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

An electrochemical treatment can be applied to remove lignin from the weak black liquor (WBL) from pulping plants, concomitantly with sodium salts' convertion into caustic soda, that can be reused in the pulping process or in other sequences, depending on the required. concentration. The electrolytic processing of kraft weak black liquor from a pulp mill, using straw as raw material, was studied at laboratory scale in a batch mode. The main problem found was anode's. high fouling, which was solved by using platinum wire anodes in combination with high current density through the anode and turbulent flow of the WBL in the anode compartment. To avoid anode's fouling, the velocity of the WBL in the cell was critical, while current density and temperature optimization were critical for the economical viability of the process.

Electrochemical treatment of straw weak black liquor from a kraft pulping plant

Cellulose nanofibers (CNF) are sustainable nanomaterials, obtained by the mechanical disintegration of cellulose, whose properties make them an interesting adsorbent material due to their high specific area and active groups. CNF are easily functionalized to optimize the performance for different uses. The hypothesis of this work is that hydrophobization can be used to improve their ability as adsorbents. Therefore, hydrophobic CNF was applied to adsorb hexavalent chromium from wastewater. CNF was synthetized by TEMPO-mediated oxidation, followed by mechanical disintegration. Hydrophobization was performed using methyl trimetoxysilane (MTMS) as a hydrophobic coating agent. The adsorption treatment of hexavalent chromium with hydrophobic CNF was optimized by studying the influence of contact time, MTMS dosage (0–3 mmol·g−1 CNF), initial pH of the wastewater (3–9), initial chromium concentration (0.10–50 mg·L−1), and adsorbent dosage (250–1000 mg CNF·L−1). Furthermore, the corresponding adsorption mechanism was identified. Complete adsorption of hexavalent chromium was achieved with CNF hydrophobized with 1.5 mmol MTMS·g−1 CNF with the faster adsorption kinetic, which proved the initial hypothesis that hydrophobic CNF improves the adsorption capacity of hydrophilic CNF. The optimal adsorption conditions were pH 3 and the adsorbent dosage was over 500 mg·L−1. The maximum removal was found for the initial concentrations of hexavalent chromium below 1 mg·L−1 and a maximum adsorption capacity of 70.38 mg·g−1 was achieved. The kinetic study revealed that pseudo-second order kinetics was the best fitting model at a low concentration while the intraparticle diffusion model fit better for higher concentrations, describing a multi-step mechanism of hexavalent chromium onto the adsorbent surface. The Freundlich isotherm was the best adjustment model.

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Modeling of Hexavalent Chromium Removal with Hydrophobically Modified Cellulose Nanofibers

Abstract In this work a wide sample analysis, under similar conditions, has been carried out and a calibration strategy based on a careful selection of input variables combined with sensitivity analysis has enabled us to build accurate neural network models, with high correlation (R &gt; 0.99), for the prediction of the aspect ratio of micro/nanofiber products. The model is based on cellulose content, applied energy, fiber length and diameter of the pre-treated pulps. The number of samples used to generate the neural network model was relatively low, consisting of just 15 samples coming from pine pulps that had undergone thermomechanical, kraft and bleached kraft treatments to produce a significant range of aspect ratio. However, the ANN model, involving 4 inputs and 4 hidden neurons and calibrated on the basis of pine dataset, was accurate and robust enough to predict the aspect ratio of micro/nanofiber materials obtained from other cellulose sources including very different softwood and hardwood species such as Spruce, Eucalyptus and Aspen (R = 0.84). The neural network model was able to capture the nonlinearities involved in the data providing insight about the profile of the aspect ratio achieved with further homogenization during the fibrillation process. 

/pdf/artificial-neural-network-for-aspect-ratio-prediction-of-1elaopnn.pdf

Artificial neural network for aspect ratio prediction of lignocellulosic micro/nanofibers

The aim of the research project presented in this paper is to devise a process to treat waste liquors from the pickling of iron or steel with hydrochloric acid in rolling mills, recovering the high iron content in the form of oxides or oxyhydroxides which can later be used in other industrial processes. In addition to reducing water pollution, such a process attaches a new value to this ferrous waste. Chlorinated liquors are oxyprecipitated, leading to the formation of different combinations of iron oxides and oxyhydroxides, with the total removal of Fe+2 and the production of ammonium chloride solutions easily broken down into hydrochloric acid and ammonia. The precipitates have different industrial outlets, making the oxyprecipitation process an attractive solution for the treatment of waste pickling liquors.

Kinetics and mechanism of the oxyprecipitation of waste hydrochloric pickling liquors

Microbial deposits (slime or biofilm) formation is one of the most important problems in the paper industry. Slime formation cause a reduction of the final product quality (spots, holes, odours), as well as in the production and equipment life, due to a greater number of web breaks, down time for cleaning and maintenance of the machinery, corrosion, etc. Microbiologically-induced corrosion cause an important economic losses due to the reduction of the equipment life. In microbially-induced corrosion studies is basic the rapid and precise determination of the evolution of slime growth on metallic surfaces. Thus, the goal of the present work have been the development of a methodology that leads to characterize the population of aerobic bacteria that compose the slimes of a board mill by means of multiparametric flow cytometry, using two different angles of light scattering and the total protein content as parameters, as first step of the studies of microbiologically-induced corrosion.

/pdf/corrosion-inducida-por-microorganismos-en-la-industria-1hz9oixezz.pdf

Carlos Negro

Papers

Electrochemical treatment of straw weak black liquor from a kraft pulping plant

Modeling of Hexavalent Chromium Removal with Hydrophobically Modified Cellulose Nanofibers

Artificial neural network for aspect ratio prediction of lignocellulosic micro/nanofibers

Kinetics and mechanism of the oxyprecipitation of waste hydrochloric pickling liquors

Corrosión inducida por microorganismos en la industria papelera