Scan Curves Research Articles

Pork carcass composition derived from a neural network model of electromagnetic scans.

We used an advanced computer logic system (NETS 3.0) to decipher electromagnetic (EM) scans in lieu of traditional linear regression for estimation of pork carcass composition. Fifty EM scans of pork carcasses were obtained on-line (prerigor) at a swine slaughter facility. Right sides were cut into wholesale parts and dissected into fat, lean, and bone to obtain total dissected carcass and primal cut lean. In this study, the input layer consisted of 81 nodes (80-point EM scan curve and warm carcass weight), one hidden layer of 42 nodes, and an output layer consisting of one node, which were run separately for outputs of ham, loin, or shoulder lean. The hidden layer connected to the output of total lean contained 50 nodes. Thirty-five scans were used for training of the network. The new network was then tested with 15 previously unseen input/output pairs. Separate neural networks were developed for the estimation of dissected total carcass, ham, loin, and shoulder lean. The NETS configuration improved on linear regression equations for estimation of total carcass lean by .31 kg, ham lean by .284 kg, and shoulder lean by .148 kg. Our results show that advanced computer logic systems have the capacity to improve upon traditional linear regression equations for prediction of pork carcass composition.

Optimization of Azimuthal Scan Procedure for Absolute Structure Determination

The paper describes the application of the azimuthal scan technique for absolute structure determination using X-ray anomalous dispersion. A diffraction pattern with rotation around the scattering vector provides information about various anisotropic effects: absorption, extinction and multi-beam interaction. Recording of azimuthal scans for Friedel pairs is proposed as an alternative to single reflection measurement. Several factors affecting the smoothness of the azimuthal scan curves are discussed and a procedure for eliminating various sources of errors, involving a Fourier filtering, is proposed in order to increase feasibility of chiral discrimination.

Crystallographic and microstructural studies of BaTiO3 thin films grown on SrTiO3 by laser molecular beam epitaxy

A series of trial tests were carried out to grow BaTiO3 thin films on SrTiO3 substrates in our newly built laser molecular beam epitaxial system. The phase, crystallographic orientation and crystalline quality of the films were investigated by x-ray diffraction θ/2θ scan, symmetric and asymmetric rocking curves (ω scans) and φ scan. The interfacial microstructures of the BaTiO3/SrTiO3 and the surface morphology of BaTiO3 films were analyzed by cross-section transmission electron microscopy and atomic force microscopy. Under appropriate growth conditions, epitaxial, single-crystal films with fully c-axis oriented tetragonal structure were obtained. The tetragonality was calculated by using {303} asymmetric rocking curve for a BaTiO3 thin film to be 1.027, which is larger than the bulk value of BaTiO3. The BaTiO3/SrTiO3 interface is very abrupt with no transitional layer and the BaTiO3 film exhibits an atomically smooth surface.

THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION. PART 46. THE CRYSTAL AND MOLECULAR STRUCTURE OF [Co(NH3)4Ox2(S4O6)·H2O (I)

Abstract Red specimens of [Co[(NH)4Ox]2(S4O6)·H2O (I), Co2S4O15N8C4H26, crystallize in the monoclinic space group P21/c. The cell is defined by the following constants: a = 7.7601(7), b = 10.079(1), c = 29.865(3) A, β = 90.914(8)°, V = 2335.59 A3, d (z = 4; M.W. = 672.42 gm – mole−1) = 1.912 gm-cm−3. A total of 3430 data was collected in the interval 4.0° ≤ 2Θ ≤ 50.0° of which 1915 were unique and had intensities greater than 3σ(I). The data were corrected for absorption using empirical Psi scan curves (five reflections, μ = 18.395 cm−1); the relative transmission coefficients ranged from 0.9697 to 0.9988. The final values of the discrepancy parameters were R(F) = 0.0388 and Rw(F) = 0.0484. The axial Col-N distances are 1.950(4) and 1.936(4) A, while those associated with Co2 are 1.949(5) and 1.952(4) A. Col-N distances in the equatorial plane are 1.942(3) and 1.918(4) A, respectively. For the second cation, the equatorial Co-N distances are 1.910(4) and 1.938(4) A. Thus, the feature of short and long Co-...

