Application of an On-machine Gage for Diameter Measurements

This paper describes the design analysis and application of a laser based gage made specifically for measuring parts on the machine tool to a high accuracy. The tri-beam gage uses three beams of light to measure the local curvature of the part in a manner similar to a V-block gage. The properties of this design include: calibration that is independent of the machine tool scales, non-contact damage free operation, low cost of the gage, and the ability to measure parts in motion

Development of Moire machine vision

Three dimensional perception is essential to the development of versatile robotics systems in order to handle complex manufacturing tasks in future factories and in providing high accuracy measurements needed in flexible manufacturing and quality control. A program is described which will develop the potential of Moire techniques to provide this capability in vision systems and automated measurements, and demonstrate artificial intelligence (AI) techniques to take advantage of the strengths of Moire sensing. Moire techniques provide a means of optically manipulating the complex visual data in a three dimensional scene into a form which can be easily and quickly analyzed by computers. This type of optical data manipulation provides high productivity through integrated automation, producing a high quality product while reducing computer and mechanical manipulation requirements and thereby the cost and time of production. This nondestructive evaluation is developed to be able to make full field range measurement and three dimensional scene analysis

Fish farm effluent as a nutrient source for algae biomass cultivation

One of the challenges of microalgae biotechnology is the cost of growth media nutrients, with microalgae consuming enormous quantities of fertilisers, more than other oil crops. The traditional use of synthetic fertilisers in mass cultivation of microalgae is associated with rising prices of crude oil and competition from traditional agriculture. The fact that fish farm wastewater (FFW) nutrients are released in the form preferred by microalgae (NH3 for nitrogen and PO4 -3 for phosphate), and the ability of microalgae to use nitrogen from different sources, can be exploited by using fish farm effluent rich in nutrients (nitrogen and phosphorus) in the cultivation of cheaper microalgae biomass for production of biodiesel. The cultivationof algae biomass in FFW will also serve as wastewater treatment. We reviewed the benefits and potential of fish effluent in algae cultivation for the production of biodiesel. Microalgae can utilise nutrients in FFW for different applications desirable for the production of biomass, including the accumulation of lipids, and produce a fuel with desirable properties. Also, treating wastewater and reducing demand for fresh water are advantageous. The high lipid content and comparable biodiesel properties of Chlorella sorokiniana and Scenedesmus obliquus make both species viable for FFW cultivation for biodiesel production. Significance: The cost associated with microalgae growth media nutrients can be saved by using fish farm wastewater,which contains nutrients (nitrogen and phosphorus) suitable for microalgae cultivation. Fish farm wastewater has lower nutrient concentrations when compared to standard growth media suitable for higher lipid accumulation. Microalgae used as a biodiesel feedstock, cultivated in fish farm wastewater, has added benefits, including wastewater treatment

Application of the water footprinting method and water accounting framework to a base metal refining process

The key to a sustainable future lies in understanding and utilising resources more efficiently. This holds especially for industries that seek to minimise water usage through better management of resources. Most mineral processing plants have high water requirements, yet often function in an environment where water is becoming increasingly scarce. Further, an increase in population will result in an even greater demand for water, potentially beyond the limits of supply. This would lead to even greater competition for the resource. In South Africa, Gauteng and the North West Provinces are likely to be the first to experience a shortage of potable water. A base metals refinery in Rustenburg sought to understand and minimise its potable water usage, as well as report its usage using global tools and frameworks. The two tools used in this study were the Minerals Council of Australia’s ‘Water Accounting Framework for the Minerals Industry’ (WAF) and the Water Footprinting method (WF). The potable water and stormwater systems were surveyed to assess and determine methods to improve water accountability. Using information from the survey, monthly and yearly water balances were presented in the form of a water balance sheet. Using data from the water balance, an input-output and operational model were drawn up in accordance with the WAF. The WAF models assisted in reporting data in a universally consistent manner. Blue, green and grey WFs were calculated for the refinery and recommendations were made to achieve savings in water consumption.Keywords: water, base metals, water footprint, water accounting framewor

Selecting hybrid pine clones for deployment - The pointy end of wood quality improvement

