A maintenance performance measurement framework that concluded maintenance human factors : a case study from the electricity transmission industry

Over the past two to three decades, maintenance management has undergone a paradigm shift; it is no longer seen as a necessary evil, but as an integral part of the business process that creates value for the organisation. The next step in the evolution of maintenance management is a maintenance performance measurement that includes human factors. The human factors in maintenance are well-known in the aviation industry, as it gained momentum in the early 1990s after a series of serious aviation accidents. Other industries, however, have been slow to integrate the human factor in their maintenance performance measurements. This paper discusses the results of a research project that investigated the use and importance of maintenance management performance measurements that focus specifically on human factors as part of the overall performance management system. From the research presented in this paper, ‘motivation’ and ‘competence’ were identified as the most important human performance factors in the maintenance of electricity transmission systems.Instandhoudingsbestuur het ’n paradigmaskuif ondergaan in die afgelope twee of drie dekades, vanaf ’n noodsaaklike euwel tot ’n integrale deel van die besigheidsproses wat waarde toegevoeg tot die organisasie. Die volgende groot ontwikkeling in instandhoudingsbestuur is prestasiemeting waarby meslike faktore ingesluit word. Menslike motiveringsfaktore is welbekend in die lugvaartindustrie sedert die vroeë 1990s na ’n rits ernstige lugvaartongelukke, maar ander industrieë was stadiger om menslike faktore in te sluit in prestasiemeting van instandhouding. Hierdie artikel bespreek die resultate van ’n navorsingsprojek wat die gebruik en belangrikheid van prestasiemetings vir instandhoudingsbestuur ondersoek het met spesifieke fokus op die menslike faktore as deel van die totale prestasiebestuurstelsel. Motivering en bevoegdheid is geïdentifiseer as die belangrikste menslike prestasiefaktore vir die instandhouding van elektriese verspreidingstelsels.http://sajie.journals.ac.za/pubam2016Graduate School of Technology Management (GSTM

Dosimeter-Type NOx Sensing Properties of KMnO4 and Its Electrical Conductivity during Temperature Programmed Desorption

An impedimetric NOx dosimeter based on the NOx sorption material KMnO4 is proposed. In addition to its application as a low level NOx dosimeter, KMnO4 shows potential as a precious metal free lean NOx trap material (LNT) for NOx storage catalysts (NSC) enabling electrical in-situ diagnostics. With this dosimeter, low levels of NO and NO2 exposure can be detected electrically as instantaneous values at 380 °C by progressive NOx accumulation in the KMnO4 based sensitive layer. The linear NOx sensing characteristics are recovered periodically by heating to 650 °C or switching to rich atmospheres. Further insight into the NOx sorption-dependent conductivity of the KMnO4-based material is obtained by the novel eTPD method that combines electrical characterization with classical temperature programmed desorption (TPD). The NOx loading amount increases proportionally to the NOx exposure time at sorption temperature. The cumulated NOx exposure, as well as the corresponding NOx loading state, can be detected linearly by electrical means in two modes: (1) time-continuously during the sorption interval including NOx concentration information from the signal derivative or (2) during the short-term thermal NOx release

Phylogeny and biogeography of the African Bathyergidae : a review of patterns and processes

