Coupling of pinned magnetic moments in an antiferromagnet to a ferromagnet and its role for exchange bias

The interaction between uncompensated pinned magnetic moments within an antiferromagnetic (AFM) layer and an adjacent ferromagnetic (FM) layer responsible for the existence of exchange bias is explored in epitaxially grown trilayers of the form FM2/AFM/FM1 on Cu3Au(0 0 1) where FM1 is ~12 atomic monolayers (ML) Ni, FM2 is 21–25 ML Ni, and AFM is 27 ML or 50 ML Ni~25Mn~75. Field cooling for parallel or antiparallel alignment of the out-of-plane magnetizations of the two FM layers does not make a difference for the temperature-dependent coercivity (H C), magnitude of exchange bias field (H eb), AFM ordering temperature (T AFM), and blocking temperature for exchange bias (T b). We explain this by a model in which the uncompensated pinned magnetic moments distributed within the volume of the AFM layer interact with both of the FM layers, albeit with different strength. Parallel and antiparallel coupling between the magnetization of the pinned moments and the FM layers equally exists. This leads to the experimentally observed independence of H C, H eb, as well as of T AFM and T b on the magnetization direction of the FM layers during field cooling. These results provide new and detailed insight into revealing the subtle and complex nature of the exchange bias effect

Effect of organic fertilizers combined with benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH) on the cucumber powdery mildew and the yield production

Organic fertilizers such as compost, compost tea and seaweed extracts (Algean) combined with benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH)) showed significant effect on the powdery mildew-infected cucumber leaves with Sphaerotheca fuliginea. We have shown that spraying the infected cucumber leaves with the BTH (0.05 mM) combined with the organic fertilizers strongly decreased the disease severity of the cucumber powdery mildew fungus from 85.1% to 3.4% as compared to the control leaves which infected only with the pathogen. Furthermore, organic fertilizers combined with BTH increased significantly vegetative growth characters of cucumber (stem length, number of leaves /plant, leaf area /plant and chlorophyll content) especially at the earlier stage of growth as compared to the control plants (chemical fertilizer only). Also, most of the organic materials produced the highest cucumber early yield and fruit quality, but total yield was equal or less than the chemical fertilizers. Interestingly enough, that organic fertilizers combined with BTH elevated the ascorbic acid content (chemical quality of cucumber fruits) and decreased the nitrate content which very harmful as well as increased the fruit yields as compared to the control plants

Entanglement Generation by Qubit Scattering in Three Dimensions

A qubit (a spin-1/2 particle) prepared in the up state is scattered by local spin-flipping potentials produced by the two target qubits (two fixed spins), both prepared in the down state, to generate an entangled state in the latter when the former is found in the down state after scattering. The scattering process is analyzed in three dimensions, both to lowest order and in full order in perturbation, with an appropriate renormalization for the latter. The entanglement is evaluated in terms of the concurrence as a function of the incident and scattering angles, the size of the incident wave packet, and the detector resolution, to clarify the key elements for obtaining an entanglement with high quality. The characteristics of the results are also discussed in the context of (in)distinguishability of alternative paths for a quantum particle.Comment: 21 pages, 19 figures, the final versio

Eco-entrepreneurship Study in Improving Competitive Human Resources: A Survey in Students in Jakarta, Semarang, and Malang

This research aims to examine the entrepreneurial behavior of students and to investigate whether the level of innovation moderates the relationship of environmental concern and entrepreneur behavior of students. The samples are the students from Jakarta, Semarang, and Malang totaling 742 data. The findings show that the level of entrepreneur behavior is still in low level. Students are also less concerned about environmental issues and have low level of innovation. The model could not find the moderation effect of level of innovation variables.     Keywords: entrepreneurship, eco-entrepreneurship, level of innovatio

Saving Cultural Heritage with Digital Make-Believe: Machine Learning and Digital Techniques to the Rescue

