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

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

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

Resonant Transport in Nb/GaAs/AlGaAs/GaAs Microstructures

Resonant transport in a hybrid semiconductor-superconductor microstructure grown by MBE on GaAs is presented. This structure experimentally realizes the prototype system originally proposed by de Gennes and Saint-James in 1963 in \emph{all}-metal structures. A low temperature single peak superimposed to the characteristic Andreev-dominated subgap conductance represents the mark of such resonant behavior. Random matrix theory of quantum transport was employed in order to analyze the observed magnetotransport properties and ballistic effects were included by directly solving the Bogoliubov-de Gennes equations.Comment: 7 pages REVTeX, 4 figures, to be published by World Scientific in Proceedings of International Symposium on Mesoscopic Superconductivity and Spintronics (NTT R&D Center Atsugi, Japan, March 2002

STAT3, a hub protein of cellular signaling pathways, is triggered by β-hexaclorocyclohexane

Background: Organochlorine pesticides (OCPs) are widely distributed in the environment and their toxicity is mostly associated with the molecular mechanisms of endocrine disruption. Among OCPs, particular attention was focused on the effects of β-hexaclorocyclohexane (β-HCH), a widely common pollutant. A detailed epidemiological study carried out on exposed population in the “Valle del Sacco” found correlations between the incidence of a wide range of diseases and the occurrence of β-HCH contamination. Taking into account the pleiotropic role of the protein signal transducer and activator of transcription 3 (STAT3), its function as a hub protein in cellular signaling pathways triggered by β-HCH was investigated in different cell lines corresponding to tissues that are especially vulnerable to damage by environmental pollutants. Materials and Methods: Human prostate cancer (LNCaP), human breast cancer (MCF-7 and MDA-MB 468), and human hepatoma (HepG2) cell lines were treated with 10 µM β-HCH in the presence or absence of specific inhibitors for different receptors. All samples were subjected to analysis by immunoblotting and RT-qPCR. Results and Conclusions: The preliminary results allow us to hypothesize the involvement of STAT3, through both its canonical and non-canonical pathways, in response to β-HCH. Moreover, we ascertained the role of STAT3 as a master regulator of energy metabolism via the altered expression and localization of HIF-1α and PKM2, respectively, resulting in a Warburg-like effect

Sex-determinants and their distribution in various populations of Musca domestica L. of Western Europe

SUMMARYThe distribution of sex-determinants in field populations ofMusca domestica domesticaL. was studied in 62 samples of flies collected at 53 sites (animal farms) between 1975 and 1981 in an area stretching North–South from Denmark (+ Iceland) to Sicily.Karyological observations and genetic analyses demonstrated the existence of three types of population along a latitudinal cline. Populations of Northern Europe were of the standard type (XXfemales andXYmales) with theYchromosome determining sex. Those of Central and Southern Italy from sites below 100 m.a.s.l. (metres above sea level) were autosomal (XXfemales and males), sex in them being determined by autosomal sex-determinants for both femaleness and maleness. In the large intermediate zone the populations were mixed and had several karyotypes in both sexes. In this zone an altitudinal gradient was also observed, with autosomal determinants less common at higher altitudes. Genetic tests showed, in the autosomal and in the mixed populations, the presence of two autosomal male factors:MIII, the most common, on autosome III andMII, on autosome II.The gradient in sex determinants found in flies of Western Europe appears to be a dynamic phenomenon of relatively recent origin. Both climatic influence and selective pressure with insecticides have probably contributed towards the micro-evolution of populations with different sex-determinants in the houseflies of the area studied

Men’s reactions to gender inequality in the workplace: From relative deprivation on behalf of women to collective action

: Over recent years, the role of men as women's allies in the struggle for gender equality has become increasingly important. Previous research has shown that often men do not fight gender inequalities as they fail to recognize the severity of discrimination against women (e.g., in hiring). In this study (N = 427), we examined whether men who experienced relative deprivation on behalf of women-a form of relative deprivation that stems from the awareness that women hold a less privileged position in society-were more motivated to engage in collective action to support gender equality in the workplace. The findings showed that men's feelings of deprivation on behalf of women were associated with a greater willingness to engage in collective action for gender equality. This relationship was sequentially mediated by two emotional reactions related to deprivation-increased guilt about gender inequalities and decreased fear of a potential backlash-and the moral conviction of acting for gender equality. These results suggest that men's awareness of gender inequality at work is an important antecedent to their acting in solidarity with women and that emotions and moral conviction are two psychological processes that turn cognition into behavior. Action to reduce gender inequalities should make men more sensitive to seeing that they hold a privileged position in society and to recognizing the pervasive and harmful nature of women's deprivation

Unfolding political attitudes through the face: facial expressions when reading emotion language of left- and right-wing political leaders

Spontaneous emotionally congruent facial responses (ECFR) to others\u2019 emotional expressions can occur by simply observing others\u2019 faces (i.e., smiling) or by reading emotion related words (i.e., to smile). The goal of the present study was to examine whether language describing political leaders\u2019 emotions affects voters by inducing emotionally congruent facial reactions as a function of readers\u2019 and politicians\u2019 shared political orientation. Participants read sentences describing politicians\u2019 emotional expressions, while their facial muscle activation was measured by means of electromyography (EMG). Results showed that reading sentences describing left and right-wing politicians \u201csmiling\u201d or \u201cfrowning\u201d elicits ECFR for ingroup but not outgroup members. Remarkably, ECFR were sensitive to attitudes toward individual leaders beyond the ingroup vs. outgroup political divide. Through integrating behavioral and physiological methods we were able to consistently tap on a \u2018favored political leader effect\u2019 thus capturing political attitudes towards an individual politician at a given moment of time, at multiple levels (explicit responses and automatic ECFR) and across political party membership lines. Our findings highlight the role of verbal behavior of politicians in affecting voters\u2019 facial expressions with important implications for social judgment and behavioral outcomes