Illustrating field emission theory by using Lauritsen plots of transmission probability and barrier strength

This technical note relates to the theory of cold field electron emission (CFE). It starts by suggesting that, to emphasize common properties in relation to CFE theory, the term 'Lauritsen plot' could be used to describe all graphical plots made with the reciprocal of barrier field (or the reciprocal of a quantity proportional to barrier field) on the horizontal axis. It then argues that Lauritsen plots related to barrier strength (G) and transmission probability (D) could play a useful role in discussion of CFE theory. Such plots would supplement conventional Fowler-Nordheim (FN) plots. All these plots would be regarded as particular types of Lauritsen plot. The Lauritsen plots of -G and lnD can be used to illustrate how basic aspects of FN tunnelling theory are influenced by the mathematical form of the tunnelling barrier. These, in turn, influence local emission current density and emission current. Illustrative applications used in this note relate to the well-known exact triangular and Schottky-Nordheim barriers, and to the Coulomb barrier (i.e., the electrostatic component of the electron potential energy barrier outside a model spherical emitter). For the Coulomb barrier, a good analytical series approximation has been found for the barrier-form correction factor; this can be used to predict the existence (and to some extent the properties) of related curvature in FN plots.Comment: Based on a poster presented at the 25th International Vacuum Nanoelectronics Conference, Jeju, S. Korea, July 2012. Version 3 incorporates small changes made at proof stag

Developing Strategic Reports for National Co-Operative of Malaysia (Angkasa) Using Data Warehouse and Decision Tree Model

Managing an organization requires access to information in order to monitor activities and assess performance. Business Intelligence (BI) solutions provide organizations with timley, itegrated information that is crucial to the understanding of their business. Data Warehouse (DW) technology is one of the important strategic management approaches for decision making in an organizations. The BI combines architectures, tools, databases, analytical tools, and methodologies to enable the implementation of interactive information in generating analytical reports. Strategic reports, which influence the enduring way of the whole company, are typically used by top managers. These kinds of decisions are repeatedly complex and the outcomes unsure, because existing information is habitually incomplete. Managers at this point must normally depend on history experiences and their instincts when making strategic decisions. DW is a technology allows integrating and transforming enterprise data for strategic decision making. Furthermore, Decision Tree (DT) is a decision support tool that uses a tree-like graphof decisions and their possible consequences, including chance event outcomes, resource costs, and utility. The organization, which is, responsible to manage people activities need strategic decisions making. This paper will be focused how to design and develop Strategic Reports using DW and DT Model for National Co-operative Organization of Malaysia (ANGKASA) called DSRNCO, as a case study. This system has been evaluated through the system user feedback by using Computer System Usability Questionnaire (CSUQ), which measures system usability and user satisfaction

MOLECULAR AND CHEMICAL THERAPEUTIC FEATURES OF URTICA SPECIES

The present review study was conducted to review the current understanding of molecular aspects of Urtica species. We refer to the most recent published articles addressing the therapeutic potential of this plant. A wide spectrum of diseases has been associated with Urtica species including cancer, arthritis, autoimmune diseases, diabetes, and fatigue. Some molecular mechanisms and chemical properties have been discussed. Taken together, studies have confirmed the beneficial effects of Urtica all over the world and understanding of the molecular mechanisms underlying the beneficial effects opens new horizon to understand new therapeutic options. The extracts of Urtica should be prepared based on separating effective ingredients for optimal therapeutic benefits

Mn+2 and Cd+2 Removal from Industrial Wastewater Using Phillipsitic Tuff from Jabal Uniza, Southern Jordan

