Effects of adding organic materials to an acid sulfate soil on the growth of cocoa (Theobroma cacao L.) seedlings

Acid sulfate soils having a pH of less than 3.5 are widespread in Malaysia. Some of these soils are planted to cocoa, but the yield is reported to be low due to soil infertility related to Al toxicity. Cocoa growth is sensitive to the presence of Al in the soil. To a certain extent, Al toxicity in soils can be reduced by organic matter application and to a greater extent in iron-poor acid sulfate soil. A study was conducted to determine the efficacy of various types of organic materials easily available in the country to ameliorate acid sulfate soil infertility for growing cocoa seedlings. The treatments were control (nil), lime (3 t/ha), peat (10% w/w), peat plus green manure (10% w/w), peat plus rice straw (10% w/w), peat plus chicken dung (10% w/w) and peat plus POMS (Palm oil mill sludge) (10% w/w). The growth of cocoa seedlings was affected significantly by the presence of Al in the cocoa tissues. As the amount of Al in the leaves increased, the relative top dry weight of cocoa seedlings decreased. Likewise, the relative plant height was negatively correlated with Al in the leaves. Peat as well as peat in combination with green manure, rice straw, chicken dung or palm oil mill sludge was able to reduce Al toxicity in acid sulfate soil; the highest top dry weight of cocoa seedlings were obtained in the peat plus green manure treatment. The best cocoa seedlings root growth was found for the peat treatment alone. The relative top dry weight of cocoa seedlings was negatively correlated with Al(3+) as well as Al(3+)+Al(OH)(2+)+Al(OH)(2)(+) activity in the soil solution. The critical values for Al(3+) and the combination of Al(3+)+Al(OH)(2+)+Al(OH)(2)(+) activity in the soil solution were 10 microM and 15 microM, respectively.     

Noise impact caused by electrical energy substations in the city of Curitiba, Brazil

This survey is intended to characterize the noise impact due to electrical energy substations in the city of Curitiba over the population living in their vicinity. This impact has been studied with the aid of a computational tool capable of mapping the acoustical field of substations and their vicinity. Several factors have been considered in this survey: (1) sound power of the transformers; (2) vehicle flow on the surrounding roads; (3) positioning of the firewalls, buildings and walls; and (4) terrain topography. Four substations have been analyzed, and an acoustical map has been traced for each of them. With these maps it was possible to visualize what was the incident noise level on the building facades. The predicted noise levels have been compared to the environmental legislation of the noise emissions in effect in the city.     

Experience with the preconstruction of thawing of soils in the foundation bed of the main building of the Neryungrinsk state area power plant

Conclusions 1. The scheme that we developed is efficient and ensures thawing over a period of 40–45 days. 2. To accelerate thawing by 8–10 days when using two electric heaters in each hole, it is necessary to raise the heaters by 3–4 m after 25 days and continue thawing. 3. An 8–10-day reduction in the thaw time is also possible by using three 1.25-kW electric heaters in each hole in place of two heaters of the same capacity, installing them at depths of 20, 14, and 8 m from the surface. Taking the results of the experimental work account, the State Institute for Special Design developed a plan for the production preconstruction thawing of soils over a area of 12,380 m². The volume of soil thawed was 324,400 m³. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 3, pp. 7–8. May–June, 1982.     

Extending the Q system's prediction of support in tunnels employing fuzzy logic and extra parameters

Rock mass classifications predict support measures according to expert rules by rating rock mass and taking into account the span of the opening. A similar procedure is adopted, in this work, and computerized using statistics and fuzzy logic. Fuzzy expert systems are trained with data of previously constructed underground openings. Using subtractive clustering the systems have the intelligence to pick up the relations between input and output and define the rules that represent the system's behavior automatically. These systems are found to predict support to be used more successfully than the Q system. With the introduction of extra input variables, which are important in numerical analysis, such as depth and intact rock strength, an extended fuzzy system is developed. This system is suggested for preliminary use as it is able to predict support even better.     

