Value Of Eff Research Articles

Measurements of radon, thoron and their progeny concentrations using twin cup dosimeter for indoor Al-Madaan city – Baghdad – Iraq

In this study, the activity concentrations of indoor radon, thoronand their progeny have been measured in air for 61 differentlocations of Al-Maddan city using twin cup dosimeter. Furthermore,some useful parameters concerning the health hazards have beenestimated; working level month (WLM), annual effective dose (Eff),and excess lung cancer per million person per year (ELC).The resultsshow that the values of radon gas levels in the investigated districtsvaried from 56.28 to 194.43Bq/m3with an overall average value132.96Bq/m3, while 0.313 to 1.085 for WLM with an overall average0.740, respectively. The value of Eff and ELC have been found tovary from 1.420 to 4.918 mSv/y with an overall average value3.354mSv/y, and 852 to 2951 with an overall average value 2013,respectively. For thoron gas only, the results showed that the thoronactivity concentration varied from 15.05 to 172.40 Bq/m3 with anoverall average 76.48 Bq/m3, and 0.021to 0.240for WLM with anoverall average 0.106, respectively. The values of Eff and ELC havebeen found to vary from 0.256 to 2.94 mSv/y with an overallaverage1.30 mSv/y and from 57 to 652 with an overall average of298, respectively. The concentration of radon progeny varied from59.44 to 301.39 Bq/m3 with an overall average 157.62 Bq/m3. Theresults illustrated that there is a large variation in the values of themeasured concentrations. This is due to the wide variation in theconstruction of the houses in Al-Madaan city. However, allinvestigated locations have radon concentration below the actionlevel (200-300Bq/m3) that recommended byICRP. Therefore, there isno health hazard of radon in the region of Al-Madaan city wheremeasurements have been performed.

Energy input and dissipation in a temperate lake during the spring transition

ADCP and temperature chain measurements have been used to estimate the rate of energy input by wind stress to the water surface in the south basin of Windermere. The energy input from the atmosphere was found to increase markedly as the lake stratified in spring. The efficiency of energy transfer (Eff), defined as the ratio of the rate of working in near-surface waters (RW) to that above the lake surface (P10), increased from ∼0.0013 in vertically homogenous conditions to ∼0.0064 in the first 40 days of the stratified regime. A maximum value of Eff∼0.01 was observed when, with increasing stratification, the first mode internal seiche period decreased to match the diurnal wind period of 24 h. The increase in energy input, following the onset of stratification was reflected in enhancement of the mean depth-varying kinetic energy without a corresponding increase in wind forcing. Parallel estimates of energy dissipation in the bottom boundary layer, based on determination of the structure function show that it accounts for ∼15% of RW in stratified conditions. The evolution of stratification in the lake conforms to a heating stirring model which indicates that mixing accounts for ∼21% of RW. Taken together, these estimates of key energetic parameters point the way to the development of full energy budgets for lakes and shallow seas.

DEVELOPMENT OF A SUGAR BEET TOPPER

The aim of this research is to develop and evaluate a topper unit for sugarbeet suitable for Egyptian conditions. Field experiments were carried out at El-Serw Agric. Res. Station, Damietta Governorate during 2013/2014 season. The performance of the developed topper unit was evaluated at different speed ratios of 0.007, 0.0076, 0.0080 and 0.0085 under knives positions; faced (F) and edged (E) and flails number solo (S) and doubled (D). Different flail lengths of 15, 20, 25 and 30 cm were tested. Over topping, under topping beets, un-topped beets, damaged beets, topping efficiency, actual field capacity, field efficiency, energy requirement and total costs were estimated. Due to increasing speed ratio increased actual field capacity and field eff. Both doubled and faced flails showed the best results under all treatments. Generally, the results recommended that topper unit should be used at speed ratio of 0.0085 with doubled-faced-flail (DFF) that recorded highest value of topping eff. (97.30%). On the other hand, the lowest value for over topping beet (2.4%), undertopping beets (2.8%), un-topped beets (2.2%) and damaged beets (2.77% ) were recorded. Hence, the best value of actual field capacity (0.92 fed/h) and field eff.(83.4%) were recorded at speed ratio of (0.0085). Energy requirement decreased by 13.22 % while total costs decreased by 78.27% comparing to manual topping costs. Flail length of 25 cm showed the desirable results with all treatments. Doubling and facing flails position had a high significant effect on all treatments.

