Correlated mesoscopic fluctuations in integer quantum Hall transitions

We investigate the origin of the resistance fluctuations of mesoscopic samples, near transitions between Quantum Hall plateaus. These fluctuations have been recently observed experimentally by E. Peled et al. [Phys. Rev. Lett. 90, 246802 (2003); ibid 90, 236802 (2003); Phys. Rev. B 69, R241305 (2004)]. We perform realistic first-principles simulations using a six-terminal geometry and sample sizes similar to those of real devices, to model the actual experiment. We present the theory and implementation of these simulations, which are based on the linear response theory for non-interacting electrons. The Hall and longitudinal resistances extracted from the Landauer formula exhibit all the observed experimental features. We give a unified explanation for the three regimes with distinct types of fluctuations observed experimentally, based on a simple generalization of the Landauer-Buttiker model. The transport is shown to be determined by the interplay between tunneling and chiral currents. We identify the central part of the transition, at intermediate filling factors, as the critical region where the localization length is larger than the sample size.Comment: 18 pages 17 figure

Improvement of growth and nutritional quality of Moringa oleifera using different biofertilizers

AbstractMoringa seeds were cultivated in polyethylene bags (1kg capacity) filled with clay loamy soil. Bags were treated with microorganisms using three methods of inoculation i.e. soil inoculation (single or mixed cultures); leaf inoculation (single culture), and soil and leaf inoculation (mixed inoculation). Plants were harvested after 3months of cultivation. Shoot and root lengths, shoot and root dry weights, leaves fresh and dry weights, vitamin C g/g fresh leaf, protein g/g leaves dry weight and mineral contents (Mg, P, K, Zn, Mn, Fe and Cu) were recorded. Biofertilization by different inoculation methods increased most of the parameters tested. The highest records of shoot and root lengths, and shoot and root dry weights were obtained with soil inoculation with mixed cultures of (Azotobacter chroococcum and Saccharomyces cerevisiae) and (Azot. chroococcum and Bacillus circulans). The same trend in respect of Vitamin C was obtained. But, the highest protein contents (g/g dry weight leaves) were obtained with soil inoculation with (Azot. chroococcum and B. circulans), (Bacillus megatherium) and (Azot. chroococcum and S. cerevisiae), which gave 0.73, 0.59 and 0.58gprotein/g leaves dry weight respectively. Generally, soil inoculation with either B. megatherium, B. circulans, (Azot. chroococcum and Pseudomonas fluorescens), (Azot. chroococcum and B. circulans), Azot. chroococcum, and (Azospirillum brazilense and B. megatherium) gave the highest records of Mg, P, K, Zn, Mn, Fe and Cu respectively

Gambaran Karakteristik Pengguna Metode Kontrasepsi Jangka panjang (MKJP) dan Non-MKJP di Puskesmas Kasonaweja

Metode Kontrasepsi Jangka Panjang atau dikenal dengan MKJP merupakan metode yang sedang digandrungi oleh Pasangan Usia Subur (PUS) pada beberapa daerah di Indonesia, hal ini disebabkan karena efektifitas dari MKJP tersebut terbilang tinggi dalam menjcegah kehamilan, berbeda halnya dengan PUS yang ada di wilayah Kerja Puskesmas Kasonaweja, dimana PUS lebih memilih menggunakan Non-MKJP dalam mencegah kehamilan. Tujuan dari penelitian ini melihat gambaran karakteristik Pengguna Metode Kontrasepsi Jangka Panjang (MKJP) dan Non-MKJP di Puskesmas Kasonaweja. Penelitian ini merupakan penelitian deskriptif kuantitatif yang dilakukan di wilayah kerja Puskesmas Kasonaweja selama ? 5 bulan dari Bulan Juni – Oktober 2021, populasi pada penelitian ini ada WUS yang berkunjung ke Puskesmas dari Januari – Desember 2021 sejunlah 157 orang, sedangkan sampel pada penelitian ini adalah total populasi. Data pada penelitian ini di analisis sampai analisis univariat dengan menggunakan software SPSS 24. Hasil dari penelitian ini menemukan sebagian kecil WUS yang menggunakan MKJP dengan rata – rata usia WUS yaitu 29,2%, median paritas 3 anak, jarak kehamilan 2 tahun, dengan suku terbanya adalah Papua yang sebagian besar tinggal di daerah perkotaan. Penelitian ini merekomendasikan perlunya pendekatan tokoh adat dan tokoh agama dalam membantu mensosialisasikan penggunaan KB pada WUS yang ada di Papua, mengingat masalah kesehatan ibu dan anak di Papua masih tinggi

WHY DO KUWAITI STUDENTS IN THE COLLEGE OF ARTS THINK THAT LEARNING ENGLISH IS BOTH DIFFICULT AND UNNECESSARY?

