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OALib Journal期刊

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匹配条件: “Philip K. Maritim” ,找到相关结果约144242条。
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Evaluation of Hexadate Ligand 1, 3-bis(2,2’:6’,2’’-Terpyridyl-5-Ylmethylsulfany l)Propane in the Determination of Iron(II) in Solution by Spectrophotometric and Fluoremetric Methods of Analysis  [PDF]
Philip K. Maritim
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1103715
Abstract:
Uv-visible and fluorescence spectra of the ligand 1,3-bis(2,2’:6’,2’’-ter- pyridyl-5-ymethylsulfanyl)propane L and it’s iron(II) complex have been investigated for analytical purposes. The two spectra of L and terpy are very similar which confirmed the ability of L to co-ordinate through the six N atoms of L with minimum distortion of the metal ion’s octahedral geometry. The ligand-based absorption band of L is shifted to the longer wavelength. It was found that L is able to displace the two terpyridine groups in the complex to give [FeL]2 . The high stability of the complex makes it good in spectrophotometry analysis of metals ions in solution. The fluorescence of L was progressively quenched with an increasing concentration of iron(II). This makes L a possible reagent for the quantitative analysis of metal by measuring fluorescence quenching.
Speciation of Trace Metals Pb, Zn, Cu and Cd in Surficial Sediment from Makupa Creek Mombasa, Coastal Kenya  [PDF]
Philip K. Maritim, A. N. Gachanja, T. M. Munyao
Open Access Library Journal (OALib Journal) , 2016, DOI: 10.4236/oalib.1102679
Abstract:

Trace metals (Zn, Pb, Cu, Cd) speciation of surface sediments from Makupa creek, coastal Kenya were determined by sequential extraction procedure. The procedure was used to extract the trace metals in sediments geochemical phases (exchangeable, carbonates, Fe-Mn oxides, organic matter/sulphide, and residual). Trace metals analysis was done using ICP/MS. The trace metal speciation results indicated that Pb, Zn, and Cd were mainly associated with the exchangeable, carbonates and Fe-Mn oxides in most of the sampling sites. The highest concentration of the trace metals were associated with Fe-Mn oxides with Zn concentration at 362.5 μg/g, Pb, 31.5 μg/g. Copper was mostly associated with the organic matter/sulphide and carbonate at concentration of 117.5 μg/g and 69.9 μg/g respectively. Generally, trace metals in sediment from Makupa creek were mainly associated with the bioavailable fractions (BAF) and their ranges were: Pb (60%-98%), Zn (90%-99%), Cu (70%-91%). It was found therefore, that there was trace metals enrichment in sediments from Makupa from anthropogenic sources and bioavailable to biota.