BACKGROUND : We review genealogical relationships, biogeographic patterns and broad historical drivers of speciation within the Bathyergidae, a group of endemic African rodents, as well as identify key taxa which need further research. METHODS : We sourced comparable cytochrome b sequence data (comparable data available for all members for the Family) and geographic information for all six genera of the African subterranean rodent. This information was combined into the most comprehensive and geographically representative evolutionary study for the Bathyergidae to date. RESULTS : Species richness within the Bathyergidae appears to be underestimated, with undescribed taxa in five of the six genera. Biogeographic patterns suggest large historical distributions, which were repeatedly fragmented by major landscape changes (especially rifting, uplift and drainage evolution) since the Miocene. Aside from vicariant events, other factors (ecological specialization, population-level responses and climatic change) may have been instrumental in driving divergences in the Bathyergidae. As such, adaptive differences may exist among both populations and species across their discrete ranges, driving independent evolutionary trajectories among taxa. In addition, highly fragmented distributions of divergent (and often relict) lineages indicates the possibility of narrow endemics restricted to diminishing suitable habitats. From this, it is clear that a systematic revision of the Bathyergidae is necessary; such a revision should include comprehensive sampling of all putative taxa, the addition of genomic information to assess adaptive differences, as well as ecological information.Supplement 1: Phylogeny of the Bathyergidae based on cytochrome b sequence data. Phylogeny of the Bathyergidae constructed through Bayesian analysis (in BEAST) and based on the cytochrome b sequence data for all the available sample haplotypes listed in Table S1. The various mole-rat species included and identified within each genus are indicated. Values above nodes represent posterior probability values derived from the Bayesian analysis in BEAST and MrBayes respectively, while values below nodes indicate bootstrap values derived after Maximum Likelihood analysis in RAxML.Supplement 2: Specimen/sequence information of the bathyergids included in this study. Accession numbers of the cytochrome b haplotypes used in this study, also indicating the species (as designated on the public database), reference to the original study in which the sequence was generated, the species designation in the original study, the species designation in the current study and geographic information and coordinates of the sampling locality from where the species originates.Supplement 3: Species authorities on the bathyergid species included in this study.Supplement 4: Uncorrected sequence divergences among the six bathyergid genera. Pairwise estimates of uncorrected sequence divergence among the six bathyergid genera.Supplement 5: Uncorrected sequence divergences among the species within Heliophobius. Pairwise estimates of uncorrected sequence divergence among the various species included and identified within the genus Heliophobius.Supplement 6: Uncorrected sequence divergences among the species within Georychus. Pairwise estimates of uncorrected sequence divergence among the various species included and identified within the genus Georychus.Supplement 7: Uncorrected sequence divergences among the species within Bathyergus. Pairwise estimates of uncorrected sequence divergence among the various species included and identified within the genus Bathyergus.Supplement 8: Uncorrected sequence divergences among the species within Cryptomys. Pairwise estimates of uncorrected sequence divergence among the various species (subspecies) included and identified within the genus Cryptomys.Supplement 9: Uncorrected sequence divergences among the species within Fukomys. Pairwise estimates of uncorrected sequence divergence among the various species included and identified within the genus Fukomys.https://peerj.comam2020Zoology and Entomolog

Radio-Frequency-Based NH₃-Selective Catalytic Reduction Catalyst Control : Studies on Temperature Dependency and Humidity Influences

The upcoming more stringent automotive emission legislations and current developments have promoted new technologies for more precise and reliable catalyst control. For this purpose, radio-frequency-based (RF) catalyst state determination offers the only approach for directly measuring the NH3 loading on selective catalytic reduction (SCR) catalysts and the state of other catalysts and filter systems. Recently, the ability of this technique to directly control the urea dosing on a current NH3 storing zeolite catalyst has been demonstrated on an engine dynamometer for the first time and this paper continues that work. Therefore, a well-known serial-type and zeolite-based SCR catalyst (Cu-SSZ-13) was investigated under deliberately chosen high space velocities. At first, the full functionality of the RF system with Cu-SSZ-13 as sample was tested successfully. By direct RF-based NH3 storage control, the influence of the storage degree on the catalyst performance, i.e., on NOx conversion and NH3 slip, was investigated in a temperature range between 250 and 400 °C. For each operation point, an ideal and a critical NH3 storage degree was found and analyzed in the whole temperature range. Based on the data of all experimental runs, temperature dependent calibration functions were developed as a basis for upcoming tests under transient conditions. Additionally, the influence of exhaust humidity was observed with special focus on cold start water and its effects to the RF signals

Radio-Frequency-Controlled Urea Dosing for NH3-SCR Catalysts : NH3 Storage Influence to Catalyst Performance under Transient Conditions

