Impact of Aisami Solid Waste dumping site, Kano Metropolis, Nigeria on the quality of ground water of the neighbouring environment

Open dumping and uncontrolled landfilling of solid wastes are the most widely practiced waste disposal methods in many cities of the less-developed regions, especially those in sub Saharan Africa. These practices are unsustainable and pose a major threat to the environment and public health. Of particular concern is the leachate produced at the disposal sites, which is concentrated with biological and chemical substances that could contaminate the soil, surface and groundwater sources in the environment. The effects of leachate percolation on the quality of groundwater sources is of great concern especially in sub Saharan Africa, where untreated self-supply groundwater options represent a major source of water supply for many inhabitants. Given this perspective, the physicochemical characteristics of some groundwater samples from wells around a major waste disposal site; Aisami in Kano metropolis, Nigeria, were examined. The samples were collected from the north, east, south and west directions around the disposal site and analysed for parameters that include: pH, turbidity, total dissolved solids, electrical conductivity, total alkalinity, total hardness, Ca+2, Mg+2, Na+, K+, NO3-, SO4(2-), Cl-, Cu+2, Fe+2 ,Mn+2, Pb, Zn, and Cr. Significant concentrations of most parameters were revealed, often above the WHO recommended thresholds. Accordingly, some measures were highlighted towards protecting, preserving and sustaining groundwater quality as a strategic source of water supply in the area and beyond

Studies on mosquito density in urban Kano: a study to calculate larval indices in municipal area of Gwale, Kano, Nigeria

The study is carried out to standardize larval indices namely House Index, Container Index and Breteau Index and also to identify the major breeding sources of mosquitoes in the residential environment in and around the Gwale Local government area of  Kano, Nigeria. A cross-sectional study by selecting 50 houses randomly from the 6 wards of Municipality was employed. Every water holding container indoors and outdoors were counted and searched for larval presence and noted on a pretested format. In this study, 300 houses were surveyed in 21 days out of which 94.33% (283 houses) were found to have potential sources for mosquito breeding. All the entomological indices were found to be above the critical level. House Index = 28.67%; Container Index = 12.14%; Breteau Index = 64.00% showing high chances for outbreaks of mosquito borne diseases. The area is prone to mosquito borne disease like malaria and therefore warrants interventions from the competent

Land Resources and Productivity Potential - Agro-Ecological Methodology for Agriculture Development Planning

Understanding the nature and dimension of the land and water resources for food and agriculture development and the policies available to develop them have been the focal point of the work of the Land and Water Division of the Food and Agricultural Organization of the United Nations and the Food and Agriculture Program at the International Institute for Applied Systems Analysis. As we anticipate over the coming decades a technological transformation of agriculture which will be constrained by resource limitations and which could have serious environmental consequences, a number of important questions arise: (a) What is the stable, sustainable production potential of the world? of regions? of nations? (b) How does this production potential in specific areas (within countries as well as groups of countries) compare to the food requirements of the future populations of these areas? potential? (c) What alternative transition paths are available to reach desirable levels of this production potential? (d) What are the sustainable and efficient combinations of techniques of food production? (e) What are the resource requirements of such techniques? (f) What are the policy implications at national, regional and global levels of sustainability? Stability and sustainability are both desirable properties of agricultural land resources development, inter-generational equity as well as of political stability and peace. We hold ecological considerations to be of critical importance in answering the questions posed above. Limits to food production are set by soil and climatic conditions and by the use, and management, of the land. In the long term, any "mining" of land beyond these limits will result in degradation and decreased productivity. Accordingly, there are critical levels of production obtainable, in perpetuity, from any given land area and hence critical levels of populations that can be supported from this area. It is crucial to take account of the physical resource base for potential production as well as the socio-economic aspects that will influence the actual production. The population and land resources study, carried out by the Food and Agriculture Organization of the United Nations in collaboration with the International Institute for Applied Systems Analysis, with funding from the United Nations Fund for Population Activities, is concerned with the quantitative evaluation of the land resources' food productive capacity on the basis of soil, climate and crop data under specified technological conditions. The methodology and resource data base developed within this study provides a first approximation of the food production potentials and the population supporting potentials for 117 countries in five regions of the developing world. The most fruitful and promising avenue for further work and application of the methodology is in relation to detailed country case studies. The aim of this report is to describe the agro-ecological methodology and specify the data needs, with special emphasis on methodological and data refinements for detailed country agricultural planning studies. The report should be of particular interest and use to institutions in countries considering an ecological--technological--economic approach to the planning of agricultural development

End reflections in a layered piezoelectric circular cylinder

AbstractEnd reflection phenomenon in a semi-infinitely long layered piezoelectric circular cylinder is constructed with modal data from a spectral decomposition of the differential operator governing its natural vibrations. These modal data consist of all propagating modes and edge vibrations and they constitute the basis for a wave function expansion of the reflection of waves arriving at the traction-free end of the cylinder. Without any other external stimulus, a passive reflection event occurs. This traction-free end condition is enforced at the Gaussian integration points over the end cross-section on the combination of incoming and reflected wave fields. Reflections due to monochromatic incoming axisymmetric (m=0) and flexural (m=1) waves are studied and two numerical examples are presented.For an incoming axisymmetric wave, there is a particular frequency that induces an end resonance, which is characterized by high (but finite) amplitudes of end displacements vis-a-vis those of neighboring (i.e., slightly different) frequencies. This phenomenon is illustrated in the two cylinder examples.It is possible to modify the passive reflection event by imposing some voltage distribution over the free end. For an oscillating end voltage that is out-of-phase with the incoming wave, it is possible to extract electrical energy from it, i.e., energy harvesting. Examples of such an oscillating voltage with a particular radial distribution are given, that illustrate the amount of extracted energy as a function of the frequency of the incident monochromatic wave

