Developments in undergraduate wood science education at Stellenbosch University, South Africa

In South Africa, Stellenbosch University (SU) is the designated provider of Bachelor, Master and Doctorate level qualifications in Forestry and Wood Products Science. SU provides educational programs to both mechanical (sawmilling, preservation, composite products, furniture, etc.) and the chemical (pulp & paper) processing sectors. To ensure academic quality, SU regularly has her academic programs assessed externally. In 2000, several changes to the then existing 4 year B.Sc. Wood Science program were recommended. A restructured SU undergraduate program, similar to the B.Sc. Wood Products Processing program at the University of British Columbia (UBC), Vancouver, Canada, was consequently introduced in 2003. That same year, to provide more support to this effort, a partnership between UBC, SU and the Nelson Mandela Metropolitan University, the SA institution responsible for the National Diploma and Bachelor of Technology degrees in similar subjects, was established. The objective was to develop and deliver successful tertiary programs in value-added wood product processing education for South Africa and later, for other African countries as well. A Wood Products Processing Education Project, implemented in 2004 and running until mid 2010, funded by the respective partner institutions and the Canadian International Development Agency (CIDA) through the University Partnership in Cooperation and Development Program, was established. In addition to curriculum developments based on the UBC model, module content was modified to address relevant South African conditions. To make modules accessible to part-time students and members of industry off-campus, conversion of several Wood Products Science modules into e-learning format was implemented.A concise overview of Wood Science education at Stellenbosch University is given and the implementation and progress of the CIDA project at SU is briefly discussed. Solutions to the educational needs of the SA pulp & paper sector are also highlighted

Ultrastructural characterization (morphological and topochemical) of wood pulp fibres

Different electron microscopy techniques including SEM (scanning electron microscopy), FE-SEM (field emission-scanning electron microscopy), TEM (transmission electron microscopy) and Immuno-gold TEM (immuno-gold transmission electron microscopy) were applied in order to gain a better understanding of the influence of the native softwood fibre cell wall ultrastructure including morphology and topochemistry (i.e. lignin and glucomannan distribution) during mechanical pulping. In thermomechanical pulp (TMP) processing, wood fibres undergo structural changes (cell wall delamination and fibrillation) that are regulated by the native fibre micro- and ultrastructure. In addition, novel information was obtained on the fibre cell wall architecture. In contrast, the stoneground wood (SGW) process inflicted severe damage to the fibre structure resulting in transverse and longitudinal fibre breakage. However, juvenile wood SGW fibres showed improved properties (strength and light scattering) compared to mature wood. Ultrastructural aspects of fibre processing and development explained the differences in physical properties observed. During the SGW process, the native morphological fibre cell wall ultrastructure and microfibrillar organization governed the manner of juvenile wood fibre development similar to TMP fibres. Ultrastructural studies on Norway spruce and Scots pine TMPs revealed fundamental features that governed the different behaviour exhibited by the two wood species. Specific ultrastructural characteristics of pine TMP fibre cell walls were explored in relation to both morphology and topochemistry and that regulating the different pine fibre development mechanisms compared to spruce. The negative behaviour shown by Scots pine during TMP processing was most likely attributable to the observed fibre development mechanism. Histochemical techniques were applied to study wood resin associated problems during mechanical and kraft pulping. Studies provided information on the spatial micro-morphological distribution/redistribution of lipophilic extractives that were visualized on single fibre and cell wall fractions. Results from histochemical staining and chemical analysis performed on Norway spruce and Scots pine TMPs showed that there were morphological and chemical differences in the redistribution of extractives between the two species. This may further contribute to the effects of extractives on pulp- and paper properties and processing. Localization of lipophilic birch wood extractives involved in pitch problems was performed using histochemical techniques. Correlated information from gas chromatography-mass spectrometry and specific staining methods gave details on how extractives are removed during processing as well as information on the mechanisms of removal

User Interface and RF-Front End Design for Radio Direction Finding-Miniature Unmanned Air Vehicles (RDF-MUAV)

