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Laboratory-scale investigation of wastewater purification in filters with dolomite chippings media 全文
2011
Kazakeviciene, J., Lithuanian Univ. of Agriculture, Vilainiai, Kedainiai (Lithuania). Faculty of Water and Land Management. Water Research Inst. | Askinis, S.
The article explores the possibility of the vertical filter instead of sand used for more coarse media for recharging, which would reduce the risk of freezing and clogging and ensure the cleaning of wastewater up to the limits. For this purpose the dolomite chippings have been chosen for research. It was equipped with two 0.2 m2 filters area: one of their models was 0.4 m dolomite chippings layer, the other 0.8 m. They have been loaded by the wastewater after the primary cleaning in the septic system. Medium contamination in organic pollutants have been 358 mg O2 LE-1, Ptotal 14.6 mg LE-1, Ntotal 108.5 mg LE-1, suspended solids 161.1 mg LE-1, pH 7.8. Hydraulic load of the filters was 0.03 m3 mE-2 dE-1. Wastewater flowing through a vertical sand layer by an average of 98.2% of the organic pollutants to be detained. The average of effluent wastewater contamination of the filter was 22 mg O2 LE-1. In the filter with dolomite chippings media can be cleaned wastewater with pollution reaches 500 mg O2 LE-1. The maximum load of organic pollutants is 14 mg O2 LE-1. The filtration path length to ensure wastewater cleaning up tolerance 0.8 m. In the filter with dolomite chippings media Ptotal is cleaned even 87.0%, Ntotal only 13.0% efficiency.
显示更多 [+] 显示较少 [-]The method of landscape identity assessment 全文
2011
Nitavska, N., Latvia Univ. of Agriculture, Jelgava (Latvia)
The theme of landscape identity becomes actualized beside with the impact of globalization. Landscape identity is closely linked to the Latvian national identity. The concept of identity is multifaceted and touches on a number of scientific areas that currently in Latvia are actively investigating this phenomenon. Landscape investigators admit the multidisciplinary structure of the concept of identity, including in their researches the investigations of historical, visual and associative aspects. Landscape identity is related to detection, identification and definition of landscape elements, because landscape elements are the key to the perception of identity. The method of landscape identity assessment is based on three stages: the assessment of the historic, visual and cognitive elements in formation of landscape identity. The assessment of historic elements in formation of landscape identity is associated with the investigation of historic materials and description of structural elements according to the stages of development. The assessment of visual structural elements of landscape identity is based on the material collected during the field work by filling in the landscape assessment matrix. The assessment of cognitive structural elements of landscape identity is based on the opinion survey, which makes it possible to find out the concealed associative identity. The information obtained in all stages of landscape identity assessment forms the landscape identity model. The aim of the research is to develop the method of landscape identity assessment. The research was carried out at Latvia University of Agriculture in 2010.
显示更多 [+] 显示较少 [-]Evaluation of art interventions for the public space in Latvia since the 1980'ies 全文
2011
Alle, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The main aim of this paper was to investigate the development of art for the public space as a result of the historical impact through which the artworks have been evaluated. The context of social, ideological and economical changes is related. The author examined principal art practices in the public domain and discussed the main types of artworks created for the public space in Latvia in the period between 1980 and 2010. Seven art events were selected to analyze the main occurrence of historic periods as certain paradigms. Empirical and qualitative data collection methods were used to clarify the development of art for the public space in the Latvian landscape taking into account the historical point of view. According to the typology of artworks the following features were investigated: the aim, the location, the form and the size, and the function of artworks. The majority of art for the public space occurred in the city environment and the financial support of the project played an important role.
显示更多 [+] 显示较少 [-]Professional education teacher further education 全文
2011
Aizsila, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Bierande, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
The requirements for education, school and teachers become increasingly varied and complicated. The Latvian education system needs to be changed. The aim of the education reform is to establish a qualitative, accessible, competitive education system. The role of the teacher in studies changes with the economical and labour market changes. It determines new requirements and makes the knowledge, skills and competences of teachers change. To foster the development of teacher skills and acquisition of information, it is necessary to promote further education of teachers. The involvement of Latvia in the today’s global processes makes it necessary to substantially reconsider the aims and tasks of the education system – to ensure modernization of the education system and attain the introduction of new education content and methods. The article theoretically and empirically analyses and summarizes the further education experience of teachers at the Centre for Lifelong Education of the Latvia University of Agriculture in 2009/2010. The research target group - professional education teachers. The aim of the article is to justify teacher further education as development of professional and pedagogical competences in ensuring a modern and qualitative study process. The novelty of the research is related to the idea of the professional education reform and optimization of the network of professional schools.
