5,813 research outputs found
Absence of structural correlations of magnetic defects in heavy fermion LiV2O4
Magnetic defects have pronounced effects on the magnetic properties of the
face-centered cubic compound LiV2O4. The magnetic defects arise from crystal
defects present within the normal spinel structure. High-energy x-ray
diffraction studies were performed on LiV2O4 single crystals to search for
superstructure peaks or any other evidence of periodicity in the arrangement of
the crystal defects present in the lattice. Entire reciprocal lattice planes
are mapped out with help of synchrotron radiation. No noticeable differences in
the x-ray diffraction data between a crystal with high magnetic defect
concentration and a crystal with low magnetic defect concentration have been
found. This indicates the absence of any long-range periodicity or short-range
correlations in the arrangements of the crystal/magnetic defects.Comment: 6 pages, 4 figure
Time trend analysis of social inequalities in psychological distress among young adults before and during the pandemic: evidence from the UK Household Longitudinal Study COVID-19 waves
BACKGROUND: Despite concerns about mental health problems among those aged 16-24 in England, which social groups have been most at risk, both over the past decade and during the COVID-19 pandemic, remains unclear. METHODS: We examined trends in psychological distress among young adults 16-24 years old in England using data from the UK Household Longitudinal Study. Using longitudinal data as repeated cross-sectional waves, we examined differences over time in mean General Health Questionnaire (GHQ) scores from wave 1 (2009-2010) to wave 10 (2018-2019) and six COVID-19 waves collected between April and November 2020, by economic activity, cohabitation with parents, parental education, area deprivation, ethnicity, age and sex. RESULTS: Compared with 2009-2010, increases in GHQ scores in 2018-2019 were higher in women than men (2.1 vs 1.3), those aged 16-18 than aged 22-24 (2.6 vs 0.9), those from white UK group versus other ethnic minorities, and those out of the labour force (3.6) or employed part time (2.2) than those employed full time (0.8). Compared with 2018-2019, psychological distress in 2020 also further increased among young adults residing in the most deprived areas (4.1 vs 1.2 in the least deprived areas). In 2020, losing one's job or most of one's work hours was associated with higher psychological distress and attenuated the differences between deprivation quartiles by 17%. CONCLUSION: In England, inequalities in psychological distress among young adults may have changed and increased during the COVID-19 pandemic. Investing in opportunities for young adults, particularly in more deprived areas, may be key to improve population levels of mental health
Scaling of NonOhmic Conduction in Strongly Correlated Systems
A new scaling formalism is used to analyze nonlinear I-V data in the vicinity
of metal-insulator transitions (MIT) in five manganite systems. An exponent,
called the nonlinearity exponent, and an onset field for nonlinearity, both
characteristic of the system under study, are obtained from the analysis. The
onset field is found to have an anomalously low value corroborating the
theoretically predicted electronically soft phases. The scaling functions above
and below the MIT of a polycrystalline sample are found to be the same but with
different exponents which are attributed to the distribution of the MIT
temperatures. The applicability of the scaling in manganites underlines the
universal response of the disordered systems to electric field
Testing gravity at the Second post-Newtonian level through gravitational deflection of massive particles
Expression for second post-Newtonian level gravitational deflection angle of
massive particles is obtained in a model independent framework. Several of its
important implications including the possibility of testing gravitational
theories at that level are discussed.Comment: 5 pages, couple of equations of the previous version are correcte
PERBANDINGAN KONFIGURASI ELEKTRODA METODE GEOLISTRIK RESISTIVITAS UNTUK IDENTIFIKASI LITOLOGI DAN BIDANG GELINCIR DI KELURAHAN PIDADA BANDAR LAMPUNG
Longsoran merupakan bencana yang terjadi dipengaruhi oleh faktor morfologi, litologi, struktur geologi, hidrogeologi dan penggunaan lahan. Kelurahan Pidada, Kecamatan Panjang, Bandar Lampung merupakan daerah yang kondisi morfologinya berupa perbukitan dengan kelerengan yang curam. Berdasarkan data dari Pusat Vulkanologi dan Mitigasi Bencana (PVMBG) pada bulan Januari-Oktober 2019, daerah penelitian yang berada di Kecamatan Panjang memiliki potensi gerakan tanah menengah-tinggi. Kriteria terjadinya longsoran adalah kelerengan yang cukup curam, terdapatnya bidang gelincir di bawah permukaan tanah yang jenuh air dan banyaknya kandungan air yang berasal dari air hujan yang meresap ke dalam tanah. Salah satu metode geofisika yang dapat mendeteksi litologi dan bidang gelincir adalah metode Geolistrik Resistivitas. Melalui metode ini diketahui daerah yang memiliki kandungan air tinggi yang ditunjukkan dengan nilai resistivitas yang rendah. Pada penelitian ini, dilakukan identifikasi litologi dan bidang gelincir di kawasan rawan longsor dengan menggunakan metode geolistrik resistivitas konfigurasi Wenner-Schlumberger dan Wenner-Alpha. Konfigurasi Wenner-Schlumberger mempunyai penetrasi pengukuran yang lebih dalam tetapi gambaran penampang bawah permukaan beresolusi rendah, sedangkan konfigurasi Wenner-Alpha mempunyai penetrasi pengukuran yang tidak terlalu dalam tetapi gambaran penampang bawah permukaan beresolusi relatif tinggi. Penggunaan kedua konfigurasi ini untuk memanfaatkan kelebihan dan mengurangi kelemahan dari masing-masing konfigurasi pada analisis kelongsoran. Setelah dilakukan pengukuran terhadap 2 lintasan, diidentifikasi litologi dan bidang gelincir daerah penelitian. Berdasarkan hasil pengukuran, konfigurasi Wenner-Schlumberger mempunyai gambaran penampang bawah permukaan yang lebih detail dan penetrasi yang lebih dalam untuk identifikasi litologi perlapisan dan bidang gelincir dibandingkan konfigurasi Wenner-Alpha
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