During the phase change, it is necessary to supply the latent heat of LPG to prevent excessive low temperature. Engine coolant is circulated in the pressure regulator for this purpose. Therefore, pressure regulator is a type of heat exchanger that should be designed for different engine operating conditions. The design of the regulator should ensure that the flow of LPG is in gaseous phase to the injectors during the engine steady state and transient operating conditions. The pressure regulators in the LPG gaseous injection systems currently used can easily change the phase of LPG, however, there is no any control on the LPG temperature in conventional LPG injection systems. It is possible to increase temperature excessively. In this study, a control unit has been tested to keep the LPG temperature in a band. Result of the study showed that the engine performance characteristics can be increased by using the system.

Keywords: temperature, pressure regulator, LPG, PID

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3973 Refractory Visceral Leishmaniasis Responding to Second-Line Therapy

Authors: Preet Shah, Om Shrivastav

Abstract:

Introduction : In India, Leishmania donovani is the only parasite causing Leishmaniasis. The parasite infects the reticuloendothelial system and is found in the bone marrow, spleen and liver. Treatment of choice is amphotericin-B with sodium stibogluconate being an alternative. Miltefosine is useful in refractory cases. In our case, Leishmaniasis occurred in a person residing in western India (which is quite rare) and it failed to respond to two different drugs (again an uncommon feature) before it finally responded to a third one. Description: A 50 year old lady, a resident of western India, with no history of recent travel, presented with an ulcer on the left side of the nose since 8 months. She was apparently alright 8 months back, when she noticed a small ulcerated lesion on the left ala of the nose which was immediately biopsied. The biopsy revealed amastigotes of Leishmania for which she was administered intra-lesional sodium stibogluconate for 1 month (4 doses every 8 days).Despite this, there was no regression of the ulcer and hence she presented to us for further management. On examination, her vital parameters were normal. Barring an ulcer on the left side of the nose, rest of the examination findings were unremarkable. Complete blood count was normal. Ultrasound abdomen showed hepatomegaly. PET-CT scan showed increased metabolic activity in left ala of nose, hepatosplenomegaly and increased metabolic activity in spleen and bone marrow. Bone marrow biopsy was done which showed hypercellular marrow with erythroid preponderance. Considering a diagnosis of leishmaniasis which had so far been unresponsive to sodium stibogluconate, she was started on liposomal amphotericin-B. At the time of admission, her creatinine level was normal, but it started rising with the administration of liposomal amphotericin-B, hence the dose was reduced. Despite this, creatinine levels did not improve, and she started developing hypokalemia and hypomagnesemia as side effects of the drug, hence further reductions in the dosage were made. Despite a total of 3 weeks of liposomal amphotericin-B, there was no improvement in the ulcer. As had so far failed to respond to sodium stibogluconate and liposomal amphotericin-B, it was decided to start her on miltefosine. She received the miltefosine for a total of 12 weeks. At the end of this duration, there was a marked regression of the cutaneous lesion. Conclusion: Refractoriness to amphotericin-B in leishmaniasis may be seen in up to 5 % cases. Here, an alternative drug such as miltefosine is useful and hence we decided to use it, to which she responded adequately. Furthermore, although leishmaniasis is common in the eastern part of India, it is a relatively unknown entity in the western part of the country with the occurrence being very rare. Because of these 2 reasons, we consider our case to be a unique one.

Keywords: amphotericin-b, leishmaniasis, miltefosine, tropical diseases

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3972 The Mainspring of Controlling of Low Pressure Steam Drum at Lower Pressure than Its Design for Adjusting the Urea Synthesis Pressure

Authors: Reza Behtash, Enayat Enayati

Abstract:

The pool condenser is in principal a horizontal reactor, containing a bundle of U-tubes for heat exchange, coupling to low pressure steam drum. Condensation of gas takes place in a condensed pool around the tubes of the condenser. The heat of condensation is removed by the generation of low pressure steam on the inner tube side of the bundle. A circulation pump transfers ample boiler feed water to these tubes. The pressure of the steam generated influenced the heat flux. Changing the steam pressure means changing the steam condensate temperature and therefore the temperature difference between the tube side and the shell side. 2NH3 + CO2 ↔ NH2COONH4 + Heat. This reaction is exothermic and according to Le Chatelier's Principle if the heat is not removed enough, it will come back to left side and generate of the gas and so the Urea synthesis pressure will rise. The most principal reasons for high Urea synthesis pressure are non proportional of Ammonia/Dioxide Carbon ratio and too high a pressure in low pressure steam drum. Proportional of Ammonia/Dioxide Carbon ratio is 3.0 and normal pressure for low pressure steam drum is 4.5 bar. As regards these conditions were proportional but we could not control the synthesis pressure the plant endangered, therefore we had to control the steam drum pressure at about 3.5 bar. While we opened the pool condenser, we found the partition plate used to divide inlet and outlet boiler feed water to tubes, was broken partially and so amount of boiler feed water bypass the tubes and the heat was not removed totally and it resulted in the generation of gases and high pressure in synthesis.

