Fire development theory—An overview

Man's qualitative understanding of fire phenomena has enabled him to develop the fire prevention, control, and extinguishment methods in use today Quantitative understanding derived from the application of engineering science has resulted in significant improvements in many areas of technology. Would not the same approach, the author asks, benefit fire protection engineering?     

Managing a deteriorating process in a batch production environment

When manufacturing processes have a tendency to deteriorate over time and begin producing defective products, there is always a trade-off between the cost and/or rework time that is associated with such defectives and the amount of time that is spent inspecting and restoring the process. Although a considerable amount of attention has been devoted to this trade-off as it is found in high-volume, repetitive manufacturing, we study it in a job shop environment. In particular, we study the way in which inter-job setups affect the inspection policy. After modeling the problem as one of maximizing the throughput of defective-free jobs, we describe a simple algorithm which identifies optimal inspection intervals.     

Respiratory response to cigarette smoking among adolescent smokers: a pilot study

BACKGROUND: Because cigarette smoking affects the respiratory system earlier than many other systems of the human body, an attempt was made to identify objective and subjective respiratory problems among adolescent smokers. METHODS: Two studies based on a pulmonary function test (PFT), respiratory symptom assessment, and other smoking-related variables were undertaken. Study 1 involved cigarette smokers (N = 18, 22% males, mean age 18.7 years) from a freshman college class who participated in an acute smoking experiment that involved performing a PFT before and after smoking a single cigarette. Study 2 was performed on a combined group of vocational-technical high school students and freshman college students (N = 44, 48% males, mean age 17.8 years) where PFT parameters, respiratory symptoms, and smoking-related health vulnerability were assessed among smokers vs nonsmokers. RESULTS: In Study 1, the average reduction across PFT parameters was 4.4% and the mean estimated lung age increased from 27.15 to 29.84 years. In Study 2, a consistent trend toward reduction of PFT values among smokers vs nonsmokers was observed; the mean forced expiratory volume in 1 sec/forced vital capacity ratio (90.51% vs 94.59%), peak expiratory flow rate (80.32% vs 92.06%), and flow rate of 50% of forced vital capacity (88.39% vs 102.81%) differed significantly. Significant differences in respiratory symptoms were also observed among smokers vs nonsmokers. CONCLUSIONS: The beginning of respiratory health disorders can be identified among adolescent smokers. These findings might provide important clues on how to improve outcomes from health care provider-based adolescent smoking cessation counseling.     

The analysis of a tragedy

This analysis shows the great importance of smoke barriers in isolating a fire in a large structure. The author is attempting to estimate mathematically fire growth and fire gas spread rate in the Beverly Hills Supper Club fire.     

MULTIPLE-SHIFT WORKFORCE SCHEDULING UNDER THE 3-4 COMPRESSED WORKWEEK WITH A HIERARCHICAL WORKFORCE

This paper provides efficient optimal workforce scheduling algorithms for 7-days-a-week operations, not necessarily 24 hours a day, under a compressed workweek arrangement called the 3-4 workweek. The model incorporates both the possibilities of shift rotation and downward worker substitutability. The model is readily usable in many 7-days-a-week operations (e.g., hospitals and utilities).     

1997 American Urological Association Gallup survey: Changes in diagnosis and management of prostate cancer and benign prostatic hyperplasia, and other practice trends from 1994 to 1997

PURPOSE: The American Urological Association first commissioned the Gallup Organization to conduct a study to assess urologist practice patterns in 1992. We present the results of the 1997 survey, the sixth consecutive Gallup survey performed for the Association. MATERIALS AND METHODS: A random sample of 502 American urologists who had completed urological residency and practiced at least 20 hours weekly in 1996 was interviewed by telephone in February and March 1997. RESULTS: Emerging trends showed significant changes since 1994 in how urologists diagnosed and treated prostate cancer. The survey revealed a significant change in the tests routinely ordered to stage newly diagnosed prostate cancer and for diagnostic evaluation of patients with benign prostatic hyperplasia. CONCLUSIONS: Urologists are becoming more cost conscious and effective in ordering pretreatment testing. Urologists are becoming more oriented toward medical treatment for the management of benign prostatic hyperplasia, and less laser surgery is being performed.     

Practice trends of American urologists in the treatment of impotence, incontinence and infertility

PURPOSE: Trends of urologist practice patterns in evaluating and treating impotence, incontinence and infertility in the United States were assessed. MATERIALS AND METHODS: In July 1995 the executive interviewing branch of the Gallup Organization selected randomly and interviewed by telephone 533 practicing urologists in the United States who had provided urological patient care for more than 20 hours per week, practiced in 1994 and completed a urological residency program. RESULTS: Treatment of male sexual dysfunction and female urinary incontinence comprises a significant portion of the professional activity of United States urologists. However, evaluation and management of male infertility occupy a small portion of the average urological work load. While more than half of United States urologist office clinical laboratories were inspected in 1994, only 2% failed evaluation due to major deficiencies. CONCLUSIONS: Male sexual dysfunction and female urinary incontinence are major areas of urological practice in the United States but male infertility is not. Few United States urologist clinical laboratories failed inspection because of major deficiencies.     

Transpiration drying of porous hygroscopic materials

The phenomenon of transpiration drying of porous hygroscopic bodies has been investigated, both experimentally and theoretically, to understand the process of heat and mass transfer involved in the drying.The experiments consist of measuring the drying rates of thin sheets of paper dried by passing dry air through the sheets. The time history of drying was measured, under different air flow conditions and for different paper thicknesses, by a gravimetric method. The drying rates were deduced from these data and correlated against flow variables. Characteristic constant and falling drying rates were observed.A two region theoretical analysis of the problem is made. In the first phase, a bulk analysis of the constant drying regime is worked out. This analysis provides a means of properly defining the heat- and mass-transfer coefficients. The analysis is extended to include a specific internal evaporative mechanism within the fibrous body. Analytical and numerical solutions in the form of an evaporative coefficient have been obtained. In the second phase of the analysis, the falling drying rate regime is accounted for by the fact that the vapor pressure inside the body decreases with decreasing moisture content. A numerical solution to the transient mass-energy equation is obtained (incorporating the effects of solid matrix conduction and fiber shrinkage) to predict the drying rate as a function of time. The results agree well with observed data.Based on the analytical and experimental results correlations are given to predict the time to dry from a given initial moisture content to a specific final moisture content.