Two-stage code acquisition in wireless optical CDMA communications using optical orthogonal codes

In this paper, we analyze the performance of code acquisition system in atmospheric optical code division multiple access (OCDMA) communications using optical orthogonal codes. Memory introduced by temporal correlation of optical fading process precludes us from using the Markov chain model for a code acquisition analysis. By considering this issue, we discuss how to extend the applicability of the Markov chain model to the atmospheric OCDMA communications. We analyze and compare the performance of correlator and chip level detector (CLD) structures in the acquisition system. In our analysis, we consider the effects of free space optical channel impairments, multiple access interference, and receiver thermal noise in the context of semi-classical photon-counting approach. Furthermore, we evaluate the performance of various two stage schemes that utilize different combinations of active correlator, matched filter, and CLD in search and verification stages, and we find the optimum acquisition scheme among them. Numerical results show significant improvement in reducing the acquisition time and required power for synchronization using our optimum scheme in the wireless OCDMA communications

Designing and defining the knowledge sharing management system between governmental organizations

The knowledge management has become important after information explosion and human's entrance into science era. Therefore, science became the most important source for organizations and countries. Science management is the process of creating value from invisible assets (Human force) of the organization. The private sector has taken the first steps to put into operation 'Science Management ‘’but the government follows the private sector with the distance of one step. However, the studies concerning sharing science out are rare as the most important part of science management process in governmental sector. This article discusses the designing of the system to share science out in governmental organizations as an essential pattern of the systems (Entrance, process, and exit). Having examined the sources concerning science management and sharing it out, our final model of the study has considered the elements important in science management frame as input in governmental sector (People, organization, technology) influencing sharing science out, the science management activities as process and finally organizational operation improvement and favorable services as the output

The effect of corrugation on heat transfer and pressure drop in channel flow with different Prandtl numbers

Large Eddy Simulation and Direct Numerical Simulation are applied to study the turbulent flow field in a wavy channel at two Prandtl numbers, Pr = 0.71 and Pr = 3.5, and Reynolds number Re b = 10,000. The characteristics of the separated shear layer and the near wall recirculating zone are discussed in relation to the turbulent heat transfer. Special attention is paid to the behavior of the flow and thermal boundary layers and various turbulent characteristics and their effects on the distribution of the Nusselt number and friction coefficient in the separation and reattachment regions. The results indicate that the thickness of the thermal boundary layer rather than the turbulent fluctuations has a significant effect on the local variation of the averaged Nusselt number. The results are compared with Direct Numerical Simulation results of a plane channel at the same Reynolds number. \ua9 2013 Elsevier Ltd. All rights reserved

Evaluation of the ultrastructure and expression of desmoglein 2 in breast cancer: A novel biomarker

Background and purpose: Breast cancer is the most common malignancy among Iranian women. In recent years, the study of dysfunction in the expression of cell-cell junction genes and the related proteins in the malignant process has been at the center of attention. Materials and methods: In this study, 50 patients were selected who had both cancerous tissue and adjacent healthy tissue. The expression of the desmoglein 2 gene was evaluated. Healthy and cancerous tissue were compared using routine hematoxylin and eosin staining. The total protein was also compared between these two groups. The ultrastructural examination was performed. Results: The real-time polymerase chain reaction results showed a decrease in the expression of the desmoglein 2 gene in all tumor samples compared to the healthy samples (p<0.0001). Besides, receiver operating characteristic curve analysis showed that the area under the curve was equal to 0.98. Transmission electron microscopy microscopic studies revealed a change in the status of desmosomal junctions. Conclusions: Overall, the findings showed that the association between desmoglein 2 gene expression and alterations in cellular connections leads to impaired cellular connections, which is an important risk factor for breast cancer. This result proposed the understudy gene as a new biomarker in the development of breast cancer

Tetra­kis{4-[(2H-tetra­zol-5-yl)meth­yl]morpholin-4-ium} dodeca­tungstosilicate hexa­hydrate

The crystal structure of the title compound, (C6H12N5O)4[W12(SiO4)O36]·6H2O, consists of an α-Keggin-type [W12(SiO4)O36]4− polyoxidoanion, four [(2H-tetra­zol-5-yl)meth­yl]morpholinium cations and six uncoordinated water mol­ecules. In the cations, the morpholine rings display chair conformations. Extensive N—H⋯O, N—H⋯N, O—H⋯O and O—H⋯N hydrogen bonds are present in the crystal structure

Analyzing Cytotoxic and Apoptogenic Properties of Scutellaria litwinowii Root Extract on Cancer Cell Lines

The Scutellaria species (Lamiaceae) is used as a source of flavonoids to treat a variety of diseases in traditional medicine. In spite of many reports about the cytotoxic and antitumor effects of some species of this genus, anticancer researches on one of the Iranian species S. litwinowii have not yet been conducted. The cytotoxic properties of total methanol extract of S. litwinowii and its fractions were investigated on different cancer cell lines including AGS, HeLa, MCF-7, PC12 and NIH 3T3. Meanwhile, the role of apoptosis in this toxicity was explored. The cells were cultured in DMEM medium and incubated with different concentrations of herb plant extracts. Cell viability was quantitated by MTT assay. Apoptotic cells were determined using propidium iodide staining of DNA fragmentation by flow cytometry (sub-G1 peak). Scutellaria litwinowii inhibited the growth of malignant cells in a dose-dependent manner. Among solvent fractions of S. litwinowii, the methylene chloride fraction was found to be more toxic compared to other fractions. The IC50 values of this fraction against AGS, HeLa, MCF-7 and PC12 cell lines after 24 h were determined, 121.2 ± 3.1, 40.9 ± 2.5, 115.9 ± 3.5 and 64.5 ± 3.4 μg/ml, respectively. Scutellaria litwinowii induced a sub-G1 peak in the flow cytometry histogram of treated cells compared to control cells indicating that apoptotic cell death is involved in S. litwinowii toxicity. Scutellaria litwinowii exerts cytotoxic and proapototic effects in a variety of malignant cell lines and could be considered as a potential chemotherapeutic agent in cancer treatment

