Asymmetric effects of monetary policy in the United States

This paper tests for the presence of asymmetric effects of monetary policy on output. The asymmetries that the authors examine are related to the size and sign of monetary policy shocks and are based on economic theory. Using M1 as the basis for measuring monetary policy shocks, they find evidence in line with previous evidence of larger real effects resulting from positive shocks than from negative shocks—although the authors cannot reject symmetry either. However, using the federal funds rate instead, a measure that is more closely related to the actual conduct of monetary policy, they find that only small negative shocks affect real aggregate activity. The results are interpreted in terms of menu-cost models.Monetary policy ; Macroeconomics

Tailoring laser pulses with spectral and fluence constraints using optimal control theory

Within the framework of optimal control theory we develop a simple iterative scheme to determine optimal laser pulses with spectral and fluence constraints. The algorithm is applied to a one-dimensional asymmetric double well where the control target is to transfer a particle from the ground state, located in the left well, to the first excited state, located in the right well. Extremely high occupations of the first excited state are obtained for a variety of spectral and/or energetic constraints. Even for the extreme case where no resonance frequency is allowed in the pulse the algorithm achieves an occupation of almost 100%

Wideband magnetic losses and their interpretation in HGO steel sheets

The magnetic properties of high-permeability grain-oriented (HGO) Fe-Si sheets have been investigated in the frequency range 1 Hz-10 kHz, with attention devoted to the role of thickness on the behavior of the magnetic losses and the phenomenology of skin effect. The study is focused on the wideband response of 0.174 mm and 0.289 mm thick sheets, comparatively tested at peak polarization values ranging between 0.25 T and 1.7 T. The experiments associate fluxmetric measurements with direct Kerr observations of the dynamics of the domain walls. A picture of the magnetization process comes to light, where the dynamics of the flux reversal takes hold under increasing frequencies through the motion of increasingly bowed 180 degrees walls, eventually merging at the sheet surface for a fraction of the semi-period. This effect can be consistently predicted, starting from the Kerrbased knowledge of the equilibrium wall spacing, by the numerical modeling of the motion of an extended array of 180 degrees domain walls, subjected to the balanced action of the applied and eddy current fields, and the elastic reaction of the bowed walls. This model can be incorporated into the general concept of loss separation, by calculating the classical loss component through the solution of the Maxwell's diffusion equation under a magnetic constitutive law identified with the normal DC curve. The numerical domain wall model and the loss decomposition consistently predict that the excess loss component, playing a major role in these grain-oriented materials at power frequencies, tends to disappear in the upper induction-frequency corner

Can electro-magnetic field, anisotropic source and varying Λ\Lambda be sufficient to produce wormhole spacetime ?

It is well known that solutions of general relativity which allow for traversable wormholes require the existence of exotic matter (matter that violates weak or null energy conditions [WEC or NEC]). In this article, we provide a class of exact solution for Einstein-Maxwell field equations describing wormholes assuming the erstwhile cosmological term $\Lambda$ to be space variable, viz., $\Lambda = \Lambda (r)$. The source considered here not only a matter entirely but a sum of matters i.e. anisotropic matter distribution, electromagnetic field and cosmological constant whose effective parts obey all energy conditions out side the wormhole throat. Here violation of energy conditions can be compensated by varying cosmological constant. The important feature of this article is that one can get wormhole structure, at least theoretically, comprising with physically acceptable matters.Comment: Some changes have been mad

Microcanonical mean-field thermodynamics of self-gravitating and rotating systems

We derive the global phase diagram of a self-gravitating $N$-body system enclosed in a finite three-dimensional spherical volume $V$ as a function of total energy and angular momentum, employing a microcanonical mean-field approach. At low angular momenta (i.e. for slowly rotating systems) the known collapse from a gas cloud to a single dense cluster is recovered. At high angular momenta, instead, rotational symmetry can be spontaneously broken and rotationally asymmetric structures (double clusters) appear.Comment: 4 pages, 4 figures; to appear in Phys. Rev. Let

Preliminary Studies on the Development and Evaluation of Instant Pounded Yam from Dioscorea alata

Of all the species of Dioscorea , Dioscorea alata possesses higher multiplication ratio and better storability, and requires less capital and labour to produce than the most common specie, Dioscorea rotundata . Exploitation of the industrial potential of D. alata by diversifying its utilisation through the development of novel products will expand its utilisation. This study therefore investigated the potential of developing instant poundo yam flour from D. alata. Instant poundo yam flour was prepared from D. alata by peeling, dicing and immersing yam tubers in sodium metabisulphite solution (800 ppm for 20 min). The tubers were thereafter blanched at 70 \ub0C for either 5 or 10 min, dried in a cabinet dryer at 60 \ub0C for 72 hr, milled and sieved (600 \ub5m) to obtain two experimental samples of poundo yam flours. The proximate composition of the flours was determined using standard methods. Sensory evaluation was conducted to determine the sensory attributes [colour, flavour, taste, textural quality (strecthability, adhesiveness, cohesiveness, smoothness) and general acceptability] of the flours. The two instant poundo yam samples were further compared with a commercial poundo yam in terms of the sensory attributes. There was no significant difference (p 640.05) in the proximate composition of the two experimental instant poundo yam samples but their textural quality differed significantly (p 640.05). Instant poundo yam blanched for 10 min recorded higher sensory scores than the one blanched for 5 min and compared fairly well with the reference sample. An acceptable instant poundo yam has been developed from D. alata

Prospects and constraints on utilization of Jatropha curcas seeds in animal feedstuff

Combined physical, chemical and biochemical methods were used to process virgin seed meal of Jatropha curcas L. into treated Jatropha Seed Meal (JSM). Graded levels (0, 5, 10, 15, 20 and 25%) JSM treated by the various methods was included in the test diets which were fed ad libitum to 360 albino rats for a month in a single factor design trial. The results revealed that feed intake was numerically highest (p > 0.05) for the rats on the 5 % treated JSM diet, while feed efficiency was highest (p > 0.05) for those on the 10 % treated JSM diets. Weight gain was significantly highest (p< 0.05) for the rats on 10 and 15 % treated JSM diets. Lowest survival rate (17%) was observed on treated JSM diet processed by boiling, roasting followed by fermenting. Biochemical indices measured on treated JSM based diets were comparable with those obtained on the conventional diet (p > 0.05) except for blood cholesterol level (p < 0.05) which was elevated with increasing treated JSM in diets. There were also no significant differences recorded on AST and ALP activities (p > 0.05) between the treatments. Haematological indices investigated including PCV, RBC, Hb were insignificantly influenced by the 5% dietary treated JSM compared with the control diet (p > 0.05) and there was non-significant effect of the dietary treatment on the WBC differential counts of lymphocytes, eosinophils, monocytes and neutrophils. It was established in this study that inclusion of 5% treated JSM in diets had no detrimental effect on albino rats. Further researches are in progress to investigate inclusion of the treated JSM in diets at levels higher than the 5% used in this study.Keywords: JSM, Cockerels, Performance, Biochemical and haematological parameter

The Running of the Cosmological and the Newton Constant controlled by the Cosmological Event Horizon

We study the renormalisation group running of the cosmological and the Newton constant, where the renormalisation scale is given by the inverse of the radius of the cosmological event horizon. In this framework, we discuss the future evolution of the universe, where we find stable de Sitter solutions, but also "big crunch"-like and "big rip"-like events, depending on the choice of the parameters in the model.Comment: 14 pages, 7 figures, minor improvements, references adde