Magnetotransport in the CeIrIn5{_5} system: The influence of antiferromagnetic fluctuations

We present an overview of magnetotransport measurements on the heavy-fermion superconductor CeIrIn$_5$. Sensitive measurements of the Hall effect and magnetoresistance (MR) are used to elucidate the low temperature phase diagram of this system. The normal-state magnetotransport is highly anomalous, and experimental signatures of a pseudogap-like precursor state to superconductivity as well as evidence for two distinct scattering times governing the Hall effect and the MR are observed. Our observations point out the influence of antiferromagnetic fluctuations on the magnetotransport in this class of materials. The implications of these findings, both in the context of unconventional superconductivity in heavy-fermion systems as well as in relation to the high temperature superconducting cuprates are discussed

An integrated approach for the characterization of groundwater quality using multivariate statistical techniques and spatial analysis

ABSTRACT. Ground water accessed via wells in areas of Tiruvallur district of the southern Indian state of Tamil Nadu has been a subject to increase sea-water intrusion. The present study highlights the potable water crisis in the northern district evaluated using GIS-assisted determination of water quality parameters across fifty sampling sites. The most informative parameters evaluated within this study were TDS, EC, TH, Na+, Mg2+, Ca2+, Cl- and SO42- while parameters such as pH, CO32-, etc. had limited correlated significance to water quality. The total dissolved solids (TDS) and electrical conductivity (EC) determined in the study area indicated significantly elevated levels across the sampling sites. Weighted arithmetical indexing (WAI) of the water quality parameters indicated 30 out of 50 water sources meet the tolerance limits for both drinking and irrigation. Based on BIS standards, only 13 sites met acceptable limits for safe drinking water. Principal component analysis and piper plot analysis revealed a significant involvement of Mg2+, Na+, Cl- and SO42- in the impairment of water quality, particularly in the coastal zones. Spatial hydro-chemical profiles developed in this study reveal ‘hot-spots’ of sea-water tainted water sources, and the hydro-chemical dominance of alkali earth components. Altogether, the study findings indicate a widening water crisis on top of over-exploited water resources and discuss possible factors and remedial steps in addressing the situation.   KEY WORDS: Ground water, Principal component analysis, Piper Plot, Water quality index, Irrigation suitability   Bull. Chem. Soc. Ethiop. 2022, 36(2), 241-260.                                                           DOI: https://dx.doi.org/10.4314/bcse.v36i2.1                                                       &nbsp

Femtosecond carrier dynamics and saturable absorption in graphene suspensions

Nonlinear optical properties and carrier relaxation dynamics in graphene, suspended in three different solvents, are investigated using femtosecond (80 fs pulses) Z-scan and degenerate pumpprobe spectroscopy at 790 nm. The results demonstrate saturable absorption property of graphene with a nonlinear absorption coefficient, $beta$, of ~2 to 9x10^-8 cm/W. Two distinct time scales associated with the relaxation of photoexcited carriers, a fast one in the range of 130-330 fs (related to carrier-carrier scattering) followed by a slower one in 3.5-4.9 ps range (associated with carrier-phonon scattering) are observed.Comment: 3 pages, 2 figures, 2 table

