Investigations of the Surface Dielectric Function by Means of the Scanning Ellipsometry and Transition Radiation Methods

This paper was supported by the Project CPBP 01.08.We describe the scanning ellipsometry and transition radiation methods as well as their applications to surface dielectric function measurements. In particular, we present the results for a gadolinium sample in the visible and ultraviolet spectral ranges. We compare our experimental results obtained by both methods.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę

Analytical model for the uncorrelated emittance evolution of externally injected beams in plasma-based accelerators

This article introduces an analytical formalism for the calculation of the evolution of beam moments and the transverse emittance for beams which are externally injected into plasma wakefield accelerators. This formalism is then applied to two scenarios with increasing complexity - a single beam slice without energy gain and a single beam slice with energy gain, both propagating at a fixed co-moving position behind the driver. The obtained results are then compared to particle-in-cell (PIC) simulations as well as results obtained using an semi-analytic numerical approach (SANA). We find excellent agreement between results from the analytical model and from SANA and PIC

Bank involvement with SMEs : beyond relationship lending

The"conventional wisdom"in academic and policy circles argues that, while large and foreign banks are generally not interested in serving SMEs, small and niche banks have an advantage in doing so because they can overcome SME opaqueness through relationship lending. This paper shows that there is a gap between this view and what banks actually do. Banks perceive SMEs as a core and strategic business and seem well positioned to expand their links with SMEs. The recent intensification of bank involvement with SMEs in various emerging markets documented in this paper is neither led by small or niche banks nor highly dependent on relationship lending. Rather, all types of banks are catering to SMEs and larger, multiple-service banks have in fact a comparative advantage in offering a wide range of products and services on a large scale, through the use of new technologies, business models, and risk management systems.Banks&Banking Reform,Access to Finance,,Financial Intermediation,Debt Markets

Post harvest losses of rice in the Dominican Republic

A national survey of post-harvest losses of rice was conducted in the Dominican Republic during the period March· November 1979. Quantitative and qualitative losses during harvesting, milling and storage of rice were studied and an attempt was made to assess their economic value. Recorded losses due to inefficient harvesting and threshing practices totalled 18.1 per cent. At the rice mills significant breakage of grains occurred when sun dried rice was milled. lt was estimated that millers using this drying method were losing, on average, 9.75 per cent of the value of the product because of the lower grade obtained. The milling process itself appeared to cause no significant losses of quantity or quality. An average weight loss of 0.35 per cent, recorded during storage at government warehouses, was attributable mainly to spillage and handling. No insect losses were observed. The loss during storage is small, but the total annual loss is estimated to be 680 metric tons

On the toughness of thermoplastic polymer nanocomposites as assessed by the essential work of fracture (EWF) approach

The essential work of fracture (EWF) approach is widely used to determine the plane stress fracture toughness of highly ductile polymers and related systems. To shed light on how the toughness is affected by nanofillers EWF-suited model polymers, viz. amorphous copolyester and polypropylene block copolymer were modified by multiwall carbon nanotube (MWCNT), graphene (GR), boehmite alumina (BA), and organoclay (MMT) in 1 wt% each. EWF tests were performed on deeply double-edge notched tensile-loaded specimens under quasistatic loading conditions. Data reduction occurred by energy partitioning between yielding and necking/tearing. The EWF prerequisites were not met with the nanocomposites containing MWCNT and GR by contrast to those with MMT and BA. Accordingly, the toughness of nanocomposites with homogeneously dispersed and low aspect ratio fillers may be properly determined using the EWF. Results indicated that incorporation of nanofillers may result in an adverse effect between the specific essential and non-essential EWF parameters

The property RNT on dendroids

A continuum is said to be retractable onto near trees (abbreviating RNT) provided that for each > 0 there exists > 0 such that if T is a tree in X and H(T,X) < , then there exists an -retraction r of X onto T. In this paper it is proved that an arcwise connected continuum with the property RNT is a dendroid. We focus our study on dendroids. Dendrites are characterized as: (a) smooth dendroids with property RNT, (b) dendroids with the property RNT hereditarily. Finally, an example of a nonlocally connected dendroid with property RNT is shown