Production efficiency and economic potential of different soil fertility management strategies among groundnut farmers of Kenya
A.K Kipkoech, M.A Okiror, J.R Okalebo, H.K Maritim
Science World Journal , 2007,
Abstract: This paper provides the economic evaluation of different soil fertility replenishing technologies (use of inorganic fertilizers, organic manure, and rhizobium inoculant) that were tested during field studies and recommended to groundnut farmers. Data on soil fertility technologies used by households, groundnut yields, and resource use and farm and farmers characteristics were collected through administration of a questionnaire to a sample of 332 farmers from three districts of western Kenya. The data was analyzed to determine whether adoption of the technologies would increase household incomes and production efficiency. Benefits and costs of each technology were computed through the use of budgets. Technical and allocative inefficiencies are investigated by fitting a Cobb-Douglas production function. The technical efficiency of the farmers varied between 0.56 and 0.69 while labor allocative efficiency varied between 0.81 and 0.93. Farmers applying organic fertilizers only were technically more efficient but had lower potential yield compared to farmers who applied inorganic or a combination of organic and inorganic fertilizers. Use of inorganic fertilizers lead to a benefit cost ratio of up to 3:1. Organic manure had the lowest benefit-cost ratio (2.2:1) even when compared with that obtained when farmers did not apply any fertility replenishing input resulting from high cost of labor required to use this technology. There is a high potential for farmers to increase their groundnut yields and incomes by improving on production efficiency and by fertilizing their groundnut farms.
Does Soil Conservation Pay? Evidence from Machakos and Kitui Districts, Kenya
S.M. Mwakubo,H.K. Maritim,W.K. Yabann
Asian Journal of Plant Sciences , 2004,
Abstract: Using data from a 2000 household survey in Machakos and Kitui districts in Kenya, the factors that influence the rates of return in soil conservation are examined. A Cobb-Douglass regression analysis is employed. The results show that land tenure; slope besides other factors explain the pattern of natural resource management in semi-arid areas. The policy implication hinges on better access to markets, improvement of land tenure security, increasing yields and better crop choice.
Rural Roads and Natural Resource Management in the Semi-arid Lands of Kenya
S.M. Mwakubo,H.K. Maritim,W.K.Yabann
Journal of Applied Sciences , 2004,
Abstract: This research uses data from a 2000 household survey of smallholder farmers in Kenya`s marginal areas to investigate the effects of road infrastructure on farm level soil conservation investments. A logistic regression was used to determine the decision to invest in soil conservation measures. Three Stage Least Squares at the household level was also used for estimating a system of Cobb-Douglas type simultaneous equations. The study findings show clearly that poor road infrastructure reduces soil conservation investments. Improvement of road infrastructure thus creates an incentive to invest in soil conservation measures. However, in the absence of significant investments in road infrastructure due to budgetary constraints, the policy challenge is to involve a number of stakeholders such as the local communities and non-governmental organizations in the provision of rural road infrastructure.
Rural Roads and Sustainable Agriculture in Semi-arid Areas: Evidence from Machakos and Kitui Districts, Kenya
S.M. Mwakubo,H.K. Maritim,W.K. Yabann,G.A. Obare
Journal of Applied Sciences , 2005,
Abstract: Using data from a 2000 household survey, the effects of rural roads on sustainable agriculture was examined in selected semi-arid areas in Kenya. A Tobit model was used to establish the factors that influence the decision to invest in soil conservation measures and the level of investment in terracing and a Three Stage Least Squares (3SLS) method was used to determine the direct and indirect impact of road infrastructure on terracing. The study findings show that poor physical road infrastructure endowment, distance to crop fields and degree of farm orientation significantly influence the likelihood of reduced terracing intensity. However, slope, household wealth status, household size and erosion status of crop fields significantly influence the likelihood of intensified terracing. The direct effect of road infrastructure is not significant on maize though negative, while on beans it is negative and significant. Other factors that are significant include: degree of farm orientation, wealth, slope, distance to and erosion status of crop fields. Given the high costs of provision of roads, the policy challenge is to involve non-governmental organizations and local communities to upgrade and maintain rural roads.
Inequality and economic marginalisation: How the structure of the economy impacts on opportunities on the margins
K Philip
Law, Democracy & Development , 2010,
Abstract: In the face of a long-standing unemployment crisis that increasingly threatens social and economic stability, employment has at last taken centre stage in South African policy, and with this, focus is shifting to the structural constraints on employment creation within the economy. The New Growth Path, approved by Cabinet in November 2010, starts to tackle these issues. Its emphasis on inclusive growth places issues of distribution more clearly on the agenda than they have been; and the Competition Commission has become poor consumers’ knight in shining armour, tackling collusion and highlighting the negative economic (and employment) consequences of South Africa’s highly centralized core economy. What does this mean, however, for what used to be called ‘the second economy’? While much scholarship has focused on critiquing the concept of the second economy – with good reason – the stark inequalities that characterize South African society and its economy mean that policy-making processes still struggle to straddle both ends of the spectrum. What is good for the developed end of the economy can seem to be far removed from concerns in more marginalised contexts. This article argues that the sharp divides in access and opportunity need to be located within the context of structural inequality. It focuses in particular on how the highly unequal structure of the economy impacts on economic opportunities at the more marginalised end of the economy, and how common sets of processes within a single economy produce and reproduce these outcomes. This locks people into poverty in ways that cannot simply be dismissed as a problem of ‘dependency’ - despite a growing tendency to do so. The article concludes by considering what this analysis means for development strategies targeting the unemployed and those eking out survivalist incomes.
Colon Targeted Drug Delivery Systems: A Review on Primary and Novel Approaches
Anil K. Philip,Betty Philip
Oman Medical Journal , 2010,
Abstract: The colon is a site where both local and systemic delivery of drugs can take place. Local delivery allows topical treatment of inflammatory bowel disease. However, treatment can be made effective if the drugs can be targeted directly into the colon, thereby reducing the systemic side effects. This review, mainly compares the primary approaches for CDDS (Colon Specific Drug Delivery) namely prodrugs, pH and time dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery which are unique in terms of achieving in vivo site specificity, and feasibility of manufacturing process.
Seeds as a Source of Carbon, Nitrogen, and Phosphorus for Seedling Establishment in Temperate Regions: A Synthesis  [PDF]
Byron B. Lamont, Philip K. Groom
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.45A005
Abstract:

