762 research outputs found
Study of performance of Adiabatic Carry Look Ahead Adder Using Dynamic CMOS Logic
Performance of adiabatic carry look ahead adder using dynamic CMOS are studied and compared with Adiabatic carry look ahead adder using Pass Transistor. adiabatic carry look ahead adder using pass transistor has higher delay and lower power consumption while adiabatic carry look ahead adder using dynamic cmos logic has lower power dissipation and higher speed. adiabatic carry look ahead adder using dynamic cmos are design using 180 nm cmos technology and compared power dissipation and delay with respect to supply voltage and frequency. simulation result show that power dissipation of carry look ahead adder using dynamic cmos has higher performance comparison adiabatic CLA using pass transistor. simulation result show that adiabatic CLA using dynamic cmos reduce the power consumption 45% and delay reduce to 70% comparison to adiabatic CLA using pass transistor
Performance evaluation of rice bran biodiesel in small size agricultural diesel engines
India is the second largest rice producing country in the world.  The estimated yield of crude Rice Bran Oil (RBO) is about 400,000 tons of which only 50% is of edible grade, 50% of the total available rice bran oil is left unutilized due to the presence of active lipase in bran and lack of economic stabilization methods most of the bran is used as animal feed or for industrial application. One of the best ways for the potential utilization of RBO is the production of biodiesel.  This study targets at finding the effects of the engine parameters to compare the performance of diesel and rice bran biodiesel blends.  Rice Bran (RB) blends were found to be substitute for diesel fuel.  Brake Thermal Efficiency (BTHE) was maximum for RB05 blend and minimum for RB20 blend.  RB05 blend can be considered as a substitute for diesel with lower Brake Specific Fuel Consumption (BSFC) and Brake Specific Energy Consumption (BSEC), RB15 was found to have minimum smoke opacity.  Keywords: Rice bran oil, Blend, Brake parameters and opacit
Les cysticerques des animaux abattus Ă l'abattoir de Port-Bouet (Abidjan)
Les auteurs exposent les résultats des observations faites à l'abattoir d'Abidjan sur les taux d'infestation des bovins, des ovins et caprins et des porcins par C. bovis, C. tenuicollis et C. cellulosae. Ils étudient l'épidémiologie de ces affections, en soulignent l'importance économique et suggÚrent la prophylaxie à mettre en ouvre pour en limiter l'étendue. Ils font état de l'évolution de C. tenuicollis chez des chiots et des chatons expérimentalement infestés, qu'ils comparent avec les descriptions antérieurement faites par divers auteur
Etude de la trypanotolérance de taurins dans la région de Boundiali en CÎte d'Ivoire
D'octobre 1976 à octobre 1977, une étude sur la trypanotolérance de deux races principales Baoulé et N'Dama a été conduite dans le nord de la CÎte-d'Ivoire. L'influence de la trypanosomose a été observée sur le gain de poids, la valeur hématocrite, la répartition des globules blancs, l'état clinique des races des animaux porteurs en comparaison avec les animaux indemnes. Il a été noté que: Certains animaux parasités perdent du poids alors que d'autres poursuivent leur croissance ou leur gain de poids normaux. Le nombre des bovins porteurs des trypanosomes et présentant des signes cliniques de trypanosomose diminue en saison sÚche et augmente en saison des pluies. - La valeur hématocrite des animaux positifs n'est pas inférieure à celle des animaux négatifs mais elle varie beaucoup plus chez les porteurs. - Il existe, d'aprÚs le test de "T", une différence significative seulement pour les éosinophiles chez les Baoulé. - Le caractÚre de trypanotolérance est plus affirmé chez le N'Dama que chez les Baoul
Bayesian Statistics: Concepts and Applications in Animal Breeding â A Review
Statistics uses two major approaches- conventional (or frequentist) and Bayesian approach. Bayesian approach provides a complete paradigm for both statistical inference and decision making under uncertainty. Bayesian methods solve many of the difficulties faced by conventional statistical methods, and extend the applicability of statistical methods. It exploits the use of probabilistic models to formulate scientific problems. To use Bayesian statistics, there is computational difficulty and secondly, Bayesian methods require specifying prior probability distributions. Markov Chain Monte-Carlo (MCMC) methods were applied to overcome the computational difficulty, and interest in Bayesian methods was renewed. In Bayesian statistics, Bayesian structural equation model (SEM) is used. It provides a powerful and flexible approach for studying quantitative traits for wide spectrum problems and thus it has no operational difficulties, with the exception of some complex cases. In this method, the problems are solved at ease, and the statisticians feel it comfortable with the particular way of expressing the results and employing the software available to analyze a large variety of problems
Summary of International Transport Energy Modeling Workshop
The NextSTEPS program at ITS-Davis convened a one-day workshop on international transportation energy modeling (iTEM), focused on comparing the frameworks and scenario projections from four major global transport models:
-- Global Change Assessment Model (GCAM) by Pacific Northwest National Laboratory (PNNL) and ITS-Davis,
-- MESSAGE-Transport (Model for Energy Supply Strategy Alternatives and their General Environmental Impact) by the International Institute for Applied Systems Analysis (IIASA),
-- Mobility Model (MoMo) by the International Energy Agency, and
-- Roadmap by the International Council on Clean Transportation (ICCT).
