Shortcuts to Thermodynamic Computing: The Cost of Fast and Faithful Erasure

Landauer's Principle states that the energy cost of information processing must exceed the product of the temperature and the change in Shannon entropy of the information-bearing degrees of freedom. However, this lower bound is achievable only for quasistatic, near-equilibrium computations -- that is, only over infinite time. In practice, information processing takes place in finite time, resulting in dissipation and potentially unreliable logical outcomes. For overdamped Langevin dynamics, we show that counterdiabatic potentials can be crafted to guide systems rapidly and accurately along desired computational paths, providing shortcuts that allows for the precise design of finite-time computations. Such shortcuts require additional work, beyond Landauer's bound, that is irretrievably dissipated into the environment. We show that this dissipated work is proportional to the computation rate as well as the square of the information-storing system's length scale. As a paradigmatic example, we design shortcuts to erase a bit of information metastably stored in a double-well potential. Though dissipated work generally increases with erasure fidelity, we show that it is possible perform perfect erasure in finite time with finite work. We also show that the robustness of information storage affects the energetic cost of erasure---specifically, the dissipated work scales as the information lifetime of the bistable system. Our analysis exposes a rich and nuanced relationship between work, speed, size of the information-bearing degrees of freedom, storage robustness, and the difference between initial and final informational statistics.Comment: 19 pages, 7 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/scte.ht

An overview on problems and prospects of transplanted maize with special reference to India

Transplanting is the technique of moving of a plant from one location to another. This strategy is commonly practiced to establish crops when conditions are less favourable for direct seeding.  Birds and squirrels damage to seedlings of maize is a serious problem resulting in poor crop stand and low yield. Delayed germination and plant growth receives a major setback due to late sowing of maize which reduces grain yield; however, reduction of yield can be compensated by transplantation technique. Transplanting of maize is a strategy that can be used to achieve optimum plant densities, better crop stand and obviously to get optimum yield. It reduces the nutrient requirement and also shortens the growth period of crop that helps farmers to harvest a third crop in intensive cropping system. Transplanted crop produces about 15.44% higher grain yield and can be harvested 10-12 days earlier that of direct seeding crop, so, late maturity high yielding cultivars can be fitted in to available growing season. Though, there are several advantages of transplanted maize, it is not popular in India due to lack of awareness, lacking in proper rational scientific technology and very little information about age of seedling and optimum dose of nutrient. Farmers can be benefitted if proper technology regarding age of seedling, process of transplanting and other cultivation techniques of raising transplanted maize is supplied to them

Weed management in kharif rice in new alluvial zone of West Bengal

A field experiment was carried out during the Kharif season of two consecutive years 2015 and 2016 at Instructional Farm, Jaguli, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal with the focal objective to assess the effect of different weed control measures on yield of transplanted kharif rice, IET 4786. Experiment having 3 replications was conducted in Randomized Block Design with nine treatments, namely, T1- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 675 + 15 g a.i, T2- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 900 + 200 g a.i, T3- Pendimethalin 30% EC + Pyrazosulfuron ethyl 10 % WP @ 1125 + 25 g a.i, T4- Pendimethalin 30% EC @ 1500 g a.i, T5- Pyrazosulfuron ethyl 10 % WP @ 15 g a.i, T6- Pyrazosulfuron ethyl 10 % WP @ 20 g a.i, T7- Metsulfuron methyl 10 % + Chlorimuron ethyl 10 % WP @ 4 g a.i, T8- Hand weeding and T9- Weedy check. Significant variations were observed on the mixed weed flora as well as on performance of rice under the different herbicidal treatments.Pendimethalin 30% EC + Pyrazosulfuron ethyl 10% WP @ 1125+25 g a.i) was found to be the most effective recording the lowest weed population and weed dry weight with  the highest weed control efficiency (83.5% in 2015 and 79.8 % in 2016) and the highest number of panicles m-2 (215.1 in 2015 and 231 in 2016), number of filled grains panicle-1 (85.39 in 2015 and 115.47 in 2016) and grain yield of rice (3.60 t/ha in 2015 and 5.30 t/ha in 2016). The lowest grain yield(2.20 t/ha in 2015 and 3.40 t/ha in 2016) and the highest weed density were observed in weedy check plots

Superheavy nuclei in relativistic effective Lagrangian model

Isotopic and isotonic chains of superheavy nuclei are analyzed to search for spherical double shell closures beyond Z=82 and N=126 within the new effective field theory model of Furnstahl, Serot, and Tang for the relativistic nuclear many-body problem. We take into account several indicators to identify the occurrence of possible shell closures, such as two-nucleon separation energies, two-nucleon shell gaps, average pairing gaps, and the shell correction energy. The effective Lagrangian model predicts N=172 and Z=120 and N=258 and Z=120 as spherical doubly magic superheavy nuclei, whereas N=184 and Z=114 show some magic character depending on the parameter set. The magicity of a particular neutron (proton) number in the analyzed mass region is found to depend on the number of protons (neutrons) present in the nucleus.Comment: 26 pages, REVTeX, 10 ps figures; changed conten

Environmental and Waste Management in Some Mining Operations in Orissa

This paper attempts to provide a survey on environmental parameters, viz. solids and liquids collected from five different mines in Orissa. These mines are (i) Dolomite Quarry, or Gomardih (Tisco) (ii) Fireclay Mines, Talabasta (Grind)(iii) Iron Ore Mines, Joribahal (Patnaik Minerals Pvt.Ltd.) (iv) Limestone Quarry,Lanjiherna (O CL) and (v) Graphite Mines, Patnagarh (T. Pradhan). The solid samples consisted of (a) top more often the undisturbed soil near the mine, (b) the overburdenlwastelspoilt dump, (c) soil from nearby paddyfield, (d) plantation area and (e) garden. These are analysed for agricultural parameters .such aspll, organic carbon content, available phosphate and potassium, heavy metals such as copper, lead, zinc, chromium etc. and bacterial count. The liquid sample consisted of water and effluent collected from (i) mine pit/flow both active and abandoned, (ii) mine discharge, (iii) mineral spring, (iv) accumulated water in mines, (v) piped water in mine office and residential colony and (vi) dug well used by mine workers. These samples were analysed for heavy metals similar to solid samples, physical parameters such as total suspended solids (TSS), total dissolved solids (TDS) and the bacterial count. The analysed results were compared with the standards set by the Bureau of Indian Standards (BIS) and Central Pollution Control Board (CPCB) and recommendations on pollution control measures and strategy by other means are made for better environmental management

Superheavy nuclei in relativistic effective Lagrangian model

Isotopic and isotonic chains of superheavy nuclei are analyzed to search for spherical double shell closures beyond Z=82 and N=126 within the new effective field theory model of Furnstahl, Serot, and Tang for the relativistic nuclear many-body problem. We take into account several indicators to identify the occurrence of possible shell closures, such as two-nucleon separation energies, two-nucleon shell gaps, average pairing gaps, and the shell correction energy. The effective Lagrangian model predicts N=172 and Z=120 and N=258 and Z=120 as spherical doubly magic superheavy nuclei, whereas N=184 and Z=114 show some magic character depending on the parameter set. The magicity of a particular neutron (proton) number in the analyzed mass region is found to depend on the number of protons (neutrons) present in the nucleus.Comment: 26 pages, REVTeX, 10 ps figures; changed conten

Sinuosity Dependency in Boundary Shear Distribution Modeling for Meandering Compound Channels

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv