On the Correction of the Melting Curve of the Eutectic Co–C for the Effect of the Thermal Inertia of the Furnace

This paper considers the influence of the thermal inertia of the furnace on the shape of the melting curve of the eutectic Co–C. To this end, melting experiments have been performed in a uniform three-zone furnace, with an inherent substantial thermal inertia. The thermal inertia has been quantified by measuring the step-response of the furnace with the sample in its solid state, just below its melting temperature. From the analysis of the effect of the thermal inertia of the furnace, it turned out that during melting the temperature distribution within the furnace, surrounding the crucible, is bound to be in a non-stationary state. This provided the key to properly finalizing the correction to be applied. The shape of the corrected curve differs considerably from that of the curve, as measured, in that the former shows a flatter melting plateau, and a larger curvature on the way down to the solidus point. As regards the liquidus temperature \(T_{\mathrm{liq}}\)—of major interest in the characterization of the transition temperature of high-temperature fixed points—it is demonstrated that the thermal inertia of the furnace shows a kind of self-compensating mechanism. But the effects of the thermal inertia of the furnace on the parameters defining the Scheil fit, involved in the correction procedure, were considerable.     

On the Origin of the δk-Model and the Model of Plastic Strips

On the basis of a survey of works, we demonstrate the priority of the Lviv school of mechanics in the field of creation and development of the deformation theory of limiting equilibrium of bodies with cracks known as the _k -model. The theory is based on the criterion of crack opening displacement proposed by Leonov and Panasyuk and on the procedure of evaluation of this quantity by modeling the inelastic zones in front of the crack by cuts the edges of which are loaded by certain stresses ₀ whose physical meaning is determined by the properties of the material. This method (known as the model of plastic strips) is also used for the determination of the development of plastic zones at the crack tip for various configurations of plates and loads and also in twisted bodies. The results of numerical calculations agree with the experimental data.     

Great differences in the ways of implementing the new EIA Directive – the offerings of the EIALAW 2018 conference

On the 23 March 2018, the most recent developments of the environmental impact assessment (EIA) law were examined by experts in Helsinki. The main theme of the conference was the comparison of the implementation experiences of various countries concerning the reformed EU EIA Directive. The European EIA debate was reflected against experiences in Canada. This paper examines the key points of the conference presentations and the lessons of the event.     

The improvement of the amorphous environment of the germanate–tellurate glasses in the presence of the gadolinium ions

Glasses in the system xGd₂O₃·(100 − x)[TeO₂·GeO₂] with 0 ≤ x ≤ 50 mol% have been prepared from melt quenching method. In this paper, we investigated changes of the coordination numbers of germanium, tellurium, and gadolinium ions by investigations of FTIR, EPR, and UV–VIS spectroscopy. By analyzing the structural changes resulted from the IR spectra we found that the bending modes of [GeO₄] structural units and the deformed modes of the Te–O–Te linkages produce intercalation of the [GdO _n ] entities in the germanate–tellurate chain network and densification of the glasses by increasing the number of [GeO₆] structural units. EPR spectra of the studied samples reveal that the gadolinium ions play a role of network former. The UV–VIS spectra show broad UV absorption bands located in the 250–350 nm region. Their intensity increase with the increasing of Gd₂O₃ content showing that these stronger transitions can be due to the presence of the O=Ge bonds (n–π* excitations) of [GeO₅] structural units. The [GeO₅] structural units are more stable thermodynamically than their analogues and the [GeO₆] structural units produce the improvement of the amorphous character of these glasses.     

the Developing SRIMTC

Testing C enter,ShanghaiR esearch Institute ofM aterials(SR IM T C),w hich isalso M aterials Testing C enter forM achinery Industry,w as founded on D ec.1994,based on the relevanttesting departm ents ofShanghaiR esearch Institute ofM ate-rials(SR IM).T he centerhas carried forw ard the experience and achievem ents onm aterials testing technology thatSR IM gained overthe past60years and achievedan increasingly good creditin the sam e profession hom e and abroad.In D ec.1996,SR IM …     

