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The autoignition kinetics of hydrocarbons is an important criterion for selecting fuels for piston reciprocating engines, and it can be determined by relative performance to mixtures of alkanes, n-heptane and iso-octane, under certain standardized operating conditions. 2-methylfuran is a potential biofuel candidate, whose autoignition chemistry is markedly different from alkanes. Its octane behavior when blended with paraffins also shows a marked difference. The blending octane behavior of a fuel is characterized by its Blending Octane Number (BON). The BON of 2-methylfuran was extensively characterized in this work. 2-methylfuran's BON was mapped from experimental ignition delay times measured in a constant volume combustion chamber using established correlations. The effect on BON was studied depending on the RON of the base fuel into which 2-methylfuran was blended, as well as the quantity of 2-methylfuran blended. BON of 2-methyfuran was greater than its RON by a factor of four or more for some blends studied. BON reduced with increasing RON of the base fuel, as well as with increasing quantity of 2-methylfuran blended. A chemical kinetic model was created by integration of well validated sub-models for the blend components, and then used to explain the chemical kinetics leading to the extremely high BON values of 2-methylfuran. The synergetic anti-knock blending effect of 2-methylfuran is partially due to its physical properties leading to a greater molar fraction per volume fraction in the blend compared to iso-octane. Analysis using chemical kinetic model revealed that the chemical action behind 2-methylfuran's blending octane behavior was due to its ability to quench OH radicals which are important to the low-temperature oxidation chemistry of alkanes. This quenching effect is achieved due to the more rapid reaction rate of 2-methylfuran with OH radical compared to iso-octane, followed by the immediate conversion of the adduct shifting the equilibrium towards the product.

Pile Foundation is a type of foundation where the super structural load is transferred to the weak or compressive layers of soil. This type of pile foundations are majorly used for the construction of bridges, buildings as a support system to avoid excess settlement, the super structural load is safely transferred to the mother earth. Due to the heavy major earthquake, Failure of pile foundations has been observed in many cases. In this paper, three Building model are considered for the study (1 regular building and 2 irregular buildings). The Building consists of G+5 storied RCC structure. The analysis was carried out in “ETABS” software. First the building was analyzed for dead load and imposed load combinations and then the structure was analyzed by Equivalent static method. In this paper black cotton soil was considered for the design of Pile foundation. Design of piles was done using Indian Standards IS 2911 (Part-1 /Sec-2), IS 456:2000 and IS 1893:2002 (Part-1). Graphs were plotted for all three types’ structures. It was found that for C-Type of structure more number of piles has to be provided for seismic analysis rather than static analysis, were as for L-Type number of piles for static analysis yielded more compared to seismic analysis., {"references":["1.\tBhattacharaya, S, \"Safety Assessment of Existing Piled Foundations in Liquefiable Soils against Buckling Instability\", ISET Journal of Earthquake technology | Volume 43, Page no: 133-147 | December 2006. 2.\tBhattacharaya, S, \"A review of Methods for Pile Design in Seismically Liquefiable Soils\", Design of Foundations in Seismic Area: Principles and Applications, Edt. Bhattacharaya, NICEE Publication, page No: 255-295 | 2007. 3.\tXiao WEI, Qing qiao WANG, Junjie WANG, \"Damage Patterns and Failure Mechanisms of Bridge Pile Foundation Under Earthquake\", The 14th World conference on Earthquake Engineering Beijing China, Volume 1 | October 12-17-2008. 4.\tA. Murali Krishna, A. Phani Teja, S. Bhattacharaya, Barnali Ghosh, \"Seismic Design of Pile Foundations for Different Ground conditions | 15 WCEE LISBOA | 2012. 5.\tDr. R.S. Talikoti, Mr. Vinod R. Throat, \"Base Isolation in Seismic Structural Design\", Journal of Research in Engineering and Technology (IRJET), Volume 3, ISSN: 2278-0181 | Issue-7 | Page no: 863-868 | 7th July 2014. 6.\tSubhamoy Bhattacharaya and Andreas Kappos, \"On the Collapse of Bridge Foundations in Liquefiable Soils during Earthquake\", Second European Conference on Earthquake Engineering and Seismology, University of Survey | Istanbul | Aug 25-29 2014. 7.\tSamridhi Singh, Faizan Ahmad, Bandita Paikaray, \"Effects of Earthquake on Foundations\", International Journal of Research in Engineering and Technology (IRJET), Volume 4 | Issue 13 | ICISE-2015 | December 2015. 8.\tNilanjan Tarafdar, SM ASCE, Kamalesh Bhowmik, SM ASCE, K.V. Naveen Kumar, \"Earthquake Resistant Techniques and Analysis of Tall Building\", Journal of Research in Engineering and Technology (IRJET), Volume 4 | eISSN: 2319-1163 | pISSN: 2321-7308 | Pages 99-104 | December 2015. 9.\tSaurabh M. Chaturvedi, Yashraj Singh & Akhil Batavia, \"Failure of Pile Foundations due to Earthquake & Its Remedial Measures\", The International journal of Engineering and Science (IJES), Volume 1, ISSN: 23-19-1805, Pages: 32-36, 2018. 10.\tDr. BC Punmia, Ashok kr. Jain, Soil Mechanics & Foundations, 16th Edition. 11.\tIS 1893 \"Criteria for Earthquake resistant Design of Structures\", Bureau of Indian Standards, New Delhi, Part 1, 2002. 12.\tIS 456-2000: \"Plain and Reinforced Concrete\", Bureau of Indian Standards, New Delhi, 2000. 13.\tIS 2911 \"Design and Construction of Pile Foundations\", Bureau of Indian Standards, New Delhi, Part: 1 – sec 2, 2010."]}

