219 research outputs found

    A study on pattern of placentation in post caesarean pregnancy

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    Background: It appears that the rate of caesarean delivery has been increasing over the past two decades. Various western studies have shown that with previous caesarean section, increased risk of placenta previa, adherent placenta, and greater incidence of antepartum haemorrhage. Nonetheless, the extent to which previous caesarean delivery predisposes women to the development of placenta previa is unclear from earlier studies. Also, there are not many Indian studies regarding the association of placenta previa and previous caesarean section. This study aims to find the association between prior caesarean delivery and subsequent development of placenta previa and adherent placenta.Methods: A descriptive study was conducted on 600 antenatal women with post cesarean pregnancy in a tertiary care centre. Similar number of women with previous normal delivery was included in comparison group and placental location was studied. Those patients with previous caesarean were further divided into those with placenta previa and without previa to study the determinants of previa in those with previous caesarean section.Results: Placenta previa was found in 2.8% of the study group compared to 1.2% of comparison group. Adherent placenta was found only in post caesarean group. In the post caesarean group, the incidence of anterior previa was 41.2% compared to posterior previa (29.3%). In those with post cesarean pregnancy, determinants of placenta previa found were multiparity (35.3%), previous history of abortions (35%), multiple previous caesarean sections (29.4%), interpregnancy interval <2 years (35.29%).Conclusions: In post cesarean pregnancy, the risk of placenta previa is 2 times compared to those with a previous normal delivery. Anterior previa occurred with sufficient frequency in post-caesarean pregnancy to warrant ultrasonic placentography prior to surgical entry into lower segment. When the combination of previous caesarean and placenta previa occurs the risk of adherent placenta is 17.6%

    XRD TEM EELS Studies on Memory Device Structures

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    Over the past decade, numerous emerging memory technologies are being considered as contenders to displace either or both NAND flash and DRAM as scaling limitations of these conventional memories are perceived for applications in mobile devices. Some of these include Magnetic and Spin Transfer Torque Random Access Memory MRAM, STTRAM , Phase Change RAM PCRAM , Ferroelectric RAM and Resistive RAM memories. These technologies can be classified as relying on one of the movements atomic, ionic, electron charge or spin in nanoscale thin films comprising of a variety of materials. The literature shows about 50 elements of the periodic table being investigated for these memory applications owing to their unique physical and chemical properties. Engineering memory devices requires nanoscale characterizations of film stacks for their chemical compositions and crystalline nature in addition to electronic properties such as resistance, magnetization and polarization depending upon the principle involved. This paper focuses on how x ray diffraction XRD , transmission electron microscopy TEM and electron energy loss spectroscopy EELS techniques have been employed to obtain insight into engineering magnetic tunnel junctions MTJ and PCM device

    Seasonal dependence of the "forecast parameter" based on the EIA characteristics for the prediction of Equatorial Spread F (ESF)

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    In an earlier study, Thampi et al. (2006) have shown that the strength and asymmetry of Equatorial Ionization Anomaly (EIA), obtained well ahead of the onset time of Equatorial Spread F (ESF) have a definite role on the subsequent ESF activity, and a new "forecast parameter" has been identified for the prediction of ESF. This paper presents the observations of EIA strength and asymmetry from the Indian longitudes during the period from August 2005-March 2007. These observations are made using the line of sight Total Electron Content (TEC) measured by a ground-based beacon receiver located at Trivandrum (8.5° N, 77° E, 0.5° N dip lat) in India. It is seen that the seasonal variability of EIA strength and asymmetry are manifested in the latitudinal gradients obtained using the relative TEC measurements. As a consequence, the "forecast parameter" also displays a definite seasonal pattern. The seasonal variability of the EIA strength and asymmetry, and the "forecast parameter" are discussed in the present paper and a critical value for has been identified for each month/season. The likely "skill factor" of the new parameter is assessed using the data for a total of 122 days, and it is seen that when the estimated value of the "forecast parameter" exceeds the critical value, the ESF is seen to occur on more than 95% of cases

    The Impact of Operation Revitalisation Strategies in Power Generation Plants on Customer Satisfaction

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    Purpose: The purpose of this manuscript is to examine the influence of operation revitalization strategies and management reforms on customer satisfaction in the power plant industry.   Theoretical framework: The conceptual model for this study was developed based on previous research in the field of project management in Malaysia and globally. The conceptual model has three operations revitalization variables that affect customer satisfaction.   Design/methodology/approach: A survey instrument in the form of a structured questionnaire was designed based on a careful review of pertinent literature. This study collected empirical data from 196 respondents. Multiple regression analysis is used to test the significance of the research model.   Findings: The regression results reveals that business process reengineering, agile and lean manufacturing and reconfigurable manufacturing system effects customer satisfaction.   Research, Practical &amp; Social implications: The implication drawn from this study aids project managers in providing a focus on the key variables that affect customer satisfaction in the power plant industry.   Originality/value: The key value of this research lies in its findings of the key variables influencing customer satisfaction in the power plant industry in Malaysia which is currently under researched