Minimization of thermal expansion of symmetric, balanced, angle ply laminates by optimization of fiber path configurations

Optimal fiber path configurations that minimize the sum of the coefficients of thermal expansion (CTE) values along the principal material directions for a class of laminates are presented. Previous studies suggest that balanced, symmetric, angle ply laminates exhibit negative CTE values along the principal directions. Using the sum of the CTE values along the principal material directions as an effective measure of the coefficient of thermal expansion (CTE eff ), we have shown and provided a proof that the smallest value of CTE eff is rendered by straight fiber path configurations. The laminates considered are sufficiently thin so as to neglect the thermal stresses induced through the thickness of the laminate. It is found that the minimal CTE eff values occur for [+45/−45] ns lay-ups. This result is supported by numerical studies that consider curvilinear fiber paths. The possibility of obtaining zero CTE values along both principal material directions and the conditions that render this situation are also examined.

On the correctness of the thermoluminescent high-temperature ratio (HTR) method for estimating ionization density effects in mixed radiation fields

The high-temperature ratio (HTR) method which exploits changes in the LiF:Mg,Ti glow-curve due to high-LET radiation, has been used for several years to estimate LET in an unknown radiation field. As TL efficiency is known to decrease after doses of densely ionizing radiation, a LET estimate is used to correct the TLD-measured values of dose. The HTR method is purely empirical and its general correctness is questionable. The validity of the HTR method was investigated by theoretical simulation of various mixed radiation fields. The LET eff values estimated with the HTR method for mixed radiation fields were found in general to be incorrect, in some cases underestimating the true values of dose-averaged LET by an order of magnitude. The method produced correct estimates of average LET only in cases of almost mono-energetic fields (i.e. in non-mixed radiation conditions). The value of LET eff found by the HTR method may therefore be treated as a qualitative indicator of increased LET, but not as a quantitative estimator of average LET. However, HTR-based correction of the TLD-measured dose value (HTR-B method) was found to be quite reliable. In all cases studied, application of this technique improved the result. Most of the measured doses fell within 10% of the true values. A further empirical improvement to the method is proposed. One may therefore recommend the HTR-B method to correct for decreased TL efficiency in mixed high-LET fields.

Spectrophotometric investigation of the monomer–dimer process of C.I. Basic Blue 9 in aqueous polymer–surfactant system

The monomer–dimer process of C.I. Basic Blue in an aq. solution of the anionic surfactant, sodium dodecyl sulfate and the nonionic polymer, polyvinyl alcohol, was investigated spectrophotometrically. The effective dimerization constant of the dye ( eff K D) was determined in the presence of the surfactant and polymer, both individually and in combination, from a low ionic strength buffered aq solution; the value of eff K D increased in the order: PVA < SDS < PVA–SDS < H 2O. Aggregation of the dye in the polymer–surfactant system was exothermic and displayed large negative Δ H o and negative Δ S o values. Below the CAC, the presence of surfactant facilitated dye dimerization whereas > CAC the dye dissolved monomerically in the surfactant/polymer complex; the monomer–dimer process of the dye was influenced by hydrophobic interactions.

Some variants of Newton's method with fifth-order and four-order convergence for solving nonlinear equations

Chun's two-step predictor-corrector type iterative method for solving nonlinear equations (Iterative Methods Improving Newton's Method by the Decomposition Method, J . Comput. Math. Appl.50, 1559-1568 ) is improved and a kind of new iterative method is presented. Some present methods derived from Adomian Decomposition method are unified in a form and a series of new methods with high convergence order and the value of EFF are obtained by introducing parameter also. Those methods can be considered as a significant improvement of the Newton's method and its variant forms.

DEVELOP AND EVALUATE SUGAR BEET TOPPER UNIT TO SUIT IN SMALL HOLDING

The aim of this investigation is develop and evaluate a topper unit to suit small holding farms. Field experiment were carried out in Rice mechanization centers, Meet El–Deba, Kafr El–Shikh Governorate 2004 seasons. To evaluate the performance of the developed topper unit at different leveling methods (LASER and traditional), different forward speed (0.5, 0.75 and 1m/s) and different cutting disc speed (7.72, 12.54 and 16.72m/s), the Topping efficiency, technical topping efficiency, correct topped, over topped, under topped beets, topping losses, actual field capacity and field efficiency, were studied. The result indicated that increase speeds (topper forward speed & cutting disc speed) due to decrease both topping eff., technical topping eff., and correct topped beet. Hence, it is due to increase both under topped beet, over topped beet, topping losses, actual field capacity and field eff. at both leveling methods. Generally, the results recommended that topper unit can be used at LASER leveling land and speeds (0.5&7.72m/s)(1& 16.72 m/s) treatments. It was recorded highest values for topping eff. (97.39%), technical topping eff. (90.2%) correct topped beet (92.62%) at speeds (0.5&7.72m/s).On the other hand, it was recorded lowest value for undr topped beet (2.68%), over topped beet (4.7%) and topping losses (77.91kg/fed).Hence, the best value of actual field capacity (0.444 fed/h) and field eff.(86.4%) were recorded at speeds (1& 16.72 m/s). Leveling methods had high significant effect on topped and correct topped beet No. Meanwhile, topper forward speed had high significant effect on under topped beet.

Metamaterial transmission lines based on broad-side coupled spiral resonators

Microstrip lines periodically loaded with broad-side coupled spiral resonators (BC-SRs) are designed, fabricated and characterised for the first time. These structures inhibit signal propagation in the vicinity of the resonance frequency of the spirals, f o . This stopband behaviour is due to magnetic coupling between the line and the BC-SRs at resonance. As long as the electrical size of the BC-SRs is small, the structures can also be considered as metamaterial transmission lines with negative effective permeability, mu eff . This negative value of mu eff takes place in a narrow band above f o , as occurs in split ring resonator (SRR) loaded lines, or in transmission lines coupled to spiral resonators etched in a single metal level (edge-coupled spiral resonators (EC-SRs). However, because each loop of the BC-SR is etched in a different metal level (face-to-face loops), the equivalent capacitance of the resonant tank can be substantially enhanced. Thus, by using narrow microwave substrates, the BC-SRs loaded lines can be made much smaller than SRR or EC-SR loaded lines

Architecture‐driven thermodynamic interactions in blends of star‐branched and linear poly(methyl methacrylate)

In blends of two polymer chains of identical architecture, the bulk thermodynamic interaction can vary with differences in blend concentration, microstructure, tacticity, and isotopic labeling. The strength of this interaction is typically expressed in terms of an effective segment–segment-interaction parameter, eff, the value of which varies with all these molecular particulars. The fluctuation theory of Fredrickson et al. suggests that if one component in a polymer blend is linear and the other has a long-chain branched architecture, the bulk interaction will increase over that in the case of an analogous blend with two linear components. This increase in the bulk interaction should manifest itself in an architectural contribution to the value of the eff parameter derived from small-angle neutron scattering (SANS) data, although the architectural effect is intrinsically a nonlocal effect. Recently, the magnitude of the architectural contribution to the bulk thermodynamic interaction has been probed experimentally in star/linear polystyrene (PS) blends and star/linear polybutadiene (PB) blends. Greenberg and coworkers found that values of eff for blends of star and linear PS measured with SANS increased monotonically with an increasing number of arms of the star, although the overall molecular weight of the stars was not kept rigorously constant and two different types of arm linking were used. Estimates of the thermodynamic interaction resulting from architectural effects alone, , were made by measuring separately the magnitude of the interaction because of isotopic labeling and subtracting this from the value of the overall interaction, eff. increased with the number of arms of the star as expected from Fredrickson’s theory, but there was near-quantitative agreement only for the case of a four-arm star. The rate of change in the value of with the number of star arms, p, was much larger for a change in p from 4 to 8 than when p increased from 14 to 21. Martter et al. measured the value of eff for blends of star and linear PB with SANS and found that eff and varied nonmonotonically with an increase in the number of arms from 4 to 12. This result differed from the expectation from theory that a monotonic increase in with the number of arms of the star should be universally observed regardless of the chemical structure of the repeat unit. In this work, a brief study of star/linear blend for a third type of repeat unit was undertaken to further test the universality of the predictions of Fredrickson et al. Poly(methyl methacrylate) (PMMA) was chosen because methods exist for the preparation of well-defined star polymers by atom transfer radical polymerization (ATRP). However, two other differences between the stars studied here and those examined previously must be noted. First, the star core chemistries differ from those used for the PS or PB stars as necessitated by the PMMA star synthesis. Although linear PMMA can be polymerized anionThe Supplementary Material referred to in this article can be found at http://www.interscience.wiley.com/jpages/08876266/suppmat/0202017B.html Correspondence to: M. D. Foster (E-mail: foster@ polymer.uakron.edu)

Nonlinear phase shift without cascaded second-order processes and third-order nonlinearity

A new mechanism for obtaining a nonlinear phase shift has been proposed and schemes are described for its implementation. As it is shown, the interference of two waves with intensity-dependent amplitude ratio coming from the second-harmonic generation should produce the nonlinear phase shift. The sign and amount of nonlinear distortion of a beam wavefront is dependent on the relative phase of the waves that is introduced by the phase element. The calculated value of n2 eff exceeds that connected with cascaded quadratic nonlinearity, at the same conditions.

Stationary properties of SINIS double-barrier Josephson junctions

This paper reports on the evaluation of the effective suppression parameter eff in double-barrier Josephson junctions realized in Nb-Al/AlxOy/Al/AlxOy/Al-Nb SINIS technology. This parameter describes the overall resistance of current flow across the interfaces within the whole structure configuration and characterizes its ICRN product attainable. By comparison with theoretical descriptions of tunnelling structures in the dirty-limit approximation, the effective suppression parameter eff has been extracted from the measured temperature dependence of the ICRN product. For SINIS junctions of a series of different wafer productions with various critical currents of the fabricated junctions, the evaluated values of eff range between 80 and 250. With reference to the proximity effect and to the possibility of removing the Al layers at the Nb electrodes, a value of eff has been deduced, which ranges between 50 and 120. This is very close to the assigned value between 10 and 20 ideally suitable for integrated circuit applications, e.g. Josephson voltage standards and rapid single flux quantum circuits.

Highly efficient high-speed/low-power architectures for the 1-D discrete wavelet transform

In this paper, we propose two scalable architectures (say, Arc/sub J/ and Arc/sub 2/*) that perform the discrete wavelet transform (DWT) of an N/sub 0/-sample sequence in only N/sub 0//2 clock cycles. Therefore, they are at least twice as fast as the other known architectures. Also, they have an AT/sup 2/ parameter that is approximately 1/2 that of already existing devices. This result has been achieved by means of a carefully balanced pipelining, and it has two faces. First, Arc/sub J/ and Arc/sub 2/* can be employed for performing two times faster processing than allowed by other architectures working at the same clock frequency (highspeed utilization). Second, they can be employed even using a two times lower clock frequency but reaching the same performance as other architectures. This second possibility allows for reducing the supply voltage and the power dissipation, respectively, by a factor of two and four with respect to other architectures (low-power utilization). As a final result, we show that a parallel architecture implementing an L-tap filter-based DWT with J decomposition levels [say, ArC/sub OPT/(J, L)] can be defined, aiming at having an excellent efficiency (say, eff[Arc/sub OPT/(J, L)]) for any value of J and L. For instance, the average value of eff[Arc/sub OPT/(J, L)] [computed in very wide set /spl Sigma/' of points (J, L)] is 99.1%. The minimum value of eff[Arc/sub OPT/(J, L)] in /spl Sigma/' is 93.84, and, except for five points. in all the others, eff[Arc/sub OPT/(J, L)] is not lower than 96.99.

