Affiner votre recherche
Résultats 1-10 de 63
Influence of Veneer Density on Plywood Thickness and Some Mechanical Properties
2021
Kūliņš, Laimonis | Meija, Anete | Roziņš, Rihards | Liepa, Kārlis Hermanis | Spulle, Uldis
It has been common knowledge that as the density of wood increases, the mechanical properties also improve. In turn, the density of wood depends on many factors, including the wood moisture content, location and cross-section in the trunk, the type of treatment and the parameters of technological processes. There is a great deal of research reported in the scientific literature on the effect of solid wood density on mechanical properties for different wood species as well as for structural timber. However, no research data can be found related investigation of the influence of veneer density on the properties of the birch plywood. In the present study, researching the properties of 7-ply birch plywood (thickness 9 mm), it was concluded that as the density of veneers increases, the bending properties of plywood in the direction of wood fibers (covered veneers) increases. When determining the plywood gluing quality, similar tendencies have been observed. For plywood with a lower density in all veneer plies the gluing quality (tensile-shear test) for perpendicular wood fiber veneers increases in the direction from the symmetry axis or middle veneer to the plywood outer plies, which can be explained by the fact that the outer plies become denser at the time of the hot pressing process. The results of the study will allow birch plywood manufacturers in direct production, sort veneers by density, to produce plywood with very predictable gluing quality, plywood thickness and mechanical properties in bending.
Afficher plus [+] Moins [-]The Significance of “Green” Skills and Competencies Making the Transition Towards the “Greener” Economy
2021
Nikolajenko-Skarbalė, Jelena | Viederytė, Rasa | Šneiderienė, Agnė
Climate change and environmental deterioration have been recognized as global drivers of change, and the shift to the “greener” economy is the key to sustainable development. The green economy is a priority field for developing and developed economies. However, as the authors of the publication have realised, there is no consensus about the meaning of the green economy and “green” jobs, that is why an uncertainty as in measurement of economic trends and an impact of it, as well as in what skills and competencies should be assigned to the “green” ones, arises. The new “green” processes and technologies are arising in a progressive trend, that is why it is important to ensure there are properly skilled candidates with appropriate “green” skills and competencies on the labour market, as well as to prepare fresh graduates with the “green” skills that will meet requirement of both, the recent and the future companies, especially operating in the “green” sector. In the framework of “SB Bridge” project an online survey was conducted by interviewing the “green” companies to identify which skills and competencies are needed for “green” jobs recently, and whether candidates and fresh graduates are enough with the “green” skills and competencies for fruitful engagement to “green” jobs. As the survey identified, fresh graduates and candidates for “green” jobs lack technical and (or) mechanical knowledge, IT skills, as well as experience and ability to work independently and in the team to resolve arising problems.
Afficher plus [+] Moins [-]Status of the Precision Beekeeping Development in Latvia
2021
Zacepins, Aleksejs | Kviesis, Armands | Komasilovs, Vitalijs | Brusbardis, Valters | Kronbergs, Janis
Information and communication technologies are part of almost any branch of human lives. During the last decade also beekeeping joined the direction of application of IT tools and solutions and precision beekeeping was defined. Still in the beekeeping many operations and observations are completed manually, and there is a potential to switch to the digital realisation. Information technologies can be used in the beekeeping to partly support the beekeepers by implementation of automatic or semi-automatic solutions for bee colony remote monitoring, apiary record making and other actions. The aim of this paper is to make a summary of the usage of information technology tools by the beekeepers in Latvia, summarizing precision beekeeping development status and conclude about its future development potential. To achieve this aim, in cooperation with Latvian Beekeepers Association, a beekeepers survey was conducted. More than 200 beekeepers shared thoughts and opinions about their application of information and communication technologies for monitoring the bee colonies and apiary management. The summary of the survey conducted is described in this study.