From the Editor-in-Chief

Oursocietyisinanerafullofchangesandref0rms.Insuchanera,enterprisesneedreform,andtheyshouldseizetheopportunitiesinachangingenvironmenttoseekdevelopmentwithprospectsforfuturegrowth-Atpresent,theChineseenterprisesarejustsituatedinsuchanenvi-ronmenttoseektheirsurvivalanddevel0pment.Theyarefacingboth0pportunitiesandchal-lenges.Theestablishmentofmodernenterprisesystemshallprovidethemwithagreatopportu-nitytoadvancetotheoutsideworldandtoachievesuccess.Thereformofanenterprisecannotbeseparatedfromthepr…     

To the Readers

Weareinaneraofgreatchangeandreform.ThepoIiticaIandeconomicchangeshaveraisedfresherandhigherdemandsonthemanufacturingindustry.ManyoftheoIdmarketstructureshavebeenbrokendown,andmoreandmoreenterpriseshavecometoreaIizethattheirproductionandorganizationsimpIymustundergoreformingandrestructuring.Toachieveandmaintaincompetitiveability,anenterpriseshouIdnotonIyneedIeanandfIexibleproductionsystemsbutaIsopossesspersonneIwhoarebothofstronginitiativeandwelI-trained.Thisisthekeytosuccessofanyenter-pri…     

On the transformations of the ψ-AlCuFe icosahedral phase

In the present investigation, different alloy compositions close to the ternary composition values, where the icosahedral phase in AlFeCu is obtained, have been studied. The specimens were obtained using a rapid solidification technique with subsequent thermal treatments of 600°C, 700°C, 800°C and 900°C. The obtained specimens were characterized with X-ray diffraction patterns (XRD) and transmission electron microscopy (TEM). The experimental results show different transformations of the icosahedral phase to crystalline phases between 800°C and 700°C .The cubic β-phase is a solid solution which regulates the formation and decomposition of the ψ-Al₆Cu₂Fe phase to different crystalline phases such as the tetragonal (Al₇Cu₂Fe) and monoclinic (Al₁₃Fe₄) phases.     

Analysis of the ellipse of polarization by the senarmont method as the phase difference varies in the range 0–2π

An analysis of the Senarmont method is performed using Müller marices and Stokes, vectors. It is proved that the traditional undrstanding of the Senarmont method is applicable in the case of phase differences not exceeding one-half wave. For measurements of phase differences in the range 0–2π, a preliminary identification of the rapid and slow axes of the phase plate is required. A method is presented by means of which it is possible to distinguish the axes on the basis of the direction of the rotation of the resultant plane oscillations in the case of continuous variation of the phase differences. Translated from Izmeritel'naya Tekhnika, No. 11, pp. 22–25, November, 1999.     

Is the proton radius a player in the redefinition of the International System of Units?

