Essential aspects of power system planning in developing countries

AbstractIn developing countries, power system planning faces enormous challenges and problems as, for example, future load growth in the face of uncertainties, the constraints imposed on investment, the type and availability of fuel for the generating units, the need for consolidating the dispersed electric utilities in the isolated regions as a prerequisite for future interconnecting these regions via local national grids and with other neighboring countries. Also, how an optimal reliability level can be achieved that will guarantee a continuous power flow with a reasonable costs. All these obstacles made power systems planners and concerned agencies face tremendous difficulties in planning electric power facilities and making sound and appropriate decisions in constructing new power plants or adding new generating units or reinforcing the transmission and distribution networks. The proposed work attempts to display the most tedious and prominent problems and challenges that face the electric power systems in developing countries and influence the decision-making process which must be based on two major factors, namely, reliability and cost

Reliability Evaluation of Power Systems

Reliability evaluation of electric power systems is an essential and vital issue in the planning, designing, and operation of power systems. An electric power system consists of a set of components interconnected with each other in some purposeful and meaningful manner. The object of a reliability evaluation is to derive suitable measures, criteria, and indices of reliable and dependable performance based on component outage data and configuration. For evaluating generated reliability, the components of interest are the generating units and system configuration, which refer to the specific unit(s) operated to serve the present or future load. The indices used to measure the generated reliability are probabilistic estimates of the ability of a particular generation configuration to supply the load demand. These indices are better understood as an assessment of system-wide generation adequacy and not as absolute measures of system reliability. The indices are sensitive to basic factors like unit size and unit availability and are most useful when comparing the relative reliability of different generation configurations. The system is deemed to operate successfully if there is enough generation capacity (adequate reserve) to satisfy the peak load (maximum demand). Firstly, generation model and load model are convolved (mutually combined) to yield the risk of supply shortages in the system. Secondly, probabilistic estimates of shortage risk are used as indices of bulk power system reliability evaluation for the considered configuration

Conceptualizing corporate identity in a dynamic environment

Purpose – The study revisits the meaning of Corporate Identity (CI) in practice to identify its key dimensions and the interrelationships between them, and to provide insights on how to operationalize the construct. Design/methodology/approach – This study is based on a comprehensive literature review and qualitative research consisting of 22 semi-structured interviews with senior managers from 11 UK-leading companies, and three in-depth interviews with corporate brand consultants who worked closely with these firms in cognate areas. Findings – The study identifies six key dimensions of CI in UK industry: communication, visual identity, behavior, organizational culture, stakeholder management, and founder value-based leadership. Research limitations/implications – The focus on UK leading companies limits the generalizability of the results. Further studies should be conducted in other sectors and country settings to examine the relationships identified in the current study. Originality/value – This study identifies the salient dimensions of CI and, for the first time, the role of founder transformational leadership, employee identification and top management behavioral leadership as key dimensions and sub-dimensions of CI. The study also provides novel insights about the measurements for these dimensions. Additionally, this study introduces a model for the interrelationships between CI dimensions and their influence on corporate image, based on rigorous theoretical underpinnings, which lays the foundation for future empirical testing

Nonexistence of nonzero derivations on some classes of zero-symmetric 3-prime near-rings

We give some classes of zero-symmetric 3-prime near-rings such that every member of these classes has no nonzero derivation. Moreover, we extend the concept of “3-prime” to subsets of near-rings and use it to generalize Theorem 1.1 due to Fong, Ke, and Wang concerning the transformation near-rings M o (G) by using a different technique and a simpler proof.Наведено дєякі класи 3-простих майже-кілець з нульовою симєтрією таких, що будь-який елемент цих класів не має ненульової похідної. Крім того, поняття „3-простих" узагальнено на підмножини майже-кілець i застосовано, щоб узагальнити теорему 1.1 Фонга, Ке i Ванга про трансформацію майже-кілець M o (G) за допомогою іншої техніки та більш простого доведення

An Arabic CCG approach for determining constituent types from Arabic Treebank

AbstractConverting a treebank into a CCGbank opens the respective language to the sophisticated tools developed for Combinatory Categorial Grammar (CCG) and enriches cross-linguistic development. The conversion is primarily a three-step process: determining constituents’ types, binarization, and category conversion. Usually, this process involves a preprocessing step to the Treebank of choice for correcting brackets and normalizing tags for any changes that were introduced during the manual annotation, as well as extracting morpho-syntactic information that is necessary for determining constituents’ types. In this article, we describe the required preprocessing step on the Arabic Treebank, as well as how to determine Arabic constituents’ types. We conducted an experiment on parts 1 and 2 of the Penn Arabic Treebank (PATB) aimed at converting the PATB into an Arabic CCGbank. The performance of our algorithm when applied to ATB1v2.0 & ATB2v2.0 was 99% identification of head nodes and 100% coverage over the Treebank data

Cathepsin b: a potential prognostic marker for inflammatory breast cancer

<p>Abstract</p> <p>Background</p> <p>Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. In non-IBC, the cysteine protease cathepsin B (CTSB) is known to be involved in cancer progression and invasion; however, very little is known about its role in IBC.</p> <p>Methods</p> <p>In this study, we enrolled 23 IBC and 27 non-IBC patients. All patient tissues used for analysis were from untreated patients. Using immunohistochemistry and immunoblotting, we assessed the levels of expression of CTSB in IBC versus non-IBC patient tissues. Previously, we found that CTSB is localized to caveolar membrane microdomains in cancer cell lines including IBC, and therefore, we also examined the expression of caveolin-1 (cav-1), a structural protein of caveolae in IBC versus non-IBC tissues. In addition, we tested the correlation between the expression of CTSB and cav-1 and the number of positive metastatic lymph nodes in both patient groups.</p> <p>Results</p> <p>Our results revealed that CTSB and cav-1 were overexpressed in IBC as compared to non-IBC tissues. Moreover, there was a significant positive correlation between the expression of CTSB and the number of positive metastatic lymph nodes in IBC.</p> <p>Conclusions</p> <p>CTSB may initiate proteolytic pathways crucial for IBC invasion. Thus, our data demonstrate that CTSB may be a potential prognostic marker for lymph node metastasis in IBC.</p