48 research outputs found
Effect of Changing in Air Intake Temperature on Engine Performance Using Thermocouple
This study will present the experimental result on the performance of spark ignition engine at various cooled air intake temperatures on four-stroke four-cylinder spark ignition engine. This study also investigated the level of emission released to the environment due to decrease in air intake temperature. In this study, the exhaust emissions percentage values of CO2 and HC are recorded by using Chassis Dynamometer (MD-2WD-500). The data was taken under three different gears (gear 2,3 and 4) at varying speed ( 1000,1500,2000,2500 and 3000 rpm) and intake temperature range (15℃~25℃). Based on the data and result recorded, decrease in temperature do increase the engine performance and also decrease the emission percentage as wel
Quantum Noise Randomized Ciphers
We review the notion of a classical random cipher and its advantages. We
sharpen the usual description of random ciphers to a particular mathematical
characterization suggested by the salient feature responsible for their
increased security. We describe a concrete system known as AlphaEta and show
that it is equivalent to a random cipher in which the required randomization is
effected by coherent-state quantum noise. We describe the currently known
security features of AlphaEta and similar systems, including lower bounds on
the unicity distances against ciphertext-only and known-plaintext attacks. We
show how AlphaEta used in conjunction with any standard stream cipher such as
AES (Advanced Encryption Standard) provides an additional, qualitatively
different layer of security from physical encryption against known-plaintext
attacks on the key. We refute some claims in the literature that AlphaEta is
equivalent to a non-random stream cipher.Comment: Accepted for publication in Phys. Rev. A; Discussion augmented and
re-organized; Section 5 contains a detailed response to 'T. Nishioka, T.
Hasegawa, H. Ishizuka, K. Imafuku, H. Imai: Phys. Lett. A 327 (2004) 28-32
/quant-ph/0310168' & 'T. Nishioka, T. Hasegawa, H. Ishizuka, K. Imafuku, H.
Imai: Phys. Lett. A 346 (2005) 7
One-Loop Gauge Theory Amplitudes in N=4 Super Yang-Mills from MHV Vertices
We propose a new, twistor string theory inspired formalism to calculate loop
amplitudes in N=4 super Yang-Mills theory. In this approach, maximal helicity
violating (MHV) tree amplitudes of N=4 super Yang-Mills are used as vertices,
using an off-shell prescription introduced by Cachazo, Svrcek and Witten, and
combined into effective diagrams that incorporate large numbers of conventional
Feynman diagrams. As an example, we apply this formalism to the particular
class of MHV one-loop scattering amplitudes with an arbitrary number of
external legs in N=4 super Yang-Mills. Remarkably, our approach naturally leads
to a representation of the amplitudes as dispersion integrals, which we
evaluate exactly. This yields a new, simplified form for the MHV amplitudes,
which is equivalent to the expressions obtained previously by Bern, Dixon,
Dunbar and Kosower using the cut-constructibility approach.Comment: Latex, 35 pages, 3 figures. v2: remarks on gauge invariance added.
Published version to appear in Nuclear Physics
Eff ects of bidi smoking on all-cause mortality and cardiorespiratory outcomes in men from south Asia: an observational community-based substudy of the Prospective Urban Rural Epidemiology Study (PURE)
Background Bidis are minimally regulated, inexpensive, hand-rolled tobacco products smoked in south Asia. We
examined the eff ects of bidi smoking on baseline respiratory impairment, and prospectively collected data for all-cause
mortality and cardiorespiratory events in men from this region.
Methods This substudy of the international, community-based Prospective Urban Rural Epidemiology (PURE) study
was done in seven centres in India, Pakistan, and Bangladesh. Men aged 35–70 years completed spirometry testing
and standardised questionnaires at baseline and were followed up yearly. We used multilevel regression to compare
cross-sectional baseline cardiorespiratory symptoms, spirometry measurements, and follow-up events (all-cause
mortality, cardiovascular events, respiratory events) adjusted for socioeconomic status and baseline risk factors
between non-smokers, light smokers of bidis or cigarettes (≤10 pack-years), heavy smokers of cigarettes only (>10 packyears),
and heavy smokers of bidis (>10 pack-years).
Findings 14 919 men from 158 communities were included in this substudy (8438 non-smokers, 3321 light smokers,
959 heavy cigarette smokers, and 2201 heavy bidi smokers). Mean duration of follow-up was 5·6 years (range 1–13).
The adjusted prevalence of self-reported chronic wheeze, cough or sputum, dyspnoea, and chest pain at baseline
increased across the categories of non-smokers, light smokers, heavy cigarette smokers, and heavy bidi smokers
(p<0·0001 for association). Adjusted cross-sectional age-related changes in forced expiratory volume in 1 s (FEV1)
and FEV1/forced vital capacity (FVC) ratio were larger for heavy bidi smokers than for the other smoking categories.
Hazard ratios (relative to non-smokers) showed increasing hazards for all-cause mortality (light smokers 1·28
[95% CI 1·02–1·62], heavy cigarette smokers 1·59 [1·13–2·24], heavy bidi smokers 1·56 [1·22–1·98]), cardiovascular
events (1·45 [1·13–1·84], 1·47 [1·05–2·06], 1·55 [1·17–2·06], respectively) and respiratory events (1·30 [0·91–1·85],
1·21 [0·70–2·07], 1·73 [1·23–2·45], respectively) across the smoking categories.
Interpretation Bidi smoking is associated with severe baseline respiratory impairment, all-cause mortality, and
cardiorespiratory outcomes. Stricter controls and regulation of bidis are needed to reduce the tobacco-related disease
burden in south Asia
Household and personal air pollution exposure measurements from 120 communities in eight countries: results from the PURE-AIR study
Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study
Introduction. Switchingfrom polluting (e.g. wood, crop waste, coal)to clean (e.g. gas, electricity) cooking
fuels can reduce household air pollution exposures and climate-forcing emissions.While studies have
evaluated specific interventions and assessed fuel-switching in repeated cross-sectional surveys, the role
of different multilevel factors in household fuel switching, outside of interventions and across diverse
community settings, is not well understood. Methods.We examined longitudinal survey data from
24 172 households in 177 rural communities across nine countries within the Prospective Urban and
Rural Epidemiology study.We assessed household-level primary cooking fuel switching during a
median of 10 years offollow up (∼2005–2015).We used hierarchical logistic regression models to
examine the relative importance of household, community, sub-national and national-level factors
contributing to primary fuel switching. Results. One-half of study households(12 369)reported
changing their primary cookingfuels between baseline andfollow up surveys. Of these, 61% (7582)
switchedfrom polluting (wood, dung, agricultural waste, charcoal, coal, kerosene)to clean (gas,
electricity)fuels, 26% (3109)switched between different polluting fuels, 10% (1164)switched from clean
to polluting fuels and 3% (522)switched between different clean fuels