Engineering Model to Calculate Mass Flow Rate of a Two-Phase Saturated Fluid Through An Injector Orifice

An engineering model is developed to calculate mass flow rate of nitrous oxide, a self-pressurizing saturated oxidizer commonly used in hybrid rocket motors. While use of N_{2}0 cannot be accurately modeled using traditional ideal gas, compressible, or incompressible flow assumptions. To obtain accurate mass flow rate this one-dimensional analysis includes both incompressible fluid and homogeneous equilibrium mass flow rate models. Mass flow calculations from the two models are independently weighted and summed to obtain representative two-phase mass flow rate. Fluid properties are iterated in time by keeping track of fluid enthalpy and are propagated across the injector using either isentropic or adiabatic assumptions. The model excellently predicts mass flow rates as verified by comparison to experimental cold flow data. The experimental conditions resulting from the test apparatus set-up produces fluid stratification and mixing effects that cannot be modeled by the algorithm as developed. Thus the run tank and temperature drops as predicted by the model are significantly larger than measured

Voice Recognition and Mobility in the Legal Industry

In a typical legal work environment, attorneys work with their staff to generate and send case related legal documents and communications. Traditionally the attorney will dictate to a device capable of recording audio and the legal assistant will transcribe the audio directly from the source. In the early days of recorded dictation audio was recorded and saved to analog tape. Once the technology became available, dictation was saved digitally to flash memory and transmitted to hard disk for playback by the legal assistant. It has been this way for years, and due to advances in voice recognition technology and computer processing there are alternative options to the traditional dictation/transcription process. The focus of this paper is to examine the traditional process of dictation/transcription and how it compares to the process of using voice recognition software. Analysis of each process as well as an evaluation of voice recognition software will be performed. The document generation process will also be examined as it relates to transcription and creating a document, regardless of the content. The most efficient solution which benefits a small to medium size law firm will be recommended. According to Understanding How Law Offices Do Business, a small law firm has between one and ten lawyers and a mid-size law firm has up to 50 lawyers. These firms are the target audience. The goal of this paper is to determine if the use of voice recognition software can help an attorney and their staff be more efficient, and if so, which voice recognition software and methods work the best. Tests will be performed analyzing both Dragon Naturally Speaking 12 Professional and Windows 7 voice recognition software on the desktop. The software with the higher accuracy rate based on our tests will be used to evaluate voice recognition processes throughout this paper

Workers Who Care: A Graphical Profile of the Frontline Health and Health Care Workforce

Presents data about the professionals and paraprofessionals who provide a range of direct patient care and client services, including occupational growth outlook, per capita employment, demographic information, and wage outlook and trends

Assisting Dislocated Workers: Dimensions, Needs and Tax Policy Options

The involvement of the federal government in retraining of dislocated workers raises the specter of rigidity, bureaucracy, paternalism, and cost. After examining the dimensions of the dislocated worker problem and the need for governmental involvement, this article examines the use of tax policy to enable workers to bridge the gap between old and new jobs and to thrive in an economy in transition. The policy making challenge can be succinctly stated: is it possible to use the federal income tax system to the advantage of society by creating tax incentives for a retraining program based on individual choice and limited government involvement

Engaging Faculty and Students through Collection Assessment

How do faculty and graduate students provide input for collection development? How well have librarians understood the research needs of recently tenured faculty or recent graduates? Four librarians from four different collection areas- the humanities, the social sciences, and 2 unique areas in engineering- all set out to see if evaluating the collection against recent publications by faculty and students can foster stronger engagement between them and the subject collectors in their areas

Fabrication and characterization of nano-engineered membranes for oil-water separation

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 55-58).The focus of this thesis is the design and testing of membranes for separation of water-in- oil (w/o) emulsions. A polycarbonate membrane treated with octadecyltrichlorosilane (OTS) is used to filter a 3 wt% w/o emulsion. The permeate is characterized to have no measurable water content by microscopy, dynamic light scattering (DLS) and differential scanning calorimetry (DSC). To extend this work, a method for fabricating an asymmetric polysulfone membranes is presented. The polysulfone membrane has the feature of allowing much higher flow rates for a given applied pressure. The research is largely motivated by a need for low cost methods for separating o/w and w/o emulsions. The largest source of wastewater is generated by the petroleum industry as o/w emulsions. Currently, industry has a number of methods for cleaning produced water. The inherent problem is that the smaller dispersed droplets are the more expensive they are to separate. In addition, the fundamental equations and models that govern interfacial phenomena and hydrophobic/oleophilic membranes are developed. In all, this work present a method for successfully separating oil droplets smaller than a micron from water by a novel methodology.by Brian R. Solomon.S.M