Keywords: boiler, pressure, pool condenser, partition plate

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3971 Negative Pressure Waves in Hydraulic Systems

Authors: Fuad H. Veliev

Abstract:

Negative pressure phenomenon appears in many thermodynamic, geophysical and biophysical processes in the Nature and technological systems. For more than 100 years of the laboratory researches beginning from F. M. Donny’s tests, the great values of negative pressure have been achieved. But this phenomenon has not been practically applied, being only a nice lab toy due to the special demands for the purity and homogeneity of the liquids for its appearance. The possibility of creation of direct wave of negative pressure in real heterogeneous liquid systems was confirmed experimentally under the certain kinetic and hydraulic conditions. The negative pressure can be considered as the factor of both useful and destroying energies. The new approach to generation of the negative pressure waves in impure, unclean fluids has allowed the creation of principally new energy saving technologies and installations to increase the effectiveness and efficiency of different production processes. It was proved that the negative pressure is one of the main factors causing hard troubles in some technological and natural processes. Received results emphasize the necessity to take into account the role of the negative pressure as an energy factor in evaluation of many transient thermohydrodynamic processes in the Nature and production systems.

Keywords: liquid systems, negative pressure, temperature, wave, metastable state

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3970 Gas Pressure Evaluation through Radial Velocity Measurement of Fluid Flow Modeled by Drift Flux Model

Authors: Aicha Rima Cheniti, Hatem Besbes, Joseph Haggege, Christophe Sintes

Abstract:

In this paper, we consider a drift flux mixture model of the blood flow. The mixture consists of gas phase which is carbon dioxide and liquid phase which is an aqueous carbon dioxide solution. This model was used to determine the distributions of the mixture velocity, the mixture pressure, and the carbon dioxide pressure. These theoretical data are used to determine a measurement method of mean gas pressure through the determination of radial velocity distribution. This method can be applicable in experimental domain.

Keywords: mean carbon dioxide pressure, mean mixture pressure, mixture velocity, radial velocity

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3969 Effect of Hypertension Exercise and Slow Deep Breathing Combination to Blood Pressure: A Mini Research in Elderly Community

Authors: Prima Khairunisa, Febriana Tri Kusumawati, Endah Luthfiana

Abstract:

Background: Hypertension in elderly, caused by cardiovascular system cannot work normally, because the valves thickened and inelastic blood vessels. It causes vasoconstriction of the blood vessels. Hypertension exercise, increase cardiovascular function and the elasticity of the blood vessels. While slow deep breathing helps the body and mind feel relax. Combination both of them will decrease the blood pressure. Objective: To know the effect of hypertension exercise and slow deep breathing combination to blood pressure in elderly. Method: The study conducted with one group pre-post test experimental design. The samples were 10 elderly both male and female in a Village in Semarang, Central Java, Indonesia. The tool was manual sphygmomanometer to measure blood pressure. Result: Based on paired t-test between hypertension exercise and slow deep breathing with systole blood pressure showed sig (2-tailed) was 0.045, while paired t-test between hypertension exercise hypertension exercise and slow deep breathing with diastole blood pressure showed sig (2-tailed) was 0,343. The changes of systole blood pressure were 127.5 mmHg, and diastole blood pressure was 80 mmHg. Systole blood pressure decreases significantly because the average of systole blood pressure before implementation was 135-160 mmHg. While diastole blood pressure was not decreased significantly. It was influenced by the average of diastole blood pressure before implementation of hypertension exercise was not too high. It was between 80- 90 mmHg. Conclusion: There was an effect of hypertension exercise and slow deep breathing combination to the blood pressure in elderly after 6 times implementations.

