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  • Springer  (40)
  • Oxford University Press  (8)
  • Springer Nature  (7)
  • 1995-1999  (55)
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  • 1
    Electronic Resource
    Electronic Resource
    Improved yields of oxalate, glyoxylate and glycolate from the electrochemical reduction of carbon dioxide in methanol (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 706-712 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The yields of oxalate and especially of glyoxylate and glycolate were enhanced by the use of methanol containing hydroxylamine and tetramethylammonium chloride in the controlled potential electrochemical reduction of carbon dioxide at a lead electrode. An eightfold increase in the solubility of CO2 was found compared with water so that the initial concentration was 4.48 × 10−3m. Products were mainly glyoxylate (up to 9.7 × 10−3m at −2.0 V) and glycolate (up to 6.6 × 10−3m at −2.3 V) with some oxalate (up to 1.3 × 10−4m at −1.7 V) depending on the time and electrode potential. Very little formate was produced. Current densities were about 30 A m−2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018444022321
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  • 2
    Electronic Resource
    Electronic Resource
    Dialdehyde starch and zein plastic: Mechanical properties and biodegradability (1995)
    Springer
    Journal of polymers and the environment 3 (1995), S. 69-74 
    Details
    ISSN: 1572-8900
    Keywords: Biodegradable plastic ; corn starch ; dialdehyde starch ; zein ; soil degradation ; respirometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Dialdehyde starch (DAS) and zein, a hydrophobic corn protein, were investigated to produce biodegradable plastics with improved water resistance and mechanical properties. In the study, dialdehyde starch and zein ratio, plasticizers, and degree of starch oxidation were examined. Increased molding temperature and level of starch oxidation decreased water absorption of the plastic. Tensile strength and Young's modulus increased with starch oxidation. The biodegradation of starting materials and ground plastic specimens was studied in aerobic soil reactors maintained at 25°C for 180 days. Biodegradation of corn starch, zein, and dialdehyde starch for 180 days produced CO2 equivalent to 64, 63, and 10% of theoretical carbon, respectively. Specimens of molded DAS and zein (3 : 1) plastic showed accelerated CO2 evolution compared to DAS and other raw materials alone. By 180 days, specimens made with starch of low oxidation (1 and 5% oxidized) demonstrated a 60% biodegradation, and specimens with highly oxidized starch (90% oxidized) achieved 37% biodegradation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02067482
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  • 3
    Electronic Resource
    Electronic Resource
    Seismic Subduction of the Nazca Ridge as Shown by the 1996–97 Peru Earthquakes (1999)
    Springer
    Pure and applied geophysics 154 (1999), S. 753-776 
    Details
    ISSN: 1420-9136
    Keywords: Key words: Seismotectonics, subduction, Nazca Ridge, asperity, earthquake rupture, aftershocks, seismic gap, great earthquakes, earthquake potential.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract —By rupturing more than half of the shallow subduction interface of the Nazca Ridge, the great November 12, 1996 Peruvian earthquake contradicts the hypothesis that oceanic ridges subduct aseismically. The mainshock’s rupture has a length of about 200 km and has an average slip of about 1.4 m. Its moment is 1.5 × 1028 dyne-cm and the corresponding M w is 8.0. The mainshock registered three major episodes of moment release as shown by a finite fault inversion of teleseismically recorded broadband body waves. About 55% of the mainshock’s total moment release occurred south of the Nazca Ridge, and the remaining moment release occurred at the southern half of the subduction interface of the Nazca Ridge. The rupture south of the Nazca Ridge was elongated parallel to the ridge axis and extended from a shallow depth to about 65 km depth. Because the axis of the Nazca Ridge is at a high angle to the plate convergence direction, the subducting Nazca Ridge has a large southwards component of motion, 5 cm/yr parallel to the coast. The 900–1200 m relief of the southwards sweeping Nazca Ridge is interpreted to act as a "rigid indenter," causing the greatest coupling south of the ridge’s leading edge and leading to the large observed slip. The mainshock and aftershock hypocenters were relocated using a new procedure that simultaneously inverts local and teleseismic data. Most aftershocks were within the outline of the Nazca Ridge. A three-month delayed aftershock cluster occurred at the northern part of the subducting Nazca Ridge. Aftershocks were notably lacking at the zone of greatest moment release, to the south of the Nazca Ridge. However, a lone foreshock at the southern end of this zone, some 140 km downstrike of the mainshock’s epicenter, implies that conditions existed for rupture into that zone. The 1996 earthquake ruptured much of the inferred source zone of the M w 7.9–8.2 earthquake of 1942, although the latter was a slightly larger earthquake. The rupture zone of the 1996 earthquake is immediately north of the seismic gap left by the great earthquakes (M w ∼8.8–9.1) of 1868 and 1877. The M w 8.0 Antofagasta earthquake of 1995 occurred at the southern end of this great seismic gap. The M w 8.2 deep-focus Bolivian earthquake of 1994 occurred directly downdip of the 1868 portion of that gap. The recent occurrence of three significant earthquakes on the periphery of the great seismic gap of the 1868 and 1877 events, among other factors, may signal an increased seismic potential for that zone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000240050251