Seeds are a source of organic (carbon, C) and mineral (nitrogen, N and phosphorus, P) nutrients for the growing seedling. There is much information on seed mass and N and P contents, and the relationship between these and seedling mass. Within the world’s temperate regions, these collectively show that N and P concentrations remain constant or rise with increase in seed mass and that seeds are larger and more nutrient-enriched in poorer soils. Seed N and P were more important than seed C in accounting for seedling mass in 85% of studies we assessed. In nutrient- and water-limited environments that are not light-limited, large seeds routinely provision the seedling with N and P that enhance C-fixation and thus general growth in the first wet season. This system is so efficient that growth response to soil nutrients may be negligible in first-year seedlings arising from seeds > 15 mg mass, N content > 5 mg and P content > 1.6 mg. The elongating taproot system absorbs nutrients and maintains water uptake as soil water retreats, enhancing the chances of survival in the first dry season. We outline an interpretative scenario for the special role of large seeds (>15 mg) in nutrient- and water-limited environments that recognizes the critical role of N and P for photosynthesis in ensuring sufficient C-supply to the rapidly descending roots for effective drought-avoidance by the young plant.

Spatial Modeling of Risk in Natural Resource Management
Peter Jones,Philip K. Thornton
Ecology and Society , 2002,
Abstract: Making decisions in natural resource management involves an understanding of the risk and uncertainty of the outcomes, such as crop failure or cattle starvation, and of the normal spread of the expected production. Hedging against poor outcomes often means lack of investment and slow adoption of new methods. At the household level, production instability can have serious effects on income and food security. At the national level, it can have social and economic impacts that may affect all sectors of society. Crop models such as CERES-Maize are excellent tools for assessing weather-related production variability. WATBAL is a water balance model that can provide robust estimates of the potential growing days for a pasture. These models require large quantities of daily weather data that are rarely available. MarkSim is an application for generating synthetic daily weather files by estimating the third-order Markov model parameters from interpolated climate surfaces. The models can then be run for each distinct point on the map. This paper examines the growth of maize and pasture in dryland agriculture in southern Africa. Weather simulators produce independent estimates for each point on the map; however, we know that a spatial coherence of weather exists. We investigated a method of incorporating spatial coherence into MarkSim and show that it increases the variance of production. This means that all of the farmers in a coherent area share poor yields, with important consequences for food security, markets, transport, and shared grazing lands. The long-term aspects of risk are associated with global climate change. We used the results of a Global Circulation Model to extrapolate to the year 2055. We found that low maize yields would become more likely in the marginal areas, whereas they may actually increase in some areas. The same trend was found with pasture growth. We outline areas where further work is required before these tools and methods can address natural resource management problems in a comprehensive manner at local community and policy levels.
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