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Influence of the vertical filter media on phosphorus removal from the domestic wastewater Full text
2011
Kazakeviciene, J., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst. | Askinis, S., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst.
Modelling of the domestic wastewater treatment and removal of the Ptotal in the vertical filters with the sand, dolomite powder and dolomite chippings each separately used as a filter media was performed. Six filter models taking 0.2 m2 each were installed. The length of the filtration path was equal to 0.8 m in three of these models and 0.4 m in the other three models. The hydraulic load on the filters was equal to 0.03 m3 mE-2 dE-1 in 2008, and it was equal to 0.06 m3 mE-2 dE-1 in 2009. The domestic wastewater which had undergone the pre-cleaning in the septic systems was poured into the models. Their average pollution with the Ptotal reached 14.6 mg LE-1 in the first year and 9.2 mg LE-1 in the second year. When the filtration path was equal to 0.8 m and the hydraulic load was equal to 0.03 m3 mE-2 dE-1, the Ptotal was removed from the wastewater with the efficiency of 99.9% in the dolomite powder filter. In the filter models with the sand and dolomite chippings, the Ptotal was removed with the same efficiency of 87.7%. When the hydraulic load doubled, the efficiency of P removal decreased to 59.8% in the sand filter and down to 45.7% in the dolomite chippings filter. When the hydraulic load reached 0.06 m3 mE-2 dE-1, only the dolomite powder filter could ensure the adequate cleaning of the domestic wastewater up to the allowable norms.
Show more [+] Less [-]Principles for planning residential area greenery Full text
2011
Ile, U., Latvia Univ. of Agriculture, Jelgava (Latvia)
The article presents information on the greenery in the large-scale residential area courtyards built in the Soviet period. The data on the importance of the greenery in the large-scale residential areas of the Baltic States were analysed. The analysis was carried out on the large-scale residential area courtyards built in the second half of the 20th century in Pärnu, Jelgava, and Siauliai, which until present have not experienced any changes of the landscape. The research established that these courtyards can be characterised as the unused territory resources. Consequently, there is a necessity to resolve the topical issues of the greenery in the Soviet period large-scale residential area courtyards. From the theoretical aspect, the information gathered in the research on the greenery in the large-scale residential areas has revealed relevant suggestions for the improvement of the present condition. The variety of information reflects the significance of the greenery in the large-scale residential area courtyards that have to provide an aesthetically pleasant image of the territory for every inhabitant of the territory. The methods applied in the research describe the present condition of the Soviet period courtyards.
Show more [+] Less [-]The historical development of watermills and small-scale hydroelectric power plants landscape in Latvia Full text
2011
Lazdane, L., Latvia Univ. of Agriculture, Jelgava (Latvia)
The change in landscape is a never-ending process. In this article information regarding watermills and small-scale hydroelectric power plants historical development in Latvia has been summarized. The research was conducted from September 2010 till April 2011 with the aim of summarizing information regarding impacts to landscape from changes occurring from 12th century till 21st century. The research had a detailed view about the usage history of the watermills, small-scale hydroelectric power plants buildings, and energy producing constructions. The fundamental changes in energy producing mechanisms and legislation regulations changes that have an impact on river open space landscape and on landscape use in surrounded territories of watermills and small-scale hydroelectric power plants landscape were analyzed and studied carefully. The territories were described and analysed using historical, monographic, and comparative methods. The paper gives possible descriptive historical classification of these industrial landscape elements. The historical progress and legislation evolution until the 21st century has also been summarized.
Show more [+] Less [-]The estimation of the emission of greenhouse gasses by the treatment of sewage sludge in Latvia Full text
2011
Arina, D., Latvia Univ. of Agriculture, Jelgava (Latvia);Institute of Physical Energetics, Riga (Latvia) | Bendere, R., Institute of Physical Energetics, Riga (Latvia)
The report presents the assessment of emission of greenhouse gases (GHG) generated by the treatment, disposal and storage of sewage sludge in Latvia. The aim of the study was to determine GHG emissions from stored sludge because those were not previously estimated. The proposals for the further reduction of the GHG emissions are elaborated on the provided estimations of different treatment models. The calculations of GHG emissions are conducted by using acknowledged software and data from Latvian Environment, Geology and Meteorology Centre. Data from the year 2005 till 2009 about the amount of stored sludge were used by the authors for mathematical calculations in the year 2010. The long-term storage of sewage sludge and their disposal in landfills were detected as the main sources of GHG. It was detected that the average GHG reduction of 5 Gg per year can be ensured by using biological treatment of sewage sludge.
