Investigation into alternative sludge conditioning prior to dewatering

1997 ◽  
Vol 36 (11) ◽  
pp. 115-119 ◽  
Author(s):  
Maryla Smollen ◽  
Achmad Kafaar
Keyword(s):  
Laboratory Experiments ◽  
Structural Strength ◽  
Effective Alternative ◽  
Principal Objective ◽  
Solids Concentration ◽  
The Common ◽  
Sludge Conditioning ◽  
Domestic Refuse

The principal objective of this work is to provide a more effective alternative for sludge conditioning prior to mechanical dewatering. The common use of polyelectrolytes often results in the final cake solids concentration not sufficiently high for the sludge to be beneficially reused or safely disposed. The pyrolysed domestic refuse (char) was used to increase the structural strength and permeability of biological sludges in order to increase final cake solids concentration. The laboratory experiments have proven that the mixture of char and a small quantity of polyelectrolyte (0.5 to 1kg per ton of dry solids), used as a conditioner prior to centrifugation and filtration tests, produced cake solids concentration superior to that obtained by using polyelectrolyte on its own. Laboratory dewatering by filtration with admixture of char and polymer, resulted in cake solids concentration of 30 and above 40 per cent.

8. Experimental Research

2017 ◽  
Author(s):  
Sandra Halperin ◽  
Oliver Heath
Keyword(s):  
Experimental Design ◽  
Research Design ◽  
Experimental Research ◽  
External Validity ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Ethical Issues ◽  
Natural Experiments ◽  
The Common ◽  
Internal And External Validity

This chapter explores the principles of experimental research design as well as the issues and problems associated with different aspects of the approach. In particular, it considers the issue of internal and external validity, the common obstacles associated with experimental research, and what can be done to try and avoid or minimize them. The chapter first describes the five steps involved in the classic version of the experimental design before discussing three types of experimental design: laboratory experiments, field experiments, and natural experiments. It also examines the ethical issues that arise from experimental research and concludes by highlighting some of the advantages of experimental research.

scholarly journals Apples and Oranges: A Framework to Explore the Practiced Pedagogy in Experiential Learning

2015 ◽  
Vol 5 (3) ◽  
pp. 67 ◽  
Author(s):  
George Peter Banky ◽  
Aaron S Blicblau
Keyword(s):  
Teaching And Learning ◽  
Laboratory Experiments ◽  
Tertiary Education ◽  
Science And Engineering ◽  
Online Student ◽  
Scientific Training ◽  
Face To Face ◽  
Educational Environments ◽  
Experimental Learning ◽  
The Common

Experimental learning, traditionally conducted in on-campus laboratory venues, is the cornerstone of science and engineering education. To satisfy online student and accreditation requirements, the common practice has been to offer equivalent remote and/or simulated laboratory experiments in lieu of the ones delivered, face-to-face, on campus. The current implementations of both remote and simulated laboratories tend to be specified with a focus on technical characteristics, instead of pedagogical requirements. This work attempts to redress this situation by detailing a framework for the investigation of quality teaching and learning in existing and proposed experimental educational environments. For the tertiary education sector, involved with technical or scientific training, a tool capable of comparatively assessing the pedagogical limitations of laboratory venues is an important aid during the planning, designing and evaluating stages of face-to-face and online environments that facilitate student experimentation. Providing quality experimental learning venues has been identified as one of the distance-education providers’ greatest challenges.

Kaolin Particle Film Prevents Galling by Gynaikothrips uzeli

2009 ◽  
Vol 10 (1) ◽  
pp. 21 ◽  
Author(s):  
David W. Held ◽  
Corey Wheeler ◽  
David W. Boyd
Keyword(s):  
Laboratory Tests ◽  
Laboratory Experiments ◽  
Ornamental Plant ◽  
Effective Alternative ◽  
Ficus Benjamina ◽  
Choice Tests

Feeding by Gynaikothrips uzeli Zimmerman (Thysanoptera: Phlaeothripidae), a pest thrips, induces galls on the ornamental plant Ficus benjamina, which disfigures plants and can facilitate incidental transport of pests. This study evaluated foliar applications of azadirachtin (Azatin XL), bifenthrin (Talstar), or kaolin (Surround WP) to prevent galling in field and laboratory experiments. Azadirachtin did not significantly prevent galling, but kaolin-treated cuttings had 80% reduction in number of galls in laboratory tests, and in the field, kaolintreated plants had ≥ 74% reduction in number of galls versus unprotected plants. Weekly applications of kaolin provided comparable protection to bifenthrin. Laboratory choice and no-choice tests indicate kaolin is not lethal and adult G. uzeli do not avoid kaolin-treated surfaces. Particle film products are an effective alternative to insecticides for preventing leaf galls on weeping fig. Accepted for publication 18 February 2009. Published 7 April 2009.

