Aerosol speckle effects on atmospheric pulsed lidar backscattered signals

Lidar systems using atmospheric aerosols as targets exhibit return signal amplitude and power fluctuations which indicate speckle effects. The effects of refractive turbulence along the path on the aerosol speckle field propagation and on the decorrelation time are studied for coherent pulsed lidar systems

Spectroscopic investigations and measurements of certain ARC jet parameters

The NASA/JSC Atmospheric Reentry Materials and Structures Evaluation Facility (ARMSEF) was intensively and extensively involved in ground testing of spacecraft materials and thermal protection systems (TPS) in simulated reentry conditions. Ground experiments on surface catalytic efficiency of such TPS requires a knowledge of the flow system in the arc jet. In the work described, spectroscopic diagnostic techniques are used to determine the free stream constituents. Specifically, the emission spectrum of the free stream constituents was obtained and the species therein identified. A laser system was added on, which will give the added capacity of studying the arc jet flow using Laser Raman Spectroscopy (LRS). The LRS technique will complement information obtained from the emission spectra. A short list of further work that can be done in the area of spectroscopic investigations on the arc jet is mentioned

LARGE FARMERS IN THE LEASE MARKET - How and Why Do They Enter the Market? Are Marginal Farmers Affected in the Process?

1. The importance of economically dominant farmers is increasing in the lease market for agricultural land. This is particularly evident from the NSS data of 1981-82 and 1991-92 on the percentage of operational holdings and operated area under tenancy and on the shares of large farmers in total tenanted holdings and tenanted area. Increase in the significance of large farmers in the lease market is a disquieting development because : m Taking advantage of tenancy laws the farmers can get conferred ownership or occupancy rights on tenanted lands under their control. m They can take advantage of the laws and cause hardship to petty lessors (landlords) and, in particular, to institutional lessors. m They can displace petty peasants from the lease market. m They can expose poor tenants to a process of self-exploitation by vying with them for land in the lease market. 2. The once isolated incidents of the practice of large farmers taking land on lease by now (1991-92) spread to new regions and got intensified in certain others. Thus in the states of AP, Assam, Haryana, Karnataka, Kerala, Punjab, Rajasthan, and to a lesser extent in MP, UP and TN large farmers have become a force to reckon with in the lease market. 3. The modus operandi of large farmers seeking to edge-out their competitors in the lease market is that they offer rent in fixed cash, invariably at the beginning of the season, to their lessors in return for the lease of land. The farmers appeal to the compulsions of the lessors for secure rental receipts by offering to pay fixed cash rents. Petty peasants, being less able to do so, lose out to these farmers in competition for tenanted land. 3 4. The increasing dominance of large tenants does not, however, appear to be at the expense of the poorest of the poor marginal tenants. Although marginal tenants got dislodged in some states consequent upon an increase in the importance of large tenants between 1981-82 and 1991- 92, there are also states where both classes of tenants secured greater hold on the lease market. The proportions of holdings and area under tenancy with large farmers and those with marginal farmers bear no relationship whatever in the 1991-92 cross-section data of major states. But it should not come as a great relief, for it is possible that marginal tenants are now obliged to pay higher rents than earlier in trying to stay in competition with large tenants. 5. The notion that the costliness of new technology compels poor peasants to voluntarily opt out of the lease market and the resultant increase in the supply of land for lease enables large farmers to gain ascendancy in the lease market has little support in the data of recent times. There is only one state, Haryana, where the increase in the real cost of cultivation between 1981-82 and 1991-92 culminated in a decrease in the hold of marginal farmers and a simultaneous increase in the importance of large farmers in the lease market. The cost factor is also found unimportant in influencing the leasing behaviour of marginal farmers even when the crosssection data of Indian states pertaining to 1991-92 is examined. The peasants do not appear to be opting out, rather, they are being driven out. 6. High wage rates seem to favour mechanization of farming operations and with it the operation of large holdings. Farmers who are constrained to increase their ownership holdings because of ceiling laws are, therefore, making their way into the lease market for agricultural land. 7. The entry of large farmers into the lease market may further capitalist development in the agricultural sector. But in the process numerous prospective tenants from the poorer sections can get distanced from the lease market. The institution of land tenancy which derives its legitimacy on the ground that it would help poor peasants to gain access to tenanted land and thereby would fulfill their hope of advancing on the agrarian ladder 4 will be of no avail. It can also give rise to a situation where, petty tenants, in trying to compete with large tenants for tenanted land will end up paying rents higher than the usual to their landlords. Besides, sooner or later, the process can have a dampening effect on real wages of agricultural labour and can stunt the growth of rural employment. 8. Therefore, it seems important to make tenancy laws sufficiently stringent to restrict the entry into the lease market only to petty peasants. The quantitative significance of the incidence of tenancy among large farmers is high enough, though in a relative context, to enact and enforce such exacting laws. The surplus land distributed in the country up to September, 1991 was 19.48 lakh hectares while the tenanted land under the control of large farmers (with operated land in excess of 10 hectares) as of 1991- 92 was 21.63 lakh hectares. Apart from the land leased-in by this class of farmers there is also the land which was leased-in by other relatively higher classes of farmers. And what is more, even the NSS estimates of land under lease, though are on a far higher side compared to the leased-in land as per Agricultural Census, are admittedly underestimates themselves. By preventing large farmers from entering into the lease market, it should be possible to bring down inequity in the distribution of operated land, an objective which is sought to be achieved by allowing tenancy. Such a step is also desirable in the interest of wages and employment in the agricultural sector. Also, as a means to increase the access of land to the rural poor, the policy of barring large farmers from the lease market assumes importance, in view of the closing-in of the possibilities to acquire and distribute land accruing on account of ceiling laws. 9. In sum, it is necessary to rid the large tenant of the lease market in the interest of the poor peasant, who yearns to lease-in a piece of land. The notion that the petty peasant is opting out of the lease market because of costliness of new technology seems unfounded. The peasant is not opting out, rather the large farmer is forcing him to withdraw from the market by appealing to the need of his lessor for secure rental receipts and by paying him rent in fixed cash. It is in the interest of the large farmer to drive out the petty cultivator from the lease market and thereby gain control over it, be5 cause mechanization of farming operations, in the context of high wages, is making heavy demands on him to expand the size of his operational holding. With the scope to enlarge the ownership holding having decreased, more because of the deterrent effect of the land ceiling laws, the large farmer has no option but to lease-in land to expand the size of holding to put his capital assets to optimum use. Large farmers may contribute to capitalist development in agriculture. But development of capitalist relations may lead to proletarianisation of large sections of the rural working classes.Farmers, Lease market, Marginal farmers