A clonal forestry research programme on Pinus elliottii Engelm. (slash pine) x P. caribaea Morelet var. hondurensis Barrett & Golfari (Caribbean pine) hybrids commenced in Queensland in 1986. Each cycle of clonal tests covered about 5 calendar years from field planting, and studies of wood quality variation have so far been used in selecting superior clones from the first three series of tests for commercial plantation deployment. Experience from the Series III clonal selection round is used to highlight the difficulties of ranking elite clones given a large number of growth, form, and wood property traits. Three to six ramets were felled from the best 32 clones in the Series III trials at age 6.8 years and a 3-m butt log from each was sawn into 70 × 35-mm structural boards. The clones sawn were ranked for routine deployment using data on growth, form, and wood traits. All recovered boards were assessed for distortion and tested for modulus of elasticity and modulus of rupture. Various non-destructive wood evaluation methods were used to estimate modulus of elasticity (wood stiffness) in these trees. Standing tree acoustic velocity assessed with an ST300 tool was slightly less strongly correlated phenotypically with the average modulus of elasticity of the recovered boards (r = 0.88**) than with predictions of modulus of elasticity from resonance vibration test samples and SilviScan estimates (both r = 0.89**). Moderate phenotypic relationships were found for individual tree means between average twist of the sawn boards and the average spiral grain angle of growth rings 2, 3, and 4 (r = 0.70**) assessed using a breast-height 12-mm increment core, and between average bow in the boards and average microfibril angle (r = 0.64**) from SilviScan assessments of core samples

Evaluation of fuel quality of invasive alien plants and tropical hardwoods as potential feedstock materials for pyro-gasification

DATA AVAILABILITY : Experimental data and material used in this study may be made available on request.INTRODUCTION: Despite several studies carried out on the effects of the fuel properties of raw biomass on the final fuel properties of the biofuel after a thermochemical conversion, an identification and grading of various biomass types with respect to the level of their viability for pyro-gasification has not been established. OBJECTIVES: The primary objective of this study was to identify and rank eight waste wood feedstocks based on the suitability of their fuel properties for an efficient pyro-gasification using experimental data. METHODS: The wood samples were characterized using standard experimental procedures to determine their fuel properties. Five fuel evaluators relevant to the efficiency of a pyro-gasification process, were developed. The experimental data collated for each sample was used to carry out an evaluation exercise of the samples under each of the five fuel evaluators. Finally, the result of this exercise was used to rank the wood samples based on their suitability as feedstock for pyro-gasification. RESULTS: The hardwoods such as the Eucalyptus and African mesquite exhibited high fuel ratios, heating value and energy density which was as result of their higher lignin content. However, they exhibited minimal char reactivity. Conversely due to its higher holocellulose-to-lignin ratio, the Bugweed exhibited high char reactivity but lower fuel ratio, heating value and energy density. In comparison to the literature, the experimental results in this study were somewhat consistent with those of other biomass samples previously reported. The Fuel characterization exercise reveals that no wood sample can be considered completely efficient for pyro-gasification. The Jacaranda was however ranked lowest across the board. CONCLUSION: The variations in the hierarchy of the samples under the different fuel evaluators due to the disparities in their fuel properties paves way for further studies on the blending of waste wood samples with contrasting fuel properties in different mix ratios. This would enable the production of feedstock with the right balance in fuel properties suitable for an efficient pyro-gasification process. This study provides stakeholders with a framework for blending different lignocellulosic biomass species for thermochemical conversion.The TWAS-NRF doctoral research grant.https://link.springer.com/journal/12649hj2023Chemical Engineerin

Potentials of torrefied pine sawdust as a renewable source of fuel for pyro-gasification : Nigerian and South African perspective

The impacts of fossil energy on the climate and environment emphasize the need for alternative energy resources. The use of waste wood is one such method to potentially reduce fossil-based energy dependence. However, raw biomass fuel properties are generally poor and unpredictable, thus requiring pretreatment to maximize their energy potentials for an efficient conversion to syngas via pyrogasification. Two species of pine sawdust (PSD) wastes generated in abundance from large-scale timber industries in Nigeria and South Africa were investigated for improvements in their fuel properties after torrefaction. Samples were torrefied under optimum conditions of 300 °C and 45 min. Different analytical procedures show that the higher heating value (HHV), enhancement factor, energy density, and solid yield of the Nigerian PSD exceeded those of their South African counterpart by 2.38, 5.37, 3.49, and 11.15%, respectively. The HHV of the torrefied fuels increased by 57.29 and 37.9% for the Nigerian and South African PSDs, respectively, when compared to the raw fuels. Also investigated were improvements in their H/C and O/C ratios and thermal degradation at varied heating rates.http://pubs.acs.org/journal/acsodfpm2021Chemical Engineerin