GAUGE COUPLINGS CALCULATED FROM MULTIPLE POINT CRITICALITY YIELD α-1 = 137 ± 9: AT LAST, THE ELUSIVE CASE OF U(1)

We calculate the U(1) continuum gauge coupling using the values of action parameters coinciding with the multiple point. This is a point in the phase diagram of a lattice gauge theory where a maximum number of phases convene. We obtain for the running inverse fine structure constant the values [Formula: see text] and [Formula: see text] at the Planck scale and the MZ scale, respectively. The gauge group underlying the phase diagram in which we seek multiple point parameters is what we call the Anti-grand-unified theory (AGUT) gauge group SMG 3, which is the Cartesian product of three Standard Model Groups (SMG's). There is one SMG factor for each of the N gen =3 generations of quarks and leptons. In our model, this gauge group SMG 3 is the predecessor of the usual SMG. The latter arises as the diagonal subgroup surviving the Planck scale breakdown of SMG 3. This breakdown leads to a weakening of the U(1) coupling by a N gen -related factor. For N gen =3, this factor would be N gen (N gen +1)/2=6 if phase transitions between all the phases convening at the multiple point were purely second order. The factor N gen (N gen +1)/2=6 corresponds to the six gauge-invariant combinations of the N gen =3 different U(1)'s that give action contributions that are second order in Fμν. The factor analogous to this N gen (N gen +1)/2=6 in the case of the earlier considered non-Abelian couplings reduced to the factor N gen =3 because action terms quadratic in Fμν that arise as contributions from two different of the N gen =3 SMG factors of SMG 3 are forbidden by the requirement of gauge symmetry. Actually we seek the multiple point in the phase diagram of the gauge group U(1) 3 as a simplifying approximation to the desired gauge group SMG 3. The most important correction obtained from using multiple point parameter values (in a multiparameter phase diagram instead of the single critical parameter value obtained, say, in the one-dimensional phase diagram of a Wilson action) comes from the effect of including the influence of also having at this point phases confined solely w.r.t. discrete subgroups. In particular, what matters is that the degree of first-orderness is taken into account in making the transition from these latter phases at the multiple point to the totally Coulomb-like phase. This gives rise to a discontinuity Δγ eff in an effective parameter γ eff . Using our calculated value of the quantity Δγ eff , we calculate the above-mentioned weakening factor to be more like 6.5 instead of the N gen (N gen +1)/2=6, as would be the case if all multiple point transitions were purely second order. Using this same Δγ eff , we also calculate the continuum U(1) coupling corresponding to the multiple point of a single U(1). The product of this latter and the weakening factor of about 6.5 yields our Planck scale prediction for the continuum U(1) gauge coupling, i.e. the multiple point critical coupling of the diagonal subgroup of U(1) 3∈ SMG 3. Combining this with the results of earlier work on the non-Abelian gauge couplings leads to our prediction of α-1-137 ± 9 as the value for the fine structure constant at low energies.

Ferromagnetic resonance in evaporated Co-CoO films

The magnetic properties of ∼2500-Å-thick Co films evaporated in various oxygen pressures have been studied. Our results show that as the saturation magnetization is reduced, the coercive force in the perpendicular direction (Hc⊥) increases to a maximum (1.6 kOe); this change is consistent with results of previous investigations. The sign of the effective perpendicular anisotropy field (Hk eff=2K/Ms−4πMs), as determined by ferromagnetic resonance (FMR), is always negative (&amp;lt;−4 kOe), indicating that the anisotropy field (2K/Ms) does not overcome the demagnetizing field (4πMs). Our FMR results also confirm that films having an Hc⊥ value larger than that in-plane coercive force (Hc∥ ) do not always demonstrate a value of Hk eff≳0.

Spin-wave resonance in Fe-amorphous FeCrB multilayered structures

Fe/amorphous FeCrB multilayers were studied by ferromagnetic resonance measurements as a function of the interlayer thickness. The experimental determined value of (4Π M) eff was compared with that computed from a model corresponding to a layered structure, built up of perfectly homogeneous and strongly coupled interlayers. The agreement is satisfactory except for too thin FeCrB or very thick Fe layer thickness, a result explained by the crystalline structure of the Fe interlayers. Generally in perpendicular resonance a well defined standing spin wave spectrum is detected from which the value of A eff was extracted. Some anomalies of the spectra are also presented.

Study by ferromagnetic resonance of Fe/CoNbZr multilayer structures

The magnetic properties of Fe/CoZrNb multilayers were studied by ferromagnetic resonance as a function of CoZrNb interlayer thickness t c. For t c⩾40 Å the CoZrNb remains amorphous, a fairly good agreement exists between the as computed and experimental value of (4π M s) eff and the resonance linewidth δ H is independent of t c. For t c⩽30 Å the experimental (4π M s) eff deviates from the computed value, and δ H increases progressively when t c becomes smaller. These results correlate with structural properties which shown that thin CoZrNb interlayers are crystalline and Fe exhibits a columnar growth in the film thickness direction.