The efficiency of spark-ignition engines is limited by the phenomenon of knock, which is caused by auto-ignition of the fuel-air mixture ahead of the spark-initiated flame front. The resistance of a fuel to knock is quantified by its octane index; therefore, increasing the octane index of a spark-ignition engine fuel increases the efficiency of the respective engine. However, raising the octane index of gasoline increases the refining costs, as well as the energy consumption during production. The use of alternative fuels with synergistic blending effects presents an attractive option for improving octane index. In this work, the octane enhancing potential of 2-methylfuran (2-MF), a next-generation biofuel, has been examined and compared to other high-octane components (i.e., ethanol and toluene). A primary reference fuel with an octane index of 60 (PRF60) was chosen as the base fuel since it closely represents refinery naphtha streams, which are used as gasoline blend stocks. Initial screening of the fuels was done in an ignition quality tester (IQT). The PRF60/2-MF (80/20 v/v%) blend exhibited longer ignition delay times compared to PRF60/ethanol (80/20 v/v%) blend and PRF60/toluene (80/20 v/v%) blend, even though pure 2-MF is more reactive than both ethanol and toluene. The mixtures were also tested in a cooperative fuels research (CFR) engine under research octane number and motor octane number like conditions. The PRF60/2-MF blend again possesses a higher octane index than other blending components. A detailed chemical kinetic analysis was performed to understand the synergetic blending effect of 2-MF, using a well-validated PRF/2-MF kinetic model. Kinetic analysis revealed superior suppression of low-temperature chemistry with the addition of 2-MF. The results from simulations were further confirmed by homogeneous charge compression ignition engine experiments, which established its superior low-temperature heat release (LTHR) suppression compared to ethanol, resulting in better blending octane numbers. This work explores and provides a chemically sound explanation for the potential of 2-MF as an octane enhancer.