Potentials of torrefied pine sawdust as a renewable source of fuel for pyro-gasification : Nigerian and South African perspective

Abstract: The impacts of fossil energy on the climate and environment emphasize the need for alternative energy resources. The use of waste wood is one such method to potentially reduce fossil-based energy dependence. However, raw biomass fuel properties are generally poor and unpredictable, thus requiring pretreatment to maximize their energy potentials for an efficient conversion to syngas via pyrogasification. Two species of pine sawdust (PSD) wastes generated in abundance from large-scale timber industries in Nigeria and South Africa were investigated for improvements in their fuel properties after torrefaction. Samples were torrefied under optimum conditions of 300 °C and 45 min. Different analytical procedures show that the higher heating value (HHV), enhancement factor, energy density, and solid yield of the Nigerian PSD exceeded those of their South African counterpart by 2.38, 5.37, 3.49, and 11.15%, respectively. The HHV of the torrefied fuels increased by 57.29 and 37.9% for the Nigerian and South African PSDs, respectively, when compared to the raw fuels. Also investigated were improvements in their H/C and O/C ratios and thermal degradation at varied heating rates

Systematics expertise and taxonomic status of New Zealand’s freshwater insects

Insects are important to ecosystem functioning in freshwater habitats. They have a rich diversity, fill every ecological niche, and as predators and scavengers and the prey of larger species, they play a vital role in nutrient cycling. There is no doubt that aquatic insects are under considerable threat in New Zealand (Grainger et al. 2014, Joy & Death 2014, Weeks et al. 2016, Collier et al. 2016). Some freshwater species are iconic to New Zealanders, like the ubiquitous sandflies with aquatic larvae (Craig et al. 2012), but also known to many systematists worldwide are New Zealand’s endemic species, like the primitive dragonfly Uropetala chiltoni Tillyard (Petaluridae) or the ice worm Zelandochlus latipalpis Brundin (Chironomidae). To most biologists and almost any informed layperson, aquatic insects (along with a number of other invertebrates) are well-known biological indicators of water quality. The exact number of freshwater insects is unknown, but estimates range from 640–800 described species in New Zealand (McFarlane et al. 2010, Weeks et al. 2016). They exhibit intriguing adaptations to their stream environments that include symbiotic relationships (commensalism and phoresy) of chironomid midge larvae with mollusks, flies and mayflies (Forsythe & McCallum 1978, Winterbourn 2004, Cranston 2007), live birth (viviparity) in the caddisfly Triplectides cephalotes (Walker) (Pendergrast & Cowley 1966; Morse & Neboiss 1982) and adaptations to torrential water velocities (e.g. Blephariceridae) that make them interesting model organisms for ecological and evolutionary study (Buckley et al. 2015, McCulloch et al. 2016). New Zealand’s long geographic isolation has led to high levels of regional and national endemism (Gibbs 2006), and biogeographic studies of aquatic insects have helped to reconstruct the geologic and climatic histories of New Zealand’s ancient terrains and weathered landscapes

GRB Polarimetry with POET

POET (Polarimeters for Energetic Transients) represents a concept for a Small Explorer (SMEX) satellite mission, whose principal scientific goal is to understand the structure of GRB sources through sensitive X‐ray and γ‐ray polarization measurements. The payload consists of two wide field‐of‐view (FoV) instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2–15 keV and a high energy polarimeter (Gamma‐Ray Polarimeter Experiment or GRAPE) that would measure polarization in the 60–500 keV energy range. The POET spacecraft provides a zenith‐pointed platform for maximizing the exposure to deep space. Spacecraft rotation provides a means of effectively dealing with any residual systematic effects in the polarization response. POET provides sufficient sensitivity and sky coverage to measure statistically significant polarization (for polarization levels in excess of 20%) for ∼80 GRBs in a two‐year mission. High energy polarization data would also be obtained for SGRs, solar flares, pulsars and other sources of astronomical interest