Mass Transfer In Dispersed And Continous Phases For Creeping Flow Of Fluid Spheres Through Power Law Fluids

The diffusion equation was numerically solved by an implicit finite-difference method for the purpose of calculating the continuous phase Sherwood number, Sh, for mass transfer from an internally circulating Newtonian droplet traveling through a non-Newtonian power-law-type continuous phase in the creeping flow regime. The Mohan stream functions were used in the calculations in order to approximate the velocity profile inside and outside the droplet. The calculated Sh is presented as a function of the Peclet number, Pe, power-law index, n, and a viscosity ratio parameter, X. Sh increases as n decreases in the pseudoplastic region. The dependence of Sh on n is important when Pe is greater than 102, except when both X \u3e 1 and Pe \u3e 104. When used with the Mohan stream functions, the Baird and Hamielec short-range diffusion equation provides a close approximation for Sh when X \u3c 3, provided that Pe \u3e 104. The mass transfer model for the dispersed phase was also numerically solved in order to determine the effect of continuous phase pseudoplasticity, n. Although a slight increase in the total amount of mass transferred, Amt, with a decrease in n was determined, it is concluded that the power-law behavior in the continuous phase does not affect to any appreciable extent the internal mass transfer, either with or without chemical reaction in the fluid sphere. Amt increases with decreasing X, and this dependency is particularly important when mass transfer occurs with chemical reaction in the dispersed phase. © 1976, American Chemical Society. All rights reserved

Mass Transfer To Drops Moving Through Power Law Fluids In The Intermediate Reynolds Number Region

The mass transfer rate to fluid spheres is calculated for power law and Newtonian fluids by using the intermediate Reynolds number stream functions of Nakano and Tien (1970) and Yamaguchi et al. (1974), respectively. The Sh increases with increases in Re and Pe and decreases in n. Better results are obtained with Nakano and Tien\u27s functions when Re \u3e 10 and with Yamaguchi\u27s functions when Re \u3c 10. Copyright © 1976 American Institute of Chemical Engineer

Are Preoperative Routine Laboratory Tests Necessary in Minor and Moderate Surgical Procedures?

Preoperative routine tests are commonly used to evaluate patients who will have planned elective surgical procedure. In this study, we aimed to identify the preoperative tests required for ASA I-II patients, over 40 years old, who will undergo elective minor and moderate surgeries. Totally 140 patients were included in the study. They were separated into 2 groups equally [Group I (40-59 years) and Group II (≥60 years)] according to their ages. The patients’ preoperative tests; including chest radiography, electrocardiography, hemoglobin, white blood cell, platelets, glucose, sodium, potassium, aspartate transaminase, alanine transaminase, ürea and creatinine were evaluated together with history and physical examination. After routine monitoring, balance anaesthesia was performed. The patients were followed during the peroperative and postoperative 24 hours for any problems occurred. In Group I; excluding ürea in both male and female patients and haemoglobin in only female patients; preoperative tests had no effect on the management of the asymptomatic patients. In Group II; electrocardiography, chest radiography, ürea, glucose and hemoglobin tests effected the management of the patients in the preoperative and postoperative period. In conclusion, preoperative tests could be ordered according to history and physical examination of the patients

Bloqueio dos nervos ílio‐hipogástrico/ilioinguinal em correção de hérnia inguinal para tratamento da dor no pós‐operatório: comparação entre a técnica de marcos anatômicos e a guiada por ultrassom

