There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

비만아 부모의 돌봄 경험: q 방법론

Transformation and leaching behavior of Pb in hazardous waste incineration fly ash after thermal treatment with addition of Fe2O3.

Preparation of High-strength ceramsite from municipal solid waste incineration fly ash and clay based on CaO-SiO2-Al2O3 system

The structure and composition of the organic matter in landfilled refuse might have an influence on the migration and transformation of dibutyl phthalate (DBP). Humic acid (HA) and humin (HU) were separated from aged-refuse to determine the influences of different organic fractions in the refuse on the sorption and bioavailability of DBP. The sorption kinetics and isotherms for the sorption of DBP to HA, HU, and whole refuse were determined. The results showed that the sorption constants (K) and nonlinearities decreased in the order HU > whole refuse > HA. The HA had lower K values than did the other refuse fractions, and it retarded the biodegradation of DBP over a short degradation period (48 h). Increasing the amount of HA present caused the amount of DBP that was biodegraded to decrease significantly, 81.3% of the DBP sorbed to HA being degraded in the original experiments after 48 h but 21.8% of the DBP being degraded when three times as much HA was used. Similar results were not observed when the am...

The influences of different organic fractions in refuse on the sorption and bioavailability of dibutyl phthalate

Nitrogen pollution from landfills needs urgent treatment. A batch experiment was designed to explore the possible in situ nitrogen removal in landfills based on the hypothesis of microbial-pumping-iron behavior, namely anaerobic microbial iron oxidation and reduction. The results confirm that a simultaneous Fe(II) oxidation, accompanied by nitrate (NO3−-N) reduction and dissimilatory Fe(III) reduction, can happen in aged municipal solid waste (AMSW). This phenomenon can last at least 10 years after landfilling. Organics is an important intermediate medium in that process. The dynamic anaerobic Fe redox cycle has the potential of denitrification without ammonia nitrogen (NH4+-N) accumulation. AMSW with deposited ages of 1–3 years is a good choice to enhance this redox cycle behavior coupled with denitrification. Conversely, AMSW with longer deposited ages (8–10 years) has a quicker iron cycle and a smaller NH4+-N accumulation. This suggests a possible method for in situ nitrogen removal in landfills.

A possible method for in situ nitrogen removal in landfills by microbial-pumping-iron behavior.

In order to speed up rural domestic refuse resources utilization, intermittent aeration and continuous aeration were applied to treat rural domestic refuse after anaerobic fermentation. Three kinds of refuse were selected on base of fermentative age, i.e. three months, five months and seven months. Results showed that aeration could remove water and organic materials of the refuse effectively. Points of view on aeration, continuous aeration was better than intermittent aeration, and on the other side, water removal rate increased with ventilation and decreased with fermentative age in the condition of intermittent aeration. On organic materials removal point, it was affected by fermentative age significantly, i. e. increase of fermentative age could resulted in decrease in the removal efficiency. In conclusion, intermittent aeration of 0.06 m3/(min x m3) was considered to be feasible for treatment. The water removal efficiency of three months, five months and seven months fermentative age refuse could be up to 49.1%, 45.3% and 44.0%, and organic compound removal efficiency was 41.9%, 24.8% and 13.1%, respectively, after intermittent aeration for 21 d. Moreover, concentrated effect was presented on major nutrient ingredients, such as total nitrogen, phosphorus, and potassium during the aeration, which realized for resources utilization.

Dongsheng Shen

Papers

Transformation and leaching behavior of Pb in hazardous waste incineration fly ash after thermal treatment with addition of Fe2O3.

Preparation of High-strength ceramsite from municipal solid waste incineration fly ash and clay based on CaO-SiO2-Al2O3 system

The influences of different organic fractions in refuse on the sorption and bioavailability of dibutyl phthalate

A possible method for in situ nitrogen removal in landfills by microbial-pumping-iron behavior.

Novel resources utilization technique for rural domestic refuse