High-octane quality fuels are important for increasing spark ignition engine efficiency, but their production comes at a substantial economic and environmental cost. The possibility of producing high anti-knock quality gasoline by blending high-octane bio-derived components with low octane naphtha streams is attractive. 2-phenyl ethanol (2-PE), is one such potential candidate that can be derived from lignin, a biomass component made of interconnected aromatic groups. We first ascertained the blending anti-knock quality of 2-PE by studying the effect of spark advancement on knock for various blends 2-PE, toluene, and ethanol with naphtha in a cooperative fuels research engine. The blending octane quality of 2-PE indicated an anti-knock behavior similar or slightly greater than that of toluene, and ethylbenzene, which could be attributed to either chemical kinetics or charge cooling effects. To isolate chemical kinetic effects, a model for 2-PE auto-ignition was developed and validated using ignition delay times measured in a high-pressure shock tube. Simulated ignition delay times of 2-PE were also compared to those of traditional high-octane gasoline blending components to show that the gas phase reactivity of 2-PE is lower than ethanol, and comparable to toluene, and ethylbenzene at RON, and MON relevant conditions. The gas-phase reactivity of 2-PE is largely controlled by its aromatic ring, while the effect of the hydroxyl group is minimal. The higher blending octane quality of 2-PE compared to toluene, and ethylbenzene can be attributed primarily to the effect of the hydroxyl group on increasing heat of vaporization.

The paper is based upon work supported by Saudi Aramco Research and Development Center FUELCOM 3 program under Master Research Agreement Number 6600024505/01. FUELCOM (Fuel Combustion for Advanced Engines), is a collaborative research undertaking between Saudi Aramco and KAUST intended to address the fundamental aspects of hydrocarbon fuel combustion in engines, and develop fuel/ engine design tools suitable for advance combustion modes.The author would like to thank King Abdullah University of Science and Technology (KAUST) and the Clean Combustion Research Center (CCRC) for lab facilities and research support. Last but not least, the authors would like to convey gratitudetowards the IC Engine Lab Safety Supervisor Adrian I. Ichim and the lab technician Riyad H. Jambi for their kind input and assistance in performing the experiments.

© 2015 The Combustion Institute. Chain-branching reactions represent a general motif in chemistry, encountered in atmospheric chemistry, combustion, polymerization, and photochemistry; the nature and amount of radicals generated by chain-branching are decisive for the reaction progress, its energy signature, and the time towards its completion. In this study, experimental evidence for two new types of chain-branching reactions is presented, based upon detection of highly oxidized multifunctional molecules (HOM) formed during the gas-phase low-temperature oxidation of a branched alkane under conditions relevant to combustion. The oxidation of 2,5-dimethylhexane (DMH) in a jet-stirred reactor (JSR) was studied using synchrotron vacuum ultra-violet photoionization molecular beam mass spectrometry (SVUV-PI-MBMS). Specifically, species with four and five oxygen atoms were probed, having molecular formulas of C8H14O4(e.g., diketo-hydroperoxide/keto-hydroperoxy cyclic ether) and C8H16O5(e.g., keto-dihydroperoxide/dihydroperoxy cyclic ether), respectively. The formation of C8H16O5species involves alternative isomerization of OOQOOH radicals via intramolecular H-atom migration, followed by third O2addition, intramolecular isomerization, and OH release; C8H14O4species are proposed to result from subsequent reactions of C8H16O5species. The mechanistic pathways involving these species are related to those proposed as a source of low-volatility highly oxygenated species in Earth's troposphere. At the higher temperatures relevant to auto-ignition, they can result in a net increase of hydroxyl radical production, so these are additional radical chain-branching pathways for ignition. The results presented herein extend the conceptual basis of reaction mechanisms used to predict the reaction behavior of ignition, and have implications on atmospheric gas-phase chemistry and the oxidative stability of organic substances.