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  • 4
    Electronic Resource
    Electronic Resource
    Detection of Hopf points by counting sectors in the complex plane (1996)
    Springer
    Numerische Mathematik 75 (1996), S. 43-58 
    Details
    ISSN: 0945-3245
    Keywords: Mathematics Subject Classification (1991):65F15
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary. Let $A(\alpha)$ ( $\alpha$ real) be a family of real $n$ by $n$ matrices. A value $\alpha^0$ of $\alpha$ is called a Hopf value if $A(\alpha^0)$ has a conjugate pair of purely imaginary eigenvalues $\pm {\rm i}\omega^0$ , $\omega^0 〉 0$ . We describe a technique for detecting Hopf values based on the evolution of the Schur complement of $A-zI$ in a bordered extension of $A-zI$ where $z$ varies along the positive imaginary axis of the complex plane. We compare the efficiency of this method with more obvious methods such as the use of the QR algorithm and of the determinant function of $A$ as well as with recent work on the Cayley transform. In particular, we show the advantages of the Schur complement method in the case of large sparse matrices arising in dynamical problems by discretizing boundary value problems. The Hopf values of the Jacobian matrices are important in this setting because they are related to the Hopf bifurcation phenomenon where steady state solutions bifurcate into periodic solutions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002110050229
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  • 5
    Electronic Resource
    Electronic Resource
    Numerical Solutions to the Partially Separated, Equal-Mass, Wick-Cutkosky Model (1995)
    Springer
    Few body systems 19 (1995), S. 109-120 
    Details
    ISSN: 1432-5411
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. We discuss a numerical technique for solving four-dimensional, relativistic, bound-state, two-body equations that have not been completely separated. The angular variables are first separated what is always possible for a rotationally invariant system. The resulting partially separated equation is, in general, a set of coupled integral or partial differential equations in two variables that is solved numerically by expressing the solutions in terms of B-splines. We demonstrate the efficacy of the method by solving the partially separated Bethe-Salpeter equation for the equal-mass, Wick-Cutkosky model in the ladder approximation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s006010050020
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  • 6
    Electronic Resource
    Electronic Resource
    General geometric modelling approach for machining process simulation (1997)
    Springer
    The international journal of advanced manufacturing technology 13 (1997), S. 237-247 
    Details
    ISSN: 1433-3015
    Keywords: Boundary representation ; Curve modelling ; Milling ; NC machining ; Process simulation ; Solid modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Machining process simulation systems can be used to verify NC (numerically controlled) programs as well as to optimise the machining phase of the production. These systems contribute towards improving the reliability and efficiency of the process as well as the quality of the final product. Such systems are particularly needed by industries dealing with complex cutting operations, where the generation of NC code represents a very complex and error-prone task. A major impediment to implementing these systems is the lack of a general and accurate geometric method for extracting the required geometric information. In this paper, a novel approach to performing this task is presented. It uses a general and accurate representation of the part shape, removed material, and cutting edges, and can be used for any machining process. Solid models are used to represent the part and removed material volume. Bezier curves (in 3D space) are used to represent cutting edges. It is shown that by intersecting the removed material volume with the Bezier curves, in-cut segments of the tool cutting edges can be extracted. Using these segments, instantaneous cutting forces as well as any other process parameters can be evaluated. It is also shown that by using B-rep (Boundary representation) polyhedral models for representing solids, and cubic Bezier curves for representing cutting edges, efficient, generic procedures for geometric simulation can be implemented. The procedure is demonstrated and verified experimentally for the case of ball end-milling. A very good agreement was found between simulated cutting forces and their experimental counterparts. This proves the validity of the new approach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01179605
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  • 7
    Electronic Resource
    Electronic Resource
    Accounting for Net Entry into Greek Manufacturing by Establishments of Varying Size (1998)
    Springer
    Small business economics 11 (1998), S. 125-144 
    Details
    ISSN: 1573-0913