    A case report of manic episode following SARS-CoV-2 infection

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    The novel coronavirus infection has been associated with various neuropsychiatric sequelae, including manic episodes, but only a few cases have been described in the literature. Here we present a case of a manic episode in an individual following COVID-19 infection, probably linked to the virus. This case report highlights the need to identify and assess various neuropsychiatric manifestations of COVID-19 and the need for further research on its manifestations, biological mechanisms, and long-term sequelae

    Development of Thiobacillus ferrooxidans ATCC 19859 strains tolerant to copper and zinc

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    A study was carried out to develop strains of Thiobacillus ferrooxidans ATCC 19859 tolerant to higher levels of heavy metal ions. Strains of T. ferrooxidans capable of growing in Cu2+ (30 g/L) and Zn2+ (60 g/L) have been obtained. The ability of strains tolerant to either copper or zinc to grow in medium containing both the metals has been examined. The copper-tolerant strain (25 g/L) grows better in the medium containing both metals (Cu2+ 25 g/L and Zn2+ 40 g/L) compared to the zinc-tolerant strain (40 g/L)

    The combined effects of electrojet strength and the geomagnetic activity (<I>K<sub>p</sub></I>-index) on the post sunset height rise of the F-layer and its role in the generation of ESF during high and low solar activity periods

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    International audienceSeveral investigations have been carried out to identify the factors that are responsible for the day-to-day variability in the occurrence of equatorial spread-F (ESF). But the precise forecasting of ESF on a day-to-day basis is still far from reality. The nonlinear development and the sustenance of ESF/plasma bubbles is decided by the background ionospheric conditions, such as the base height of the F-layer (h'F), the electron density gradient (dN/dz), maximum ionization density (Nmax), geomagnetic activity and the neutral dynamics. There is increasing evidence in the literature during the recent past that shows a well developed Equatorial Ionization Anomaly (EIA) during the afternoon hours contributes significantly to the initiation of ESF during the post-sunset hours. Also, there exists a good correlation between the Equatorial Ionization Anomaly (EIA) and the Integrated Equatorial ElectroJet (IEEJ) strength, as the driving force for both is the same, namely, the zonal electric field at the equator. In this paper, we present a linear relationship that exists between the daytime integrated equatorial electrojet (IEEJ) strength and the maximum elevated height of the F-layer during post-sunset hours (denoted as peak h'F). An inverse relationship that exists between the 6-h average Kp-index prior to the local sunset and the peak h'F of the F-layer is also presented. A systematic study on the combined effects of the IEEJ and the average Kp-index on the post-sunset, peak height of the F-layer (peak h'F), which controls the development of ESF/plasma bubbles, is carried out using the ionosonde data from an equatorial station, Trivandrum (8.47° N, 76.91° E, dip.lat. 0.5° N), an off-equatorial station, SHAR (13.6° N, 79.8° E, dip.lat. 10.8° N) and VHF scintillations (244 MHz) observed over a nearby low-latitude station, Waltair (17.7° N, 83.3° E, dip.lat. 20° N). From this study, it has been found that the threshold base height of the F-layer at the equator for the development of plasma bubbles is reduced from 405 km to 317 km as the solar activity decreases from March 2001 (mean Rz=113.5) to March 2005 (mean Rz=24.5). This decrease in threshold height with the decreasing solar activity is explained on the basis of changes in the local linear growth rate of the collisional Rayleigh-Taylor instability, due to the variability of various terms such as inverse density gradient scale length (L?1), ion-neutral collision frequency (?in) and recombination rate (R) with the changes in the solar activity

    Electrodynamics of the equatorial F-region ionosphere during pre-sunrise period

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    The electrodynamics of the pre-sunrise equatorial F-region is investigated using HF Doppler radar and digital ionosonde. The observations are limited to those days for which the radar probing frequency is below the Æ’oF2 value. The ionosphere observation using HF Doppler radar exhibit interesting features during pre-sunrise period similar to the post sunset pre-reversal enhancement. The most striking feature observed during pre-sunrise period is the sudden downward excursion in the vertical drift around local sunrise followed by an upward turning. Pre-sunrise observations of vertical plasma drift and the sunrise downward excursion followed by an upward turning after the ground sunrise related to the zonal electric field at the equatorial F-region are the most significant results not reported earlier
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