Show more [+] Less [-]Characterization of fish production and marketing practices under small-holder fish farming systems of eastern Kenya Full text
2013
Oyieng, Edwin P. | Charo, H.K. | Kahi, A.K. | Ojango, Julie M.K.
Aquaculture, a sub-component within the fisheries sector is a vital economic activity and livelihood component of rural communities living beside rivers and river floodplains in East Africa. It provides a good alternative source of income and proteins for rural communities. This study aimed to characterize fish production and marketing practices in smallholder farming systems under a national Economic Stimulus Programme (ESP) in the Eastern province of Kenya, and to determine the traits of economic importance to the farmers. Information was collated from 198 farmers, 13 traders and three key informants within Meru District of Eastern Province. The predominant species of fish reared was the Nile Tilapia, followed by the African Catfish and in some instances a combination of the two species were reared under polyculture. Good growth rate and survival of fish were noted to be the most important traits of economic importance to the farmers. Fish produced was mainly sold to the local community and within local markets. Traders, however, indicated that the demand for fish was much higher than the supply, hence also sourced fish from Lake Victoria in Nyanza for sale. It was also indicated that the taste of fish differed greatly depending on the source, with wild fish strains from Lake Victoria having a “sweeter” taste than the farmed strains. Strains of fish selected for improved growth and reproduction were not available for aquaculture. Feeds and feeding management of farmed fish was also a challenge. It was evident that there is a great need for supportive research on environmental impacts, productivity and quality of fish reared, and marketing of fish products within the riverine environments of Kenya. Key words: aquaculture, fish marketing, traits of economic importance
Show more [+] Less [-]Pastoralists’ perception of the impact of East Coast fever on cattle production under extensive management in Northern Rift Valley, Kenya Full text
2011
Kipronoh, K.A. | Gathuma, J.M. | Kitala, P.M. | Kiara, Henry K.
A study using participatory epidemiology (PE) methodologies was conducted in West Pokot and Baringo districts, Northern Rift Valley, Kenya to assess the status of East Coast Fever (ECF) and obtain livestock keepers’ perceptions of how the disease impacts on their livelihoods. A total of 658 livestock keepers comprising of 480 men and 178 women were invited to participate in community meetings held in twenty two purposively selected locations each in West Pokot and Baringo. Fifty six percent of the livestock keepers were from West Pokot while the remaining 54 percent were from Baringo District. Nearly all the households in both communities depended on cattle keeping as the major source of livelihood. The activity was ranked as priority enterprise by 96.2% and 93.3% of the groups in West Pokot and Baringo district respectively. Cattle diseases were identified as the main constraint affecting production and in particular, ECF and trypanosomosis were reported as the most important compared to other diseases. The informants were relatively consistent in estimating the impact of cattle diseases on derived benefits. There was good agreement among the various groups with coefficient of concordance (W) values ranging between 0.43 and 0.60 (p < 0:05 – p < 0.01). East Coast fever was found to have the greatest impact. Based on the findings from this study, there is need for stakeholders in the livestock industry to develop control strategies for ECF control that are supportive to the production system in a particular the region.
Show more [+] Less [-]Factors influencing the prevalence of trypanosomosis in Orma Boran (trypanotolerant) and Teso zebu (trypanosusceptible) cattle crosses in Teso District, western Kenya Full text
2009
Gachohi, John M. | Bett, Bernard K. | Murilla, G.A.
The objective of this study was to determine factors associated with occurrence of trypanosomosis in the first generation (F1) crossbreds between trypanotolerant Orma Boran and trypanosusceptible Teso zebu cattle in a trypanosomosis endemic area in Teso District, western Kenya. The offspring were screened for trypanosomosis and other haemoparasites using parasitological methods. Packed cell volume (PCV), body weights and tsetse density (FTD) were also determined. Factors considered in the analysis included sex, age, body weight and season of the year. Generalized linear mixed models (GLMM) were used for multivariable analysis to account for clustering of observations at the animal level and estimate outcome variance parameters. The overall trypanosomosis prevalence was 2.3% (n=477) probably corresponding to low FTD in the area (<1fly/trap/day). The risk of trypanosomosis infection was higher in dry than wet season (OR = 5.4) and in older than younger offspring (OR = 1.1). The variance parameters obtained indicated that variation of trypanosomosis prevalence lay only at the animal level. Intercurrent haemoparasites detected included Anaplasma marginale, Theileria and Babesia species. Overall, the results suggested that when the tsetse density is very low, control of trypanosomosis in the Orma-Teso zebu offspring in western Kenya require targeting of individual affected animals in the dry seasons.
