The paper attempts to assess the extent of crop loss in rubber plantations in India, measured in terms of loss in latex and timber output and thereby to examine the comparative economics of plant protection measures against Phytophtora spp. induced abnormal leaf fall (ALF). The specific objectives were: a) to examine the extent of loss in latex and timber output in unsprayed plots vis-a-vis sprayed plots across prominent rubber clones; b) estimate the value of loss in latex and timber output across clones between sprayed and unsprayed plots; c) examine the comparative economics of plant protection measures in terms of the incremental costs and the incremental returns from sprayed plots across clones; and d) reflect upon the policy imperatives with respect to region specific Research and Development (R&D) interventions on plant protection measures in India. The study brings out significant clonal differences in loss of latex and timber output in the absence of prophylactic spraying against ALF. The observed clonal differences with respect to feasibility of plant disease control measures indicate the need for region and clone-specific recommendations for plant protection measures in India instead of the currently followed unilateral prescription with due allowance to the costs and potential benefit accrued from the control measures. The study also highlight the need for evolving interventions and agro-management/ plant protection measures for minimising the incidence of tree casualty in rubber plantation, as it amounts to loss of potential income from latex and timber from rubber plantations in India, dominated by the smallholder sector
It is now widely recognized that the evaluation of the uncertainty associated with a result is an essential part of any quantitative analysis. One way to use the estimation of measurement uncertainty as a metrological critical evaluation tool is the identification of sources of uncertainty on the analytical result, knowing the weak steps, in order to improve the method, when it is necessary. In this work, this methodology is applied to fuel analyses and the results show that the relevant sources of uncertainty are: beyond the repeatability, the resolution of the volumetric glassware and the blank in the analytical curve that are little studied.
Current source inverters (CSI) is one of the widely used converter topology in medium voltage drive applications due to its simplicity, motor friendly waveforms and reliable short circuit protection. The current source inverters are usually fed by controlled current source rectifiers (CSR) with a large inductor to provide a constant supply current. A generalized control applicable for both CSI and CSR and their extension namely current source multilevel inverters (CSMLI) are dealt in this paper. As space vector pulse width modulation (SVPWM) features the advantages of flexible control, faster dynamic response, better DC utilization and easy digital implementation it is considered for this work. This paper generalizes SVPWM that could be applied for CSI, CSR and CSMLI. The intense computation involved in framing a generalized space vector control are discussed in detail. The algorithm includes determination of band, region, subregions and vectors. The algorithm is validated by simulation using MATLAB /SIMULINK for CSR 5, 7, 13 level CSMLI and for CSR fed CSI.
When John Dee, an influential English mathematician, natural philosopher, and scientist, in the later part of his life decided that the only way of gaining even greater knowledge was through magic, he started a series of meticulously documented séances of communicating with angels through his medium Edward Kelley, later an alchemist in his own right. He soon made an acquaintance of a Polish magnate Olbracht Łaski and at his request travelled to Poland, and then to Bohemia, together with Kelley, their wives, children, and servants. There is vast literature on their stay in Central Europe and its consequences, both real and imaginary, but little attention was paid to the actual journey as recorded by Dee. From the scanty notes devoted to the company’s passage through Great Poland in the winter of 1583/1584 the harsh reality of early modern journeys can be discerned. Some of his very short but precise observations shed new light on such topics as the monument of Boleslaus the Brave in the Poznań Cathedral (this important source was not known to any of the numerous participants in the discussion going on since the early 19th c.) or its library. The description of the bridge in Konin is also of interest, as are Dee’s notes on the use of the newly introduced Gregorian calendar in Poland.