Composting is an alternative for recycling agricultural residues and sewage sludge, and the end pro- duct can be used as fertilizer for land application. In order to study the composting process with sludge from water sewage treatment... more
Composting is an alternative for recycling agricultural residues and sewage sludge, and the end pro- duct can be used as fertilizer for land application. In order to study the composting process with sludge from water sewage treatment plants and rice straw, environmental factors should be controlled. The aim of our study was to investigate the optimum C/N ratio, moisture and pH to maximize microbial activity. The incubation of sewage sludge and rice straw mixtures were conducted using an experiment design with three different C/N ratios (17, 24 and 41), moistures (40, 60 and 70 %) and pH (5.65, 6.65 and 8.75). The micro- bial activity was measured as manometric measurement of oxygen consumption. The enhancement of microbial activity is induced by low C/N ratio, high moisture content, and pH basic. Our results suggest that the initial blend with these raw materials must be about 17 C/N ratio, while moisture content must be between 60 % and the pH 8.75 in the composting process.
The aim of this work is to develop a study of Taguchi optimization method for low surface roughness value in terms of cutting parameters when face milling of the cobalt-based alloy (stellite 6) material. The milling parameters evaluated... more
The aim of this work is to develop a study of Taguchi optimization method for low surface roughness value in terms of cutting parameters when face milling of the cobalt-based alloy (stellite 6) material. The milling parameters evaluated are feed rate, cutting speed and depth of cut, a series of milling experiments are performed to measure the surface roughness data.
The processing of Jatrophacurcas (tubang-bakod) to produce biodiesel entails wastes in the form of seedcake which can be converted into valuable product that can help nurture and improve soil properties. The College of Industrial... more
The processing of Jatrophacurcas (tubang-bakod) to produce biodiesel entails wastes in the form of seedcake which can be converted into valuable product that can help nurture and improve soil properties. The College of Industrial Technology and the Chemical Engineering Department of Batangas State University (BatstateU) conducted an experimental study which includes the composting of the combination of Jatropha Seed-Cake(JSC) and Chicken Manure(CM) , formulating ratios of JSC and CM andcharacterization of the organic fertilizer produced. Generally, this study aimed to promote proper waste disposal by producing an organic fertilizer from the waste of biodiesel production which uses Jatropha plant and proving the feasibility of making the fertilizer as the main source of nutrient for plants. Specifically, the nutrients that were considered were Nitrogen (N), Phosphorus (P), Potassium (K) and the Carbon: Nitrogen (C:N) ratio. Composting lasted for 6 weeks, three formulations were used, 30(CM):70(JSC), 50(CM):50(JSC) and 70(CM):30(JSC). The result implies that theorganic fertilizers produced can be a good substitute to the commercially available fertilizers.
Benthic primary production and nutrient dynamics were examined along a transect in the Bangrong mangrove forest in Thailand. Six stations were established extending from a high-intertidal site within the mangrove forest to low-intertidal... more
Benthic primary production and nutrient dynamics were examined along a transect in the Bangrong mangrove forest in Thailand. Six stations were established extending from a high-intertidal site within the mangrove forest to low-intertidal flats and seagrass beds in front of the mangrove forest. Benthic processes (O2 and CO2 fluxes) and nutrient dynamics (mineralization, sediment-water fluxes, pore water and sediment pools)
The concentration of dissolved inorganic nitrogen (DIN), dissolved nitrate-N, Total-N (TN), dissolved inorganic phosphate (DIP), total phosphorus (TP), dissolved silicate-Si (DSi) and their ratios in the world's largest rivers are... more
The concentration of dissolved inorganic nitrogen (DIN), dissolved nitrate-N, Total-N (TN), dissolved inorganic phosphate (DIP), total phosphorus (TP), dissolved silicate-Si (DSi) and their ratios in the world's largest rivers are examined using a global data base that includes 37% of the earth's watershed area and half its population. These data were compared to water quality in 42 subbasins of the
Investigations into trophic ecology and aquatic food web resolution are increasingly accomplished through stable isotope analysis. The incorporation of dietary and metabolic changes over time results in variations in isotope signatures... more