Show more [+] Less [-]Stinging nettle - the source of biologically active compounds as sustainable daily diet supplement Full text
2014
Zeipina, S., Latvia Univ. of Agriculture, Jelgava (Latvia);Pure Horticultural Research Centre, Pure parish, Tukuma municipality (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lepse, L., Pure Horticultural Research Station, Pure parish, Tukuma municipality (Latvia)
Environmental conditions and climate change on a global scale affects the overall agriculture and food supply. Consumers demand for vegetables with high nutritional value is increasing. Consumers more and more are thinking about a healthy and balanced diet, but it is not easy to provide year-round fresh vegetables. Nettle (Urtica) leaves traditionally are used in early spring as a leafy vegetable in salads and soups. Young leaves before flowering are used for human consumption. Nettle contains a lot of vitamins and biologically active compounds. The research aim was to evaluate different stinging nettle clones, which grow in Pūre village (Tukuma district, Latvia). Samples were collected, when shoots were 10 – 15 cm long. Content of chlorophyll, carotenoids and anthocyanins in five nettle clones leaves were analysed. Biochemical analysis was done in Latvia University of Agriculture, Institute of Soil and Plant Science laboratory. Differences were observed between all clones. Significant difference between genotypes was observed in anthocyanins content, but not in chlorophylls and carotenoids content. Higher anthocyanins content was observed in samples, which grow in places with low nitrogen and phosphorus content. Content of biochemical compounds can influence some metal ions, environmental and other factors.
Show more [+] Less [-]Agrobiological estimation of introduced grape varieties in the conditions of the South-East of Kazakhstan Full text
2014
Manarova, D., Kazakh National Agrarian Univ., Almaty (Kazakhstan) | Kazybaeva, S., Kazakh Scientific Research Inst. of Fruit Growing and Viticulture, Almaty, Kazahkstan
Assortment improvement is a natural process of updating varieties and improving the quality of variety assortment. The article presents the results of studying the introduced grape (Vitis vinifera) varieties in the conditions of the southeast of Kazakhstan, in particular in the bottom-mountain area of Almaty region. The beginning and the end of the main phenological phases passing for the vegetative period in a grape plant directly depended on climatic and weather conditions of this district. It is established that varieties ‘Kuibyshevsk early-maturing’, ‘Iyulsky’ and ‘Priusadebny’ have a good degree of eyes wintering buds and are able to give a yield of high quality in this area in comparison with recognized variety ‘Almaty early-maturing’.
Show more [+] Less [-]Lodging cause height at the centre of gravity changes during vegetation period for oat Full text
2014
Brunava, L., Latvia Univ. of Agriculture, Jelgava (Latvia);State Stende Cereals Breeding Inst., „Dižzemes”, Dižstende, Lībagi parish, Talsi municipality (Latvia) | Alsina, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Height at the centre of gravity is a part of mathematical model to interpret risk of lodging used for cereal crops. Because of the anatomical changes during vegetation period, several measured parameters in early milk stage (stem and panicle weight) will differ from over-ripe stage results in their values. The aim of this study was to define approximate values of calculated parameters describing oat (Avena sativa L.) height at the centre of gravity in early milk and over-ripe stages as well as determine connection with lodging risk. The trial was carried out at the State Stende Cereals Breeding Institute in 2013. There were 5 oat cultivars studied. At the investigated growing stages plant samples were taken from a field and in laboratory conditions stem/panicle weight and length measured. The height at the centre of gravity and gravity ratio were calculated using mathematical model by Berry (1998). Results showed that the value of the height at the centre of gravity in over-ripe stage was significantly higher (p is less than 0.01) than in early milk stage, but correlation with risk of lodging remained. Such lodging resistance describing mathematical model can be useful for oat as well as wheat cultivars.
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