Keywords: hypertension exercise, slow deep breathing, elderly, blood pressure

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3968 Estimation of Pressure Profile and Boundary Layer Characteristics over NACA 4412 Airfoil

Authors: Anwar Ul Haque, Waqar Asrar, Erwin Sulaeman, Jaffar S. M. Ali

Abstract:

Pressure distribution data of the standard airfoils is usually used for the calibration purposes in subsonic wind tunnels. Results of such experiments are quite old and obtained by using the model in the spanwise direction. In this manuscript, pressure distribution over NACA 4412 airfoil model was presented by placing the 3D model in the lateral direction. The model is made of metal with pressure ports distributed longitudinally as well as in the lateral direction. The pressure model was attached to the floor of the tunnel with the help of the base plate to give the specified angle of attack to the model. Before the start of the experiments, the pressure tubes of the respective ports of the 128 ports pressure scanner are checked for leakage, and the losses due to the length of the pipes were also incorporated in the results for the specified pressure range. Growth rate maps of the boundary layer thickness were also plotted. It was found that with the increase in the velocity, the dynamic pressure distribution was also increased for the alpha seep. Plots of pressure distribution so obtained were overlapped with those obtained by using XFLR software, a low fidelity tool. It was found that at moderate and high angles of attack, the distribution of the pressure coefficients obtained from the experiments is high when compared with the XFLR ® results obtained along with the span of the wing. This under-prediction by XFLR ® is more obvious on the windward than on the leeward side.

Keywords: subsonic flow, boundary layer, wind tunnel, pressure testing

Procedia PDF Downloads 300
3967 Influence of Pressure from Compression Textile Bands: Their Using in the Treatment of Venous Human Leg Ulcers

Authors: Bachir Chemani, Rachid Halfaoui

Abstract:

The aim of study was to evaluate pressure distribution characteristics of the elastic textile bandages using two instrumental techniques: a prototype Instrument and a load Transference. The prototype instrument which simulates shape of real leg has pressure sensors which measure bandage pressure. Using this instrument, the results show that elastic textile bandages presents different pressure distribution characteristics and none produces a uniform distribution around lower limb. The load transference test procedure is used to determine whether a relationship exists between elastic textile bandage structure and pressure distribution characteristics. The test procedure assesses degree of load, directly transferred through a textile when loads series are applied to bandaging surface. A range of weave fabrics was produced using needle weaving machine and a sewing technique. A textile bandage was developed with optimal characteristics far superior pressure distribution than other bandages. From results, we find that theoretical pressure is not consistent exactly with practical pressure. It is important in this study to make a practical application for specialized nurses in order to verify the results and draw useful conclusions for predicting the use of this type of elastic band.

Keywords: textile, cotton, pressure, venous ulcers, elastic

Procedia PDF Downloads 342
3966 Blood Pressure and Anthropometric Measurements: A Correlational Study

Authors: Abdul-Monim Batiha, Manar AlAzzam, Mohammed ALBashtawy, Loai Tawalbeh, Ahmad Tubaishat, Fadwa N. Alhalaiqa

Abstract:

Background: Obesity is the major modifiable risk factor for many chronic illnesses especially high blood pressure. Objectives: To evaluate the relationship between anthropometric indices and high blood pressure, and which one was most strongly correlated with high blood pressure in Jordanian population. Methods: A cross-sectional study was conducted with a total 622 students and workers from three Jordanian universities. Results: Nearly half of the participant are overweight (34.7%) and obese (15.4%) and hypertension was detected among 138 (22.2%) of the participants. Linear correlation was significant (p<0.01) between both systolic blood pressure and diastolic blood pressure for all anthropometric indices, except for A body shape index and diastolic blood pressure was significant at p< 0.05. Stepwise multiple linear regression analysis was used to assess the influence of age and anthropometric measurements. Conclusions: The waist circumference was the only independent predictor of hypertension, showing that this simple measurement may be an importance marker of high blood pressure in Jordanian population.

Keywords: anthropometric indices, Jordan, blood pressure, cross-sectional study, obesity, hypertension, waist circumference

Procedia PDF Downloads 267
3965 Cavitating Flow through a Venturi Using Computational Fluid Dynamics

Authors: Imane Benghalia, Mohammed Zamoum, Rachid Boucetta

Abstract:

Hydrodynamic cavitation is a complex physical phenomenon that appears in hydraulic systems (pumps, turbines, valves, Venturi tubes, etc.) when the fluid pressure decreases below the saturated vapor pressure. The works carried out in this study aimed to get a better understanding of the cavitating flow phenomena. For this, we have numerically studied a cavitating bubbly flow through a Venturi nozzle. The cavitation model is selected and solved using a commercial computational fluid dynamics (CFD) code. The obtained results show the effect of the inlet pressure (10, 7, 5, and 2 bars) of the Venturi on pressure, the velocity of the fluid flow, and the vapor fraction. We found that the inlet pressure of the Venturi strongly affects the evolution of the pressure, velocity, and vapor fraction formation in the cavitating flow.

Keywords: cavitating flow, CFD, phase change, venturi

Procedia PDF Downloads 56