Current developments in exhaust gas aftertreatment led to a huge mistrust in diesel driven passenger cars due to their NOx emissions being too high. The selective catalytic reduction (SCR) with ammonia (NH3) as reducing agent is the only approach today with the capability to meet upcoming emission limits. Therefore, the radio-frequency-based (RF) catalyst state determination to monitor the NH3 loading on SCR catalysts has a huge potential in emission reduction. Recent work on this topic proved the basic capability of this technique under realistic conditions on an engine test bench. In these studies, an RF system calibration for the serial type SCR catalyst Cu-SSZ-13 was developed and different approaches for a temperature dependent NH3 storage were determined. This paper continues this work and uses a fully calibrated RF-SCR system under transient conditions to compare different directly measured and controlled NH3 storage levels, and NH3 target curves. It could be clearly demonstrated that the right NH3 target curve, together with a direct control on the desired level by the RF system, is able to operate the SCR system with the maximum possible NOx conversion efficiency and without NH3 slip

The interactive web-based program MSmonitor for self-management and multidisciplinary care in multiple sclerosis:utilization and valuation by patients

Background: MSmonitor is an interactive web-based program for self-management and integrated, multidisciplinary care in multiple sclerosis. Methods: To assess the utilization and valuation by persons with multiple sclerosis, we held an online survey among those who had used the program for at least 1 year. We evaluated the utilization and meaningfulness of the program's elements, perceived use of data by neurologists and nurses, and appreciation of care, self-management, and satisfaction. Results: Fifty-five persons completed the questionnaire (estimated response rate 40%). The Multiple Sclerosis Impact Profile (MSIP), Medication and Adherence Inventory, Activities Diary, and electronic consultation (e-consult) were used by 40%, 55%, 47%, and 44% of respondents and were considered meaningful by 83%, 81%, 54%, and 88%, respectively. During out-patient consultations, nurses reportedly used the MSmonitor data three to six times more frequently than neurologists. As to nursing care, more symptoms were dealt with (according to 54% of respondents), symptoms were better discussed (69%), and the overall quality of care had improved (60%) since the use of the program. As to neurological care, these figures were 24%, 31%, and 27%, respectively. In 46% of the respondents, the insight into their symptoms and disabilities had increased since the use of the program; the MSIP, Activities Diary, and e-consult had contributed most to this improvement. The overall satisfaction with the program was 3.5 out of 5, and 73% of the respondents would recommend the program to other persons with multiple sclerosis. Conclusion: A survey among persons with multiple sclerosis using the MSmonitor program showed that the MSIP, Medication and Adherence Inventory, Activities Diary, and e-consult were frequently used and that the MSIP, Medication and Adherence Inventory, and e-consult were appreciated the most. Moreover, the quality of nursing care, but not so neurological care, had improved, which may relate to nurses making more frequent use of the MSmonitor data than neurologists

Describing sexual dimorphism and fine scale spatial distributions in the Drab Thick-tail Scorpion, Parabuthus planicauda

Southern Africa contains a diverse and endemic scorpion fauna, but with biological aspects remaining largely unexplored for this group. In order to  gain biological insights into an understudied scorpion species, the current study investigates fine-scale spatial distributions and sexual dimorphism in the South African endemic Drab Thick-tail Scorpion (Parabuthus planicauda). The species closely track rocky areas, with the sexes homogenously distributed across habitats. Varying adult sex ratios are evident at each sampling area, likely influenced by differing vegetation cover and predation pressures. When considering size-corrected measurements, several characters are significantly sexually dimorphic in P. planicauda; this sexual dimorphism is not readily observable (<10% difference in size) based on uncorrected measurements, thereby rendering the identification of males and females in the field difficult. Even so, sexually dimorphic characters in females appear to be shaped mainly by natural selection (e.g. carapace width, pedipalp patella and metasoma), likely for enhanced feeding ability, fecundity, parental care and juvenile survival. In contrast, the male morphology may be primarily subject to sexual selection pressures on features used during courtship and mating (e.g. pectines, chela movable finger, pedipalp femur, 2nd and 4th legs). Taken together, the results reported on here add novel preliminary information on the understudied  biological aspects of a South African endemic scorpion species. Keywords: Buthidae, Fynbos Biome, lithophilous, morphology, rupicolous, sexual selection, South Afric