Separating Oil-Water Nanoemulsions using Flux-Enhanced Hierarchical Membranes

Membranes that separate oil-water mixtures based on contrasting wetting properties have recently received significant attention. Separation of nanoemulsions, i.e. oil-water mixtures containing sub-micron droplets, still remains a key challenge. Tradeoffs between geometric constraints, high breakthrough pressure for selectivity, high flux, and mechanical durability make it challenging to design effective membranes. In this paper, we fabricate a hierarchical membrane by the phase inversion process that consists of a nanoporous separation skin layer supported by an integrated microporous layer. We demonstrate the separation of water-in-oil emulsions well below 1 μm in size. In addition, we tune the parameters of the hierarchical membrane fabrication to control the skin layer thickness and increase the total flux by a factor of four. These simple yet robust hierarchical membranes with engineered wetting characteristics show promise for large-scale, efficient separation systems.MIT Energy InitiativeShell Oil CompanyMIT Energy Initiative (Fellowship

Squamous carcinoma of the paranasal sinuses in the Bantu

Thirty-three cases of squamous carcinoma of the paranasal sinuses in South African Bantu are presented. The incidence, pathology, clinical features and treatment of this disease are discussed. Radical telecobalt therapy, followed by extended maxillectomy after an interval of 4 weeks, is recommended as the most effective form of therapy in selected cases

Efficacy of sacubitril/valsartan relative to a prior decompensation: the PARADIGM-HF trial

Objectives: This study assessed whether the benefit of sacubtril/valsartan therapy varied with clinical stability. Background: Despite the benefit of sacubitril/valsartan therapy shown in the PARADIGM-HF (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) trial, it has been suggested that switching from an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker should be delayed until occurrence of clinical decompensation. Methods: Outcomes were compared among patients who had prior hospitalization within 3 months of screening (n = 1,611 [19%]), between 3 and 6 months (n = 1,009 [12%]), between 6 and 12 months (n = 886 [11%]), >12 months (n = 1,746 [21%]), or who had never been hospitalized (n = 3,125 [37%]). Results: Twenty percent of patients without prior HF hospitalization experienced a primary endpoint of cardiovascular death or heart failure (HF) hospitalization during the course of the trial. Despite the increased risk associated with more recent hospitalization, the efficacy of sacubitril/valsartan therapy did not differ from that of enalapril according to the occurrence of or time from hospitalization for HF before screening, with respect to the primary endpoint or with respect to cardiovascular or all-cause mortality. Conclusions: Patients with recent HF decompensation requiring hospitalization were more likely to experience cardiovascular death or HF hospitalization than those who had never been hospitalized. Patients who were clinically stable, as shown by a remote HF hospitalization (>3 months prior to screening) or by lack of any prior HF hospitalization, were as likely to benefit from sacubitril/valsartan therapy as more recently hospitalized patients. (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure [PARADIGM-HF]; NCT01035255)

Feasibility of Focused Cardiac Ultrasound in Pre-participation Screening

Objective: Current American Heart Association (AHA) guidelines for pre-participation athletic screening recommend a 12-point history and exam to minimize the risk of sudden cardiac death. We tested the hypothesis that focused cardiac ultrasound (FCU) performed and simultaneously interpreted by a cardiologist using a handheld ultrasound device would be a feasible addition. Methods: We performed pre-participation screening according to AHA recommendations on high school athletes in a multi-purpose room at their school. In addition to the standard 12-point assessment, a cardiologist simultaneously performed and interpreted a FCU on each athlete using a handheld ultrasound. Results: The mean age of the athletes was 16.6 ± 3.4 years; 68% were male. No evidence of left ventricular hypertrophy, cardiomyopathy, bicuspid aortic valve, or aortopathy was identified. Coronary ostia could not be visualized. Echocardiography added 1.35 ± 0.51 minutes to the standard exam. Conclusion: This feasibility study suggests that the addition of handheld echocardiography with real-time interpretation performed by a cardiologist to a standard AHA pre-participation screening adds less than two minutes of time to the assessment. While the study is not as comprehensive as an office based echocardiogram, it can provide valuable information which may be useful in ruling out some of the most common causes of sudden cardiac death in the young athlete or in selecting those who would benefit from further testing