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1.
Fikret Kaya BScFE MScFE. Ph. D. candidate Ian Smith BSc. MSc. PhD. PEng. FIWSc. 《Wood Science and Technology》1993,27(3):229-239
Summary Below-crown radial and height variations in maximum crushing strength parallel to grain, relative density and tracheid length of an immature, 55 year old, red pine were studied. All properties showed pronounced trends with radial age and increased from pith to bark. A radial age of 16 years was estimated as the age from which mature stem wood is formed. All properties studied varied with height above ground. Strong correlations were observed among properties. The study tree exhibited noticeably lower average crushing strength than is reported in the literature for wood from mature red pines.This work was undertaken with financial support from Karadeniz Technical University, Trabzon, Turkey, and the Natural Sciences and Engineering Research Council of Canada, Operating Grant 0GP0004417 相似文献
2.
Natural black poplar (Populus nigra L.) clones sampled from river courses were tested in the arid southeast region of Turkey, using a randomized complete block field design with four replications. Clones were laid out in row plots of eight ramets each. Height and apical dominance were assessed at age one year; diameter, survival, bole straightness and branchiness were measured at age two years. Clones differed significantly in survival, growth and quality traits. The results showed that promising clones exist in natural populations. Two commercial clones out of four did not grow as fast as the top new selection clones. For bole straightness, three commercial clones had significantly lower grading scores than the top best 14 clones. Principal components analysis indicated that growth, apical dominance and branching are the most important traits distinguishing black poplar clones. Diameter had a moderate correlation (0.34) with bole straightness. Relationships between geographic variables (elevation, latitude and longitude) with growth and stem quality traits were weak. Considerable genetic variation was observed among clones for all the traits. Genetic differences among the clones accounted for 27% (survival, bole straightness) to 39% (height) of the total variance. Broad-sense individual heritability ranged from 0.27 (survival) to 0.37 (apical dominance). Clonal mean heritabilities were higher than individual heritabilities and ranged from 0.60 (survival) to 0.82 (diameter), implying considerable gain could be realized via selective improvement methods. 相似文献
3.
A novel biofilm reactor named as `rotating perforated tubes biofilm reactor' was used for treatment of synthetic wastewaterwith and without liquid phase aeration. Effects of major processvariables such as feed wastewater flow rate, COD concentration and loading rate, liquid phase aeration on the rate and extent ofCOD removal were investigated. Liquid phase aeration was provento be advantageous especially for high strength wastewaters at highCOD loading rates. Kinetics of COD removal was investigated andkinetic constants were determined by using the experimental data.An empirical design equation was developed to quantify the system's performance as a function of major process variables. 相似文献
4.
• Background
Tree breeders have been reluctant to include wood traits in tree improvement programs owing to logistic difficulties and the cost associated with the assessing the traits. 相似文献5.
The effects of some fungicides used against citrus diseases, on mycelial growth and conidial germination of Isaria farinosa (Holmsk.) Fries [Sordariomycetes: Hypocreales] and also on the pathogenicity of the fungus on citrus mealybug, Planococcus citri (Risso), were determined. Systemic fungicides such as tebuconazole, penconazole and nuarimol were the most effective as regards
both conidial germination and mycelial growth. Protective fungicides such as captan, chlorothalonil, mancozeb and propineb
inhibited conidial germination at between 1 and 5 μg ml−1 concentration, but captan, chlorothalonil and propineb did not inhibit the mycelial growth at 5,000 μg ml−1. Mancozeb inhibited mycelial growth between 2,500 and 5,000 μg ml−1. Sulphur and copper oxychloride did not inhibit the fungus even at very high concentrations. Sulphur, copper oxychloride,
fosetyl-al, chlorothalonil and carbendazim did not decrease the mortality percentage caused by I. farinosa. Tebuconazole, penconazole and mancozeb were the most effective and respectively reduced the mortality from 83% to 33%, 28%
and 30% in the ovisacs, from 81% to 29%, 27% and 29% in the 1st instar larvae, and from 84% to 34% in the adult females. 相似文献
6.
The apple rust mite Aculus schlechtendali (Nal.) (Acari: Eriophyidae), is a main pest in apple-growing areas in Ankara, Turkey, and chemical control applications have
some limitations. Entomopathogenic fungi have a potential for biological control of mites. In this study, an entomopathogenic
fungus, Paecilomyces lilacinus (Thom) Samson (Deuteromycota: Hyphomycetes), was first isolated from the mite cadavers on Japanese crab apple leaves and
pathogenicity of the fungus was observed in different inoculum densities and relative humidities. The pathogen caused up to
98.22% mortality of the mite population. The effects of some fungicides on the entomopathogenic fungus were determined in
in vitro studies. Carbendazim, penconazole and tebuconazole were the most effective fungicides on mycelial growth of P. lilacinus, with EC50 values under 3 μg ml−1. In spore germination tests, captan, mancozeb, propineb were the most effective fungicides, followed by tebuconazole, penconazole,
nuarimol and chlorothalonil. Sulphur could not inhibit the conidia germination totally at 5,000 μg ml−1. Copper oxychloride and fosetyl-al prevented conidia formation at concentrations above 1,000 μg ml−1. 相似文献
7.
