An alternative approach to provisions of the Network Code on blocking HVDC LCC systems during short-circuits in AC network

The Network Code for HVDC systems introduces a requirement for such systems to remain in operation in an AC network during short-circuits. This requirement (among others) is determined by a time curve of a minimum voltage in HVDC connection point. The HVDC system is not allowed to be turned-off while the voltage value exceeds the values of the curve, however the HVDC system in LCC technology does not meet this requirement. The Network Code introduces the possibility of blocking the LCC systems. After the LCC system is blocked it stops transmitting the power, which prevents the LCC system from being turned off during a short-circuit in the network but results in a lack of power exchange between the network and the LCC system. Therefore, the authors developed a proposal to limit the power level being transmitted by the LCC system, thus there is no necessity to block the LCC system operation. The simulation research carried out clearly indicate the validity of this idea. In addition, the authors presented the concept of an automation system that adaptively adjusts the scale of the LCC system power level reduction to change the network operating conditions during a short-circuit in the network. The operation of this automation system is presented for the practical LCC system model installed in the Polish Power System

The idea of non-restricted use of LV networks by electricity consumers, producers, and prosumers

Until now, electricity users are being connected to the LV networks by a physical electricity consumption point. In this point an electricity meter is assigned to each and every one user. A given user may use the flowing electricity only by the meter assigned to him at the consumer-specific point. This is a significant limitation in the non- restricted access to the power network. The Authors come with an idea to eliminate this restriction. The paper presents the concept of virtualization of a physical point of electric power consumption in a LV network. The proposed novel idea of using the power network will ensure the expected non-restricted access to any point of the power network for users. This seems particularly important nowadays and is dictated by the growing expectations of users’ mobility. The presented concept is dedicated especially to networks in the form of clusters (cooperatives) or energy clouds. Its application in LV networks will significantly simplify the users’ use of the power infrastructure, also in the aspect of financial settlements. This should also contribute to the rapid significant development of electro- mobility

Rapid assessment of the IL-6 cervico-vaginal fluid level in threatening preterm labor

Summary Objectives: The aim of the study was to check the cervico-vaginal fluid IL-6 levels using rapid, quantitive test in patients with threatening preterm labor, before and after tocolytic treatment. Material and methods: Sixty seven singular pregnant women, between 24 and 36 weeks of gestation, were included into the clinical trial. 35 women who were admitted to the Department due to clinical symptoms of threatened preterm labor formed the study group. 32 women between 24 and 36 gestational week, with uncomplicated pregnancy, formed the control group. Levels of IL-6 were measured just after material collection, using fast, quantitative spectrofotometric test. Results: The cervico-vaginal IL-6 level was higher in the study group (458pg/mL vs 123pg/mL;

The influence of patient-controlled epidural analgesia on labor progress and neonatal outcome

Abstract Aim: The aim of the study was to check the influence of patient control epidural analgesia on labor progress and neonatal outcome. Material and methods: 144 parturients were included into the clinical trial. In 73 cases patient control epidural analgesia was used and in 71 cases pethidine (meperidine) solution was given intravenously. Apgar score, umbilical artery pH, pain intensity, the time of the first, second and third stage of labor, the rate of episiotomy and uterine postpartum abrasions and the rate of caesarean sections and vaginal operative delivery were compared. Results: The time of the second stage of labor was significantly longer in the study group (40.99 vs 26.49min, p

Pregnancy, delivery and puerperium in a patient with lysinuric protein intolerance – a case report

The paper presents the course of pregnancy, delivery and early postpartum period in a 23-year-old woman with lysinuric protein intolerance (LPI). The pregnancy was uneventful and resulted in a caesarean birth to a healthy baby at 37 weeks gestation. Nevertheless, the course of pregnancy in women with LPI is associated with a significantly increased risk of serious complications, including acute hyperammonemia, preeclampsia and postpartum bleeding, as well as fetus intrauterine growth retardation. In many cases, intensive metabolic monitoring and a proper diet with protein limitation and appropriate amino acids supplementation may significantly reduce the risk for both the mother and the newborn

Vaginal and cervical bacterial colonization in patients with threatening preterm labor

Objectives: The aim of the following work was to evaluate vaginal and cervical colonization in patients with threatening preterm labor and comparing the frequency of colonization of the term and preterm labor groups. Material and methods: 532 pregnant women with threatening preterm labor were included into the clinical trial. The frequency of colonization was established and the frequency of colonization depending on the duration of pregnancy was checked. Results: Positive vaginal cultures were found in 29.5% of patients. The most frequent were: Escherichia coli and Streptoccocus agalactiae. There was no relationship between the duration of pregnancy, the frequency of colonization or the type of bacterial culture. Conclusions: 30% of positive vaginal and cervical cultures may indicate about the deficiency of the used method. The most frequent microorganisms remain to be Candida, Escherichia coli and GBS. However, the frequency of colonization with rare bacteria increases. Not only bacterial colonization but a group of different factors may be the reason of preterm labor