Productive and Unproductive Labor and the Rate of Profit in Malthus, Ricardo, and Marx

1990 ◽  
Vol 12 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Robert Chernomas
Keyword(s):  
Central Theme ◽  
Principal Objective ◽  
Common Thread ◽  
The Common ◽  
Wealth Of Nations ◽  
Rate Of Profit ◽  
The Way

A principal objective of Malthus, Ricardo, and Marx was to discover the laws that regulate and limit the growth of the wealth of nations and, in particular, the unprecedented growth of capitalism. The central theme of this paper is that their productive and unproductive labor concepts are critical to understanding their analyses of capitalist growth and the tendency for the rate of profit to fall which regulates and limits this growth. The way in which they identify productive and unproductive labor and how they apply this distinction is critical to understanding the common thread that runs through and marks the differences between them.

Study on Performance of Normal and Compaction-Free Porous Concrete Permeable Base

2013 ◽  
Vol 723 ◽  
pp. 519-526
Author(s):  
Yan Ping Sheng ◽  
Hai Bin Li ◽  
Bo Wen Guan
Keyword(s):  
Structural Strength ◽  
Construction Technology ◽  
Early Failure ◽  
Porous Concrete ◽  
The Road ◽  
Vibration Compaction ◽  
The Common ◽  
Drainage Capacity ◽  
The Stability ◽  
Good Drainage

Moisture damage is one of the main forms of early failure in the pavement. Water can be released from the road structure by setting porous concrete permeable base. The common construction technology for porous concrete is traditional vibration compaction, which is helpful for the strength formation of the base. However, it is unhelpful for the stability and smoothness of the base during the construction. In this study, compaction-free porous concrete (CPC) permeable base was proposed, which can not only satisfies both porosity and the structural strength, but also guarantees the stability and the smoothness of the base during construction. The performance of normal porous concrete (NPC) and CPC, such as strength, drainage capacity, shrinkage and frost resistance, were studied in the paper. The laboratory tests show that all of them have good performance. In addition, the field evaluations, such as strength, drainage capacity, deflection, smoothness of the base, were tested. The results show that both of NPC and CPC have good drainage capacity, and the strength of NPC is higher than CPC, but the smoothness of NPC is weaker than CPC.

V. On the absorption and radiation of heat by gaseous and liquid matter.—Fourth memoir

1864 ◽  
Vol 154 ◽  
pp. 201-225 ◽  
Keyword(s):  
Royal Society ◽  
Laboratory Experiments ◽  
Radiant Heat ◽  
Powerful Source ◽  
The Subject ◽  
The Common ◽  
The Difference ◽  
Volatile Liquids ◽  
Permanent Gases ◽  
Gaseous Form

The Royal Society has already done me the honour of publishing in the Philosophical Transactions three memoirs on the relations of radiant heat to the gaseous form of matter. In the first of these memoirs* it was shown that for heat emanating from the blackened surface of a cube filled with boiling water, a class of bodies which had been previously regarded as equally, and indeed, as far as laboratory experiments went, perfectly diathermic, exhibited vast differences both as regards radiation and absorption. At the common tension of one atmosphere the absorptive energy of olefiant gas, for example, was found to be 290 times that of air, while when lower pressures were employed the ratio was still greater. The reciprocity of absorption and radiation on the part of gases was also experimentally established in this first investigation. In the second inquiry† I employed a different and more powerful source of heat, my desire being to bring out with still greater decision the differences which revealed themselves in the first investigation. By carefully purifying the transparent elementary gases, and thus reducing the action upon radiant heat, the difference between them and the more strongly acting compound gases was greatly augmented. In this second inquiry, for example, olefiant gas at a pressure of one atmosphere was shown to possess 970 times the absorptive energy of atmospheric air, while it was shown to be probable that when pressures of 1/30th of an atmosphere were compared, the absorption of olefiant gas was nearly 8000 times that of air. A column of ammoniacal gas, moreover, 3 feet long, was found sensibly impervious to the heat employed in the inquiry, while the vapours of many of the volatile liquids were proved to be still more opaque to radiant heat than even the most powerfully acting permanent gases. In this second investigation, the discovery of dynamic radiation and absorption is also announced and illustrated, and the action of odours and of ozone on radiant heat is made the subject of experiment.

