Investigation of element-specific and bulk magnetism, electronic and crystal structures of La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3}

The magnetic interactions in La{0.70}Ca{0.30}Mn{1-x}Cr{x}O{3} (x = 0.15, 0.50 and 0.70) are investigated by x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), high-resolution x-ray powder diffraction, and bulk magnetization measurements. XAS in the Mn and Cr L{2,3} edges support stable single valent Cr{3+} ions and a varying Mn valence state with x, while the O K edge XAS spectrum reveals local maxima in the O 2p density of states close to the Fermi level due to mixing with Mn and Cr 3d states. A robust antiferromagnetic state is found for x=0.70 below TN = 258 K. For x=0.15, combined XMCD and bulk magnetization measurements indicate a fully polarized ferrimagnetic state for the Mn and Cr spins below Tc=224 K. For x=0.50, a reduced ferrimagnetic component dominated by Mn spins is present below Tc=154 K. No evidence of lattice anomalies due to cooperative charge and orbital orderings is found by x-ray diffraction for all samples. The magnetic properties of this system are rationalized in terms of a competition of ferromagnetic Mn-Mn double exchange and antiferromagnetic Cr-Cr and Cr-Mn superexchange interactions.Comment: 25 pages, 9 figure

Implementasi Kriptografi AES untuk Keamanan Pengiriman Data Internet of Things Menggunakan Web Service Rest pada NodeMCU

The emergence of the term Internet of Things in this era generally has a positive role for humans in various aspects such as health, industry, cities and even agriculture. However, there is a problem that is a serious threat in the IoT environment, namely data security. Data security is something that is required in storing or sending important information. It is dangerous if the data falls and is taken by parties who will be used irresponsibly who can later retrieve and even change the actual data. Therefore, the use of AES cryptography is needed to solve this problem. AES stands for Advanced Encryption Standard is a symmetric key encryption algorithm that has a faster data security process than an asymmetric algorithm. The purpose of this study is to describe how to apply the AES algorithm to IoT devices as an effort to secure data. Data in the form of temperature and humidity values ​​are encrypted by the AES algorithm before being sent to the database server with a container in the form of a wireless network or called wifi. In the web server, encrypted data is returned in the form of the original data before entering the database. The results of this test are to confirm that the system is running optimally. The use of the AES algorithm is declared successful in meeting the objectives, namely for data security and confidentiality.Munculnya istilah Internet of Things pada era ini pada umumnya mempunyai peran positif untuk manusia diberbagai aspek seperti kesehatan, perindustrian, perkotaan dan bahkan pertanian. Namun terdapat masalah yang menjadi ancaman serius dalam lingkungan IoT, yaitu tentang keamanan data. Keamanan data merupakan hal yang diharuskan dalam menyimpan atau mengirim sebuah informasi yang penting. Berbahaya jika data jatuh dan diambil oleh pihak yang nantinya dimanfaatkan dengan tidak bertanggung jawab yang nantinya dapat mengambil bahkan merubah data yang sebenarnya. Oleh karena itu, penggunaan kriptografi AES dibutuhkan untuk menyelesaikan masalah tersebut. AES singkatan dari Advanced Encryption Standard adalah algoritma enkripsi kunci berbentuk simetris yang memiliki proses keamanan data lebih cepat daripada algoritma asimetris. Tujuan penelitian ini yaitu untuk memaparkan cara menerapkan algoritma AES pada perangkat IoT sebagai upaya mengamankan data. Data berupa nilai suhu dan kelembaban yang dienkripsikan dengan algoritma AES sebelum nantinya dikirimkan kepada server basis data dengan wadah berupa jaringan nirkabel atau disebut wifi. Dalam web server data yang terenkripsi dikembalikan dengan bentuk berupa data asli sebelum masuk ke basis data.  Hasil dari pengujian ini yaitu mengkonfirmasi bahwa sistem berjalan dengan optimal. Penggunaan algoritma AES dinyatakan berhasil dalam memenuhi tujuan yaitu untuk keamanan serta kerahasiaan data

Real-time cell analysis by xCELLigence®: a new method for dynamic, quantitative measurement of adhesion and proliferation of cell lines

Objectives. In this study, we report the use of a real-time cell analysis (RTCA) test system, the xCELLigence® RTCA, as efficient tool for a fast growth kinetics analysis of cell lines. This new dynamic real-time monitoring and impedance-based assay allows for a combined measurement of cell adhesion, spreading and proliferation. Methods. We used four representative human OSCC derived cell lines, PE49, HSC2, HSC3 and PE15 cells. The measured impedance values could be correlated to characteristic cell culture behaviours. In parallel, were evaluated proliferation and cell viability of the cell lines by the 3-[4,5-dimethylthizol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Results. Through the analysis we were able to quantitatively characterize the growth kinetics of the cell lines. The results are in agreement with the analysis MTT and for us will be the basis for future studies with respect to these lines.Conclusions. The advantage of impedance-based measurements is mainly based on these continuous monitoring of cell responses for a broad range of different cells and with different parameters of culture. Therefore, the xCELLigence system can be used as a rapid monitoring tool for cellular viability and used for multiple applications, such as toxicity testing of xenobiotics, biocompatibility of dental materials, tests of invasion and migration using in vitro cell cultures

On the Role of Context in the Design of Mobile Mashups

This paper presents a design methodology and an accompanying platform for the design and fast development of Context-Aware Mobile mashUpS (CAMUS). The approach is characterized by the role given to context as a first-class modeling dimension used to support i) the identification of the most adequate resources that can satisfy the users' situational needs and ii) the consequent tailoring at runtime of the provided data and functions. Context-based abstractions are exploited to generate models specifying how data returned by the selected services have to be merged and visualized by means of integrated views. Thanks to the adoption of Model-Driven Engineering (MDE) techniques, these models drive the flexible execution of the final mobile app on target mobile devices. A prototype of the platform, making use of novel and advanced Web and mobile technologies, is also illustrated

Defining user perception of distributed multimedia quality

This article presents the results of a study that explored the human side of the multimedia experience. We propose a model that assesses quality variation from three distinct levels: the network, the media and the content levels; and from two views: the technical and the user perspective. By facilitating parameter variation at each of the quality levels and from each of the perspectives, we were able to examine their impact on user quality perception. Results show that a significant reduction in frame rate does not proportionally reduce the user's understanding of the presentation independent of technical parameters, that multimedia content type significantly impacts user information assimilation, user level of enjoyment, and user perception of quality, and that the device display type impacts user information assimilation and user perception of quality. Finally, to ensure the transfer of information, low-level abstraction (network-level) parameters, such as delay and jitter, should be adapted; to maintain the user's level of enjoyment, high-level abstraction quality parameters (content-level), such as the appropriate use of display screens, should be adapted

Specification of Complex Logical Expressions for Task Automation: An EUD Approach

The growing availability of smart objects is stimulating researchers in investigating the IoT phenomenon from different perspectives. In the HCI area, and in particular from the EUD perspective, one prominent goal is to enable nontechnical users to be directly involved in configuring smart object behaviour. With this respect, this paper discusses three visual composition techniques to specify logical expressions in Event-Condition-Action rules used for synchronizing the behavior of smart objects