Correlation of amniotic fluid index with fetomaternal outcome

Background: Amniotic fluid acts like a protective cover around the baby. Advances in ultrasound have increased early detection of abnormal amniotic fluid volumes. Any variation in the amniotic fluid volume warrants antenatal foetal surveillance.Methods: 300 pregnant women between 37 to 40 weeks of gestation were included in the study. A detailed history, examination and ultrasound was done. Pregnant women were divided into 3 groups’ i.e. normal liquor, oligohydramios and polyhydramnios. All the women were closely monitored during labour and puerperium. Follow-up was done till 7 days post-delivery. Maternal and neonatal data were collected.Results: 300 pregnant women were included in the study, out of which 221 had normal amniotic fluid index (AFI), 64 had oligohydramnios and 15 had polyhydramnios. All baseline characteristics were comparable between the groups except body mass index (BMI). Incidence of meconium stained liquor was significantly higher in oligohydramnios compared to normal AFI and polyhydramnios groups (34.4% versus 10.5% versus 13.3%; p=0.0001). Caesarean section rates were significantly higher in polyhydramnios and oligohydramnios compared to normal AFI group (73.3% versus 70.3% versus 19.9%; p=0.0001). Higher cases of low birth weight were recorded in oligohydramnios group compared to normal AFI and polyhydramnios group group (32.8% versus 18.6% versus 13.3%; p=0.011). Neonatal intensive care unit (NICU) admissions were higher in oligohydramnios (35.9%) and polyhydramnios (33.3%) compared to normal AFI group (35.9% versus 33.3% versus 12.7%; p=0.0001).Conclusions: Abnormal liquor volumes are associated with increased caesarean section rates, NICU admissions and neonatal mortality. Careful assessment of pregnant women is imperative for proper counselling and management

Use of Case Histories to Enhance Practical Geotechnical Engineering

Mathematical models are constructed to describe the behavior of engineering systems in quantitative terms. During conceptualization stage of modelling several valid assumptions have to be made so as to make the model predict the behavior of the system as accurately as possible. Refinement of mathematical models need feed back from practice. Many practical cases are of interest in updating and enhancing quantitative judgment of geo-technical systems behavior. This paper envisages to present a few interesting cases where the situation forced true synthesis of theory and practice for innovation and advancement of practical geo-technical engineering

The Effects of Information Technology and Service-Oriented Architectures on Joint Venture Value

Alliances represent a variety of governance contexts, and hence provide a rich empirical setting for studying the value-creation mechanisms of Information Technology (IT). We examine the influence of IT investment and flexible IT infrastructure, through Service Oriented Architecture (SOA), in the effect of alliance activity on firm performance. We find that the marginal contribution of each joint venture to intangible firm value increases with investment in IT and in SOA. We also find that the impacts of IT and SOA are greater in the case of joint ventures than in non-equity alliances. Given that the hierarchical controls built into joint ventures may be offsetting many of the transaction and coordination costs inherent in joint venture activities, our results suggest that IT and SOA, through enhancement of flexibility, are likely to be reducing the costs of reconfiguration of firm resources. We test our hypotheses using data from 375 firms that are publicly listed in the United States and that span multiple industries; these firms have collectively engaged in more than 8,000 alliances over a period of 10 years

Innovation in E-Attendance System using Biometrics

In this paper we propose a system that works on an attendance system using biometrics that authenticates the user and marks his/her attendance in the easiest way possible. The current system involves lots of paper work due to manual attendance by the faculty and even the RFID card based attendance system provides scope for proxy attendance. The proposed system is user friendly and complete wireless system that is accessible to students, admin, faculties and parents using a web portal which includes features like timetable generation, daily attendance report, weekly feedback mechanism, notifications to parents, pending approvals for admin and many more

Globalization and the Chinese Knowledge Diaspora: An Australian Case Study

In a context of intensified globalisation, knowledge diaspora as “trans-national human capital” have become increasingly valuable to society. With an awareness of a need for more empirical studies especially in Australia, this article concentrates on a group of academics who were working at a major university in Australia and came originally from the Chinese mainland. The study explores their life, work and international research collaborations, using a case study approach with semi-structured interviews as the data collection method. The study found that while globalisation shapes the work and the contributions to Australia, by academics from China, they exert their initiatives to respond to and further reshape globalisation. Equipped with their Chinese cultural and educational backgrounds, academic experience in the West, and active membership in the international knowledge system, the Chinese knowledge diaspora are a modern kind of cosmopolitan literati. They are aware of the impact of globalisation and contribute actively to higher education internationalisation in both Australia and China, have maintained their cultural identity and made good use of their Chinese educational background. Their international collaborations, however, are more likely to be with the scholars from Western countries due to some difficulties they have experienced in China and Australia, and to the current setup of the global knowledge system.postprin