People, Land and Food Production - Potentials in the Developing World

Understanding the nature and dimension of the land and water resources available for food and agriculture development, and the policies available to develop them, have been among the focal points of the work of the Land and Water Development Division of the Food and Agricultural Organization of the United Nations and of the Food and Agriculture Program at the International Institute for Applied Systems Analysis. As we anticipate, over the coming decades, a technological transformation of agriculture which will be constrained by resource limitations and which could have environmental consequences, a number of important questions arise: (a) What is the stable, sustainable production potential of the world? of regions? of nations? (b) How does this production potential in specific areas (within countries and groups of countries) compare to the food requirements of the future populations of these areas? (c) What alternative transition paths are available to reach desirable levels of this production potential? (d) What are the sustainable and efficient combinations of techniques of food production? (e) What are the input requirements of such techniques? (f) What are the policy implications at national, regional and global levels of sustainability? Stability and sustainability are both desirable properties of agricultural land resources development. We hold ecological considerations to be of critical importance in answering the questions posed above. This paper presents the results of a recent study entitled "Land Resources for the Populations of the Future" carried out by the Food and Agriculture Organization of the United Nations in collaboration with the Food and Agriculture Program of IIASA with financial support from the United Nations Fund for Population Activities. The study was designed to quantify potential population supporting capacities of land resources in the developing regions of the world, based on ecological and technological limits to food production. An understanding of these limits is critical to agricultural policy formulation and development planning. This paper highlights policy implications for developing countries

Productivity and economic evaluation of Willow (Salix alba L.) based silvopastoral agroforestry system in Kashmir valley

Performance of two fodder crops namely, sorghum (Sorghum vulgare L.) and maize (Zea mays L.) was investigated with Willow (Salix alba L.) to evaluate productivity and economics of the silvopastoral agroforestry system in Kashmir valley. The experiment was laid out by planting two year old willows at 2.0m × 2.0m spacing and dividing the main plot into sub-plots of size 8m × 2m each with 5 replications in randomized block design (RDB). The intercrops of sorghum and maize were maintained at 20cm × 10 cm spacing and supplied with recommended doses of fertilizers. The economics of the willow plantation intercropped with fodder crops was compared with sole willow farming by the benefit-cost ratio and net present worth. The study revealed the differential behaviour of Salix alba regarding growth parameters (height, diameter and girth) by different intercrops and various fodder intercrops with respect to yield, above ground biomass, dry matter production and soil nutrient status (pH, organic carbon, available nitrogen, phosphorus and potassium). The willow based silvopastoral system was estimated to have benefit-cost ratio of 2.71 with maize and 2.68 with sorghum, while as sole crop the willows accrued a benefit-cost ratio of 2.66. The study is useful in discovering growth of willows, productivity of fodder crops and soil nutrient status under various silvopastoral agroforestry systems for maximizing economic gains. The findings envisaged evidences in favour of adopting willow based silvopastoral agroforestry instead of sole tree farming and the knowledge of interactions will be helpful in proper management of the system for sustained multiple productions

Electrospinning of Chitosan-Based Solutions for Tissue Engineering and Regenerative Medicine

Electrospinning has been used for decades to generate nano-fibres via an electrically charged jet of polymer solution. This process is established on a spinning technique, using electrostatic forces to produce fine fibres from polymer solutions. Amongst, the electrospinning of available biopolymers (silk, cellulose, collagen, gelatine and hyaluronic acid), chitosan (CH) has shown a favourable outcome for tissue regeneration applications. The aim of the current review is to assess the current literature about electrospinning chitosan and its composite formulations for creating fibres in combination with other natural polymers to be employed in tissue engineering. In addition, various polymers blended with chitosan for electrospinning have been discussed in terms of their potential biomedical applications. The review shows that evidence exists in support of the favourable properties and biocompatibility of chitosan electrospun composite biomaterials for a range of applications. However, further research and in vivo studies are required to translate these materials from the laboratory to clinical applications

Are shadow economy and tourism related? International evidence

The present study attempts to investigate whether shadow economy and the tourism sector are related. In the European countries, Schneider reported that 20 to 25 per cent of the shadow economy is represented in the tourism-related industries – wholesale and retail, automotive and motorcycle sales and maintenance; transportation, storage and communications; and hotels and restaurants. For the tourism sector, the services given by operators (unregistered and/or underreporting) operate in the shadow economy will ultimately wiped off the map of high quality tourist destinations and destroyed the development of the tourism industry itself.This study examines the short-run and long-run relationships between international tourism receipts and shadow economy for 149 countries over the period 1995-2008. We use a generalized one-step error-correction model (ECM) in combination with a system Generalized Method of Moments (GMM) to explore the long-run relationship between these two variables. Our results suggest that tourism receipts and shadow economy are co integrated.This implies that shadow economy and the tourism industry worldwide are related in the long-run.The long-run elasticities indicate a negative impact of the shadow economy on the tourism sector suggesting that increase in shadow economy activities will adversely affecting the tourism industry