Fikret Berkes 《Fish and Fisheries》2012,13(4):465-476
As a dominant paradigm, ecosystem‐based fisheries have to come to terms with uncertainty and complexity, an interdisciplinary visioning of management objectives, and putting humans back into the ecosystem. The goal of this article is to suggest that implementing ecosystem‐based management (EBM) has to be ‘revolutionary’ in the sense of going beyond conventional practices. It would require the use of multiple disciplines and multiple objectives, dealing with technically unresolvable management problems of complex adaptive systems and expanding scope from management to governance. Developing the governance toolbox would require expanding into new kinds of interaction unforeseen by the mid‐twentieth‐century fathers of fishery science – governance that may involve cooperative, multilevel management, partnerships, social learning and knowledge co‐production. In addition to incorporating relatively well‐known resilience, adaptive management and co‐management approaches, taking EBM to the next stage may include some of the following: conceptualizing EBM as a ‘wicked problem’; conceptualizing fisheries as social‐ecological systems; picking and choosing from an assortment of new governance approaches; and finding creative ways to handle complexity. 相似文献
8.
Karst groundwater (the water in a karst aquifer) is a major water resource in many regions of some countries. Water requirements for most of the settlements in the karstic regions are supplied from karst aquifers. Karst environments are also used for the disposal of liquid and solid domestic agricultural, and industrial wastes, which result in karst groundwater pollution. Karst aquifers have specific hydraulic and hydrogeologic characteristics that render them highly vulnerable to pollution from human activities. Karst groundwater becomes polluted more easily and in shorter time periods than water in non-karstic aquifers. Thus, protection measures are required to preserve the quality and quantity of karst groundwater that specifically consider the vulnerability of the karst environment. In order to preserve karst groundwater, the geological, hydrological and hydrogeological characteristics of the karst area must be investigated and information on polluting activities and sources must be collected. Then, a comprehensive protection and control system must be developed consisting of the following six components: (1) develop and implement a groundwater monitoring system, (2) establish critical protection zones, (3) develop proper land use strategies, (4) determine the reasonable development capacity of the karst aquifer, (5) control and eliminate when necessary sources of pollution, (6) increase public awareness of the value and vulnerability of karst aquifers. 相似文献
9.
A three-step sequencing batch reactor was used for nutrient (COD, NH4-PO4-P) removal from synthetic wastewater by using different carbon sources. The operation consisted of anaerobic, anoxic and oxic (An/Ax/Ox) phases with durations of 2/1/4.5 h. Different carbohydrates, glucose, lactose, sucrose, maltose and a mixture of glucose/maltose (50/50), were used as the sole carbon source in the first phase of experiments. Sludge age was kept constant at 10 days. Glucose was found to be the most suitable carbohydrate source with percent COD, NH4-N and PO4-P removals of 96%, 99% and 94%, respectively. Nutrient removals obtained with sucrose as the sole carbon source were close to those obtained with glucose. A mixture of glucose and organic acids (50/50) such as acetic, citric, propionic and butyric acid were used as carbon source in the second phase of the experiments. Maximum percent COD, NH4-N and PO4-P removals were 93%, 97% and 96%, respectively when a mixture of glucose and acetic acid (50/50) was used. Glucose-citric acid (50/50) combination also resulted in comparable nutrient removals. 相似文献
10.
Fikret Demirci Murat Muştu M. Bora Kaydan Selma Ülgentürk 《Journal of pest science》2011,84(3):337-342
Citrus mealybug Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is one of the main pests on citrus trees. Biological control of the pest is based on
the release of hymenopterous parasitoids and coccinellid predators at present. The effectiveness of entomopathogen fungus
Isaria farinosa (Holmsk.) Fries ([Sordariomycetes: Hypocreales] (Syn: Paecilomyces farinosus), as an alternative biological control agent on citrus mealybug, was investigated using four different inoculum densities
and different relative humidities (RH). The entomopathogen caused 89.39% mortality in ovisacs, 84.07% mortality in second
larval stage, 84.53% mortality in adult females, and 78.71% mortality in first larval stage at 95% RH and at 1 × 108 conidia ml−1 inoculum concentration. Percent mortalities were between 50 and 60 in ovisac, first and second larval stage at 95% RH and
at 1 × 107 conidia ml−1. Percent mortality was decreased parallel to the decrease in humidity level and inoculum densities; however, the fungus caused
significant infection in 70% and 80% RH. These results demonstrated that the effectiveness of the entomopathogen is promising
for biocontrol of citrus mealybug. 相似文献