Octane number (ON) is an important empirical parameter for developing and optimizing internal combustion engine (ICE) for knock resistance. Primary reference fuels (PRF) comprising iso-octane and n-heptane are the simplest gasoline surrogates. C4 hydrocarbons: butane isomers (n-butane and isobutane), butene isomers (1-butene, 2-butene and isobutene) and 1,3-butadiene are the smallest hydrocarbons with isomeric, saturated, unsaturated and conjugated bond structures, which makes them good candidates for understanding the blending octane behavior of saturated and unsaturated hydrocarbons. In this study, the blending octane behaviors of six PRF60 & C4 hydrocarbon mixtures were systematically investigated. A state-of-the-art kinetic models were used by merging the latest KAUST gasoline surrogate model with the AramcoMech 3.0 model. IDTs of stoichiometric fuel/air mixtures were simulated at wide range of pressure (20–50 atm) and temperature (600–1400 K). Three correlation equations were employed from the literature to predict the research octane number (RON) and motor octane number (MON) of all blends based on these calculated IDTs. Compared with the experimentally measured ON, the best correlation conditions and errors were identified. With the highest degree of unsaturation, 1,3-butadiene was found to be the strongest ON enhancer. Moreover, based on a polynomial correlation, a TPRF (PRF + toluene) blend was formulated by matching the RON and MON of PRF plus 1,3-butadiene blend, for a comparative analysis. Finally, the reactants’ consumption profile, flux and sensitivity analysis were simultaneously performed for explaining the chemistry behind the blending octane behavior of the PRF blends with 1,3-butadiene and toluene.

Gasoline is the most widely used fuel for light duty automobile transportation, but its molecular complexity makes it intractable to experimentally and computationally study the fundamental combustion properties. Therefore, surrogate fuels with a simpler molecular composition that represent real fuel behavior in one or more aspects are needed to enable repeatable experimental and computational combustion investigations. This study presents a novel computational methodology for formulating surrogates for FACE (fuels for advanced combustion engines) gasolines A and C by combining regression modeling with physical and chemical kinetics simulations. The computational methodology integrates simulation tools executed across different software platforms. Initially, the palette of surrogate species and carbon types for the target fuels were determined from a detailed hydrocarbon analysis (DHA). A regression algorithm implemented in MATLAB was linked to REFPROP for simulation of distillation curves and calculation of physical properties of surrogate compositions. The MATLAB code generates a surrogate composition at each iteration, which is then used to automatically generate CHEMKIN input files that are submitted to homogeneous batch reactor simulations for prediction of research octane number (RON). The regression algorithm determines the optimal surrogate composition to match the fuel properties of FACE A and C gasoline, specifically hydrogen/carbon (H/C) ratio, density, distillation characteristics, carbon types, and RON. The optimal surrogate fuel compositions obtained using the present computational approach was compared to the real fuel properties, as well as with surrogate compositions available in the literature. Experiments were conducted within a Cooperative Fuels Research (CFR) engine operating under controlled autoignition (CAI) mode to compare the formulated surrogates against the real fuels. Carbon monoxide measurements indicated that the proposed surrogates accurately reproduced the global reactivity of the real fuels across various combustion regimes.

The concept of double compression, and double expansion engine (DCEE) for improving the efficiency of piston reciprocating engines was introduced in SAE Paper 2015-01-1260. This engine configuration has separate high, and low pressure units thereby effectively reducing friction losses for high effective compression ratios. The presence of an additional expander stage also theoretically allows an extra degree of freedom to manipulate the combustion heat release rate so as to achieve better optimum between heat transfer, and friction losses. This paper presents a 1-D modeling study of the engine concept in GT-Power for assessing the sensitivity of engine losses to heat release rate. The simulations were constrained by limiting the maximum pressure to 300 bar. The maximum motoring pressure was varied by, (a) constraining the compression ratio of the high pressure unit, and adapting the low pressure unit accordingly, (b) changing the compression ratio of the high pressure unit with a constant geometry for the low pressure unit. The effect of maximum pressure on the brake thermal efficiency was also investigated. A final set of simulations also compared the heat release rate of the model in SAE Paper 2015-01-1260 and two other models with the same start and end of combustion. The simulations were done at engine speed of 1900 rpm, and lambda 3. The results indicate the relative insensitivity of this concept engine's performance to the heat release rate when the maximum pressure constrained to a constant value of 300 bar, or even when lowering peak pressure down to 200 bar due to reduction in heat loss, and friction losses. The major limitations of the present study was the adoption of a constant convection heat loss multiplier for all the cases, and a simplistic friction model. (Less)

