Trade union liability for unprotected strike action and violence in furtherance thereof

The right to strike is a constitutional right and is integral to the process of collective bargaining. Collective bargaining tends to focus on sensitive issues like wages, as well as terms and conditions of employment. Resolving these issues often requires compromise from both parties through the collective bargaining process. However, in the earlier stages of labour law there was no collective bargaining. There was a master and servant relationship, there was no compromise, and it was limited only to the individual contract of hire. As much as a strikes are a constitutional right and are recognised by the law, they don’t seem to happen without violence and destruction of property. There are some views that view violence as being synonymous with strikes in South Africa. The legal framework is very clear and supports the right to strike, and emphasises that any demonstrations and picketing should be peaceful. Section 68(1)(b) of the LRA should be a solution to the violence that comes with unprotected strikes. This section refers to just and equitable compensation, it does not equate to full loss suffered and it also depends on the merits of each case. The ILO’s approach to illegitimate actions linked to strikes should be proportionate to the offence of fault committed. The Constitution saw South Africa making a clean break with the past. The Constitution is focused on ensuring human dignity, the achievement of equality and advancement of human rights and freedoms.1 According to the Constitution the right to assemble and demonstrate must be peaceful. According to Grogan the right is now seen as a necessary adjunct to collective bargaining and is constitutionally entrenched.2 The LRA supports participation in protected strikes. In cases of unprotected strikes allows employers to interdict that particular strike, sue for compensation in cases of damages and losses and also to discipline employees. The Regulations of the Gatherings Act (RGA) was introduced to reconcile the right of assemblers with the state’s interest in maintaining public order. Section 11 of this Act seeks to deter violence and discourages violation of others by ensuring that organisers are held liable. The LRA holds the trade union and its members liable for the damages and violence that is accompanied by unprotected strikes. Section 68(1)(b) seeks just and equitable compensation for damages caused during an unprotected strike. However even though there is recourse for the damages suffered during the protest, unprotected strikes still continue and the violence is still part of the strikes. It is proper to ask if this section is really serving what it was intended. Surely the intention of this section was to deter strikers from embarking on unprotected strikes as the LRA is very clear on the procedure to be followed before a strike action takes place. Another intention of this section is to curb the violence during strikes. This section seems to have fallen on deaf ears

Synthesis and crystal structure of an oxorhenium(V) complex containing a tridentate imidazole ligand

The reaction of equimolar amounts of (n-Bu4N)[ReOCl4] and 2-(1-ethanolthiomethyl)-1-methylimidazole (Htmi) in acetonitrile yielded cis-[ReOCl2(tmi)]. An X-ray diffraction study shows that tmiˉ coordinates as a uninegative N,S,O-tridentate ligand to give distorted octahedral geometry around the rhenium(V) ion. The three donor atoms occupy a triangular face in an octahedron, with the alcoholate oxygen coordinated trans to the oxo group.   KEY WORDS: Oxorhenium(V), N,S,O-tridentate, Imidazole  Bull. Chem. Soc. Ethiop. 2007, 21(1), 75-81

Towards mineral beneficiation: from basic chemistry to applications

The role of mineral beneficiation in the survival, growth, development and sustainability of a developing economy cannot be overstated. Our development as a human species has always been involvedly linked with the use of mineral resources from the stone, bronze and iron ages through the early modern eras to the present. In the current modern era, characterized by highly technological equipment, fourth industrial revolution (4IR) and new energy technologies, the role of mineral beneficiation has been elevated. Precious metals find use in the fine chemicals and petrochemicals industry, fuel cells, electrical and electronic products, medical and dentistry applications, jewellery, autocatalysts, and glass and ceramics. The markets for precious metals keep growing and the supply does not meet demand. The development of methods for recovery of metal value from feeds of mineral ore solutions, solutions of spent secondary resources and from mining wastewaters remains of great importance. Further beneficiation strategies for utilization of mineral products in other “value-added” applications are also important for the growth of the mineral markets. The usage of platinum, palladium and rhodium in the autocatalyst industry has grown significantly and this has further elevated the importance of platinum group metals (PGMs), but other areas of application of the strategic metals need to be harnessed. The four stages of beneficiation, namely, primary, secondary, tertiary and final stage, provide an opportunity to beneficiate to greater value for domestic or export use. Our own research work is engaged in several of these stages, from hydrometallurgical recovery of base metals and platinum group metals from feeds of primary mining and solutions of waste secondary resources such as spent catalytic converters and e-waste to the use of metals in “value added” products such as metalbased catalysts for the fuel industry and in metallodrugs. Examples of “value added” products include rhodium as a promoter in molybdenum sulfide as a catalyst for hydrodesulfurization of fuel oil, vanadium as a catalyst in oxidative desulfurization of fuel oil, vanadium and palladium as therapeutic agents for diabetes and cancer, respectively. Current and future work involves (i) the development of metal-selective scavengers to recover lost metal value in mining wastewaters, and (ii) the design of metal-based catalytic materials for refinement of bio-based oils to biofuel as well as for production of green LPG through hydroprocessing. Our work centres around both basic and applied chemistry towards mineral beneficiation and with a bias towards greener production