ResumoObjetivoComparar a eficácia de bloqueios dos nervos ílio‐hipogástrico/ilioinguinal feitos com a técnica guiada por ultrassom e a de marcos anatômicos para o manejo da dor no pós‐operatório em casos de herniorrafia inguinal em adultos.MétodosForam randomicamente divididos 40 pacientes, estado físico ASA I‐II, em dois grupos iguais: nos grupos AN (técnica de marcos anatômicos) e US (técnica guiada por ultrassom), o bloqueio dos nervos ílio‐hipogástrico/ilioinguinal foi feito com 20mL de levobupivacaína a 0,5% antes da cirurgia com as técnicas especificadas. Escore de dor na avaliação pós‐operatória, tempo de primeira mobilização, tempo de internação hospitalar, escore de satisfação com a analgesia no pós‐operatório, efeitos colaterais induzidos por opiáceos e complicações relacionadas ao bloqueio foram avaliados durante 24horas de pós‐operatório.ResultadosEscores EVA em repouso na sala de recuperação e todos os valores clínicos durante o acompanhamento foram significativamente menores no grupo ultrassom (p<0,01 ou p<0,001). Escores EVA em movimento na sala de recuperação e todos os valores clínicos durante o acompanhamento foram significativamente menores no grupo ultrassom (p<0,001 em todos os tempos avaliados). Enquanto os tempos de internação e da primeira mobilização foram significativamente menores, os índices de satisfação com a analgesia foram significativamente maiores no grupo ultrasom (p<0,05, p<0,001, p<0,001, respectivamente).ConclusãoDe acordo com o nosso estudo, o bloqueio dos nervos ílio‐hipogástrico/ilioinguinal guiado por US em herniorrafias inguinais em adultos proporciona uma analgesia mais eficaz e maior satisfação com a analgesia do que com a técnica de marcos anatômicos. Além disso, pode‐se sugerir que a observação das estruturas anatômicas com a US pode aumentar o sucesso do bloqueio e minimizar as complicações relacionadas ao bloqueio.AbstractObjectivesThe purpose of this study is to compare the efficacy of iliohypogastric/ilioinguinal nerve blocks performed with the ultrasound guided and the anatomical landmark techniques for postoperative pain management in cases of adult inguinal herniorrhaphy.Methods40 patients, ASA I–II status were randomized into two groups equally: in Group AN (anatomical landmark technique) and in Group ultrasound (ultrasound guided technique), iliohypogastric/ilioinguinal nerve block was performed with 20ml of 0.5% levobupivacaine prior to surgery with the specified techniques. Pain score in postoperative assessment, first mobilization time, duration of hospital stay, score of postoperative analgesia satisfaction, opioid induced side effects and complications related to block were assessed for 24h postoperatively.ResultsVAS scores at rest in the recovery room and all the clinical follow‐up points were found significantly less in Group ultrasound (p<0.01 or p<0.001). VAS scores at movement in the recovery room and all the clinical follow‐up points were found significantly less in Group ultrasound (p<0.001 in all time points). While duration of hospital stay and the first mobilization time were being found significantly shorter, analgesia satisfaction scores were found significantly higher in ultrasound Group (p<0.05, p<0.001, p<0.001 respectively).ConclusionAccording to our study, US guided iliohypogastric/ilioinguinal nerve block in adult inguinal herniorrhaphies provides a more effective analgesia and higher satisfaction of analgesia than iliohypogastric/ilioinguinal nerve block with the anatomical landmark technique. Moreover, it may be suggested that the observation of anatomical structures with the US may increase the success of the block, and minimize the block‐related complications

MOTION OF A CIRCULATING POWER-LAW DROP TRANSLATING THROUGH NEWTONIAN FLUIDS AT INTERMEDIATE REYNOLDS NUMBERS

The equations of motion for the flow of a power-law fluid sphere in a Newtonian continuous phase have been approximately satisfied by Galerkin's method: External and internal stream functions have been obtained for the following ranges of variables: 10-50 for Re0, 0.1-1000 for the viscosity ratio parameters, X, and 0.6-1.0 for the dispersed phase power-law index, ni,. It is predicted that pseudoplasticity in the dispersed phase causes a reduction in the circulation within the drop and that it has a minor effect on the drag coefficients and the rates of mass transfer in the continuous phasePublisher's Versio

MASS TRANSFER AND CHEMICAL REACTION IN A POWER-LAW SPHERE AT INTERMEDIATE REYNOLDS NUMBERS

The relevant mass transport equations have been numerically solved to determine the effect of power-law behavior in the dispersed phase. It is concluded that increased pseudoplasticity in the dispersed phase causes decreases in the total amount of mass transferred, C¯lt, to the droplet because of reduced circulation velocities. Maximum decreases in C¯lt, with increasing pseudoplasticity are realized for larger Peclet number, larger values of the ratio of the viscosity of the dispersed to continuous phase and for smaller Reynolds number. Substantial increases in the total amount of mass transfer are predicted as the regime changes from creeping to that of intermediate Reynolds number flow due to increased contribution of forced convection.Publisher's Versio