Anisotropic, multi-carrier transport at the (111) LaAlO3_3/SrTiO3_3 interface

The conducting gas that forms at the interface between LaAlO$_3$ and SrTiO$_3$ has proven to be a fertile playground for a wide variety of physical phenomena. The bulk of previous research has focused on the (001) and (110) crystal orientations. Here we report detailed measurements of the low-temperature electrical properties of (111) LAO/STO interface samples. We find that the low-temperature electrical transport properties are highly anisotropic, in that they differ significantly along two mutually orthogonal crystal orientations at the interface. While anisotropy in the resistivity has been reported in some (001) samples and in (110) samples, the anisotropy in the (111) samples reported here is much stronger, and also manifests itself in the Hall coefficient as well as the capacitance. In addition, the anisotropy is not present at room temperature and at liquid nitrogen temperatures, but only at liquid helium temperatures and below. The anisotropy is accentuated by exposure to ultraviolet light, which disproportionately affects transport along one surface crystal direction. Furthermore, analysis of the low-temperature Hall coefficient and the capacitance as a function of back gate voltage indicates that in addition to electrons, holes contribute to the electrical transport.Comment: 11 pages, 9 figure

The central New England sea breeze study

The synoptic and mesoscale environments conducive to the formation of sea breezes were examined, as well as the spatial and temporal evolution of sea-breeze circulations, gravity currents, and fronts along the central New England coast. Sea breeze events were defined as occurring when the observed surface wind direction began the day outside the southeast quadrant, shifted to southeast by afternoon, then shifted back out of the southeast quadrant in the evening, driven by mesoscale, insolation-induced cross-shore temperature gradients. The meso-alpha (200--2000 km) sea-breeze forcing in the study area was defined as a combination of the cross-shore potential temperature gradient (deltatheta/deltax) that may drive sea breezes inland, and the cross-shore geostrophic wind component (uG) that may resist the landward movement of sea breezes. It was found that the peak values and temporal evolution of the meso-alpha forcing were dependent on the locations and relative dominance of synoptic-scale surface pressure systems in the eastern United States. These conclusions can often be used to accurately predict sea-breeze events, and their time of onset, using surface observations recorded in the early morning. The forecasting technique is adaptable to any coastal location in the world. Meso-beta (20--200 km) horizontal variations in the sea-breeze circulation, gravity current, and front were compared to deltatheta/deltax and the cross-shore wind component at 925 hPa (u925) in the study area. The latter was substituted for uG because it also accounts for the synoptic-scale temperature gradient between the surface and 925 hPa via the thermal wind relation. Near-surface potential temperature (isentropic) fields were used to examine the sea-breeze gravity current, and the wind (kinematic) fields were used to examine the sea-breeze circulation. Isentropic gradient fields were used to examine the thermodynamic sea-breeze front, and convergence fields were used to examine the kinematic sea-breeze front. It was found that the most developed pattern the sea-breeze gravity current achieved, the time of the sea-breeze circulation\u27s first contact with the coast and its most advanced inland distance, and the peak meso-beta strength of the sea-breeze frontal components were all functions of the meso-alpha forcing

Pemberdayaan Masyarakat Pesisir Pantai Di Tambak Lorok, Semarang, Jawa Tengah

Kegiatan Kuliah Kerja Nyata (KKN) merupakan kegiatan lapangan bagi mahasiswa yang menempuh bagian akhir dari program pendidikan S-1. Universitas mempercayai bahwa program ini mampu mendorong empati mahasiswa, dan dapat memberikan sumbangan bagi penyelesaian persoalan yang ada di masyarakat. Tambak Lorok adalah tempat penjualan ikan segar baik dalam jumlah besar maupun secara eceran. Pada umumnya ikan yang dijual merupakan hasil tangkapan pada hari itu. Untuk maksud memperpanjang penyimpanan dan memenuhi kebutuhan konsumen ikan yang cukup besar, beberapa ikan dijual dengan cara diasap. Ikan diasap menggunakan tempurung kelapa yang sudah tua. Masalah yang dihadapi kelompok pengasapan ikan ini adalah umur simpan ikan asap, sehingga apabila dalam waktu tersebut ikan tidak habis, sisanya sudah tidak memiliki nilai jual, sehingga produsen mengalami kerugian. Tujuan dari kegiatan ini adalah peningkatan produksi ikan asap melalui metode asap cair dan memanfaakan sisa arang tempurung kelapa. Metode yang digunakan oleh tim KKN PPM meliputi penyuluhan dan pendidikan untuk memproduksi ikan asap yang higienis. Hasil dari kegiatan ini memberikan banyak pengetahuan tentang bahaya asap yang melekat pada pengasapan ikan dan manfaat briket. Dengan antusias masyarakat sekitar Tambak Lorok memberikan respon positif untuk menggunakan alat yang digunakan untuk menghasilkan asap cair dan briket. Kegiatan KKN PPM ini juga didukung oleh berbagai pihak Kecamatan, Kelurahan dan Karang Taruna

Quantum Mechanical Realization of a Popescu-Rohrlich Box

We consider quantum ensembles which are determined by pre- and post-selection. Unlike the case of only pre-selected ensembles, we show that in this case the probabilities for measurement outcomes at intermediate times satisfy causality only rarely; such ensembles can in general be used to signal between causally disconnected regions. We show that under restrictive conditions, there are certain non-trivial bi-partite ensembles which do satisfy causality. These ensembles give rise to a violation of the CHSH inequality, which exceeds the maximal quantum violation given by Tsirelson's bound, $B_{\rm CHSH}\le 2\sqrt2$, and obtains the Popescu-Rohrlich bound for the maximal violation, $B_{\rm CHSH}\le 4$. This may be regarded as an a posteriori realization of super-correlations, which have recently been termed Popescu-Rohrlich boxes.Comment: 5 page

Executive function in first-episode schizophrenia

BACKGROUND: We tested the hypothesis that schizophrenia is primarily a frontostriatal disorder by examining executive function in first-episode patients. Previous studies have shown either equal decrements in many cognitive domains or specific deficits in memory. Such studies have grouped test results or have used few executive measures, thus, possibly losing information. We, therefore, measured a range of executive ability with tests known to be sensitive to frontal lobe function. METHODS: Thirty first-episode schizophrenic patients and 30 normal volunteers, matched for age and NART IQ, were tested on computerized test of planning, spatial working memory and attentional set shifting from the Cambridge Automated Neuropsychological Test Battery. Computerized and traditional tests of memory were also administered for comparison. RESULTS: Patients were worse on all tests but the profile was non-uniform. A componential analysis indicated that the patients were characterized by a poor ability to think ahead and organize responses but an intact ability to switch attention and inhibit prepotent responses. Patients also demonstrated poor memory, especially for free recall of a story and associate learning of unrelated word pairs. CONCLUSIONS: In contradistinction to previous studies, schizophrenic patients do have profound executive impairments at the beginning of the illness. However, these concern planning and strategy use rather than attentional set shifting, which is generally unimpaired. Previous findings in more chronic patients, of severe attentional set shifting impairment, suggest that executive cognitive deficits are progressive during the course of schizophrenia. The finding of severe mnemonic impairment at first episode suggests that cognitive deficits are not restricted to one cognitive domain