© 2016 American Chemical Society. This work provides new temperature-dependent mole fractions of elusive intermediates relevant to the low-temperature oxidation of dimethyl ether (DME). It extends the previous study of Moshammer et al. [J. Phys. Chem. A 2015, 119, 7361-7374 ] in which a combination of a jet-stirred reactor and molecular beam mass spectrometry with single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation was used to identify (but not quantify) several highly oxygenated species. Here, temperature-dependent concentration profiles of 17 components were determined in the range of 450-1000 K and compared to up-to-date kinetic modeling results. Special emphasis is paid toward the validation and application of a theoretical method for predicting photoionization cross sections that are hard to obtain experimentally but essential to turn mass spectral data into mole fraction profiles. The presented approach enabled the quantification of the hydroperoxymethyl formate (HOOCH2OCH2O), which is a key intermediate in the low-temperature oxidation of DME. The quantification of this keto-hydroperoxide together with the temperature-dependent concentration profiles of other intermediates including H2O2, HCOOH, CH3OCHO, and CH3OOH reveals new opportunities for the development of a next-generation DME combustion chemistry mechanism.

This work provides new temperature-dependent mole fractions of elusive intermediates relevant to the low-temperature oxidation of dimethyl ether (DME). It extends the previous study of Moshammer et al. [ J. Phys. Chem. A 2015 , 119 , 7361 - 7374 ] in which a combination of a jet-stirred reactor and molecular beam mass spectrometry with single-photon ionization via tunable synchrotron-generated vacuum-ultraviolet radiation was used to identify (but not quantify) several highly oxygenated species. Here, temperature-dependent concentration profiles of 17 components were determined in the range of 450-1000 K and compared to up-to-date kinetic modeling results. Special emphasis is paid toward the validation and application of a theoretical method for predicting photoionization cross sections that are hard to obtain experimentally but essential to turn mass spectral data into mole fraction profiles. The presented approach enabled the quantification of the hydroperoxymethyl formate (HOOCH

The authors wish to thank Adrian Ichim for performing the engine experiments. This work was supported by KAUST and the Saudi Aramco FUELCOM program.

The recent adoption of Information Communication Technologies (ICTs, namely mobile phones and radios) in rural areas of Sub- Saharan Africa has brought new evidence that an updated and reliable flow of information can have direct benefits for farmers' welfare. However, if correct market information can benefit the users, incorrect information can be costly. In this study we explore the diffusion (quantity) and the accuracy (quality) of price information among farmers in northern Ghana, with a focus on the role of ICTs.

Relatively little evidence is available on the importance of information and the role of Information Communication Technologies (mobiles and radios) in the key aspects of marketing behaviours of developing country farmers. We included the concept of proportional and fixed transactions costs within a household framework to investigate market participation decisions of farm households with a marketable surplus of food crops. Differently to previous studies, we also modelled the behaviour of farm gale buyers. We use a novel dataset from Ghanaian farmers, which contains detailed information fro individual selling transaction that is seldom available in other household surveys. We found that larger transactions occur at the farmgale, where farmgale buyers are prepared to pay a premium price because of lower fixed transaction costs they incur. The knowledge of market information has a contrasting effect on the decision of the marketplace. In some cases, farmers use the information on prices in specific marketplaces to travel farther, in other cases they sell their commodity in closer market where they may strenghening their bargaining power. Finally we only found weak evidence on the impact of using mobile phones in reducing searching costs and attract farm gate buyers.

The paper aims at indirectly estimating a time series of food prices from household expenditure data, focusing on foods considered as ‘junk’ relative to healthy foods. The “big 6” among the HFSS (high in fats, sugar and salt) foods identified by the Food Standard Agency have been selected to compose a target ‘unhealthy’ basket, compared to a ‘healthy’ benchmark aggregate including fruit and vegetables. UK data from the National Food Surveys, the Household Expenditure Surveys and the Living Costs and Food Survey were harmonized and merged to compose a set of household level unit values from 1997 to 2009 for the healthy and unhealthy aggregates. Well-established techniques are then employed to estimate regional prices by disentangling the quality component from unit values. The analysis provides information on the geographical and time heterogeneity of estimated price of the unhealthy basket relative to fruit and vegetable prices.