Radio direction finding perform better at high altitude due to greater line of sight coverage. In this paper, the radio direction finding-miniature unmanned air vehicles (RDF-MUAVs) platform able to localize the beacon by accessing the direction of signal and report it back to the ground station immediately, improving search and rescue operations. RDF-MUAV system divided into four major part; RF front end design; RF software design; ground station design; and user interface (UI). This paper focuses on two out of the four major parts, which designing a good UI and RF front end to be integrated into the system. The UI is designed using Linux, Apache, MySQL, PHP (LAMP) architecture in Raspberry Pi platform that can display accurate data obtained from RDF-MUAVs. The UI is based on HTML which is lightweight, modifiable and can be accessed through smartphone, tablets, or personal computer. In the antenna design, phase direction finder method is chosen. The rotation of antenna can be done by moving the UAV to obtain the bearing to the source signal. Proposed type of antenna is Yagi-Uda antenna due to its high gain and relatively small size. The folded dipole is chosen as the driven element of the antenna due to its bandwidth characteristics and directivity. Result shows the function-al bandwidth is 200MHz which can accept electromagnetic waves from 500MHz to 600MHz and 900MHz to 1000MHz. Overall, the design implementations provide a feasible system in search and rescue operation

Wood and fibre properties of fertilized Norway spruce

Very intensive forest management is relatively unexplored in Sweden, and while there is interest in pursuing e.g. the use of fertilizers on selected areas, there is concern about the quality of the wood when growth rate increases. This thesis summarises three studies on wood and fibre properties of Norway spruce grown in two nutrient optimisation experiments and one study from a Norway spruce provenance trial in Sweden. The nutrient optimisation trials were located at 57'08'N, 14'45'E and at 64'07'N, 19'27'E. Increment cores (12 mm diameter) were sampled at breast height from three different treatments and a control. The treatments were irrigation, irrigation combined with liquid fertilization and solid fertilization. Density, microfibril angle, cell wall thickness and radial and tangential cell widths were measured on the wood samples and averages per annual rings and fibre property distributions were analysed. Density, microfibril angle, and cell wall thickness were clearly affected by fertilization. Density and cell wall thickness decreased due to fertilization and microfibril angle increased. Cell widths were moderately affected. Variables describing the inherent development from the pith, such as distance or ring number from pith and ring width, an expression of temporal growth rate and an indicator of varying amounts of earlywood and latewood, were the most important factors explaining differences in fibre properties. The provenance study was situated at 57'56'N, 5'39'E. The differences in density found between provenances were lower than differences caused by fertilization. The possible impact of intense commercial fertilization of Norway spruce for utilization in the pulp and paper industry is discussed

Trends and possible future developments in global forest-product markets - implications for the Swedish forest sector

This paper analyzes trends and possible future developments in global wood-product markets and discusses implications for the Swedish forest sector. Four possible futures, or scenarios, are considered, based on qualitative scenario analysis. The scenarios are distinguished principally by divergent futures with respect to two highly influential factors driving change in global wood-product markets, whose future development is unpredictable. These so-called critical uncertainties were found to be degrees to which: (i) current patterns of globalization will continue, or be replaced by regionalism, and (ii) concern about the environment, particularly climate change, related policy initiatives and customer preferences, will materialize. The overall future of the Swedish solid wood-product industry looks bright, irrespective of which of the four possible futures occurs, provided it accommodates the expected growth in demand for factory-made, energy-efficient construction components. The prospects for the pulp and paper industry in Sweden appear more ambiguous. Globalization is increasingly shifting production and consumption to the Southern hemisphere, adversely affecting employment and forest owners in Sweden. Further, technical progress in information and communication technology (ICT) is expected to lead to drastic reductions in demand for newsprint and printing paper. Chemical pulp producers may profit from a growing bio-energy industry, since they could manufacture new, high-value products in integrated bio-refineries. Mechanical pulp producers cannot do this, however, and might suffer from higher prices for raw materials and electricity