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract Adopting the view that size matters in understanding entry (exit) patterns, this research explores the nature and causes of net entry patterns of various size-defined groups of establishments in the case of a less industrialised country – Greece. The hypothesis to be tested is that the determinants of entry are not independent of firm size. Throughout this paper the analysis has had to confront difficulties arising from the use of net entry rates defined at the size class level. The degree of size disaggregation used in this paper is considerably finer than used before. Five employment-defined size classes have been used instead of sliding cut-off points discriminating between small and large firms. Unlike other research using pooled models to explain variation in entry (exit) rates across industries, the data used here are characterised by the absence of significant industry-specific systematic variation. Overall, the results obtained in this paper indicate that there is a gradation in the responses of different size classes to stimuli defined at the industry level. Evidence is offered that small firms are different in that they manage to overcome entry barriers, perhaps adopting different survival strategies, and that large firms are well aware of market conditions and are in an advantageous position to overcome many of the problems imposed by entry barriers. Size classes in the middle of the size class distribution offer a rather mixed result due to size-related advantages and disadvantages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007910318141
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  • 8
    Electronic Resource
    Electronic Resource
    Net Entry of Firms into Greek Manufacturing: The Effects of Business Conditions (1997)
    Springer
    Small business economics 9 (1997), S. 239-253 
    Details
    ISSN: 1573-0913
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Abstract This research explores the nature and causes of net entry into manufacturing industry in Greece. Previous work has rarely considered these issues in the context of small, but open, and not particularly industrialised economies. The exact nature of the focus of interest – net entry – is discussed first, illustrating that this is a complex variable to account for, although arguably still interesting and useful. Net entry needs to be considered as variable worthy of study in its own right as it reflects an outcome of processes of gross entry and exit. Certainly it need not be interpreted only as entry as is often the case. Next comes the question of the degree of variation, both temporally and sectorally, that net entry exhibits in the context of contemporary Greek manufacturing. Some temporal variation in net entry rates is demonstrated, and there follows a discussion of how such variation might be explained potentially in theory. The empirical testing of these hypotheses point to findings that are different to those discovered in different contexts. For Greek manufacturing, profitable business opportunities were not shown to be a sufficient condition of higher net entry, but the cost advantages of large scale operations did both encourage entry and discourage exit. The cost of capital and the overall condition of the economy were negatively related to net entry. However the role of industry growth, import penetration and export orientation tend to confirm findings in other studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017938904186
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  • 9
    Electronic Resource
    Electronic Resource
    STM studies of the Ge(111)4×4Ag reconstruction (1998)
    Springer
    Applied physics 67 (1998), S. 585-589 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 61.16Ch; 68.35.Bs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050826
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  • 10
    Electronic Resource
    Electronic Resource
    The Brassica napus extA extensin gene is expressed in regions of the plant subject to tensile stresses (1996)
    Springer
    Planta 199 (1996), S. 618-624 
    Details
    ISSN: 1432-2048
    Keywords: Brassica ; Extensin ; Nicotiana ; Transgenic plants ; Tensile stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The expression of extA, an extensin gene from Brassica napus L. (oilseed rape) was examined in transgenic Nicotiana tabacum L. (tobacco) and untransformed Brassica juncea L. and B. napus tissues. Northern analysis showed that this gene maintained its normal pattern of expression when transferred to tobacco. In transgenic tobacco plants containing an extA promoter/β-glucuronidase coding sequence fusion, expression of extA was detected in the external and internal phloem of the main stem. High expression levels were seen in cortical parenchyma cells at the point where the axillary flowering branch joined the main stem. Expression was greatest in regions where the maximum tensile stress would seem to be exerted on the main stem by the weight of the axillary branch. It was confirmed that this expression pattern was due to tensile stress by using weights to induce expression of the fusion gene in axillary flowering stalks. In B. juncea pods, in-situ hybridisation studies showed that the extensin gene was strongly expressed in cells of the carpel walls within which considerable tensile stresses develop.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00195195
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