We estimate the effects of the 2005 ban on vending machines in French schools using the 1998 and 2006 INCA nutrition surveys. These surveys contain no information on the presence of vending machines in schools attended by respondents, but the adoption of a Difference-in-Difference design, and a Regression Discontinuity Design enable us to obtain indirect estimates of the policy impact. Results are consistent and suggest that the measure has had a small but significant impact on teenager nutrition, especially in terms of reduced fat intakes.

Both governmental and non-governmental organizations are engaged in the promotion of soil and water conservation practices in northern Ghana, but adoption is believed to be low. This study thus examines the determinants of conservation practices by farming households in the area. Data for the study was collected from 445 households located in 15 communities in northern Ghana. Univariate, bivariate and multivariate probit models were used to analyse the decision to adopt six conservation practices in the area. Results show the major determinants of adoption are plot and cropping characteristics such as location; and socio-economic and institutional variables such as number of contacts with extension officers, membership in farmer association and distance to major market. A major policy implication of the study is the strengthening of extension service in the area to significantly boost conservation adoption.

Quantile Regression methods have much to offer the investigation of the determinants of dietary intake. Dietary inadequacy or excess occurs at the tails of nutrient and food intakes, and it seems intuitive that intake responses in these areas will differ from elsewhere along the intake distribution. We apply quantile regression to examine the drivers of a key aspect of dietary health, fat density of energy intake in China. The sample of 2612 individuals between the ages of 20 and 45 is derived from the China Health and Nutrition Survey. The following insights emerge: (i) Fat density increases with income, but worryingly the income effect is more pronounced at the upper conditional tail of fat intake (ii) While it is confirmed that an urban location contributes to higher fat density for the most part, this effect disappears at the upper conditional quantiles, suggesting that, at the most unhealthy levels of fat density conditional on covariates, the problem is as much a rural one as it is urban.

In this paper, we address the issue of perturbed information at the transmitter in a multiple-input multiple-output (MIMO) system. Two schemes, correlation matrix feedback and channel information feedback, are proposed to convey information necessary for achieving capacity to the transmitter. This information is perturbed due to various impairments. A perturbation analysis is carried out to study the variations in mutual information for each of the proposed schemes. For ergodic channels, this analysis is used to design a MIMO system with a limited rate feedback. Using a codebook-based approach, vector quantizers are designed to minimize the loss in ergodic capacity for each of the proposed schemes, and their performance is studied. A non-codebook method, parameter-based feedback, is also presented, and the underlying rate-performance tradeoff is highlighted.

Rapid economic growth in China has resulted in substantially improved household incomes. Diets have also changed, with a movement away from traditional foods and towards animal products and processed foods. Yet micronutrient deficiencies, particularly for calcium and vitamin A, are still widespread in China. In this research we model the determinants of the intakes of these two micronutrients using household panel data, asking particularly whether continuing income increases are likely to cause the deficiencies to be overcome. Nonparametric kernel regressions and random effects panel regression models are employed. The results show a statistically significant but relatively small positive income effect on both nutrient intakes. The local availability of milk is seen to have a strong positive effect on intakes of both micronutrients. Thus, rather than relying on increasing incomes to overcome deficiencies, supplementary government policies, such as school milk programmes, may be warranted.

Tropospheric ozone is an air pollutant thought to reduce crop yields across Europe. Much experimental scientific work has been completed or is currently underway to quantify yield effects at ambient ozone levels. In this research, we seek to directly evaluate whether such effects are observed at the farm level. We use both primal (production function) as well as dual (profit function) methods, with ozone as a fixed input, to explore the extent to which output and profits are affected by ozone in the UK. A panel dataset on UK farms is intersected with spatial data on ozone, and panel data production and profit function estimation methods are used. The production function does predict a statistically significant negative effect of ozone on wheat yields at the farm level. However, this elasticity is small, and indicates that ozone is unlikely to result in the imposition of substantial external costs on wheat production. The profit function implications regarding ozone are less clear. Although the estimates indicate that ozone depresses wheat farm profits and wheat supply, the elasticities are statistically insignificant, and few definite conclusions can be drawn. We conclude that the farm-level evidence does not show a substantial ozone effect in the UK, and that it may be wise to interpret economic valuations based upon experimental results with some caution.