Investigations into trophic ecology and aquatic food web resolution are increasingly accomplished through stable isotope analysis. The incorporation of dietary and metabolic changes over time results in variations in isotope signatures and turnover rates of producers and consumers at tissue, individual, population and species levels. Consequently, the elucidation of trophic relationships in aquatic systems depends on establishing standard isotope values
The archaeological record of dry rockshelters in the Red River Valley of eastern Kentucky contains botanical remains of several weedy annual seed-bearing plants that point to the independent development of agriculture during the Late... more
The archaeological record of dry rockshelters in the Red River Valley of eastern Kentucky contains botanical remains of several weedy annual seed-bearing plants that point to the independent development of agriculture during the Late Archaic and Early Woodland Period. The objective of this study is to gather quantitative data through the chemical and physical analysis of soils collected within a valley transect to gain insights into landscape processes and soil fertility that may have played a role in the early development of plant domestication and the location of garden plots
in relation to rock shelter sites in the upper Cumberland Plateau region of eastern Kentucky. Soils on upland benches formed in limestones have soil fertility values that are comparable to fertile floodplain soils. Upslope outcrops of calcareous bedrock are contributing basic cations to these bench soils. Additionally, in comparison to other landscape positions these upland soils have high levels of organic carbon, available P and greater C:N ratios. Soil morphology, radiocarbon dates, and archaeological evidence indicate that many of the numerous earthflows and debris flows within the region are Early to Middle Holocene in age. These slides were likely generated by Mid-Holocene climatic shifts in which the frequency and intensity of summer precipitation increased across the southeastern United States. These slope failures may have contributed to the development of plant domestication by creating forest canopy gaps and disturbed soils in which weedy plants thrived.
2007 Elsevier Ltd. All rights reserved.
... There appears to be little or no change in δ 13 C or δ 15 N during decay in the seagrasses Zostera noltii (Machás et al., 2006), Thalassia testudinum and Zostera marina ([Zieman et al., 1984], [Stephenson et al., 1986] and [Fenton and... more
... There appears to be little or no change in δ 13 C or δ 15 N during decay in the seagrasses Zostera noltii (Machás et al., 2006), Thalassia testudinum and Zostera marina ([Zieman et al., 1984], [Stephenson et al., 1986] and [Fenton and Ritz, 1988]) or the mangrove Rhizophora ...
A Dutch sentence test (LIST) and a Dutch number test (LINT) have been developed and validated for the accurate measurement of speech reception thresholds (SRT) in quiet and in noise with severely hearing- impaired individuals and cochlear... more
A Dutch sentence test (LIST) and a Dutch number test (LINT) have been developed and validated for the accurate measurement of speech reception thresholds (SRT) in quiet and in noise with severely hearing- impaired individuals and cochlear implant recipients in Flanders and the Netherlands. The LIST consists of 35 lists of 10 sentences of equal known difficulty uttered by a
El gas natural, cuyo componente principal es metano, fue utilizado por los pueblos chinos y persas hace miles de años como generador de temperatura; ellos lo utilizaban para calentar los baños de agua (Brakel 1980); sin embargo, tuvieron... more
El gas natural, cuyo componente principal es metano, fue utilizado por los pueblos chinos y persas hace miles de años como generador de temperatura; ellos lo utilizaban para calentar los baños de agua (Brakel 1980); sin embargo, tuvieron que pasar muchos años ...
Recombinant Saccharomyces cerevisiae YKU 131 (capable of expressing glucoamylase) was used to produce ethanol from sago starch. The optimum C/N ratio for ethanol production by the recombinant yeast was 7.9, where 4.7 and 10.1 g/l ethanol... more
Recombinant Saccharomyces cerevisiae YKU 131 (capable of expressing glucoamylase) was used to produce ethanol from sago starch. The optimum C/N ratio for ethanol production by the recombinant yeast was 7.9, where 4.7 and 10.1 g/l ethanol was produced from 20 and 40 g/l sago starch, respectively. At sago starch concentration higher than 40 g/l and C/N ratio higher than 10.4,