Research of a fibrous layer at refining in the refiners

A subject of research-a fibrous layer in the refiners at refining. By means of the tension compression chart it is shown that parameters of a fibrous layer are adequately described by Maxwell-Thompson's model for liquid friction and the Hooke model for boundary friction of a plate. Deborah's number of a fibrous layer is also investigated. Deborah's number of a fibrous layer at refining changes in the range from 7 to 2.1•106 and depends on a nature and concentration of the refining material, the angle of knife crossing, the frequency of rotation of rotor and width of the platform of contact. For decrease in power consumption at refining both chips and pulp of high concentration it is recommended to increase the speed of sliding of knife of rotor along stator knife. It is possible to reach by increase in frequency of rotation of rotor and by decrease of an angle of crossing of knife. At refining of pulp of low concentration for decrease in power consumption of refining it is recommended to reduce the frequency of rotation of rotor and to increase the angle of crossing of knife of rotor and stator. At the high density of contact of plate knife in the range from 5 to 106 of Deborah number the deformation component of friction coefficient decreases together with power consumption of refining process. © 2019 IOP Publishing Ltd. All rights reserved

Modification of kraft wood-pulp fibre with silica for surface functionalisation

A new science strategy for natural fibre modification was devised in which glass surface properties would be imparted to wood-derived fibre. The enhancements known from addition of silane reagents to glass fibre–polymer composites could therefore be realised for modified cellulose fibre–polymer composites. A process is described whereby the internal void spaces and micropores of never-dried Kraft pulp fibre walls were impregnated with silica. This was achieved by initial dehydration of never-dried fibre through azeotropic distillation to achieve substitution of fibre water with the silicon chemical solution over a range of concentrations. Kraft fibres were stiffened and made resistant to collapse from the effect of the azeotrope drying. Specific chemical reaction of azeotrope-dried fibre with the reagent ClSi(OEt)3 followed by base-catalysed hydrolysis of the ester groups formed a fibre-bound silica composite. The physico-chemical substitution of water from micropores and internal voids of never-dried fibre with property-modifying chemicals offers possibilities in the development of new fibre characteristics, including fibres which may be hardened, plasticised, and/or stabilised against moisture, biodegradation or fire. The embedded silica may also be used as sites of attachment for coupling agents to modify the hydrophilic character of the fibre or to functionalise the fibre surface

Simulation analysis of energy production in the B. C. pulp and paper industry

ABSTRACT This paper describes a dynamic simulation model of energy production and use by pulp and paper mills. The model can be used to assess the costs and benefits of the use of different proportions of wood waste (referred to as 'hog fuel') and fossil fuels to generate process steam and electricity, with the costs and benefits measured from several points of view, principally those of the mill management and of the economy as a whole. Using either point of view, the model has been fitted to the eighteen major pulp and paper mills in British Columbia, and used to assess the consequences of the size and nature of optimal hog fuel projects. Some results are reported in this paper and references are given to other papers containing more complete results of various aspects of the research project. INTRODUCTION Whenever there are big changes in technology or relative prices, many of the standard rules of thumb for optimal choices fall apart, and many new alternatives have to be considered in a systematic way. This offers great scope for the design and use of simulation models that capture the key elements of an industrial process and expose the key alternatives for This paper was presented to the conference on Simulation Modelling and Decision in Energy Systems, held in Montreal in June, 1978 and sponsored by the International Association of Science and Technology for Development. It represents early results of work also reported in [1], [2], [3] and [4]. While Helliwell is a continuing member of U.B.C.'s Department of Economics, Cox is currently at M.I.T.'s Energy Laboratory Cambridge, Mass

Vibration processes in the knife refining machines

An object of research is a vibration of the stator of the knife refining machines and its interrelation with the factors which influences the course of refining among them are technical condition of a plate and change of characteristics of the ground material. The diagnostic model of process of refining is developed and positively approved. The new method of determination of degree of wear of the refining plate of refiners is offered. The new method of management of functioning of the knife refining machines is developed. It is shown that management of work on this indirect indicator is not worse, than the management based on the earlier known diagnostic signs of refiners functioning. The developed method of management is indispensible for the refiners with stepwise regulation of a gap, in a disk-conic refiners and in a dual refiners. Realization of this method under production conditions showed stable characteristics of a gain in degree of refining of a semi-finished fibrous product and decrease in specific power consumption during refining. The developed methods can be used in other branches of industry, for example, mining and metallurgy. © 2019 IOP Publishing Ltd. All rights reserved