Determination of lattice displacements in 2 MeV Se + implanted GaAs by RBS and PIXE channeling experiments

By combining temperature dependent RBS measurements with RBS and PIXE angular scan analysis an attempt is made to study whether in weakly damaged ion implanted GaAs layers a difference in the damaging of the Ga and As sublattice occurs. It is found that the half width of the RBS angular scan curves at zero-depth reflects the dose dependence of the concentration and the displacement distance of displaced lattice atoms which were determined by means of temperature dependent RBS measurements. The analysis of the measured PIXE angular scan curves and the comparison with those calculated from RBS angular scans indicates that the As sublattice seems to be slightly more damaged than the Ga sublattice.

Atomic-structure determination of diamond using Auger-electron diffraction.

The surface structure of diamond is determined by comparing angle-resolved Auger-electron spectroscopy data to a theoretical model of electron diffraction in a cluster. The diffraction pattern of carbon KVV Auger-electron emission at 265 eV from a diamond(100) surface was obtained in an ultrahigh vacuum chamber. The polar scan curves of the experimental data at azimuthal angles 0\ifmmode^\circ\else\textdegree\fi{}, 15\ifmmode^\circ\else\textdegree\fi{}, 30\ifmmode^\circ\else\textdegree\fi{}, and 45\ifmmode^\circ\else\textdegree\fi{} are compared to theoretical predictions obtained using a single scattering cluster model. The calculated polar intensity distributions are a fairly sensitive function of surface structure. Optimal agreement with experiment occurs when there is a (2\ifmmode\times\else\texttimes\fi{}1) reconstruction at the diamond surface and there is a perpendicular expansion of 0.015(\ifmmode\pm\else\textpm\fi{}0.001) \AA{} between layers 1 and 2, 0.010(\ifmmode\pm\else\textpm\fi{}0.003) \AA{} between layers 2 and 3 and 0.005(\ifmmode\pm\else\textpm\fi{}0.005) \AA{} between layers 3 and 4. \textcopyright{} 1996 The American Physical Society.

Simple analytical method of cavity design for astigmatism-compensated Kerr-lens mode-locked ring lasers and its applications

An analytical method based on a renormalized q parameter for Gaussian-beam propagation and properly matched self-consistent complex q parameters is proposed to aid in the design of arbitrary-astigmatism-compensated Kerr-lens mode-locked ring cavity lasers. The q parameters throughout the ring cavity can be calculated by solution of an algebraically quadratic equation for an arbitrarily thick Kerr medium when the intracavity laser power is less than the self-trapping power. The Kerr-lens mode-locking strength at the curved mirror was calculated over the stable range. The results indicate that the astigmatism is best compensated so that the stable range of x and y directions have optimal overlapping. Although to maximize the hard-aperturing effect the curved mirror separation must be at the far edge of the stable range, pump and cavity field matching inside the Kerr medium is also necessary. In addition, the insertion of a vertical slit is more effective than insertion of a horizontal slit. A spiking phenomenon is found in the intracavity z scan curve, which can be observed only with thick Kerr materials and a high laser power.

Electromagnetic scanning of pork carcasses in an on-line industrial configuration.

