THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Hexagonal ferrites: A review of the synthesis, properties and applications of hexaferrite ceramics

The amendment of two agricultural soils with two biochars derived from the slow pyrolysis of papermill waste was assessed in a glasshouse study. Characterisation of both biochars revealed high surface area (115 m2 g−1) and zones of calcium mineral agglomeration. The biochars differed slightly in their liming values (33% and 29%), and carbon content (50% and 52%). Molar H/C ratios of 0.3 in the biochars suggested aromatic stability. At application rates of 10 t ha−1 in a ferrosol both biochars significantly increased pH, CEC, exchangeable Ca and total C, while in a calcarosol both biochars increased C while biochar 2 also increased exchangeable K. Biochars reduced Al availability (ca. 2 cmol (+) kg−1 to <0.1 cmol (+) kg−1) in the ferrosol. The analysis of biomass production revealed a range of responses, due to both biochar characteristics and soil type. Both biochars significantly increased N uptake in wheat grown in fertiliser amended ferrosol. Concomitant increase in biomass production (250% times that of control) therefore suggested improved fertiliser use efficiency. Likewise, biochar amendment significantly increased biomass in soybean and radish in the ferrosol with fertiliser. The calcarosol amended with fertiliser and biochar however gave varied crop responses: Increased soybean biomass, but reduced wheat and radish biomass. No significant effects of biochar were shown in the absence of fertiliser for wheat and soybean, while radish biomass increased significantly. Earthworms showed preference for biochar-amended ferrosol over control soils with no significant difference recorded for the calcarosol. The results from this work demonstrate that the agronomic benefits of papermill biochars have to be verified for different soil types and crops.

Effects of biochar from slow pyrolysis of papermill waste on agronomic performance and soil fertility

Role of organic amendments on enhanced bioremediation of heavy metal(loid) contaminated soils

A review on application of flocculants in wastewater treatment

To counteract the limitations which contaminants impose on the recycling process, the Complutense University of Madrid has developed a new method of stickie analysis and quantification. Called the Deposition Rotor Method, it comprises a rotor, a shaft and an axial flow propeller, the shaft being connected to an electric drill so that rotational speed can be controlled. The pulp suspension, propelled by centrifugal forces, is deposited on a surface, and the sticky material can be determined by surface weighting or by image analysis. A scanner developed by Pira is used to make the quantitative analysis of the deposits. The reproducibility of the deposition tester is good, and with it, it is possible to study the behaviour of the different disturbing substances which produce deposits in paper mills, and the influence of process variables on deposition.

Depositability character of disturbing substances

Learning by doing: Chem-E-Car® motivating experience

Reinforcing fibers have been widely used to improve physical and mechanical properties of cement-based materials. Most fiber reinforced composites (FRC) involve the use of a single type of fiber to improve cement properties, such as strength or ductility. To additionally improve other parameters, hybridization is required. Another key challenge, in the construction industry, is the implementation of green and sustainable strategies based on reducing raw materials consumption, designing novel structures with enhanced properties and low weight, and developing low environmental impact processes. Different recycled fibers have been used as raw materials to promote circular economy processes and new business opportunities in the cement-based sector. The valuable use of recycled fibers in hybrid FRC has already been proven and they improve both product quality and sustainability, but the generated knowledge is fragmented. This is the first review analyzing the use of recycled fibers in hybrid FRC and the hybridization effect on mechanical properties and workability of FRC. The paper compiles the best results and the optimal combinations of recycled fibers for hybrid FRC to identify key insights and gaps that may define future research to open new application fields for recycled hybrid FRC.

https://www.mdpi.com/1996-1944/14/9/2408/pdf

Recycled Fibers for Sustainable Hybrid Fiber Cement Based Material: A Review.

To optimise the retention of filler, a new measuring methodology has been developed. It utilises FBRM to control flocculant dosage and monitor the flocculation process - the interaction of fines and fillers with the flocculant is the key to filler retention. This feature presents a study of the interaction of calcium carbonate fillers - GCC and PCC - with three different flocculants, from the point of view of i) their flocculation, de-flocculation and re-flocculation; and ii) the influence of filler flocculation on retention and the drainage process. The FBRM technique, was transferred to papermaking from crystallisation processes by the author et al, and is now an established system for measuring flocculation. The methodology presented in this feature enables the optimisation of flocculant dosage, by monitoring, in real time, the mean chord size - the distribution of the chord lengths of filler particles and the number of counts - while a polymer solution is gradually added. The author describes the differences between ground and precipitated calcium carbonate in relation to flocculation mechanisms, floc properties and their effects on the retention and drainage processes. The retention of GCC particles is lower than PCC retention because GCC is more dispersed. But, PCC particles have a negative effect on drainage time, probable due to the blockage of pores.

Monitoring flocculation of fillers in papermaking

Pulp and paper industry is still an intensive water consumer, although fresh water use by this sector has decreased by 90% along the last three decades, which currently shows its long water reuse tradition Sustainable water management has been achieved by following the principle of water fit for use, which has mainly been developed through the optimization of water circuits, the cascade use of water, the implementation of internal water treatments, the optimal treatment of effluents to be reused and the use of alternative water sources, such as reclaimed water from municipal wastewater treatment plants In fact, this sector is nowadays regarded as a reference for water reuse Paper mills need to use fresh water to compensate evaporation losses and in critical applications In addition, the final degree of circuit closure depends on the quality of the final product For example, whereas unbleached paper grade mills may work with highly closed circuits, this is not usually possible for virgin pulp and bleached paper grade mills Filtration and dissolved air flotation are the most common treatments applied to internal water reuse Otherwise, the combination of physicochemical, biological and filtration technologies is generally considered to enable the reuse of mill effluents Finally, tertiary effluent from municipal wastewater treatment plants must be further treated by filtration technologies and disinfection stages to be finally reused within the papermaking process safely

Carlos Negro

Papers

Depositability character of disturbing substances

Learning by doing: Chem-E-Car® motivating experience

Recycled Fibers for Sustainable Hybrid Fiber Cement Based Material: A Review.

Monitoring flocculation of fillers in papermaking

Water Reuse Within the Paper Industry