Under the TRIPs Agreement, all member-countries of the World Trade Organization are required to provide an "effective" system of plant variety protection within a specific time frame. In many developing countries this has led to a divisive debate about the fundamental desirability of extending intellectual property rights to agriculture. But empirical studies on the economic impacts of PVP, especially its ability to generate large private sector investments in plant breeding and facilitate the transfer of technology, have been very limited. This paper examines two aspects of the international experience of PVP legislation thus far (i) The relationship between legislation, R&D expenditures and PVP grants, i.e., the innovation effect, and (ii) The role of PVP in facilitating the flow of varieties across countries, i.e., the transferability effect.

It is known that the capacity of a multi-antenna flat non-fading Gaussian channels (MIMO capacity) can be improved if the transmitter has perfect knowledge of channel. The channel information affects the input allocation and hence there is capacity degradation when the transmitter does not know the channel perfectly. In this work variation in MIMO capacity due to small perturbations that do not change the rank of the channel is studied. The need for the analysis is highlighted by the fact that at high SNR, most channel estimation algorithms give small errors. Expressions and bounds for capacity are derived using first order perturbation analysis. Further to this, the dependence of capacity on the channel parameters and total power is studied. It is shown that the upper bound on degradation in capacity for small errors varies as the square of the spectral norm of perturbation. Further the degradation has an approximate inverse square relation with total power used and channel singular values. These results are extended to a general class of communication systems and results for MIMO-OFDM systems over frequency selective channels are presented.

This paper fits a translog stochastic production frontier with inefficiency effects to a panel of 693 UK dairy farms for the period from 1982 to 1997. The Cobb Douglas is rejected as inadequate relative to the less restrictive translog functional form and the frontier model is statistically superior to the mean response function, despite the fact that on average the farms were 87% efficient. Technological progress, at 1.7% per annum, is the dominant force, but efficiency declined at 0.8% per year, which reduced productivity growth to 0.9% per annum. The inefficiencies are explained in the second stage of the model, where the greatest cause is financial exposure, captured here by the ratio of debts to assets. Older farmers, those in less favoured areas and owner-occupiers were also less efficient, but large farms were more efficient, which suggests increasing returns to scale.

Under the TRIPs Agreement , all member-countries of the World Trade Organization (WTO) are required to provide an "effective" system of plant variety protection (PVP) within a specific time frame. In many developing countries this has led to a divisive debate about the fundamental desirability of extending intellectual property rights (IPRs) to agriculture. But empirical studies on the economic impacts of PVP, especially its ability to generate large private sector investments in plant breeding and facilitate the transfer of technology, have been very limited. This paper examines two aspects of the international experience of PVP legislation thus far (i) The relationship between R&D expenditures and PVP grants and (ii) The role of PVP in facilitating the flow of varieties across countries. This analysis can generate useful insights for policy makers in developing countries currently contemplating PVP legislation.

We investigate the comparative static effects of environmental and agricultural policies on pesticide and fertilizer use. Since such effects depend on technology and risk preference parameters, we estimate these from a panel data set of Illinois farms. Generalized method of moments is used on a set of nonlinear first order conditions.

Appendix A: Sub models of the Integrated Framework. Appendix B: Additional Results. Figure S1: Decomposition of Household Income and Household Consumption. Table S1: Nutrient Matching Economic Results Decomposition. Table S2: Nutrient Matching Nutrition, Biomarker and Health Results Decomposition. Table S3: Nutrient Matching Demographic and workforce Results Decomposition (DOCX 43 kb)

Appendix A: Sub models of the Integrated Framework. Appendix B: Additional Results. Figure S1: Decomposition of Household Income and Household Consumption. Table S1: Nutrient Matching Economic Results Decomposition. Table S2: Nutrient Matching Nutrition, Biomarker and Health Results Decomposition. Table S3: Nutrient Matching Demographic and workforce Results Decomposition (DOCX 43 kb)