Modeling energy demand aggregators for residential consumers

Energy demand aggregators are new actors in the energy scenario: they gather a group of energy consumers and implement a demand-response paradigm. When the energy provider needs to reduce the current energy demand on the grid, it can pay the energy demand aggregator to reduce the load by turning off some of its consumers loads or postponing their activation. Currently this operation involves only greedy energy consumers like industrial plants. In this paper we want to study the potential of aggregating a large number of small energy consumers like home users as it may happen in smart grids. In particular we want to address the feasibility of such approach by considering which scale the aggregator should reach in order to be able to control a significant power load. The challenge of our study derives from residential users' demand being much less predictable than that of industrial plants. For this reason we resort to queuing theory to study analytically the problem and quantify the trade-off between load control and tolerable service delays

Essure transcervical tubal sterilization: a 5-year x-ray follow up.

Abstract OBJECTIVE: To evaluate the x-ray appearance of Essure microinserts 5 years after their insertion. DESIGN: Prospective controlled study. SETTING: Tertiary referral centers for gynecologic care. PATIENT(S): Forty-five consecutive women with successful hysteroscopic bilateral placement of the Essure devices and postprocedure satisfactory hysterosalpingography confirmation test. INTERVENTION(S): Pelvic anteroposterior x-ray. MAIN OUTCOME MEASURE(S): Stability and and symmetric appearance of Essure microinsert positions; measurement of the intrauterine distance between the two devices. RESULT(S): After 5 years from their placement, no detachment nor fracture of devices was observed. x-Ray recognition of the device after 5 years showed findings similar to those recorded at 3 months' follow-through hysterosalpingography. CONCLUSION(S): x-Ray evaluation of findings related to stability of position, symmetric appearance, and distance between the two Essure microinserts corroborates the irreversibility and the reliability of the fibrotic reaction that ensured tubal occlusion after devices placement

Factors associated with climacteric symptoms in women around menopause attending menopause clinics in Italy

Objective: To obtain data on correlates of climacteric symptoms in women around menopause attending menopause clinics in Italy. Methods: Since 1997 a large cross sectional study has been conducted on the characteristics of women around menopause attending a network of first level menopause outpatient's clinics in Italy. A total of 66,501 (mean age 54.4 years) women are considered in the present paper. Results: The odds ratios of moderate and severe hot flashes/night sweats were lower in more educated women and (for severe symptoms only) in women reporting regular physical activity. Depression, difficulty to sleep, forgetfulness and irritability tended to be less frequent in more educated women and (depression only) in women reporting regular physical activity. Parous women reported more frequently these symptoms. Conclusions: This large study confirms in Southern European population that low education, body mass index and low physical activity are associated with climacteric symptoms. Parous women are at greater risk of psychological symptoms