Towards mineral beneficiation: from basic chemistry to applications

The role of mineral beneficiation in the survival, growth, development and sustainability of a developing economy cannot be overstated. Our development as a human species has always been involvedly linked with the use of mineral resources from the stone, bronze and iron ages through the early modern eras to the present. In the current modern era, characterized by highly technological equipment, fourth industrial revolution (4IR) and new energy technologies, the role of mineral beneficiation has been elevated. Precious metals find use in the fine chemicals and petrochemicals industry, fuel cells, electrical and electronic products, medical and dentistry applications, jewellery, autocatalysts, and glass and ceramics. The markets for precious metals keep growing and the supply does not meet demand. The development of methods for recovery of metal value from feeds of mineral ore solutions, solutions of spent secondary resources and from mining wastewaters remains of great importance. Further beneficiation strategies for utilization of mineral products in other “value-added” applications are also important for the growth of the mineral markets. The usage of platinum, palladium and rhodium in the autocatalyst industry has grown significantly and this has further elevated the importance of platinum group metals (PGMs), but other areas of application of the strategic metals need to be harnessed. The four stages of beneficiation, namely, primary, secondary, tertiary and final stage, provide an opportunity to beneficiate to greater value for domestic or export use. Our own research work is engaged in several of these stages, from hydrometallurgical recovery of base metals and platinum group metals from feeds of primary mining and solutions of waste secondary resources such as spent catalytic converters and e-waste to the use of metals in “value added” products such as metalbased catalysts for the fuel industry and in metallodrugs. Examples of “value added” products include rhodium as a promoter in molybdenum sulfide as a catalyst for hydrodesulfurization of fuel oil, vanadium as a catalyst in oxidative desulfurization of fuel oil, vanadium and palladium as therapeutic agents for diabetes and cancer, respectively. Current and future work involves (i) the development of metal-selective scavengers to recover lost metal value in mining wastewaters, and (ii) the design of metal-based catalytic materials for refinement of bio-based oils to biofuel as well as for production of green LPG through hydroprocessing. Our work centres around both basic and applied chemistry towards mineral beneficiation and with a bias towards greener production

An ion-imprinted polymer for the selective extraction of mercury(II) ions in aqueous media

A double-imprinted polymer exhibiting high sensitivity for mercury(II) in aqueous solution is presented. Polymer particles imprinted with mercury(II) were synthesised by copolymerising the functional and cross-linking monomers, N’–[3– (Trimethoxysilyl)–propyl]diethylenetriamine (TPET) and tetraethylorthosilicate (TEOS). A double-imprinting procedure employing hexadecyltrimethylammonium bromide (CTAB), as a second template to improve the efficiency of the polymer, was adopted. The imprinted polymer was characterised by FTIR, scanning electron microscopy (SEM) and the average size determined by screen analysis using standard test sieves. Relative selective coefficients (k`) of the imprinted polymer evaluated from selective binding studies between Hg2+ and Cu2+ or Hg2+ and Cd2+ were 10 588 and 3 147, respectively. These values indicated highly-favoured Hg2+ extractions over the 2 competing ions. The results of spiked and real water samples showed high extraction efficiencies of Hg2+ ions, (over 84%) as evaluated from the detected unextracted Hg2+ ions by ICP-OES. The method exhibited a dynamic response concentration range for Hg2+ between 0.01 and 20 μg/mℓ, with a detection limit (LOD, 3σ) of 0.000036 μg/mℓ (36 ng/ℓ) that meets the monitoring requirements for the USA EPA of 2 000 ng/ℓ for Hg2+ in drinking water. Generally, the data (n=10) had percentage relative standard deviations (%RSD) of less than 4%. Satisfactory results were also obtained when the prepared sorbent was applied for the pre-concentration of Hg2+ from an aqueous certified reference material. These findings indicate that the double-imprinted polymer has potential to be used as an efficient extraction material for the selective pre–concentration of mercury(II) ions in aqueous environments

A colorimetric probe for the detection of Ni2+ in water based on Ag-Cu alloy nanoparticles hosted in electrospun nanofibres

