Maternal and perinatal outcome in placenta previa - one year study in tertiary care center in Tamil Nadu, India

Background: Obstetric hemorrhage is one of the most dangerous and devasting group of disorders in Obstetrics of which placenta previa contributes 1/5th of the cases. The aim of this study was to analyze the obstetrical factors and the maternal and perinatal outcome of these cases.Methods: This was a retrospective study conducted in the Department of Obstetrics and Gynecology of Thanjavur Medical College Hospital, Thanjavur from August 2014 - July 2015. Chart records of all women who had undergone cesarean section for placenta previa were reviewed. Relevant clinical findings were noted.Results: In the present study, 134 cases of placenta previa were studied regarding type of clinical presentation, clinical course, maternal and perinatal outcome. Information obtained was arranged statistically. A placenta previa case was highest in the age group 20-29 years (79.85%) and in multiparous group (63.43%). Most common risk factor was previous cesarean section (39.5%) followed by abortion in 24.6%. Major degree of placenta previa constitutes 69.4% i.e., majority of cases and minor degree constitutes 30.59% of cases. In the present study massive blood transfusion was required in 0.04% of all cases, adherent placenta previa in 1.9%, 12.68% required hysterectomy. Perinatal morbidity was 25.92% and perinatal mortality incidence was 16.41%. Prematurity contributed the most 63.6% followed by RDS about 4.58%. Newborn with weight above 2 kg has very good survival rates, whereas newborn with weight <1 kg has poor survival rates.Conclusions: Placenta previa poses danger to both the mother and the baby with high maternal morbidity and adverse perinatal outcome

Condition Monitoring Techniques of Ball Bearings in Non-stationary Conditions

Frequently, the Industry suggests non-trivial problems and new fields of research for the Academy. This is the case of the ball bearing diagnostics in direct-drive motors. Direct-drive motors are brushless motors fully controlled by the drive system. Thanks to an encoder or a resolver mounted on the shaft, they can perform complex motion profiles, such as polynomials or splines, including reverse rotation of the shaft. The main advantage of direct-drive motors is the removal of cams or gearboxes afterwards motor with a consequent strong reduction of economic and maintaining costs. Indeed, their main drawback is the difficulty to make diagnostics on the bearings. Regarding bearing diagnostics, most of the techniques present in literature are based on the search of fault-characteristic frequencies in the vibration spectrum of the motor. These fault frequencies are linearly dependent on the rotational frequency of the shaft if it is supposed constant. However, in direct-drive motors the rotational speed changes continuously and consequently the fault frequencies are meaningless. The paper reports a brief overview of some techniques for the condition monitoring of ball bearings in non-stationary conditions used by the Authors in the case of a packaging machine working under variable speed. The techniques adopted include an improved version of the computed order tracking, the cross-correlation function and three supervised learning approaches: artificial neural networks, artificial immune systems and support vector machines

Advanced radar absorbing ceramic-based materials for multifunctional applications in space environment

In this review, some results of the experimental activity carried out by the authors on advanced composite materials for space applications are reported. Composites are widely employed in the aerospace industry thanks to their lightweight and advanced thermo-mechanical and electrical properties. A critical issue to tackle using engineered materials for space activities is providing two or more specific functionalities by means of single items/components. In this scenario, carbon-based composites are believed to be ideal candidates for the forthcoming development of aerospace research and space missions, since a widespread variety of multi-functional structures are allowed by employing these materials. The research results described here suggest that hybrid ceramic/polymeric structures could be employed as spacecraft-specific subsystems in order to ensure extreme temperature withstanding and electromagnetic shielding behavior simultaneously. The morphological and thermo-mechanical analysis of carbon/carbon (C/C) three-dimensional (3D) shell prototypes is reported; then, the microwave characterization of multilayered carbon-filled micro-/nano-composite panels is described. Finally, the possibility of combining the C/C bulk with a carbon-reinforced skin in a synergic arrangement is discussed, with the aid of numerical and experimental analyses

Optimizing food ordering in a multi-stage catering supply chain network using reusable containers

Reusable plastic containers (RPCs) prevent packaging waste in the food supply chains. Food Catering Supply Chain (FCSC) made of multi-stage logistic networks represents a challenging scenario for adopting RPCs to optimize, particularly when the container's flow meets the food supplies. This paper fosters the application of RPCs in such FCSC by proposing a food-ordering MILP model to aid the cross-docking player in selecting the suppliers and releasing packaged food orders efficiently. This model optimizes logistic costs and operations as well as the influence of the container pooler's facilities network in the FCSC. A numerical example extracted by a larger case study provides validation of the model and offers insights for future research investigations

Motor Current Cyclic-Non-Stationary Analysis for Bearing Diagnostic

The Motor Current Signature Analysis (MCSA) is a research area focused on the diagnosis of components of electric motors based on post-processing of the current signal mainly. In particular, the bearing diagnostics is based on two different assumptions: the fault on the bearing causes a vibration of the shaft it supports, so there is an air gap variation between stator and rotor causing a modulation in the current signal; the fault on the bearing hinders the rotation of the shaft, so it can be modeled as an additional loading torque that the motor satisfies increasing the current signal. In this paper, a cyclic-non-stationarity analysis of the motor current is used to assess the status of ball-bearings in servomotors, running at variable speed. Both speed of the motor and motor current are provided by the control loop of the servomotor, that is no external sensors are used. The cyclic nature of the application allows an average of the cyclic-cyclic order maps to increase the signal-to-noise ratio. The proposed technique is successfully applied to both healthy and faulty bearings

Expedient synthesis of pseudo-Pro-containing peptides: Towards constrained peptidomimetics and foldamers

The reaction of sulfonyl peptides containing l- or d-configured Ser or Thr with bis(succinimidyl) carbonate in the presence of a catalytic amount of a base affords, in solution or in the solid phase, the corresponding peptides with one or two, consecutive or alternate oxazolidin-2-ones (Oxd). The Oxd ring can be regarded to as a pseudo-Pro with an exclusively trans conformation of the preceding peptide bond; homochiral Oxd-containing peptides adopt extended conformations, while the presence of a d-configured Oxd favours folded conformations. © The Royal Society of Chemistry 2012