The objective of this study was to test and validate electromagnetic scanning of whole pork carcasses in an on-line, integrated, industrial configuration. The electromagnetic (EM) scanner was installed in two pork processing facilities (Plant A and Plant B). Plant A was a small pork fabrication plant that further processed chilled pork carcasses. Carcasses were delivered to Plant A by refrigerated trucks. The amount of EM energy absorbed by the carcasses was recorded as they were conveyed through the EM field. A plot of the absorption units over time (EM scan curve) was used to obtain predictive variables for estimating carcass and primal cut composition. Forty-eight whole, chilled carcasses (Group A) were electromagnetically scanned and conveyed onto the fabrication line. The average percentage carcass lean for Group A was 49.1% (range = 36.5 to 59.5%). Right carcass sides were removed from the processing line, fabricated into primal cuts, and dissected into fat, lean, and bone. Prediction equations were developed from EM scans for weight of total dissected carcass lean (R2 = .830; root mean square error = 1.80 kg), percentage of carcass lean (R2 = .820; root mean square error = 2.29%), and weight of dissected ham, longissimus muscle, and shoulder lean. In Plant B, the electromagnetic scanner was installed at the end of a pork slaughter line to ensure carcass scanning at a consistent carcass temperature. Fifty whole, pre-rigor eviscerated carcasses (Group B) were electromagnetically scanned before entering the chill cooler where fat and loin tissue depths were obtained by an optical grading probe. The average percentage carcass lean for Group B was 46.7% (range = 30.1 to 57.3%). Prediction equations were developed from EM scans for weight of total dissected carcass lean (R2 = .904; root mean square error = 1.59 kg), percentage of carcass lean (R2 = .863; root mean square error = 2.05%), and weight of dissected ham, loin, and shoulder lean. Statistical equations developed for the prediction of dissected primal cut lean were superior from EM scans of Group B (prerigor) carcasses. Electromagnetic scanning proved more statistically efficient than optical probes for predicting weight of dissected carcass lean and percentage of carcass lean. Statistical comparison of EM scan equations from Groups A and B are not completely valid because two different populations of carcasses were tested at different times of the year. The results of this study show that EM scanning has the potential to accurately predict pork carcass composition in a fully automated, on-line industrial configuration.

Theoretical study of mechanisms of non-linear optical response in liquid crystals

Abstract Here, we carry out a theoretical analysis of the z scan experiments used to measure the non-linear optical properties of liquid crystals, with the aim of clarifying the mechanism responsible for the observed non-linearity in the nanosecond regime. We consider various orders of non-linear absorption and non-linear refraction in order to illustrate their effects on the resulting z scan curve. The shape of the z scan curve, in principle, contains information about the order of the non-linearity. Qualitative features of the experimental z scan curves are consistent with a fifth order absorption and a third order refraction. However, given the level of disagreement between the calculated and experimental curves, it is not possible to make quantitative statements about the coeffients of the various orders. The magnitude of the refractive part of the non-linearity is consistent with laser heating due to linear absorption. The temporal profile of a two pulse experiment is also consistent with this mechan...

THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION. XXVI. THE CRYSTAL AND MOLECULAR STRUCTURE OF RACEMIC NH4[Cr(EN)2OX]CL2·H2O (I) AND ATTEMPTS TO PREPARE NH4[Co(EN)2OX]CL2·H2O (II)

Abstract NH4[Cr(en)2ox]Cl2·H2O, CrCl2O5N5C6H22 (I) crytallizes as a racemate in the monoclinic space group P21/c (No. 14). The cell constants are a = 7.386(9), b = 12.138(4), c = 16.999(9)Å, β = 100.45(10)°, V = 1498.55Å3, d(Z = 4; M = 367.17) = 1.627 gm cm−3. A total of 2830 data were collected in the interval 4.0° ≤ 2Θ ≤ 50.0° of which 1785 were unique and had intensities greater than 3σ(I). The data were corrected for absorption using empirical Psi scan curves (five reflections, μ = 11.260 cm−1); the relative transmission coefficients ranged from 0.7849 to 0.9999. Refinement of the structural data leads to final values of R(F) and R w(F) of 0.050 and 0.063, respectively. All attempts to prepare the Co analogue of (I) have failed, thus far; instead, crystals of [Co(en)2ox]Cl·4H2O are obtained, despite changes in crystallization conditions, including the use of a large excess of ammonium chloride.