It is now recognized that the International System of Units (SI units) will be redefined in terms of fundamental constants, even if the date when this will occur is still under debate. Actually, the best estimate of fundamental constant values is given by a least-squares adjustment, carried out under the auspices of the Committee on Data for Science and Technology (CODATA) Task Group on Fundamental Constants. This adjustment provides a significant measure of the correctness and overall consistency of the basic theories and experimental methods of physics using the values of the constants obtained from widely differing experiments. The physical theories that underlie this adjustment are assumed to be valid, such as quantum electrodynamics (QED). Testing QED, one of the most precise theories is the aim of many accurate experiments. The calculations and the corresponding experiments can be carried out either on a boundless system, such as the electron magnetic moment anomaly, or on a bound system, such as atomic hydrogen. The value of fundamental constants can be deduced from the comparison of theory and experiment. For example, using QED calculations, the value of the fine structure constant given by the CODATA is mainly inferred from the measurement of the electron magnetic moment anomaly carried out by Gabrielse's group. (Hanneke et al. 2008 Phys. Rev. Lett. 100, 120801) The value of the Rydberg constant is known from two-photon spectroscopy of hydrogen combined with accurate theoretical quantities. The Rydberg constant, determined by the comparison of theory and experiment using atomic hydrogen, is known with a relative uncertainty of 6.6×10(-12). It is one of the most accurate fundamental constants to date. A careful analysis shows that knowledge of the electrical size of the proton is nowadays a limitation in this comparison. The aim of muonic hydrogen spectroscopy was to obtain an accurate value of the proton charge radius. However, the value deduced from this experiment contradicts other less accurate determinations. This problem is known as the proton radius puzzle. This new determination of the proton radius may affect the value of the Rydberg constant . This constant is related to many fundamental constants; in particular, links the two possible ways proposed for the redefinition of the kilogram, the Avogadro constant N(A) and the Planck constant h. However, the current relative uncertainty on the experimental determinations of N(A) or h is three orders of magnitude larger than the 'possible' shift of the Rydberg constant, which may be shown by the new value of the size of the proton radius determined from muonic hydrogen. The proton radius puzzle will not interfere in the redefinition of the kilogram. After a short introduction to the properties of the proton, we will describe the muonic hydrogen experiment. There is intense theoretical activity as a result of our observation. A brief summary of possible theoretical explanations at the date of writing of the paper will be given. The contribution of the proton radius puzzle to the redefinition of SI-based units will then be examined.     

On the beat of the drum: improving the flow shop performance of the Drum–Buffer–Rope scheduling mechanism

One of the main elements of the theory of constraints is its Drum–Buffer–Rope (DBR) scheduling (or release) mechanism that controls the release of jobs to the system. Jobs are not released directly to the shop floor – they are withheld in a backlog and released in accordance with the output rate of the bottleneck (i.e. the drum). The sequence in which jobs are considered for release from the backlog is determined by the schedule of the drum, which also determines in which order jobs are processed or dispatched on the shop floor. In the DBR literature, the focus is on the urgency of jobs and the same procedure is used both for backlog sequencing and dispatching. In this study, we explore the potential of using different combinations of rules for sequencing and dispatching to improve DBR performance. Based on controlled simulation experiments in a pure and general flow shop we demonstrate that, although the original procedure works well in a pure flow shop, it becomes dysfunctional in a general flow shop where job routings vary. Performance can be significantly enhanced by switching from a focus on urgency to a focus on the shortest bottleneck processing time during periods of high load.     

From the Editor-in-Chief

ThedevelopmentofindustrialengineeringhasundergoneacourseofoveracenturyinAmer-icasinceFrederickW.Taylorstartedhisobservationandanalysisofworkers'manualoperation.Todaywiththedevelopmentofinformationtechnology,computertechnologyhasbeenintroducedintoindustrialengineering,whichhasthusbeenfurtherdividedintoClassicalIEandModernIE.Industrialengineersareplayingagreatroletoday.Then,whatisanindustrialengineer?Andwhattypesofenterprisesuseindustrialengi-neers?Thisisoneofthequestionswhichmanypeoplearep…     

To the Readers

IndustrialEngineeringandManagementisalreadyoneyearoldsincethepublicationofitsfirstissuelastDecember.Overthepastyear,ourreadershavewitnessed,togetherwithus,thevariouschangesofthisjournal.Atthemomentofitsfirstan-niversary,theurgentandimportanttaskforusistoreviewtheexperiencesandlessonswehavegainedinourworkandoutlinetheprospectiveorientationofdevelopmentforthefurtherimprovementofthejournalinthefollowingyear.AnnafterthepublicationofthefirstissueofIE&MinDecember,1996,wereceivedalargenumberoflett…     

When should we change the definition of the second?