Southern Jordanian natural zeolitic tuffs outcropped in Uniza volcano have been investigated and tested for their heavy metals' removal capacity. The main species identified in Uniza natural zeolitic tuffs are: phillipsite and, subordinately, chabazite. The effects of particle size and stirring time were examined in the removal experiments. Two types of Uniza phillipsitic tuff were used in the removal of Mn+2 and Cd+2 from treated industrial wastewater. The first type is the reddish bulk sample (UZ1), while the second type is the separated size (UZ2) fraction between 1 and 0.3 mm. Batch and column tests were performed to determine the removal capacity of Mn+2 and Cd+2 from treated industrial wastewater. In batch experiments (static regime), the use of UZ2 type shows a higher removal percentage of Mn+2 and Cd+2 compared to UZ1 type for the same time. The results of column experiments indicate that toxic metal ions such as Mn+2 and Cd+2 can be removed with approximately 100% efficiency from industrial wastewater containing similar ions using Jordanian zeolitic tuff. In dynamic regime, by using UZ1 the manganese ions (Mn+2) were completely removed up to 57 BV (1.71 L) and the zeolite exhaustion took place after more than 112 BV (3.36 L), while by using UZ2 the manganese ions were completely removed up to 67 BV (2.01 L) and the zeolite exhaustion took place just around 114 BV (3.42 L). For an efficient cadmium ions removal, the use of UZ1 sample showed a complete removal up to 85 BV (2.55 L) and the zeolite exhaustion took place after more than 129 BV (3.87 L), while the use of UZ2 showed that the Cd+2 ions were completely removed after 151 BV (4.53 L) and the zeolite exhaustion took place after more than 205 BV (6.15 L)

Numerical solution of linear time delay systems using Chebyshev-tau spectral method

In this paper, a hybrid method based on method of steps and a Chebyshev-tau spectral method for solving linear time delay systems of differential equations is proposed. The method first converts the time delay system to a system of ordinary dierential equations by the method of steps and then employs Chebyshev polynomials to construct an approx- imate solution for the system. In fact, the solution of the system is expanded in terms of orthogonal Chebyshev polynomials which reduces the solution of the system to the solution of a system of algebraic equations. Also, we transform the coefficient matrix of the algebraic system to a block quasi upper triangular matrix and the latter system can be solved more efficiently than the first one. Furthermore, using orthogonal Chebyshev polynomials enables us to apply fast Fourier transform for calculating matrix-vector multiplications which makes the proposed method to be more efficient. Consistency, stability and convergence analysis of the method are provided. Numerous numerical examples are given to demonstrate efficiency and accuracy of the method. Comparisons are made with available literature

QoS Routing of VoIP using a Modified Widest-Shortest Routing Algorithm

Implementation of current real time services (of which one of the more important is Voice over IP) on the current Internet face many obstacles, among them the issue of routing. Quality of service (QoS) routing, attempts to provide real time services with the required guarantees to achieve acceptable performance. In this paper we study VoIP routing using the Quality of Service (QSR) network simulator utilizing the Widest-Shortest routing algorithm to provide QoS using different metrics. We show that this algorithm using a modified cost metric based on the hop-normalized is able to route real time traffic away from congested links thus providing acceptable jitter, end-to-end delay and throughput to satisfy real time services requirements

Antecedent and Consequences of Blockchain-as-a-Service for E-Voting: The Mediating Role of Perceived Trust