An investigation of the crystalline structure of the quasi-two-dimensional metamagnet of composition [C6H22N4]4+[CuCl4]Cl2 (I), with [C6H22N4]4+=[1,4,7,10-tetraazadecane]�4HC1

[C6H22N4]4+[CuCl4 2−]Cl2 (I) crystallizes in the monoclinic space groupP21/c with cell constantsa=15.573(2) A,b=7.281(2),c=7.092(2),β=91.496(14)°,V= 803.874 A3, andd(z= 2 mol/cell)=1.762 gm cm−3. Data were collected in the range 4° ≤ 2θ ≤ 50°, for a total of 2662 reflections, of which 2201 were independent and hadI ≽ 3σ(I). These were used in the solution and refinement of the structure. TheF(hkl) obs were corrected for absorption (μ=23.558 cm−1) using Psi scan curves of eight suitable reflections, leading to relative transmission coefficient adjustments ranging from 0.9999 to 0.5722. Structural refinement converged atR(F)= 0.023 and R W (F)=0.026. The coordination around the metal consists of polymeric, axially elongated, six-bonded, trigonal antiprismatic CuCl6 species, not the hoped for, discrete, molecular CuCl6 4− species implied by their chemical formulation. The crystalline lattice contains three different types of ions: the (C6H22N4)4+ cation, a pair of Cl− anions which are hydrogen bonded to the secondary ammonium (-NH2 +-) hydrogens of the cation, and a CuCl4 2− anion. The latter is polymerized into two-dimensional sheets linked to each other by the agency of the cations, in which the two sets of terminal (-NH3 +) hydrogen bond to the axial Cl− ligands. The Cu-Cl distances are 2.279, 2.315, and 2.847 A. The distance between nearest coppers in adjacent sheets is 15.573(2)A, the length of thea-axis. The magnetic behavior of the compound is that of a metamagnet, which requires a somewhat unusual set of conditions and is very rare in Cu2+ compounds. Comparison of the magnetic behavior of (I) with that of related compounds is made. The thermal behavior of (I) was studied using differential scanning calorimetric measurements in the range of 120 K to its melting(dec) point (463 K). It undergoes a phase transition from green (low temperature phase) to golden yellow (room temperature phase) at 168 K, another phase transition (golden yellow to red) at 340.6 K, and another at 383.2 K during which there is not evident color change. Finally, it melts with decomposition at ca. 463 K.

THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION. XXV. SPONTANEOUS RESOLUTION IN COORDINATION COMPOUNDS. THE CRYSTAL STRUCTURE OF [cis-Co(en)2(NH3)Br]Br2

Abstract Br3CoN5C4H19, (I), crystallizes in the monoclinic system, space group C2/c, with cell constants a = 24.579(9),b = 8.665(3),c = 14.409(5) A, and β = 92.69(3)˚; V = 2988.87 A3 and d (MW = 435.875, Z = 8) = 2.097 gm cm−3. Data were collected in the range 4˚ ≤ 2θ ≤ 50˚, for a total of 2823 reflections, of which 1409 were independent and had I ≥ 3σ(I). The structure factors were corrected for absorption (μ = 90.882 cm−1) using psi scan curves obtained from reflections near X = 90˚. The transmission coefficients ranged from 0.68 to 0.99. The structure was solved by direct methods and refinement converged to final discrepancy indices of R(F) = 0.0601 and Rw(F) = 0.0663. The cobalt configuration and chelate ring conformations for (I) were found to be the preferred (lel)2-Δ(δδ) and Δ(λλ). The Co-N distances to the en rings are 1.961(6), 1.960(6), 1.977(6), 1951(6) A, while that to the -NH3 ligand is 1.963(6) A. The C-C distances are 1.52(1) and 1.50(1) A; finally, the Co-Br distance is 2.403(1) A.