显示更多 [+] 显示较少 [-]Influence of warmth conditions characterizing parameters on yield and chemical composition of maize in Latvia 全文
2011
Bartusevics, J., Latvia Univ. of Agriculture, Jelgava (Latvia) | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia)
Maize yield and quality are affected by many factors, including production practices, diseases, pests, and differences in the climate. Usually it is not possible to do much to change the effect of temperature, but it is important to grow better adapted or characterized with right maturity rating hybrids. The paper is aimed to determine the impact of accumulated growing degree days (GDD) on maize development, organic dry matter yield, ODM and chemical composition of maize hybrids. A field trial was carried out in the Research and Study farm ’’Vecauce’’ of the Latvia University of Agriculture (LLU) from 2008 till 2010. Ten (in 2008), eleven (in 2009) and fifteen (2010) maize hybrids with different maturity ratings according to FAO numbers (FAO 180-340) were harvested at three different times beginning on 5 September at fourteen-day intervals. GDD were calculated when maize reached a certain growth stage (full emergence, first tassels, full tassels, first ears, full ears, specific harvest date) to characterize conditions for maize growing in a specific year. Composition of fresh maize was analyzed for all hybrids using standard methods. Results were statistically processed using methods of correlation and regression analysis. Our results presented evidence that ODM yield in 2008 and 2009 on last harvest dates was lower than that on the first harvest date in 2010. Organic dry matter yield was higher in years when more GDD were accumulated. Results also showed that GDD negatively correlated with the total N, protein, fibre cellulose, hemi-cellulose, NDF, and ADF concentration.
显示更多 [+] 显示较少 [-]The evaluation of oil-flax (Linum usitatissimum L.) quality parameters for biofuel production 全文
2011
Poisa, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Adamovics, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Oil-flax has a wide range of utilization possibilities, inclusive of bioenergy production. In our research evaluated out two oil-flax varieties 'Scorpion' and 'Flanders' after the calorific value, oil, lignin, and ash content; and also the chemical composition in 2008 -2010. The results show that oil-flax shoves have a high calorific value and high lignin content but a low temperature for ash fusion. It was established that the growth year and some unexplored factors have influence on the ash content. The oil content in the seeds was 336-458 g kgE-1, depending on the chosen variety. The flax shoves can be used as a supplement for biofuel combustion, as they have a low fusion temperature, a high calorific value, but a comparatively low yield makes oil-flax unprofitable to grow for biofuel production.
显示更多 [+] 显示较少 [-]Evaluation of some qualitative characteristics of new plum cultivars 全文
2011
Gravite, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvian State Inst. of Fruit-Growing, Dobele (Latvia) | Kaufmane, E., Latvian State Inst. of Fruit-Growing, Dobele (Latvia) | Abolins, M., Latvia Univ. of Agriculture, Jelgava (Latvia)
A study was done at the Latvia State Institute of Fruit-Growing, evaluating new domestic plum (Primus domestica L.) selections, for which in 2008 -2010 some fruit quality characteristics were studied. In result of evaluation four new cultivars were selected from the breeding material and in 2010 handed in for cultivar registration in Latvia. Cultivar 'Ance' is early ripening one month before 'Victoria'. Cultivar 'Adele' is medium ripening one week before 'Victoria'. Fruits keep well in cool storage. Cultivar 'Sonora' is medium ripening one week after 'Victoria' and self-fertile. Fruits of this cultivar keep well in cool storage, too. Cultivar 'Lotte' is medium-late ripening two weeks later than 'Victoria', and is partially self-fertile. Average of three years, the highest soluble solids content was found for cultivar 'Adele' (13.28 Brix%), but cultivar 'Sonora' had the total content of acids (1.28 g 100 gE-1). Significant changes in flesh firmness were observed at different storage times for cultivars 'Ance' and 'Lotte'. Significant variations in the total content of acids were determined for 'Ance'. Whereas cultivar 'Sonora' demonstrated substantial fluctuations in soluble solids content. Correlations between firmness and soluble solids content were observed for cultivars 'Ance' (r=-0.731), 'Adele' (i=-0.436) and 'Sonora' (r=0.526). Cultivar 'Lotte' produced correlations between firmness and total content of acids (i=-0.536). Significance of interaction was determined within cultivars, years, and years x cultivars.