Online Documentation for Engineering Software: A Hypertext Application

Abstract: This article describes the use of 'hypertext' as a means to document engineering software online. An extensive hypertext document can be built with relative ease using an authoring tool. Hypertext documents enhance the learning process through the association of facts. The user has the freedom to arrange his/her own study sequence in a particular session. The article provides a brief introduction to the hypertext technology and authoring tools, and describes a Mohr's Circle program, which has been developed to explore the use of hypertext for online users' manuals. The strengths and weaknesses of the software tool, KnowledgePro, as well as the development techniques, are discussed.     

Hybrid reactor for priority pollutant-trichloroethylene removal

The present study was initiated to explore the potential of a hybrid biological reactor, combining trickling filter (TF) and activated sludge process (ASP), to treat wastewater containing trichloroethylene (TCE) at ambient temperature at different hydraulic retention time (HRT). The biofilm acclimation was achieved in 55-60 days with gradual increase in TCE concentration from 1 mg/l to 100 mg/l with a parallel increase in the concentration of substrate sodium acetate and other nutrients. COD and TCE concentration were taken as prime parameters for monitoring the growth of biofilm. During acclimation COD removal varied between 54.6-97.5% while TCE was removed 72.6-99.9%. HRT study was performed after acclimation. The removal efficiency increased with decreasing flow rate with maximum TCE removal (99.99%) at 6 l/d corresponding to an HRT of 28 h (TF 18 h + ASP 10 h). This was followed by a C:N:P ratio study. A ratio of 100:20:1 led to the sustenance of maximum TCE removal. Maximum TCE removal (99.99%) was observed at a substrate:cosubstrate ratio of 100:1. A pH of 7.4 +/- 0.2 was found to be optimum for degradation. Finally, volatilization losses were estimated to be 18.5%. A mass balance gave an efficiency of 81.51% for biological removal of TCE.     

Probabilistic calculation for the bed under an individual foundation in accordance with the second group of limiting states

Conclusions 1. The method proposed for the probabilistic design of beds makes it possible to obtain a well-founded design solution corresponding to a given reliability level, which, in many cases, is more economic than the solution recommended in the Construction Rules and Regulations. 2. The design solution adopted as a result of the calculation set forth in the Construction Rules and Regulations possesses a reliability level, which, for some unknown reason, is on the high side. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 18–20, March–April 1991.     

SEM-EDX analysis in the source apportionment of particulate matter on Hypogymnia physodes lichen transplants around the Cu smelter and former mining town of Karabash, South Urals, Russia

Scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX) of particulate matter on lichen transplant thalli (Hypogymnia physodes) was assessed as a complementary technique to wet chemical analysis for source apportionment of airborne contaminants. Transplants (2 month exposure) stationed in the Cu smelter and former mining town of Karabash were compared with those from a control site 30 km south. Particulate matter in Karabash samples (715 analyses) showed higher levels of S, Pb, Cu, Sn and Zn compared with the control (598 analyses). Complex element associations among the particles confounded detailed mineralogical identifications, and therefore a simplified particle classification scheme was devised for source apportionment. Karabash samples contained high levels of particles classified as mining-related (MRP), and these were also identified in control samples, indicating wide spatial dispersion from the smelter and highlighting the sensitivity of the method. It was noted that MRP <2.5-microm diameter were poorly represented on lichen surfaces suggesting this may limit the usefulness of Hypogymnia transplants as proxies when assessing human health impacts from airborne particulates. Analyses of the lichen thallus surface (away from surface particulates) revealed high levels of Cu, Zn, Fe and Pb associated with organics in the Karabash samples compared with the control, with a proportionate loss of K, interpreted as being due to a stress-related increase in cell membrane permeability. This type of analysis may provide a novel SEM-EDX-based method for assessing lichen vitality. The techniques developed are presented and further implications of the study are discussed.