A method for the determination of atomic displacements in compound crystals by means of RBS-PIXE-channeling experiments

A method which combines proton-induced X-ray emission (PIXE), Rutherford backscattering (RBS) and ion channeling, which enables the determination of static or dynamic root-mean-square displacements of constituent atoms in compound crystals is described. Full PIXE and RBS channeling angular scan curves are measured simultaneously by scanning through a major axis of the crystal under study. The experimental data are interpreted by using two different methods: A) a simple semi-analytical model which takes advantage of the depth information contained in RBS spectra to estimate depth correction factors needed to analyze the PIXE angular scan data, and B) a Monte Carlo simulation program of channeling, which takes into account the special structural features of the materials studied and allows for a direct comparison of simulated results with experimental PIXE data. The use of the technique is demonstrated by deducing rms displacements of constituent atoms of some II–VI (binary and ternary) semiconductors analyzed by both methods. The present results agree well with vibrational amplitude data obtained from X-ray diffraction measurements available from the literature.

The Phenomenon of Conglomerate Crystallization. XXII. Synthesis and Structural Characteristics of H-Carbonato(O,O')-trans-[CO(2,3,2-tet)(NO2)]2Cl2.3H2O

Abstract The unique, dinuclear, symmetrically μ-CO3 bridged compound, μ-carbonato(O,O')-trans-[Co(2,3,2-tet)-(NO2)]2C12.3H2O (I), was prepared by hydrogen peroxide oxidation of Co+2 in the presence of the 2,3,2-tet polyamine ligand, followed by addition of NaNO2. (I) crystallizes in the racemic space group P21/n with cell constants a = 9.187(1) A, b = 23.520(2), c = 14.201(1), β = 103.87(9), V= 2978.90 A3 and d(Z = 4 mol/cell) = 1.599 g cm−3. Data were collected in the range 4° ≤ 20 ≤ 50°, for a total of 5361 reflections, of which 3285 were independent and had I ≥ 3σ(I). These were used in the solution and refinement of the structure. The F(hkl)abs were corrected for absorption (μ = 13.540 cm−1) using Psi scan curves of eight suitable reflections, leading to transmission coefficient adjustments ranging from 0.9049 to 0.9967. The structure was solved by Patterson methods. Convergence of the refinement using anisotropic thermal parameters for the heavy atoms and idealized hydrogens (fixed B = 5.00 A2) gave ...

Étude de la susceptibilité à la corrosion d’aciers inoxydables AISI 304 ET AISI 316 soumis à des contraintes mécaniques dans l’acide nitrique dilué bouillant en présence de chlorures

A detailed study of corrosion of stressed 304 and 316 stainless steels in boiling solutions of diluted nitric acid in presence of chloride is presented. After a chemical study of the electrolyte, the different kinds of corrosion observed are represented on HNO 3 concentration - Cl − concentration diagrams. A more fundamental study based on several electrochemical techniques (forward scan and return potentiodynamic curves, potentiokinetic curves with different scan rates, sample depassivation by rapid straining under potentiostatic control) is carried out. The results allow to confirm the observations and to explain them in terms of competition between anodic dissolution, depassivation, repassivation processes with a precise analyze of the role of the solution and of the mechanical stress

The effect of Co2+, Cu2+, Fe2+ and Fe3+ during electrowinning of nickel

The effects of the impurities Co2+, Cu2+, Fe2+, Fe3+ on the current efficiency, physical appearance, purity, crystallographic orientation and surface morphology of the deposit and on nickel deposition polarization behaviour during nickel electrowinning were determined. The current efficiency did not change significantly in the presence of these impurities over the concentration range studied, but certain changes in the purity and physical appearance of the deposit were observed. Based on the physical appearance of the electrodeposited nickel, the tolerance limits of the impurities in the electrolyte are reported. The tolerance limit of Co2+ was a maximum at 500 p.p.m. and a minimum at 5 p.p.m. in the case of Fe2+. No deviation of nickel structure from fcc was observed in the presence of any of these impurities but the peak height values for different orientations showed variations with all the impurities and the values also changed with increase in the impurity concentrations. The surface morphology of electrodeposited nickel also changed in the presence of the impurities. The potentiodynamic scan curves for electrodeposition of nickel showed deviations in the presence of all the impurities except Cu2+. Based on the results, an attempt is made to correlate the effects of the various factors investigated.