The dipole moment of 7LiH and 7LiD in the excited A 1Σ + state: A test of the born-oppenheimer approximation

Continuing our Stark quantum beat experiments on 7LiH at electric field strengths of 100 kV/cm and above, we were le to observe quantum beat signals for the vibrational level v′ = 5 of the A 1 v + state. The evaluation of these signals yields a field reduced splitting Δ W/ E 2 = 1.157(70) kHz/(kV/cm) 2 which would correspond to an “effective” value of 1μ eff( v′ = 5)1 = 0.051 (5) D for the dipole moment, if the ordinarily used formula were applicable. A serious check of all available data, however, shows that neighbouring vibrational levels of the A 1 v + state and also the sum over the levels of the electronic ground state X 1Σ +, though counteracting, have the main effect on the residual splitting thus preventing a straightforward evaluation for the dipole moment. Taking account of these polarizability effects and including the possibility for a slight shift of the theoretical dipole moment function a value of 1μ( v′ = 5)1 = 0.089(14) D is the most probable one. In the case of 7LiD according to the usual formula an “effective” value of 1μ eff( v′ = 6)1 = 0.425(20) D was deduced from a beat signal obtained at an electric field strength of 24 kV/cm. Here the influence of neighbouring vibrational levels and electronic states is only of minor importance leading to a corrected value of 1μ( v′ = 6)1 = 0.43(2) D for the dipole moment. This value differs by 13% from the theoretical one calculated on the basis of the dipole moment function of 7LiH and the adiabatically corrected potential energy curve of 7LiD, thus indicating non-adiabatic effects.

Crack closure and crack propagation rates in 7050 aluminum

The effects of crack closure on fatigue crack growth rate in 7050 Al were studied with the aid of small-foil strain gages glued at positions near to the crack plane. The crack closure stress was determined from the change in the slope of the local strain-nominal stress curves. The crack closure stress was found to increase slightly with crack length under a cyclic loading total amplitude of Δσ = 88 MPa and R ratio R = 0.95. The crack closure stress σ c was found to increase moderately with increasing R-ratio ( R = σ min σ max ) for th1e same cyclic stress level of 88 MPa. Above a critical R-ratio value of 0.25 the crack closure stress is smaller than the minimum applied stress. The modified crack growth law, which states that crack growth rate ( da dN ) is proportional to the nth power of the effective stress intensity factor ( ΔK eff = K max- K in), cannot account for the dependence in growth rate on the R-ratio. For cyclic loadings with R-ratios less than 0.25 the da dN vs ΔK eff curves did not emerge as expected from the modified law. For cyclic loadings with R-ratios larger than 0.25 the crack growth rate still increased with R-ratio even though the value of ΔK eff remained the same. The retardation of crack growth rate that occurred after tensile overloads was accompanied by an increase in crack closure stress. A log-log plot of da dN vs ΔK eff showed that the modified crack growth law was reasonably obeyed. But it was found that after a single overload the minimum value of ΔK eff generally was reached only after the minimum value da dN had occurred. Cyclic compressive stresses which decreased the retardation effect of tensile overloads were found to depress the crack closure stress to a low value. A large compressive spike also depressed the crack closure stress and increased the crack growth rate after a tensile overload.

The electron-phonon mean free path in potassium: a comparative study of radio frequency size effect measurement techniques

Previous radio frequency size effect measurements in potassium have suggested that (1/lep)eff, the effective inverse electron-phonon mean free path, depends upon the mode of RF excitation employed in the experiment. The authors report new measurements, made using both bilateral and unilateral excitation, which show that (1/lep)eff is not affected by the mode of excitation. This result is supported by simple physical arguments and confirmed by a numerical calculation. It was impossible, however, to resolve the discrepancy between the value of (1/lep)eff measured in this work and that measured by Tsoi and Gantmakher (1969) and Blaney and Parsons (1970) in earlier work.