An international interlaboratory comparison of the measurement capabilities of four National Metrology Institutes (NMIs) and one Designated Institute (DI) in the determination of the chemical composition of thin Fe-Ni alloy films was conducted via a key comparison (K-67) of the Surface Analysis Working Group of the Consultative Committee for Amount of Substance. This comparison was made using XPS (four laboratories) and AES (one laboratory) measurements. The uncertainty budget of the measured chemical composition of a thin alloy film was dominated by the uncertainty of the certified composition of a reference specimen which had been determined by inductively coupled plasma mass spectrometry using the isotope dilution method. Pilot study P-98 showed that the quantification using relative sensitivity factors (RSFs) of Fe and Ni derived from an alloy reference sample results in much more accurate result in comparison to an approach using RSFs derived from pure Fe and Ni films. The individual expanded uncertainties of the participants in the K-67 comparison were found to be between 2.88 and 3.40 atomic %. The uncertainty of the key comparison reference value (KCRV) calculated from individual standard deviations and a coverage factor (k) of 2 was 1.23 atomic %.

A new heterogeneous ruthenium-copper-hydrotalcite catalyst for the efficient and selective conversion of a variety of aliphatic, allylic and aromatic alcohols to either aldehydes or ketones is described. Suitable co-oxidants include iodosylbenzene, tetrabutyl ammonium periodate and, depending on substrate, oxygen.Heteronuclear catalysts have often been found to be more active than their individual mononuclear components. 1 A classical example is the Pd/Cu/O 2 -based Wacker process for the industrial preparation of acetaldehyde. 2 To our knowledge there has been a single prior report of a bimetallic Ru/Cu system for the partial oxidation of alcohols. The report describes a mixture of mononuclear ruthenium and copper containing compounds which shows fairly low rates of conversion and selectivity -possibly because the Ru and Cu are not in close proximity. 3 This prompted us to investigate a new Ru/Cu-containing hydrotalcite system as a catalyst for the oxidation of alcohols -a process of key importance in synthetic organic chemistry. The hydrotalcite permits the bringing together of different metals within the same compound, whilst it also contains interlayer spaces which are reactive environments. Some previous applications of hydrotalcite-type anionic clays include uses as catalysts for the polymerisation of alkene oxides, aldol condensation, reforming, alcohol synthesis, methanation, Baeyer-Villiger oxidations and the photoxidation of isopropyl alcohol to acetone. 4,5 An advantage of the hydrotalcite catalysts is that they are heterogeneous catalytic systems, thus permitting the easy removal of the catalysts from the reaction medium. Whilst a number of efficient homogeneous ruthenium catalysts for the mild oxidation of alcohols are known, 6,7 difficulties with product separation remain and often the expensive catalyst cannot be re-used after workup. The Ru-Cu-Al-hydrotalcite (Ru-Cu-HT) was prepared by adding a solution of RuCl 3 .3H 2 O (0.40 g, 1.53 mmol), CuCl 2 ·6H 2 O (2.61 g, 15.3 mmol) and AlCl 3 ·6H 2 O (1.23 g, 5.1 mmol) in water (10 mL) to a solution of Na 2 CO 3 (1.10 g) in 46.4 mL 1 M NaOH. The mixture was stirred at 65 °C for 18 h, after which the green product was filtered off, washed with water and dried at 110 °C for 12 h. The product was ground into a powder before use. EDS confirmed the presence of Ru, Cu and Al and flame emission spectroscopy showed the ruthenium content to be 6.4%.Typical oxidation procedures involved adding activated 4 Å molecular sieves and toluene (6 mL) to a Schlenk tube, after which the substrate (0.478 mmol) and isobutyl-methacrylate (80 mL) as internal standard were added. For the reactions using O 2 as co-oxidant, the reactions were carried out at 60 °C in O 2 saturated toluene under an atmosphere of oxygen. Alternatively, either iodosylbenzene (PhIO) or tetrabutylammonium periodate (TBAP) (0.717 mmol) was added as co-oxidant and the reactions carried out in N 2 saturated toluene at 60 °C under nitrogen. The hydrotalcite (250 mg) was added last in all cases. The reactio...

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The Key Comparison K67 and the parallel Pilot Study P108 on quantitative analysis of thin alloy films have been completed in the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of these inter-laboratory comparisons is to determine the degree of equivalence in the measurement capability of national metrology institutes (NMIs) and designated institutes (DIs) for the determination of the composition of thin alloy films. The measurand is expressed in atomic percent. A Fe–Ni alloy film with a certified composition was available for the participants of the inter-laboratory comparison. It has been used as a reference specimen to determine the relative sensitivity factors (RSF) of Fe and Ni for the different analytical methods used by the participants to determine the composition of the test sample. As was shown in the preceding Pilot Study P98, the degrees of equivalence in the measurement capabilities of the participants can be improved in that way. The composition of the reference specimen was certified by inductively coupled plasma mass spectrometry (ICP-MS) using the isotope dilution method. The in-depth and lateral homogeneity, determined in terms of elemental composition, of the certified reference sample and the unknown test sample were confirmed by secondary ion mass spectrometry (SIMS) using C60 primary ions by the leading laboratory. Five laboratories participated in the key comparison. Four of them used x-ray photoelectron spectroscopy (XPS) and one Auger electron spectroscopy (AES). One laboratory participated in the parallel P108 pilot study using electron probe micro analysis with an energy-dispersive spectrometer (ED EPMA) and XPS.Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

The land reform debate in South Africa has always been as contentious as it is controversial. Up to now, however, it has not reached the intensity of bringing about changes to South Africa’s fundamental law. In February 2018, Parliament resolved in favour of adopting an amendment to the Constitution that would allow government to expropriate private property without being required to pay compensation.1 This began a process that eventually culminated in the December 2019 publication of the draft Constitution Eighteenth Amendment Bill. This is the first time since the Constitution was enacted that an amendment has been introduced to change a provision in chapter 2, in this case section 25. The basic structure doctrine is a judicial doctrine that features most prominently but not exclusively in the constitutional law of India.2 The doctrine’s essence is that constitutional amendments, despite complying with the formal requirements for amendment set out in the constitutional text, might still be struck down by a court because the amendment offends the constitution’s foundational principles, its identity, character, or logic — its basic structure.3 In 2005, Devenish wrote that the basic structure doctrine has been implicitly recognised by the Constitutional Court as applicable in South Africa, but that ‘the doctrine is waiting in the wings, since, should certain circumstances and a crisis situation arise, the Constitutional Court could invoke its application’.4 At the time of Devenish’s writing, there was no pending amendment of the Bill of Rights, unlike today. In this paper, I briefly summarise the amendment procedure set out in section 74 of the Constitution, and the process that has taken place between February 2018 and June 2020. Thereafter, I briefly discuss the basic structure doctrine and its potential application in South Africa. Finally, I consider whether the basic structure doctrine could be employed as a viable challenge to the draft Constitution Eighteenth Amendment Bill. The question that is inevitably considered: Has the crisis, that Devenish referred to, arrived?