Theoretical comparison of linear scan and staircase anodic stripping voltammetry: Restricted and infinitive diffusion

The rigorous conditions of the equivalence of entire linear scan and staircase anodic stripping voltammetric curves in the case of restricted and infinite diffusion are described. The fraction of the step time at which the staircase current must be sampled to be equal to that obtained by the linear scan method at the same potential changes slightly when advancing along the curve, but is practically independent of the extent of diffusion finiteness. The Hermite version of the finite element method was used in the calculations.

The effects of Mg2+, Mn2+, Zn2+, and Al3+ on the nickel deposit during electrowinning from sulfate bath

The presence of impurities like Mg2+, Mn2+, Zn2+, and Al3+ during electrowinning of nickel shows several effects. The effects include current efficiency, deposit quality, purity, crystallographic orientation, surface morphology, and polarization behavior. Addition of the impurities did not change the current efficiency significantly but did change the quality and purity of the electrodeposited nickel. Based on the quality of the deposits obtained, the tolerance limits of these impurities in nickel bath were obtained. Although no deviation of nickel structure from fee was observed, the peak height values for different orientations changed with all of the impurities and the values varied with impurity concentration. The surface morphologies of electrodeposited nickel in the presence of impurities also showed changes. The potentiodynamic scan curves for nickel deposition showed deviations in the presence of all the impurities studied. Based on the results, an attempt was made to correlate the various effects.

Face area evaluation algorithm for solids

A scan curve algorithm is presented for evaluating the face area of solids in constructive solid geometry (CSG) representation. The applicable domain is limited to solids bounded by three classes of surfaces: all quadric surfaces, cylindrical surfaces, and surfaces of revolution where the last two have rational parametric equations for their generating curves. The algorithm has been implemented in Fortran 77 on a VAX 11/780 machine. The extensions of this algorithm may also be applied to the solution of the following three problems: boundary representation (B-rep) evaluation from CSG, face area evaluation for solids in B-rep, and triangulation of the faces of solids in CSG or B-rep.

Measurement of blood-retinal barrier function in central retinal vein occlusion.

Vitreous fluorophotometry was used to measure blood-retinal barrier permeability to fluorescein in eight patients (mean age, 42.9 years; range, 30 to 55 years) with central retinal vein occlusion (CRVO). Permeability coefficient was derived by fitting a mathematical model to the posterior vitreous fluorescence scan and plasma-free fluorescein concentration curve at 60 minutes after intravenous fluorescein sodium (14 mg X kg-1). A permeability index (PI) was estimated by dividing the area under the vitreous fluorescence scan by the area under the plasma-free fluorescein curve. The permeability coefficient and PI were comparable and highly correlated. Initial mean permeability coefficient was 28.78 X 10(-7) cm X s-1 (range, 14.42 X 10(-7) to 41.10 X 10(-7) and 1.89 X 10(-7) cm X s-2 (range, 0.96 X 10(-7) to 2.76 X 10(-7) in eight affected and seven unaffected eyes, respectively. The permeability coefficient and PI in unaffected eyes did not differ significantly from 18 eyes of ten normal subjects. After three to 12 months, permeability coefficient and PI in affected eyes approached the values in the contralateral eyes of four patients with mild and one patient with moderate CRVO but remained elevated in the remaining patients. The permeability coefficient and PI correlated well with changes in severity of retinal appearances on color photographs and fluorescein angiograms. Vitreous fluorophotometry quantitated changes in blood-retinal barrier permeability in CRVO.