显示更多 [+] 显示较少 [-]Potassium removal with grass in an apple orchard under influence of mulch and irrigation 全文
2011
Surikova, V., Latvia Univ. of Agriculture, Jelgava (Latvia) | Karklins, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Potassium (K) is one of the most important nutrients necessary for many life functions of plants, like shoot growth, fruit and flower bud set, and fruit size. The aim of this study was to determine the content of potassium in orchard lawn for reduction of potassium fertilizer application and to include the potassium from mown grass into K balance and turnover calculation. The investigation was done at the Latvia State Institute of Fruit-Growing in Dobele in 2009, on the basis of an established field experiment planted in 1997 with apple (Mains domestica Borh.) cultivar 'Melba' (rootstock B9), trees spaced at 1.5 x 4 m distances. Three different treatments of soil moisture management were compared: control, sawdust mulch, and fertigation. Soil of the experimental plot was Pisocalcic Cutanic Luvisol (Hypereutric, Hyposkeletic); loam. Organic matter - 25 g kgE-1, soil reaction pH - 6.5. Plant-available P was 130.9, K - 157.7, and Mg - 102.2 mg kgE-1. Inter-row strips were covered with grass vegetation (Lolium perenne L. and Poa pratensis L.). Grass samples were collected during cutting, 3 times per season of 2009: May 19, June 20, and August 11. The uptake and removal of potassium was calculated as kilograms per hectare area. The concentration of potassium in the lawn and the height of grass growth were significantly influenced by the mowing time and the soil moisture treatment. These results can be a base for further studies of potassium turnover in an orchard, as well as for fertilizer planning and management.
显示更多 [+] 显示较少 [-]Changes in serum immunoglobulins concentration of newborn calves 全文
2011
Eihvalde, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The changes in the serum immunoglobulins concentration were investigated in newborn heifers from birth to 7 days of age. The mothers of calves were determined serum and colostrum immunoglobulins (Ig) concentration. The research was carried out at the Latvia University of Agriculture (LLU), in dairy farm ''Ligotnes'' of the Research and Study Farm ''Vecauce'', in a loose housing system with 530 cows, of which 430 were milking cows. The cows during the dry period were kept tethered in the farm. Eighteen heifers and their dams (Latvian Brown and Holstein breeds) which calved from 30 November 2010 to 23 January 2011 were used in this study. The calves' serum total immunoglobulin concentration at birth was 9.0 ±1.31 mg dLE-1 (or 0.09 mg mLE-1), and after 24 hours (h) it increased significantly to 4.3 mg dLE-1 (or 0.043 mg mLE-1), p is less than 0.05. The immunoglobulin G (IgG) concentration in calf serum after birth was 6.8 ±1.50 mg dLE-1 (or 0.068 mg mLE-1), and after 1 day and after 7 days it did not change significantly. The average Ig serum concentration in cows was 12.6 ± 1.36 mg dLE-1(or 0.126 mg mLE-1), and Ig concentration in colostrum was 18.5 ± 1.68 mg mLE-1. On average, close correlation (r=0.56) was found between cow blood serum IgM and colostrum IgM. Correlation between cow and calf IgG serum concentration proved to be weak (r=0.49).
显示更多 [+] 显示较少 [-]Relation between milk protein and urea content in different farms 全文
2011
Ruska, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
Milk production and milk composition are of prime economic importance for farmers. It is well known in dairy management that the balanced feeding and holding technology is an important lever by which milk production and milk composition can be modified. The objectives of this work are to establish relation among milk protein and urea content in different farms. Four farms represent three cow breeds (Holstein Black and White, Latvian Brown, and cross breed XP). Individual cow milk samples (n=8400) were collected monthly from September 2009 to November 2010. Milk samples were analyzed for total protein, casein, fat, lactose, and urea content with instrumental infrared spectroscopy method. The average milk yield in farms was significantly different (from 26.8 to 16.0 kg per control day), and average protein content varied from 3.32 g kgE-1 to 3.62 g kgE-1. The urea content in cow milk was between 21.3 to 42.6 mg 100 mLE-1. The average protein content was higher and significantly (p is less than 0.05) different in first yield level (up to 15 kg) for all farms. Overall, in different farm and milk yield levels correlation between protein and urea was low or very low. In the farm C, average urea content ranged between 30.0 and 60.0 mg 100 mLE-1, which indicated problems in feeding or management in the farm. It was established that milk productivity traits significantly (p is less than 0.05) varied in farms with different dairy cow holding and feeding technologies and milk protein and urea content significantly (p is less than 0.05) varied for cows with different milk yield per day.
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