Spatial genetic diversity in the Cape mole-rat, Georychus capensis : extreme isolation of populations in a subterranean environment

The subterranean niche harbours animals with extreme adaptations. These adaptations decrease the vagility of taxa and, along with other behavioural adaptations, often result in isolated populations characterized by small effective population sizes, high inbreeding, population bottlenecks, genetic drift and consequently, high spatial genetic structure. Although information is available for some species, estimates of genetic diversity and whether this variation is spatially structured, is lacking for the Cape mole-rat (Georychus capensis). By adopting a range-wide sampling regime and employing two variable mitochondrial markers (cytochrome b and control region), we report on the effects that life-history, population demography and geographic barriers had in shaping genetic variation and population genetic patterns in G. capensis. We also compare our results to information available for the sister taxon of the study species, Bathyergus suillus. Our results show that Georychus capensis exhibits low genetic diversity relative to the concomitantly distributed B. suillus, most likely due to differences in habitat specificity, habitat fragmentation and historical population declines. In addition, the isolated nature of G. capensis populations and low levels of population connectivity has led to small effective population sizes and genetic differentiation, possibly aided by genetic drift. Not surprisingly therefore, G. capensis exhibits pronounced spatial structure across its range in South Africa. Along with geographic distance and demography, other factors shaping the genetic structure of G. capensis include the historical and contemporary impacts of mountains, rivers, sea-level fluctuations and elevation. Given the isolation and differentiation among G. capensis populations, the monotypic genus Georychus may represent a species complex.A NRF research granthttp://www.plosone.orgMammal Research InstituteZoology and Entomolog

The Effect of the Thickness of the Sensitive Layer on the Performance of the Accumulating NOx Sensor

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Local and Regional Scale Genetic Variation in the Cape Dune Mole-Rat, <i>Bathyergus suillus</i>

<div><p>The distribution of genetic variation is determined through the interaction of life history, morphology and habitat specificity of a species in conjunction with landscape structure. While numerous studies have investigated this interplay of factors in species inhabiting aquatic, riverine, terrestrial, arboreal and saxicolous systems, the fossorial system has remained largely unexplored. In this study we attempt to elucidate the impacts of a subterranean lifestyle coupled with a heterogeneous landscape on genetic partitioning by using a subterranean mammal species, the Cape dune mole-rat (<i>Bathyergus suillus</i>), as our model. <i>Bathyergus suillus</i> is one of a few mammal species endemic to the Cape Floristic Region (CFR) of the Western Cape of South Africa. Its distribution is fragmented by rivers and mountains; both geographic phenomena that may act as geographical barriers to gene-flow. Using two mitochondrial fragments (cytochrome <i>b</i> and control region) as well as nine microsatellite loci, we determined the phylogeographic structure and gene-flow patterns at two different spatial scales (local and regional). Furthermore, we investigated genetic differentiation between populations and applied Bayesian clustering and assignment approaches to our data. Nearly every population formed a genetically unique entity with significant genetic structure evident across geographic barriers such as rivers (Berg, Verlorenvlei, Breede and Gourits Rivers), mountains (Piketberg and Hottentots Holland Mountains) and with geographic distance at both spatial scales. Surprisingly, <i>B. suillus</i> was found to be paraphyletic with respect to its sister species, <i>B. janetta–</i>a result largely overlooked by previous studies on these taxa. A systematic revision of the genus <i>Bathyergus</i> is therefore necessary. This study provides a valuable insight into how the biology, life-history and habitat specificity of animals inhabiting a fossorial system may act in concert with the structure of the surrounding landscape to influence genetic distinctiveness and ultimately speciation.</p></div