The microwave caesium (Cs) atomic clock has formed an enduring basis for the second in the International System of Units (SI) over the last few decades. The advent of laser cooling has underpinned the development of cold Cs fountain clocks, which now achieve frequency uncertainties of approximately 5×10(-16). Since 2000, optical atomic clock research has quickened considerably, and now challenges Cs fountain clock performance. This has been suitably shown by recent results for the aluminium Al(+) quantum logic clock, where a fractional frequency inaccuracy below 10(-17) has been reported. A number of optical clock systems now achieve or exceed the performance of the Cs fountain primary standards used to realize the SI second, raising the issues of whether, how and when to redefine it. Optical clocks comprise frequency-stabilized lasers probing very weak absorptions either in a single cold ion confined in an electromagnetic trap or in an ensemble of cold atoms trapped within an optical lattice. In both cases, different species are under consideration as possible redefinition candidates. In this paper, I consider options for redefinition, contrast the performance of various trapped ion and optical lattice systems, and point to potential limiting environmental factors, such as magnetic, electric and light fields, collisions and gravity, together with the challenge of making remote comparisons of optical frequencies between standards laboratories worldwide.     

Finding of Gray Points on the Surface of the Sn-Fe Alloy Layer and Its Effects on the Corrosion Resistance of the Alloy Layer

After removing tin coating of tinplates offered by some steel works, we discovered massive, highly disperse gray points outspreading along rolling direction on the surface of the alloy layer. Morphology of the alloy layer was observed by scanning electron microscope (SEM), and many cavities of the alloy layer were found out in the gray point. After analyzing the composition of the alloy layer, we found that content of Fe in the gray points was more than that in the normal alloy layer. Moreover, corrosion resistance of the alloy layer declines with increase of amount of gray points. In addition, the hot-humidity testing was carried out for some plates whose surface has many gray points. After 14 days, there were many rust points occurring in the edge of gray points and in the small gray points. The morphology of rust points was observed by atomic force microscope (AFM). The reason why rust points generated in the edge of gray points and in the small gray points was discussed.     

Research on the Assessment Strategies for the Product Multi-lifecycle System

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Application of the Hydrogen Diffusion Model to the Hydrogen Permeation

The model of hydrogen diffusion formerly de-veloped [1] has been applied successfully to thehydrogen permeation experiment results of threekinds of materials,α—Fe,Fe—Ti alloy and Fe—Ti—Calloy by the mathematical fitting method.From thefitting results it was shown that the model can re-fiect well the diffusion of hydrogen in the materialswith trapping.The obtained trapping parameters(αand β)can be used to explain well the diffusion ofhydrogen in the samples with trapping.     

Some features of the transgranular embrittlement of α-titanium alloys under the influence of the environment

Some common features of the transgranular embrittlement of -titanium alloys in chloride solutions, hot salts, liquid metals, and air are established. These types of brittle fracture are typical symptoms of trans-granular embrittlement along the basal (near-basal) cleavage planes of metals (alloys) with hcp crystal lattices with various values of the ratioc/a. In this connection, the role of alloying elements and the mechanism of corrosion cracking of -titanium alloys in chloride solutions are reconsidered.Central Scientific Research Institute of Structural Materials Prometheus, St. Petersburg. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 1, pp. 75–77, January–February, 1994.     

Preparation of the Silver-Superconductor Composite by Deposition of the Silver Nanoparticles in the Bismuth Cuprate Superconductor

BiSCCO (Bi–Sr–Ca–Cu–O) is high temperature superconductor with a lot of possible applications. Interfaces between superconductors and metal conductors are one of the technological problems. In this work, silver-superconductor composite was prepared by using flow of silver nanoparticles suspension in DMF (N,N-dimethylformamide) through superconductor’s pore system. Silver nanoparticles were prepared by reaction of silver nitrate with DMF. Properties of prepared composite were measured by SEM charting, XRD and critical current measurements. SEM chart showed uniform distribution of silver across sample. XRD and critical current measurements validated superconducting properties of prepared composite. In the future, materials based on this method could be used as an interface between superconductors and metals or as a base for superconducting composite with much better mechanical properties.