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A case-control study of hepatocellular adenoma (HCA), a serious though nonmalignant liver tumor, was conducted by the Center for Disease Control and the Armed Forces Institute of Pathology (AFIP). Interviews with 79 women with HCA and with 220 age- and neighborhood-matched controls were completed. Limited information was obtained on nine additional patients(More)
The histories of oral contraceptive (OC) use provided by women participating in a study of hepatocellular adenoma (HCA) were compared with records obtained from their physicians. In the HCA study two memory aids were used to assist women in their recall: a calendar of significant events during a woman's lifetime to which she might relate her use of OCs and(More)
The thermal capacity of totally enclosed fan-cooled converter-fed induction motors varies at the different operating frequencies. Main effects are due to the variation of the cooling airflow, the variation of iron losses, and eventually, the presence of harmonics. This paper presents the results of a complete evaluation of these effects and of the thermal(More)
Neonatal mortality examined by place and circumstances of delivery in North Carolina during 1974 through 1976 with attention given to home delivery. Planned home deliveries by lay-midwives resulted in three neonatal deaths per 1,000 live births; planned home deliveries without a lay-midwife, 30 neonatal deaths per 1,000 live births; and unplanned home(More)
World-wide clinicians apparently prefer to insert the intrauterine device (IUD) during the bleeding phase of the menstrual cycle. To examine the benefits and risks of inserting IUDs at various times during the menstrual cycle, data on over 9000 women having copper T-200 IUD insertions were analyzed. During the first 2 months after IUD insertion: 1) rates of(More)
Women with long-term use of oral contraception (OC) are at increased risk of developing a serious, though nonmalignant, liver tumor--hepatocellular ademona (HCA)--according to a case-control study conducted by the Center for Disease Control (CDC) in collaboration with the Armed Forces Institute of Pathology (AFIP). The tumor is sometimes fatal, deaths(More)
There are many "black boxes" offered to advise the efficiency of installed motors. The major problem with most of those devices is that access to the motor is required; motors must be taken out of service to add instrumentation resulting in excess costs and time. This approach is to take readings at the motor control center or motor starter, without having(More)
This paper describes the performance tests for variable speed drive systems. Most of the applications for VSD systems involved in variable torque loads such as fans and centrifugal pumps, where the load power varies as the cube of the speed. The performance tests of VSD systems are planned to measure efficiency of the VSD unit and the efficiency of the(More)
Three instruments have been evaluated for their ability to estimate the load conditions and efficiency of operating motors based solely on measurements of terminal voltage and current. Laboratory tests, compared to a high-accuracy dynamometer system were used to assess the instruments' accuracy. Field tests were conducted in a paper mill to determine the(More)