The application of digital methods for content-based curation and dissemination of cultural heritage data offers unique advantages for physical sites at risk of damage. In areas affected by 2011 Arab spring, digital may be the only approach to create believable cultural experiences. We propose a framework incorporating computational methods such as: digital image processing, multi-lingual text analysis, and 3D modelling, to facilitate enhanced data archive, federated search, and analysis. Potential use cases include experiential search, damage assessment, virtual site reconstruction, and provision of augmented information for education and cultural preservation. This paper presents initial findings from an empirical evaluation of existing scene classification methods, applied to detection of cultural heritage sites in the Palmyra region. Results indicate that deep learning offers an appropriate solution to semantic annotation of publicly available cultural heritage image data

Designing and Psychometric Evaluation of the Competency Inventory for Postgraduate Students of Intensive Care Nursing

Background: Today, the role of expert clinical nurses is highlighted because their presence is necessary for guaranteeing the quality of nursing care provided for the patients. However, there are no proper instruments for measuring the clinical competence of postgraduate students in intensive care nursing. Objectives: The present study aimed at development and psychometric evaluation of the clinical-competence inventory for postgraduate students of intensive care nursing. Patients and Methods: A methodological study was conducted at state nursing schools of Iran. The participants were postgraduate students of intensive care nursing, who were being trained at 16 nursing schools throughout Iran, during year 2014. After examining some relevant texts, the first draft of the inventory was designed with 60 items. In order to confirm its face and content validity, a panel of experts and students examined the inventory. The final draft, which contained 44 items, was distributed among postgraduate students of intensive care nursing, and 217 students answered the inventory. The construct validity was verified using exploratory factor analysis. The reliability of the inventory was verified using consistency tests. Results: Firstly an instrument with 60 items was developed. Next, the face and content validity of the instrument was assessed by 15 students and 11 experts. Overall, 16 items were removed through validity assessment and 44 items remained in the final draft. The content validity index of the final draft was 0.90. Moreover, the content validity ration of 44 items ranged between 0.75 and 1. The Cronbach’s alpha coefficient of the inventory was 0.95 and the intraclass correlation coefficient (ICC) of the test-retest results was 0.96. To examine the construct validity of the final draft, it was administered for 217 postgraduate students of intensive care nursing and five factors, with Eigenvalues above one and loading level equal to or above 0.4, were extracted through exploratory factor analysis. Conclusions: The inventory developed in this study is a suitable index for evaluating the efficacy of postgraduate students in the field of intensive care nursing

Effect of Small-molecule Sensitizer on the Performance of Polymer Solar Cell

For improving optical absorption of organic solar cells, a small-molecule sensitizer, as a third material, is usually incorporated into binary solar cell system. In many cases, light harvesting can be improved but on the expense of charge carrier mobility of the solar cells. This obstacle can be addressed through the understanding solar cell physics. In the present work, we try to deeply understand the physics of the long-chain polymer solar cell composed of poly(3-hexylthiophene) (P3HT), as a donor polymer, and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), as an acceptor molecule. This understanding can be acquired through the effect of coumarin 6 dye (C6), as a small-molecule sensitizer, on optical absorption and photocurrent of the most common solar cell. From optical spectroscopy we found that, the C6 dye, as a small molecule, did not vary conjugation length of the long-chain polymer in the P3HT: PCBM: C6 solar cell. This was indicated from (1) unchanged vibronic structure of the P3HT after adding C6 dye and from (2) matching in the wavelength between absorption peaks of both pristine C6 and P3HT after adding C6 dye into blend. From photocurrent spectroscopy we found that, the incorporation of C6 dye, as a sensitizer, into P3HT: PCBM binary contributed to photocurrent and formed an additional charge carrier generation site through the C6: PCBM combination, which was individually found among with P3HT: PCBM combination in the same solar cell. In the same time, the C6 dye, as a shortchain molecule, restricted the transport of charge carriers generated by P3HT as a result of low hole mobility of the C6 short-chain molecules. Through the present study, the incorporation of a small-molecule sensitizer into polymer solar cell may acquire better understanding for the performance of the most common P3HT: PCBM solar cell.Keywords: Polymer Solar Cells; Device Physics; P3HT: PCBM Solar Cell