Hope for African Agriculture

Text of the Sir John Crawford Memorial Lecture delivered during International Centers Week in 1986 by Dr. Bukar Shaib of Nigeria. Dr. Shaib described achievements in developing new technologies and farming systems for small-scale African farmers

An overview: effectiveness of different arrangement for electrode guard in electrical capacitance tomography

Electrical capacitance tomography (ECT) system is useful to obtain information about the spatial distribution of a dielectric materials mixture inside a vessel. It has been suggested by many researchers previously to use guard electrode in ECT sensors. This paper describes various types of design for guard electrode in Electrical Capacitance Tomography (ECT) sensor. The design of these electrode guards is vital to reduce crosstalk (undesired signals) between the adjacent electrodes (positioned at the outside of the measured pipe) since the crucial signals are only inside the pipe. There are three types of electrode guards designed by various researchers which are radial guard, axial guard with end guard and driven guard. The configuration and the effectiveness of each designed electrode are discussed. Other than that this paper introduced new design of electrode guards which are embedded on electrode sensor instead of placing separately between or around adjacent measuring electrodes as the previous design

Comparative analysis of different wave turbine designs based on conditions relevant to northern coast of Egypt

Wave energy has a great potential to solve the unrelenting energy deficiency in Egypt. The present work recommends Wells turbine as a suitable choice for the Egyptian coasts due to its simple and efficient operation under low input air flow. In addition, the possibility of extracting the wave energy from the Egyptian coasts was investigated using the oscillating water system based on real data from the site. To achieve this purpose, two-dimensional numerical models for Wells turbine airfoils, functioning under sinusoidal wave flow conditions, were built. Moreover, the running and starting characteristics under sinusoidal-flow conditions were investigated using a mathematical code. The results were discussed using the first law analysis, in addition to the second law analysis by using the entropy generation minimization method. It was found that the NACA0015 airfoil always gives a global entropy generation rate that is less than other airfoils by approximately -14%, -10.3% and -14.7% for the sinusoidal wave with time periods equal to 4, 6 and 8 seconds respectively. Moreover, the effects of blade profile, time period and solidity on the output power (kW) value were discussed

A case of distal extrahepatic cholangiocarcinoma with two positive resection margins

Cholangiocarcinoma is an uncommon primary malignancy of the biliary tract that is challenging to diagnose and treat effectively due to its relatively silent and late clinical presentation. The present study reports a case of a 60-year-old male with distal extrahepatic cholangiocarcinoma with a 3-week history of painless obstructive jaundice symptoms and subjective weight loss. Imaging revealed an obstructing lesion in the common bile duct, just distal to the entrance of the cystic duct. Pathology revealed moderately differentiated cholangiocarcinoma with two positive proximal resection margins. The two positive resection margins presented a challenge during surgery and points to an urgent need for further studies to better illuminate diagnostic and therapeutic options for patients with similar clinicopathological presentation

Public Rights and Freedoms in the Libyan Constitutional Declaration 2011

The most important goals of the popular revolution in Libya in February 2011, which turned into an armed clash to be issued a constitution that guarantees rights and freedoms, which was violated during the former regime. The Libyan constitutional declaration 2011 translated the ambitions and aspirations of the Libyan people. And even if it was set to only organize a period of transition. It is in accordance with the objective criterion for the definition of constitutions, considered as a constitution for containing constitutional themes. Also, according to the constitutional standard, it is considered a constitution; for the existence of the features of the formal criterion in terms of its issuance by a native constitutive authority, that is an authority that intervenes for constitution-making in the absence of a constitution in the country, as well as in terms of procedures to amend or repeal any text therein. Thus, the Libyan constitutional declaration has a constitutional nature that is not different from permanent constitutions and its texts transcend to all legal standards and norms. The texts of the rights and freedoms contained in the Libyan Constitutional Declaration (Part Two, Articles 7-16) approved many of the provisions of Islamic law, international conventions and constitutions of countries with mature constitutional experience. Its articles, which were generally considered, brief and short, came to specify many of the texts to an important issue in constitutions, namely rights and freedoms. Furthermore, the circumstances that the country is undergoing are reflected in the content of some texts, which confirms that the constitutions must reflect the conscience of society and its aspirations. Despite the existence of the texts, the transitional period lasted longer than what was issued in the constitutional declaration and witnessed many violations of rights and freedoms. Therefore, a permanent and consensual constitution that guarantees national reconciliation and recognizes transitional justice is a popular and elitist demand

Do Women Have an Advantage When Leading Across Groups? An Examination of Gender, Self-Construals, and Intergroup Leadership

Intergroup leadership, self-construals, and gender are relatively well researched. However, there has been limited research that has looked at the interplay between these areas of research. For example, past research has shown women’s tendency towards an interdependent self-construal (Cross & Madson, 1997), the various challenges women face in pursuit of leadership roles (Eagly, 1987; Schein, 1973), as well as which style of intergroup leadership is most effective in various scenarios of subgroup relations (Hogg & Rast, 2022; Hogg et al., 2012; Rast et al., 2018). Although real world leadership situations often combine all these phenomena, research has yet to catch up and explore how they interact with each other. Therefore, two studies were conducted to examine how leader gender, intergroup leadership style, and subgroup relations impact evaluations of candidates running for a leadership position (Study 1; N = 256); and how participant gender and subgroup relations impact participants’ endorsement of an intergroup leadership style when placed in a leadership role (Study 2; N = 262). Results of Study 1 showed that participants more strongly endorsed a candidate who used an intergroup relational identity (IRI) style of leadership and were also more likely to promote that candidate. Results of Study 2 showed that, in a leadership position themselves, women more strongly endorsed using IRI rhetoric than men, and that participants in the cooperation subgroup condition more strongly endorsed using IRI rhetoric than participants in the competitive subgroup condition

A study on optical sensors orientation for tomography system development

This paper describes the investigation of optical sensors performance towards the development of optical tomography system. The orientation of the transmitters has been set from 0o until 180o and then the receiver’s responses were analyzed. Hence, sensors capabilities were tested further by placing blockage object in between the transmitter and receiver and the effect of this arrangement were observed. Finally, new designs of sensor jig were introduced based on the results achieved. Copyright © 2012 IFS