Choosing a Better Delay Line Medium between Single-Mode and Multi-Mode Optical Fibers: the Effect of Bending

Optical fiber cables are materials whose core is made of silica and other materials such as chalcogenide glasses; they transmit a digital signal via light pulses through an extremely thin strand of glass. The light propagates and is being guided by the core which is surrounded by the cladding. Light travels in the optical fiber in the form of total internal reflection in the core of the fibers. The flexibility, low tensile strength, low signal loss, high bandwidth and other characteristics of optical fibers favors it for use as a delay medium in many applications. Another favorable characteristic of optical fiber delay lines is are their relative insensitivities to environmental effects and electromagnetic interferences. The immunity of optical fibers to interferences and their less weight added advantages to it for use as delay medium. Single-mode and multi-mode are the two most popular types of optical fibers. Single-mode fibers have good propagation and delay properties with a minimal loss that allows the signal to propagate in a large distance with insignificant distortion or attenuation. The percentage of power transmission of single-mode fibers is found to be higher than that of the multi-mode fibers. It is, therefore, a preferred type for use as a delay line. In this paper, relative studies of the two optical fibers modes, and the results of power input/output measurement of the two modes are presented with a view to coming up with a better type for use as a delay medium

Application of normative frameworks for assessing availability of socio-economic policies based on maqasid al shari’a principles in Muslim countries: A proposal / Mustapha Abubakar and Kabiru Jinjiri Ringim

The objective of this paper is to propose a framework that will assess the availability of maqasid al shari’a based socio-economic policies in Muslim countries, and whose nebulous institutions are perturbed by the statistic that 504 million people are living in multi-dimensional poverty, suffering from range of deprivations in forty-three member countries of the Islamic Development Bank (IDB). Lack of or weak access to adequate resources remain the primary issues faced by many nations. In the midst of this though, there is a recurring argument that the level of socio economic development of human well-being must be improved. To understand development challenges of socio-economic framing in the current Muslim world, factors such as education, health, spirituality, lives and property, economy, food security as well as youth employment as based on maqasid al shari’ah framework model merit consideration. Accordingly, this paper seeks to address the gap in the current literature by incorporating education and youth unemployment factors into the socio-economic development model which is based on maqasid al sharia’h framework. The study adapted the principles of Islamic divine law that ensures an inclusive socio-economic development policy devoid of tribal, ethnic or religious sentiments. The study offered recommendations for further research on maqasid al sharia’ah applications on the socio-economic development of both Muslim and Muslim-minority countries

Renewable Energy, Regulation, Employment and Environmental Sustainability in Sub-Saharan Africa

This paper examines the impact of employment, regulatory quality and urbanization on environmental quality by using renewable energy as a metric of environmental indicator in sub-Saharan Africa. The environmental Kuznets curve (EKC) theory was used as the theoretical framework while the difference Generalized Method of Moments (GMM) was utilised as the estimation technique. 45 sub-Saharan African countries covering the period of 2008 to 2016 were used as the sample size. The result reveals that increase in employment and income is at expense of environmental quality while regulation quality and urbanization increase environmental quality. As such, policymaking in the region should support the development of renewable energy by providing incentives that encourage private sector investment in renewable energy; implement sound policies and regulations that promote private sector employment and smart cities development. Keywords: Renewable energy; environment, regulation, employment, sub-Saharan Africa DOI: 10.7176/DCS/9-7-04 Publication date:July 31st 201

Uniaxial tensile response of coconut coir fiber-reinforced polyethylene Composites

The roles of Composite materials in a variety of engineering applications have increased due to their enhanced strength and modulus, especially polymer-based composites which is one of the commercially available composites. The uniaxial tensile properties of polyethylene matrix reinforced with coconut coir fibers has been studied and the results from experiments and analytical models are presented. The compositional dependence of tensile strength, stiffness (elastic modulus), modulus of resilience and ductility are explored for different proportions of the constituent materials through experiments and analytical models. The results from experiments showed that the properties measured were greatly affected by the fiber mass fraction with optimized properties obtained at fiber content of 10 wt%

Uniaxial tensile response of coconut coir fiber-reinforced polyethylene Composites

The roles of Composite materials in a variety of engineering applications have increased due to their enhanced strength and modulus, especially polymer-based composites which is one of the commercially available composites. The uniaxial tensile properties of polyethylene matrix reinforced with coconut coir fibers has been studied and the results from experiments and analytical models are presented. The compositional dependence of tensile strength, stiffness (elastic modulus), modulus of resilience and ductility are explored for different proportions of the constituent materials through experiments and analytical models. The results from experiments showed that the properties measured were greatly affected by the fiber mass fraction with optimized properties obtained at fiber content of 10 wt%