RURAL NON-AGRICULTURAL EMPLOYMENT IN INDIA - The Residual Sector Hypothesis Revisited

The literature on Rural Non-Agricultural Employment (RNAE) in India is replete with references as to its nature - whether or not it is residual. Vaidyanathan (1986) advanced the view that for the sector to be termed residual in nature two conditions should be satisfied : (1) the unemployment rate should be positively related to the RNAE and (2) the unemployment rate again should be negatively related to the wage ratio between the non-agricultural and agricultural sectors. These two propositions have become the corner stones of what has come to be termed as the Residual Sector Hypothesis (RSH). While the hypothesis as such seems to be theoretically sound, empirical evidence is rarely, if ever, consistent with the theoretical postulates. The present paper examines whether the propositions find validity in the NSS data at five different points of time with different statistical tools. The conclusion emerging from the statistical exercises is that the second of the two propositions is not always valid. It is argued that the absence of validity of the second proposition may have to do with the fact that the labour market does not function perfectly and therefore, even if the proposition is not valid one cannot dismiss the possibility that the sector is residual in nature. By way of conclusion it is noted that RNAS does perform the safety-net function admirably by absorbing those who could not find employment in agriculture in the service sector and, to a lesser extent, in the manufacturing sector. Insofar as this is true, the sector needs to be promoted. While rural non-agricultural activities of highproductive nature demand attention because they are a root out of poverty, the lowproductive ones count, for they make critical contribution to the livelihoods of the poor and prevent further destitution.rural, Employment, India, Residual Sector Hypothesis

Atmospheric effects on coherent laser systems

Effects of the truncation of the gaussian beam by the telescope on the signal to noise ratio were studied. Finite and infinite beams were also considered, along with the refractive index structure constant

Atmospheric effects on CO2 laser propagation

An investigation was made of the losses encountered in the propagation of CO2 laser radiation through the atmosphere, particularly as it applies to the NASA/Marshall Space Flight Center Pulsed Laser Doppler System. As such it addresses three major areas associated with signal loss: molecular absorption, refractive index changes in a turbulent environment, and aerosol absorption and scattering. In particular, the molecular absorption coefficients of carbon dioxide, water vapor, and nitrous oxide are calculated for various laser lines in the region of 10.6 mu m as a function of various pressures and temperatures. The current status in the physics of low-energy laser propagation through a turbulent atmosphere is presented together with the analysis and evaluation of the associated heterodyne signal power loss. Finally, aerosol backscatter and extinction coefficients are calculated for various aerosol distributions and the results incorporated into the signal-to-noise ratio equation for the Marshall Space Flight Center system

Securing Internet Protocol (IP) Storage: A Case Study

Storage networking technology has enjoyed strong growth in recent years, but security concerns and threats facing networked data have grown equally fast. Today, there are many potential threats that are targeted at storage networks, including data modification, destruction and theft, DoS attacks, malware, hardware theft and unauthorized access, among others. In order for a Storage Area Network (SAN) to be secure, each of these threats must be individually addressed. In this paper, we present a comparative study by implementing different security methods in IP Storage network.Comment: 10 Pages, IJNGN Journa

IIT-Hyderabad set to help Telangana govt carry out research on AI

IITH is going to collaborate with the Government of Telangana to carry out research in Artificial Intelligenc

Startup at IIT-Hyderabad develops low-cost portable ventilator

A startup at the Indian Institute of Technology-Hyderabad (IIT-H) has developed a low-cost, portable, emergency-use ventilator

IIT-H faculty developing robo for Covid ward deployment

Director of the Indian Institute of Technology-Hyderabad (IIT-H) Prof BS Murthy has said that a quite a number of faculty at the institute are working round the clock to help the government combat coronavirus pandemic by developing various technologies, medical devices, medicine and vaccine