A Ni2+ based colorimetric probe based on glutathione-stabilized silver/copper nanoparticles (GSH-Ag-Cu alloy NPs) in an electrospun polymer matrix is reported. Glutathione-Ag-Cu alloy NPs were characterized by ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The freshly synthesized GSH-Ag-Cu alloy NPs in a polymer matrix were black in colour due to an intense surface plasmon absorption band at 424 nm. However the electrospun nanocomposite fibres were green in colour and in the presence of Ni2+ the green GSH-Ag-Cu alloy NP fibres were discoloured. The sensitivity of the GSH-Ag-Cu alloy NPs towards other representative transition, alkali and alkali earth metal ions was negligible. The effect of the concentration of Ni2+ on the nanocomposite fibres was evaluated and the ‘eye-ball’ limit of detection was found to be 5.8 μg/mL.Keywords: colorimetric probes, alloy nanoparticles, electrospun nanofibres, heavy metal determinatio

Dimethylglyoxime based ion-imprinted polymer for the determination of Ni(II) ions from aqueous samples

A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was synthesised by the bulk polymerisation method. The morphology of the Ni(II)-DMG IIP and non-imprinted polymer were observed by scanning electron microscopy and the chemical structures were evaluated by infrared spectroscopy. Selectivity of the Ni(II)-DMG IIP was studied by analysing, using an inductively coupled plasma-optical emission spectrometer, for Ni(II) ions that were spiked with varying concentrations of Co(II), Cu(II), Zn(II), Pd(II), Fe(II), Ca(II), Mg(II), Na(I) and K(I) in aqueous samples. The studies revealed Ni(II) recoveries ranging from 93 to 100% in aqueous solutions with minimal interference from competing ions. Enrichment factors ranged from 2 to 18 with a binding capacity of 120 μg∙g−1. Co(II) was the only ion found to slightly interfere with the determination of Ni(II). Selectivity studies confirmed that the Ni(II)-DMG IIP had very good selectivity, characterised by %RSD of less than 5%. The limits of detection and quantification were 3x10-4 μg∙mℓ−1 and 9x10-4 μg∙mℓ−1, respectively. The accuracy of the method was validated by analysing a custom solution of certified reference material (SEP-3) and the concentration of Ni(II) obtained was in close agreement with the certified one. The Ni(II)-DMG IIP was successfully employed to trap Ni(II) ions from a matrix of sea, river and sewage water. It is believed that the Ni(II)-DMG IIP has potential to be used as sorbent material for pre-concentration of Ni(II) ions from aqueous solutions by solid-phase extraction

Sorption of toxic metal ions in aqueous environment using electrospun polystyrene fibres incorporating diazole ligands

Electrospun polystyrene fibres incorporating potassium salts of pyrazole-1-carbodithioate and imidazole-1-carbodithioate were employed as sorbents for heavy metals from aqueous environments. The equilibrating time, initial metal concentrations and sorbent mass for optimal adsorption were 40 min, 5 mg/ℓ and 8 mg, respectively. The optimal pH for metal ion uptake was between 6.3 and 9.0 and was found to be dependent on the basicity of the ligands. Protonation constants for the ligands in aqueous solutions were determined potentiometrically; pK of the imidazole was 6.82 while that of the pyrazole was 3.36. The efficiencies of adsorption and desorption of metals on the imidazolyl-incorporated sorbents were more than 95%, up to the fifth cycle of usage. The limits of quantification were ≤ 0.0145 mg/ℓ for all the metals. Accuracy of the determinations, expressed as relative error between the certified and observed values of certified reference groundwater samples was ≤ 0.2% with relative standard deviations < 3%. Electrospun polystyrene fibres incorporating imidazoles proved to be efficient sorbents for divalent heavy metal ions in aqueous environments as their efficiencies exceeded those of chitosan microspheres, ion-imprinted composites, amino-functionalised mesoporous materials and most of the biomass-based sorbents previously reported on.Keywords: electrospinning, polystyrene, heavy metals, diazol

Synthesis, characterization and DPPH scavenging activity of some benzimidazole derivatives

A base-catalyzed conversion of aldehydes to benzimidazoles has been achieved. The compounds have been characterized by IR, NMR, micoranalysis, and GC-MS. The reaction for the formation of benzimidazoles has been monitored with 1H NMR and IR. The crystal structures of two derivatives, 2-(2-chlorophenyl)-1H-benzimidazole and 2-(1H-benzimidazol-2-yl)-4-nitrophenol, are presented. A study of the DPPH scavenging activity of these compounds showed that 2-(1H-benzimidazol-2-yl)phenol (2), 2-p-tolyl-1H-benzimidazole (3) and 2-(4-methoxyphenyl)-1H-benzimidazole (7) gave IC50 values 1974, 773 and 800 µM.               KEY WORDS: Benzimidazole, o-Phenylenediamine, Aldehydes, Base catalysis, DPPH scavenging activity Bull. Chem. Soc. Ethiop. 2018, 32(2), 271-284.DOI: https://dx.doi.org/10.4314/bcse.v32i2.