A model study of surface state on optical bandgap of silicon nanowires

A theoretical approach is carried out to study the role of surface state in silicon nanowires. The influences of size and surface passivation on the bandgap energy and photoluminescence spectra of silicon nanowires with diameter between 4 to 12nm are examined. It is observed that visible PL in silicon nanowires is due to quantum confinement and surface passivation. But the energy recombination of electron and holes in the quantum confined nanostructures is responsible for the visible PL. In this work, models from quantum bandgap and photoluminescence intensity are adopted to explain the size dependent surface luminescence. Investigation show that the nanowires of smaller size with surface impurities revealed higher bandgap energy. Oxygenated surface is found to have higher energy than hydrogenated surface. The features of PL spectra of Si nanowires suggest that these models are significant for understanding the mechanism of visible PL from SINWs.Keywords: Photoluminescence, Surface State, Band gap, Quantum Confinemen

Effect of Chemically Modified Banana Fibers on the Mechanical Properties of Poly-Dimethyl-Siloxane-Based Composites

The study presents the mechanical properties of polymer-based composites reinforced with chemically modified banana fibers, by alkalization in different concentrations of sodium hydroxide (NaOH). The fiber weight fraction has a great effect on the mechanical properties of the composites. Stiff composites were obtained at 6 wt% fiber fractions with Young’s modulus of 254.00 ±12.70 MPa. Moreover, the yield strength was 35.70 ±1.79 MPa at 6 wt% fiber fractions. However, the ultimate tensile strength (UTS) and toughness of the composites were obtained at 5 wt% fiber fractions. Statistical analyses were used to ascertain the significant different on the mechanical properties of the fibers and composites. The implication of the results is then discussed for potential applications of PDMS-based composites reinforced with chemically modified banana fibers

Uniaxial tensile response of coconut coir fiber-reinforced polyethylene Composites

The roles of Composite materials in a variety of engineering applications have increased due to their enhanced strength and modulus, especially polymer-based composites which is one of the commercially available composites. The uniaxial tensile properties of polyethylene matrix reinforced with coconut coir fibers has been studied and the results from experiments and analytical models are presented. The compositional dependence of tensile strength, stiffness (elastic modulus), modulus of resilience and ductility are explored for different proportions of the constituent materials through experiments and analytical models. The results from experiments showed that the properties measured were greatly affected by the fiber mass fraction with optimized properties obtained at fiber content of 10 wt%

Retrospective histopathological study of canine mammary gland tumours diagnosed from 2006 – 2012 in Universiti Putra Malaysia

Forty-eight canine mammary tumours (CMT) diagnosed at the Histopathology Laboratory, Faculty of Veterinary Medicine, Universiti Putra Malaysia, were reviewed retrospectively. Two control groups, one comprising all other cases involving female dogs and another group comprising only cases of neoplasia involving female dogs diagnosed in the laboratory over the same period of time were used for comparisons in this study. Fisher’s exact test and logistic regression were used to determine association between the factors and the risk of CMT. Thirty-nine (81.3%) of the tumours were diagnosed as adenocarcinoma, 8.3% (n=4) each, were the diagnoses for squamous cell carcinoma and mixed cell tumour. Adenoma had 2.1% (n=1). The prevalence of canine mammary gland tumours in this study is 39%. When CMT cases were compared with all other cases, significant association was observed with adult dogs (p = 0.032, logistic regression 0.012) and intact dogs (p= 0.009, logistic regression, 0.003). When CMT cases were compared with neoplasia cases, significant association was observed with pure breeds (p = 0.025) and intact dogs (p = 0.000034, logistic regression 0.00042). This study found that pure breed dogs, intact dogs and older dogs (> 5years) have higher odds of having CMT in Malaysian dog population

Application of Mobile Technology in Information Service Delivery in Bayero University Library, Kano

Current trends in libraries especially in the academic library require remote and boundary less access to library services and services. Mobile Technology has been recognized as the simple, single most embraced technology in the world. Applying this technological innovation will bring a lot of relief to users in Bayero University, Kano library and the University community in general. The study investigates the preparedness of Bayero University, Kano library to apply mobile technology for information services delivery. The population consisted of 11 staff from the library\u27s automation unit, with only two of them being sampled. The research instrument used was an interview. The study shows that the staff agree with the impact and relevancy of the application of the service in the library. The study also revealed challenge with the application of the service such as Lack of committed of staff, lack of technical knowhow, poor of internet connection, lack of training. The study also recommends that the staff and Student at Bayero University, Kano Library should be educated about the benefits of using mobile-based library services for relevant information, Continuous training should be given to library staff in the application of mobile based- library services and Management should also develop strategy for the marketing of the mobile-based library services