7,891 research outputs found
Tapping Economies of Scale and Scope in Consumer Cooperation - A Case Analysis of Possible Cooperation among selected Cooperatives
No full textBecause of its narrow and negative perspective of safeguarding the interests of only poor consumers against unethical practices of the private traders, consumer cooperation in India seems to have failed, except probably in some isolated pockets. A number of social welfare functions like poverty alleviation and public distribution of essential items of consumption have been imposed on them at the cost of their basic economics. With the basic micro and macro-economic rationale for consumer cooperatives as a positive form of economic organization being lost sight of, they seem to be facing enormous problems both historically as well as currently in a era of economic liberalization. Their worries seem to have been compounded with the threat of impending competition from large private enterpriss - both domestic and foreign, which highlights the need for evolving strategies to rectivy their systemic weaknesses and tackling the competition head on. This case has attempted to document just such an initiative through a round table conference with several doyens of the consumer cooperative movement in India such as Warana Bazar and Amalsad Mandali as well as some fledging consumer cooperatives from West Bengal which are already in existence for some time or contemplating entry into this field. The roundtable conference organized in the spirit of Cooperation among Cooperatives attempted to evolve strategies to capture economies of scale and scope in order to take on the competition, as well as to facilitate dissemination of ideas and information across the country.
LMI based Stability and Stabilization of Second-order Linear Repetitive Processes
No full textThis paper develops new results on the stability and control of a class of linear repetitive processes described by a second-order matrix discrete or differential equation. These are developed by transformation of the secondorder dynamics to those of an equivalent first-order descriptor state-space model, thus avoiding the need to invert a possibly ill-conditioned leading coefficient matrix in the original model
Stability regime study of a nonlinear mirror mode-locked laser
No full textA diode array pumped nonlinear mirror mode-locked (ML) laser is developed and the regime of the stable operation for such a system is found to occur for a little detuning of intra-cavity second harmonic phase-matching. The existing theory of mode-locking using a fast saturable absorber (FSA) is used to derive corresponding equivalent parameters for a fast nonlinear mirror saturable absorber. The condition for stable single pulse ML operation is evaluated in terms of small signal gain of the laser medium and small signal nonlinear loss. The analysis explains the experimental observations and differentiates the regime of operation in ML, Q-switching and cw mode-locking
Wavelength shifting and amplification of optical pulses through cascaded second-order processes in periodically poled lithium niobate
No full textState of the foreign gene and of the genome in transgenic rice (Oryza sativa L.).
No full textPCR with random primers (RAPD analysis) performed on the DNA of embryogenic and non-embryogenic suspension cultured rice and of transformed rice plants allows the evaluation of the extent of DNA changes in the different biological materials. This is thus suggested as a convenient approach, in combination with restriction analysis and Southerns blotting, to evaluate the integrity of the foreign gene, the stability of the insertion site and the stability of the whole genome
Dynamic Buckling Analysis of a Composite Stiffened Cylindrical Shell
No full textThe paper investigates the dynamic buckling behaviour of a laminated composite stiffened cylindrical shell using the commercial finite element code ABAQUS. The numerical model of the composite shell is validated by static tests. In particular, the experimental collapse test is numerically simulated by a quasi static analysis carried out by both ABAQUS/Standard and ABAQUS/Explicit. The behaviour in the post-buckling field and the collapse load obtained by the analyses are close to the experimental data. The validated model is then used to study the dynamic buckling behaviour with ABAQUS/Explicit. The effects of the loading magnitude and of the loading duration are investigated, implementing in the analysis also first-ply failure criteria. It is observed that the dynamic buckling load is highly affected by the loading duration
Picosecond pulse generation and its simulation in a nonlinear optical mirror mode-locked laser
No full textA nonlinear mirror composed of a lithium triborate crystal and a dichroic output coupler is used to passively mode lock an Nd:YVO4 laser that is pumped by a diode laser array. A mode-locked output power of 3.2 W, a repetition rate of 178 MHz, a pulse width of 8.4 ps, and a beam quality parameter M2 of 1.27 are obtained at 1064 nm for a pump power of 10.0 W. The numerical simulation for the steady-state pulse width agrees well with the bandwidth-limited value. A double-pass average gain gave is defined by considering the constancy of the output energy. In the simulation gave is kept as a free parameter, and its value required for the bandwidth-limited pulse is found to be 0.047, whereas its calculated value, based on our definition, is 0.057
Hypoxic adaptation during development: relation to pattern of neurological presentation and cognitive disability
No full textChildren with acute hypoxic-ischaemic events (e.g. stroke) and chronic neurological conditions associated with hypoxia frequently present to paediatric neurologists. Failure to adapt to hypoxia may be a common pathophysiological pathway linking a number of other conditions of childhood with cognitive deficit. There is evidence that congenital cardiac disease, asthma and sleep disordered breathing, for example, are associated with cognitive deficit, but little is known about the mechanism and whether there is any structural change. This review describes what is known about how the brain reacts and adapts to hypoxia, focusing on epilepsy and sickle cell disease (SCD). We prospectively recorded overnight oxyhaemoglobin saturation (SpO 2) in 18 children with intractable epilepsy, six of whom were currently or recently in minor status (MS). Children with MS were more likely to have an abnormal sleep study defined as either mean baseline SpO2 <94 or >4 dips of >4 in SpO2/hour (p = .04). In our series of prospectively followed patients with SCD who subsequently developed acute neurological symptoms and signs, mean overnight SpO2 was lower in those with cerebrovascular disease on magnetic resonance angiography (Mann-Whitney, p = .01). Acute, intermittent and chronic hypoxia may have detrimental effects on the brain, the clinical manifestations perhaps depending on rapidity of presentation and prior exposure.</p
Realization of inverse saturable absorption by intra-cavity third harmonic generation for efficient nonlinear mirror mode-locking
No full textA technique of suppressing passive Q-switching by inverse saturable absorption in a cw nonlinear mirror mode-locked laser is presented. The nonlinear mirror saturable absorber consists of a second-harmonic generation crystal and a dichroic mirror while the inverse saturable loss is realized by intracavity third-harmonic generation. The inverse saturation reduces significantly the critical intracavity pulse energy for stable, self-starting, self-sustained, and power scalable cw mode-locking. Two LiB3O5 crystals are employed to realize the technique in a diode array pumped Nd : YVO4 oscillator providing a peak power of 918 W, pulse width of 29 ps, and repetition rate of 170 MHz
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