Electronic states of PrCoO3_3: X-ray photoemission spectroscopy and LDA+U density of states studies

Electronic states of PrCoO$_3$ are studied using x-ray photoemission spectroscopy. Pr 3d$_{5/2}$ core level and valence band (VB) were recorded using Mg K$_\beta$ source. The core level spectrum shows that the 3d$_{5/2}$ level is split into two components of multiplicity 4 and 2, respectively due to coupling of the spin states of the hole in 3d$_{5/2}$ with Pr 4f holes spin state. The observed splitting is 4.5 eV. The VB spectrum is interpreted using density of states (DOS) calculations under LDA and LDA+U. It is noted that LDA is not sufficient to explain the observed VB spectrum. Inclusion of on-site Coulomb correlation for Co 3d electrons in LDA+U calculations gives DOS which is useful in qualitative explanation of the ground state. However, it is necessary to include interactions between Pr 4f electrons to get better agreement with experimental VB spectrum. It is seen that the VB consists of Pr 4f, Co 3d and O 2p states. Pr 4f, Co 3d and O 2p bands are highly mixed indicating strong hybridization of these three states. The band near the Fermi level has about equal contributions from Pr 4f and O 2p states with somewhat smaller contribution from Co 3d states. Thus in the Zaanen, Sawatzky, and Allen scheme PrCoO$_3$ can be considered as charge transfer insulator. The charge transfer energy $\Delta$ can be obtained using LDA DOS calculations and the Coulomb-exchange energy U' from LDA+U. The explicit values for PrCoO$_3$ are $\Delta$ = 3.9 eV and U' = 5.5 eV; the crystal field splitting and 3d bandwidth of Co ions are also found to be 2.8 and 1.8 eV, respectively.Comment: 12 pages, 7 figures; to appear J. Phys.: Condens. Matte

“CSMA-Based Link Scheduling in Multihop MIMO Networks using SINR Model ”

The main aim of this study to resolve the problem of distributed scheduling in multi-hop MIMO networks. We will first develop a “MIMO pipe” model which will provide the required SINR , which gives the rate-reliability tradeoff in MIMO communications.Here we are going to study development of CSMA-based MIMO-pipe scheduling especially under the SINR model.We are going to choose the SINR model over the conventionally studied matching or protocol-based interference models because it has ability to capture the impact of interference in wireless networks. Here each node is equipped with an antenna array. In CSMA based scheduling, nodes will first sense the channel activity before attempting transmissions, whenever the channel is sensed to be idle, the nodes will continue with data transmissions. When the channel is detected to be busy, the nodes have to wait for a random amount of backoff time before reattempting the transmission.We will study that protocol model based throughput-optimal CSMA based scheduling, would not work well under the SINR model because its has dynamic and intrinsic link coupling. To tackle this challenge,CSMA-based MIMO-pipe scheduling is develpoed in both discrete-time system and continuous-time system

Effect of blood storage on electrolyte levels

Background: Blood transfusion can be an immediate life saving measure in several acute conditions such as hemorrhage and anemia. However, various post transfusion complications are observed in patients which may be associated with the storage conditions of the collected blood. Electrolytes play a major role in maintaining homeostasis within the cells. Potassium is the most important extracellular cation responsible for maintenance of the cell integrity. Prolonged and improper storage of blood can lead to leakage of electrolytes, thus changing the cell morphology. This can adversely affect the patients who receive such blood. This study helps us analyze the effect of blood storage on electrolyte levels.Methods: For the study, 10ml of blood was collected from 30 blood bags containing CPDA-1 at the time of blood donation from 30 different volunteers. This blood containing the CPDA-1 was divided into 5 parts of 2ml and each 2ml sample was stored in plain bulbs. All the samples were stored at 4°C. Samples were tested to check for changes in the electrolyte (Na+, K+, Cl-) levels on day 0, 3, 7, 14 and 21. ANOVA was used to calculate the variance in the electrolyte levels.Results: Average sodium level on day 0 was 152.9±3.8 mEq/l. There was a significant decrease and it was measured at 139.5±4.8 mEq/l on day 21. Average potassium level on day 0 was 4.2±0.4 mEq/l. A significant spike was observed in potassium levels. The final reading of potassium level on day 21 was 15.2±0.7 mEq/l. Average chloride level on day 0 was 71.9±6.6 mEq/l which significantly declined to 67±5.9 mEq/l.Conclusions: Though blood is stored in proper conditions, a biochemical change occurs within the cells due to prolonged storage and thus affects its viability

USER PERCEPTION OF DSPACE IN PDPU LIBRARY: A CASE

This paper examines the extent use of DSpace open source software and its adoption and users perceptions among PDPU libraries as an intuitional repository. Two separate questionnaires were used to gather data. 118 users are selected from stratified random sampling technique from total population of 400; questionnaires were shared to 118 users. The findings revealed that 94 responses were obtained. It is a clear sign coming out from this study is that DSpace software is becoming adoptable option to managing digital collections and building digital repository in Pandit Deendayal Petroleum University Libraries, Gandhinagar, and Gujarat. The current research is a descriptive study to evaluate DSpace digital repository open source system among PDPU Library users (Students, faculties, and staff). Through the experimental study analysis the similarities and differences between cases, identifying areas that have direct implementations for DSpace for Digital Repository to be collected from multiple sources, printed and electronic questionnaires. Web based tools for evaluation and analysis have been accepted for the study. This study it is observed that digital repositories (DR) are become formative in PDPU. Now the things have changed and DSpace has become mature and popular than another open source software for managing Institutional repository, in terms of features, DSpace is rich according to users’ perceptions, availability of community supports, and active participation of DSpace development leads make a very strong software

A Survey on Framework for Improved Web Data Clustering Using Language Processing Technique

Now a day, World Wide Web becomes very popular and interactive for transferring of information. It is a massive repository of web pages and links. It provides information about vast area for the internet user. The web is huge, diverse and active and thus increases the scalability, multimedia data & temporal matters. The growth of the web has outcome in a huge amount of information that is now freely offered for user access. Since due to tremendous usage, the log files are growing at a faster rate & the size is becoming huge. Preprocessing plays a vital role in efficient mining process as log data is normally noisy and indistinct. Reconstruction of session and paths are completed by appending missing pages in preprocessing. Additionally, the transactions which illustrate the behavior of users are constructed exactly in preprocessing by calculating the Reference Length of user access by means of byte rate, the clustering task the ability to capture the uncertainty among web user’s navigation performance

Modeling of PV Array to Study The Effects of Partial Shading on Its Characteristics and MPPT

MATLAB based modeling and simulation scheme suitable for studying the I-V and P-V characteristics of PV array under a non-uniform insolation due to partial shading and finding maximum power point from the characteristic is presented in the paper. This involved the Simulink and embedded MATLAB code for simulation. This is simple to use, accurate and economical computer aided design tool which can be used to enhance the understanding and predict the I-V and P-V characteristics of large PV arrays. It can be used to study the effect of temperature, insolation variation, varying shading patterns and the role of array configuration on the PV characteristics. Paper proposes standard algorithm to track the power peak under partially shaded conditions. The modeling and simulation of the maximum power point tracking algorithm is implemented in MATLAB / Simulink environment. The simulation results prove that with Perturb and Observe (P&O) algorithm, MPPT reaches the intended maximum power point