Electronic voting refers to internet voting (e-voting), a system for electronically casting and counting votes. The current voting service provided by the government includes balloting paper and e-voting. However, these services cannot be relied on due to several issues such as electoral fraud (e.g., counting, rigging, and election manipulation), circuitry failure (e.g., tampering with the motherboard), and, more importantly, such services do not provide the facility to track back the casted vote. Considering the problems in earlier voting services, the blockchain-as-a-service for e-voting has been introduced to make the voting process more secure, immutable, transparent, and reliable. Within the blockchain-as-a-service for e-voting, we have reviewed the available literature and witnessed that the majority of the studies have given much emphasis on the technical side but lack its focus on the adoption behavior of blockchain-as-a-service for evoting during the election period. Therefore, the foci of this study to explore the antecedent (i.e., digital literacy) and consequences (i.e., consumer wellbeing, users’ referral) of users’ adoption behavior of blockchain-as-a-service for e-voting under the mediating mechanism of users’ perceived trust between digital literacy and adoption behavior. This study collected data from a 315 US sample using the Mturk. Partial least squares – structural equation modeling (PLS-SEM) analyses were used to analyze the study data. The PLS-SEM analysis revealed that the measurement model of the study, including digital literacy as a higher-order reflective-formative construct and other reflective models (e.g., adoption behavior, consumer wellbeing, etc.), have adequate reliability and validity. Upon estimating the study’s structural model, we found that digital literacy of blockchain e-voting positively impacts on perceived trust and adoption behavior of blockchain e-voting technology. Perceived trust in blockchain e-voting also revealed to have a positive impact on users’ adoption behavior of blockchain-as-a-service for evoting. Furthermore, the results of the study indicated that blockchain adoption behavior is a significant predictor of consumer well-being and citizen referral behavior. We also tested the mediating effect of perceived trust between digital literacy and adoption behavior of blockchain-as-a-service for e-voting and found that digital literacy successfully predicts the adoption behavior of blockchain e-voting through perceived trust, signifying the pivotal role of trust. This study theoretically extends the domain of blockchain-as-a-service for evoting via investigating its potential antecedent (i.e., digital literacy) and consequences (i.e., citizen referral behavior and consumer well-being) of users’ adoption behavior of blockchain-as-a-service for evoting. Besides, we also expands the literature of perceived trust via studying it as a mediating mechanism between digital literacy and users’ adoption behavior of blockchain-as-a-service for evoting. It also helps design, prepare, and implement new technologies while considering consumers\u27 digital literacy and trust. Government officials and regulators should promote ways to improve the level of digital literacy to implement the blockchain e-voting service fully. Policymakers should collaborate with industry practitioners to create a well-thought-out plan that targets and improves public digital literacy while also increasing trust in blockchain e-voting to increase people\u27s adoption and usage of this technology

The Development of the WISE (Writing to Inspire Successful Education) Writing Mentoring Program: A University-School Collaboration

Abstract This paper describes the development of a service learning writing mentoring program designed to close the achievement gap in writing proficiency for economically disadvantaged seventh grade students. Compared to writing mentoring studies found in the published literature, this program has three distinguishing components. First, it focused on economically disadvantaged middle school students. Second, it provided writing mentoring through a university-school partnership in which college students provided the intervention in collaboration with a seventh-grade teacher. Third, the program used technology to facilitate the mentoring process. Over the course of an academic year, mentors created videos with feedback on 19 writing assignments. The writing mentoring program was associated with a four-fold increase in the percentage of students who were graded as ‘proficient’ on a state standardized writing exam. These results suggest that semi-virtual, intensive writing mentoring and individualized feedback from college students can close the achievement gap and improve the quality of middle level education provided to economically disadvantaged students

Metabolomics Profiling of Vitamin D Status in Relation to Dyslipidemia.

Vitamin D deficiency is a global disorder associated with several chronic illnesses including dyslipidemia and metabolic syndrome. The impact of this association with both dyslipidemia and vitamin D deficiency on metabolomics profile is not yet fully understood. This study analyses the metabolomics and lipidomic signatures in relation to vitamin D status and dyslipidemia. Metabolomics data were collected from Qatar Biobank database and categorized into four groups based on vitamin D and dyslipidemia status. Metabolomics multivariate analysis was performed using the orthogonal partial least square discriminate analysis (OPLS-DA) whilst linear models were used to assess the per-metabolite association with each of the four dyslipidemia/vitamin D combination groups. Our results indicate a high prevalence of vitamin D deficiency among the younger age group, while dyslipidemia was more prominent in the older group. A significant alteration of metabolomics profile was observed among the dyslipidemic and vitamin D deficient individuals in comparison with control groups. These modifications reflected changes in some key pathways including ceramides, diacylglycerols, hemosylceramides, lysophospholipids, phosphatidylcholines, phosphatidylethanol amines, and sphingomyelins. Vitamin D deficiency and dyslipidemia have a deep impact on sphingomyelins profile. The modifications were noted at the level of ceramides and are likely to propagate through downstream pathways