The study sheds lights on the basic reasons and/or obstacles that hamper Kuwaiti students in the College of Arts/Kuwait University from advancing in English learning process in ESL classes. It, on the same level, tries to answer the question: “Why Do Kuwaiti Students in the College of Arts Think that Learning English is Both Difficult and Unnecessary?“ The study moves onto a parallel direction which focuses on the various factors that affect the full and smooth L2 acquisition. The survey was answered by about 500 students from the Arts College studying English modules (090, 141, and 142). Students answered the questions in either language; English or Arabic. They, in return, disclosed their views, suggestions, ideas and reflections about the curriculum. On the other hand, the survey results demonstrated the fact that students were discontent with the traditional methods of teaching grammar; they explained that they would want a more communicative method of integrating grammar within other L2 skills.  Article visualizations

A Comprehensive Analysis of Aromatic-Proton Mediated Hydrogen Bonds

Hydrogen bonds play critical role in folding, structure and recognition of biological macromolecules (e.g., proteins, RNA, DNA). In addition to classical hydrogen bonds (e.g., ─OH---O=, ─OH---O─, ─NH---O─ etc.), structural analysis of protein and nucleic acids, almost a decade ago, showed that hydrogen bonds (e.g., CH---O) with hydrogen atoms on aliphatic carbon atoms (hereafter, aliphatic-protons) also play very important role in the structure and function of biomolecules. Even though, protons of aromatic ring systems (hereafter, aromatic-protons) are more polar than the aliphatic-protons, systematic analysis of hydrogen bonds of aromatic-protons have not been carried out. Therefore, I carried out a systematic analysis of hydrogen bonds that are made with aromatic-protons of tryptophan, tyrosine and phenylalanine amino acids in high-resolution structures of proteins and their complexes using a computer program that I created in R- and Perl languages. The analysis showed that aromatic CH---O are very common in proteins and tryptophan-CD1 is the most frequent participant in aromatic CH---O hydrogen bonds. The normalized frequency of occurrences of aromatic CH---O hydrogen bonds are greater than that of the aliphatic CH---O hydrogen bonds. Therefore, like aliphatic CH---O hydrogen bonds we anticipate that aromatic CH---O hydrogen bonds are likely to play equally, if not more, important role in macromolecular folding, stability and recognition. The numerous examples of aromatic CH---O hydrogen bonds observed here provides a good source of information that can be probed further by experiments to validate their important contribution

The role of the lattice structure in determining the magnon-mediated interactions between charge carriers doped into a magnetically ordered background

We use two recently proposed methods to calculate exactly the spectrum of two spin-${1\over 2}$ charge carriers moving in a ferromagnetic background, at zero temperature, for three types of models. By comparing the low-energy states in both the one-carrier and the two-carrier sectors, we analyze whether complex models with multiple sublattices can be accurately described by simpler Hamiltonians, such as one-band models. We find that while this is possible in the one-particle sector, the magnon-mediated interactions which are key to properly describe the two-carrier states of the complex model are not reproduced by the simpler models. We argue that this is true not just for ferromagnetic, but also for antiferromagnetic backgrounds. Our results question the ability of simple one-band models to accurately describe the low-energy physics of cuprate layers.Comment: 15 pages, 10 figure

Sedimentological and stratigraphic framework of the several hundred thousand years old lacustrine record from Lake Van, Turkey

Within the frame of the International Continental scientific Drilling Program (ICDP) project PALEOVAN, a long and continuous sediment record from Lake Van, a closed lake situated in a climatically sensitive semiarid and tectonically active region in Eastern Anatolia, has been drilled in summer 2010. At two sites, Ahlat Ridge and Northern Basin, sedimentary records of 220 and 140 m were recovered, respectively. With basal ages possibly around 500'000 years, these records span several glacial-interglacial cycles and reach back until the lake’s initial transgression in the Middle Pleistocene. First results from ongoing analysis of core-catcher samples and newly opened cores document the sedimentological and geochemical succession. Two composite profiles of the drill sites were defined. Core catcher-based geochemical data such as proxies of lake’s productivity and catchment alterations show large variations and reflect a rich paleoenvironmental history. Most of the 220 m thick succession consists of carbonate mud, mostly sub-mm-thick laminated and interbedded by either homogenous mud or pyroclastic cm-thick layers. The lowermost sediments from the Ahlat Ridge site represent the initial lake transition as the drilling could not penetrate further and the seismic data indicates coincidence with the ‘acoustic’ basement. Such an early transgressive state of the lake’s history is also supported by the lithology consisting of a gravel unit as an indicator of a beach-like environment, which is overlain by sand deposits containing fresh-water gastropods (Bithynia). Above 200 mblf, the laminated mud clearly indicates that the lake was already deep enough to form anoxic bottom water as the laminations were preserved. This unique paleoclimate archive indicates that great changes of the depositional conditions occurred that hint to a fascinating evolution of the environment and has ideal prerequisites for the investigation of the Quaternary climate evolution in the Near East