Highlights:
-- Projections of "baseline" global transportation energy use rise from 98 EJ in 2010 to 160-250 EJ by 2050.
-- There are considerable differences in historical data for some modes, both globally and for individual countries (particularly non-OECD countries). Variability in estimates of transportation activity are in most cases much larger than energy differences.
-- Global average vehicle ownership rates are projected to range from 270 to 450 per 1,000 people by 2050 with wide ranges across countries: 700-1,075 for the US by the middle of the century (US is around 700 today), 100-650 for China, and 80-380 for India across four models.
-- All models rely mainly on GDP to estimate the future demand for freight and hold the base year modal shares (e.g. truck v. rail) roughly constant through 2050. In reality, future evolution will depend on characteristics of products (e.g. type of commodities) being shipped, technologies available for freight and their efficiencies, and policies and infrastructure.
-- Current policy commitments toward EVs, PHEVs and H2FCVs (and thus baseline projections) maybe below the numbers suggested by iTEM models as required for meeting climate targets (e.g., 2 degrees C).
-- Improvements in data quality and the representation of car ownership and use across the models were identified as priorities.
Modeling transport energy use can either be done by estimating how far people travel and what mode of transportation they choose or by estimating how many vehicles there are and how far each one travels. These are complementary approaches, and in theory they should both lead to the same answer. The former approach, used in "service demand" models, seem more intuitive when one wants to model societal shifts in modes of transportation, either in emerging economies as they develop or in developed economies as they decarbonize; but collecting data on service demand is notoriously difficult. In contrast, vehicle stock models use readily-available vehicle sales data, but are harder to use in future-state, what-if scenarios (particularly in estimating modal shift behaviors) and thus require special attention by experts.
The four iTEM models are different in terms of scope (GCAM and MESSAGE cover all sectors of the energy system vs. MoMo and Roadmap which cover transportation only) and model structure (GCAM and MESSAGE rely on internal drivers, particularly the costs of technology and travel, to project future changes whereas MoMo and Roadmap rely on experts' judgments and detailed analysis of technology and policies to drive long-term changes). Yet, owing to these differences, the models are highly complementary and in some cases can be used jointly to answer questions that no single model can tackle on its own.
The following summary shares some of the comparisons and findings from the workshop
Biomass and diversity of dry alpine plant communities along altitudinal gradients in the Himalayas
A non-linear relationship between phytodiversity and altitude has widely been reported, but the relationship between phytomass and altitude remains little understood.We examined the phytomass and diversity of vascular plants along altitudinal gradients on the dry alpine rangelands of Ladakh, western Himalaya. We used generalized linear and generalized additivemodels to assess the relationship between these vegetation parameters and altitude. We found a humpshaped relationship between aboveground phytomass and altitude.Wesuspect that this is engendered by low rainfall and trampling/excessive grazing at lower slopes by domestic livestock, and low temperature and low nutrient levels at higher slopes.Wealso found a unimodal relationship between plant species-richness and altitude at a singlemountain as well as at the scale of entire Ladakh. The species-richness at the single mountain peaked between 5,000 and 5,200 m, while it peaked between 3,500 and 4,000 m at entire Ladakh level
Mesoscopic models for DNA stretching under force: new results and comparison to experiments
Single molecule experiments on B-DNA stretching have revealed one or two
structural transitions, when increasing the external force. They are
characterized by a sudden increase of DNA contour length and a decrease of the
bending rigidity. It has been proposed that the first transition, at forces of
60--80 pN, is a transition from B to S-DNA, viewed as a stretched duplex DNA,
while the second one, at stronger forces, is a strand peeling resulting in
single stranded DNAs (ssDNA), similar to thermal denaturation. But due to
experimental conditions these two transitions can overlap, for instance for
poly(dA-dT). We derive analytical formula using a coupled discrete worm like
chain-Ising model. Our model takes into account bending rigidity, discreteness
of the chain, linear and non-linear (for ssDNA) bond stretching. In the limit
of zero force, this model simplifies into a coupled model already developed by
us for studying thermal DNA melting, establishing a connexion with previous
fitting parameter values for denaturation profiles. We find that: (i) ssDNA is
fitted, using an analytical formula, over a nanoNewton range with only three
free parameters, the contour length, the bending modulus and the monomer size;
(ii) a surprisingly good fit on this force range is possible only by choosing a
monomer size of 0.2 nm, almost 4 times smaller than the ssDNA nucleobase
length; (iii) mesoscopic models are not able to fit B to ssDNA (or S to ss)
transitions; (iv) an analytical formula for fitting B to S transitions is
derived in the strong force approximation and for long DNAs, which is in
excellent agreement with exact transfer matrix calculations; (v) this formula
fits perfectly well poly(dG-dC) and -DNA force-extension curves with
consistent parameter values; (vi) a coherent picture, where S to ssDNA
transitions are much more sensitive to base-pair sequence than the B to S one,
emerges.Comment: 14 pages, 9 figure
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