scholarly journals Response of `Himrod' Grapevines to Cane Girdling

HortScience ◽  
1992 ◽  
Vol 27 (9) ◽  
pp. 975-976 ◽  
Author(s):  
Thomas J. Zabadal
Keyword(s):  
New York ◽  
New York State ◽  
Soluble Solids ◽  
Fruit Characteristics ◽  
Table Grapes ◽  
Solids Concentration ◽  
Vitis Labruscana ◽  
Central New York ◽  
The Common ◽  
Soluble Solids Concentration

The effect of cane girdling, in combination with the common commercial practices of gibberellic acid applications and/or other crop control, on vine size and fruit characteristics was measured over 3 years for `Himrod' grapevines (Vitis ×labruscana × V. vinifera) grown in central New York state. Cane girdles 4 mm wide between the second and third node from the base of each fruiting cane resulted in vines that were capable of sustaining vine size while enhancing several aspects of fruit quality. When added to several vine-manipulation regimes, cane girdling increased cluster weight as much as 106%, berries per cluster as much as 138%, and berry weight as much as 17%. Although cane girdling increased yield as much as 66%, it consistently reduced fruit soluble solids concentration (SSC). Therefore, for cane girdling to contribute to sustained production of quality `Himrod' table grapes in a cool-growing-season climate, it will be necessary to practice it in combination with a level of crop control that will ensure acceptable fruit SSC.

The Accuracy of Consumers’ Perception of Future Inflationary Price Changes

2011 ◽  
Vol 219 (4) ◽  
pp. 209-216 ◽  
Author(s):  
Fabian Christandl ◽  
Tommy Gärling
Keyword(s):  
Laboratory Experiments ◽  
Price Increase ◽  
Future Price ◽  
Time Interval ◽  
Price Changes ◽  
Price Increases ◽  
Proportional Increase ◽  
The Common

Four laboratory experiments were conducted to investigate the extent to which and how consumers encountering inflationary increases in product prices are able to accurately extrapolate future price increases. Between 32 and 48 undergraduates participated in the different experiments. In Experiment 1 it was found that participants were more able to extrapolate a proportional increase when presented with two consecutive proportional price increases compared to one price increase. This finding was not replicated for decreasing prices in Experiment 2. Experiment 3 showed that varying the time interval between prices counteracted an accurate extrapolation of proportional price increases despite that two price increases were presented. In Experiment 4 it was found that presenting the same (vs. different) proportional price increases for two products made participants able to extrapolate the common proportional price increase.

NEW APPROACHES FOR DISCOVERING EXCEPTION AND ANOMALOUS RULES

2011 ◽  
Vol 19 (02) ◽  
pp. 361-399 ◽  
Author(s):  
MIGUEL DELGADO ◽  
M. DOLORES RUIZ ◽  
DANIEL SÁNCHEZ
Keyword(s):  
Association Rules ◽  
Efficient Algorithms ◽  
Unified Framework ◽  
Useful Knowledge ◽  
New Approaches ◽  
Principal Objective ◽  
New Type ◽  
Logic Approach ◽  
The Common ◽  
The Relationship

Mining association rules is a well known framework for extracting useful knowledge from databases. Despite their proven applicability there exist other approaches that also search for novel and useful information such us peculiarities, infrequent rules, exceptions or anomalous rules. The common feature of these proposals is the low support of such type of rules. So there is a necessity of finding efficient algorithms for extracting them. The principal objective of this paper is providing a unified framework for dealing with such kind of rules. In our case, we take advantage of an existing logic approach called GUHA. This model was first presented in the middle sixties by Hájek et al. and then has been developed by Rauch and others in the last decade. Following this line, this paper also offers some interesting issues. First, it provides a deep analysis of semantics and formulation of exception and anomalous rules. Second, we define the so called double rules as a new type of rules which in conjunction with exceptions and anomalies will describe in more detail the relationship between two sets of items. Third, we give new approaches for mining them and we propose an algorithm with reasonably good performance.

8. Experimental Research

2020 ◽  
pp. 211-230
Author(s):  
Sandra Halperin ◽  
Oliver Heath
Keyword(s):  
Experimental Design ◽  
Research Design ◽  
Experimental Research ◽  
External Validity ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Ethical Issues ◽  
Natural Experiments ◽  
The Common ◽  
Internal And External Validity

This chapter explores the principles of experimental research design as well as the issues and problems associated with different aspects of the approach. In particular, it considers the issue of internal and external validity, the common obstacles associated with experimental research, and what can be done to try and avoid or minimize them. The chapter first describes the five steps involved in the classic version of the experimental design before discussing three types of experimental design: laboratory experiments, field experiments, and natural experiments. It also examines the ethical issues that arise from experimental research and concludes by highlighting some of the advantages of experimental research.

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