Comparison of Standard and Percutaneous Tracheostomy Complications in Shariati Hospital in Iran

Background: Tracheostomy is a procedure which aims at better managing patients’ airway. It can be done using two methods: standard and percutaneous. The percutaneous method is a favorable choice for critically illpatients because it is a less invasive procedure. This study compares the short-term complications of these two methods (during 7 days after the procedure).Methods: This study was a cross-sectional research performed on 50 ICU patients in need of tracheostomy.The patients were divided into two groups of percutaneous procedure (15 patients) and standard procedure(35 patients). The complications were registered in questionnaires and the data were analyzed using SPSS software (χ² test and t-test).Results: The two groups had no significant difference in age, sex, and vital signs. Average duration of the procedure was 24.4 minutes in the standard procedure (10-45 minutes) and 26.78 minutes (5-70 minutes) in the percutaneous procedure, and there was no significant difference between two groups (P = 0.814). Average bleeding during 7 days after the procedure was 44 cc (10-150 cc) in standard procedure and 24.7 cc (10-50 cc) in the percutaneous procedure, and the difference was significant (P = 0.012). The other variables were not significantly different in two groups.Conclusions: There was no difference in short-term complications between percutaneous and standard tracheostomy method should be selected considering other important factors

The influence of parent austenite characteristics on the intervariant boundary network in a lath martensitic steel

The influence of the parent austenite deformation state on the intervariant boundary network (i.e., population, plane orientation, and connectivity) of a lath martensitic microstructure was investigated using conventional EBSD mapping and five-parameter boundary analysis approach along with quantification of boundary connectivity using homology metrics. The lath martensite largely revealed a bimodal misorientation angle distribution, closely matched with the Kurdjumov–Sachs (K–S) orientation relationship. The application of deformation significantly changed the distribution, gradually reducing the intensity of the 60° misorientation angle peak. This was largely ascribed to substructure development within the parent austenite upon deformation, which stimulates particular variant/s having a habit plane (011)α′ closely parallel to the primary (111)γ and/or secondary (11¯¯¯1)γ slip plane. The interaction of these variants eventually promoted specific intervariant boundaries (e.g., 60°/[111], 10.5°/[011], and 49.5°/[110]) at the expense of 60°/[011]. The application of deformation in the parent austenite did not change the intervariant boundary plane character distribution, which mostly exhibited an anisotropic character terminated on {110} planes because of the displacive nature of the martensitic transformation. However, the extent of anisotropy progressively decreased with increasing strain in the austenite prior to transformation. The grain boundary network connectivity was markedly altered due to the local variant selection induced by the deformation. Deformation in the austenite regime generally decreased the connectivity of boundaries having a {110} plane orientation. The intervariant boundaries with the {110} twist character also displayed a similar trend, though the connectivity of {110} tilt boundaries progressively enhanced with increasing strain. The former was closely matched with a decrease in the population of 60°/[110] intervariant boundaries with the strain. The current findings suggest that the intervariant boundary network of lath martensite can be manipulated through changes in the parent austenite deformation state which, in turn, can be used to enhance key final product properties such as toughness.publishedVersio

The Problem of Paradox and its Manifestations: A Study in the Titles of Najm Wali's Novels

The irony pushes us to inquire about what is in the text of contradiction, irony, suspense, and other acts of paradox, as well as a departure from what is logical, or familiar, that attracts the attention of the addressee, and this is what drives us to introspect the text and interrogate it in order to get to know the intended product of the text or its real or metaphorical intent. On the other hand, the irony is more in the literary text than in the scientific texts. Therefore, critics add the word literature to it in their definition.  As it is represented by the paradox, we will seek to study the paradox of the title and the problematic that it may pose as the beginning of the text, and it expresses to us what is in the title of semantic overlap and existential contradiction or implicit (non-declared) with the main text or even a reference to it. From this point of view, we note that Najm Wali, as one of the most prominent Iraqi novelists who seeks to present a different and heterogeneous literature and benefits from the feature _Grebe_, especially the paradox, used titles for his novels that bear the characteristic of his paradoxes in most of them. In this study, we aim to analyze what is in these titles of irony in all its forms, based on the descriptive analytical approach. Through the following two axes: A: The theoretical dimension: This is an affirmation of what is related to the literary paradox, the paradox of the title, and the star of Wali in terms of definition, definition, and analysis. B:  The logical dimension: This is concerned with applying literary irony to Najm Wali’s titles, such as: “The Hill of Lahm,” “The War in the Tarab Neighborhood,” “The Picture of Joseph,” and “A Place Called Kumait.”   One of the results obtained by this study is that Najm Wali used the technique of title paradox, as a desire to draw the attention of the recipient to what is going on in his Iraqi society from the bitter reality, and on the other hand, he tried to reconcile the title and the cover, and to employ irony in all its forms with the main text for the same goal as well