Afficher plus [+] Moins [-]Resilience of Milk Supply Chains during and after the COVID-19 Crisis in Latvia
2021
Pilvere, Irina | Upīte, Ilze | Muska, Aina | Zdanovskis, Kristaps | Nipers, Aleksejs | Janmere, Lana
The impacts of the COVID-19 pandemic on national economies are characterized as the worst economic turmoil in recent years, as economic growth slowed to the level of the 2008 global financial crisis. At the end of 2019 and the beginning of 2020, economic growth surveys did not project that the novel virus could have a negative impact on economic growth. As a result of the rapid spread of the virus and the increase in the number of infection cases, national governments took strict measures to limit the spread of the virus, which led to a significant deterioration in the economic situation in all industries of the economy. Agriculture plays an important role in providing food to the country’s population, yet the pandemic made a negative impact on sales volumes and prices in the domestic and international markets. The research aims to assess the impacts of the pandemic on milk supply chains in Latvia and come up with solutions to stabilizing the situation in the dairy sector. The national restrictions to combat the pandemic also hampered the dairy sector concerning the sale of raw milk and finished products in foreign markets, thereby leading to overproduction and stockpiling of the finished products, price dumping and a significant decrease in milk purchase prices to or below the production cost level for many dairy farms. Although there is no indication that the pandemic would lead to a decrease in the numbers of livestock and farms or output in early 2021, it is too early to assess the overall impact of the pandemic on dairy farming, as uncertainty over the duration of pandemic restrictions is a major risk to farm survival. The operation of the dairy sector was stabilized by means of the support provided by the government, as well as the farms’ accumulated financial and feed resources. In order to identify future challenges for milk supply chains, the research performed an analysis of operational risks for milk producers and processors to identify the most important risks and design recommendations for their elimination. The longer there is uncertainty about the return of the dairy sector to pre-pandemic output levels, the more likely it is that the pandemic is going to lead to a decrease in the numbers of dairy livestock and farms.
Afficher plus [+] Moins [-]The Influence of Technological Peculiarities on Fermented Sausages’ Quality and Sensory Properties
2021
Gramatina, Ilze | Sauka, Janis | Semjonovs, Aleksandrs | Strode, Sintija | Straumite, Evita
Fermentation is one of the ancient technological processes used in food production which influences the shelf-life of meat and meat products, also significantly affects the sensory properties like aroma and flavour. The objective of the present study was to evaluate the elaborated technology for a new fermented sausage production on the product quality and sensory properties. Sausages were produced by the standard technology using glucono-delta-lactone or starter culture. The drying of samples differs from 3 to 4 weeks at the same conditions; samples were dried for 4 weeks which produced with the starter culture, and 3 weeks which produced with glucono-delta-lactone. The sausages were tested at the end of the production, analysing pH, water activity, moisture and salt content, as well as the presence of Listeria monocytogenes, colony forming units of Listeria monocytogenes and Enterobacteriaceae in the sausage samples were analysed. The sensory evaluation was organised after getting Listeria monocytogenes testing results. The moisture content, water activity and salt content significantly differed (p < 0.05) among samples, no differences were established in pH, taste and flavour liking. The presence of Listeria monocytogenes was not established in samples which indicates that the producer properly applies a hurdle technology in fermented sausage production. Sensory evaluation results showed higher scores for texture and appearance in fermented sausages with glucono-delta-lactone. The study results confirmed that fermented sausages with glucono-delta-lactone during 3 weeks of drying can achieve corresponding safety criteria and sensory properties which are set for semidry fermented sausages.
Afficher plus [+] Moins [-]Agriculture Policy Scores of Selected Countries Through the Technique for Order of Preference (TOPSIS) Method
2021
Madiyoh, Abdulhakim | Turan, Özlem | Gürlük, Serkan
The purpose of this paper is to demonstrate the performance of agricultural sectors in the Association of Southeast Asian Nations (ASEAN) countries using selected criteria, to identify the deficiencies in agricultural policies, to explore competitive advantages and to guide food and nutrition policies. The analyses of this research use the secondary of time series data between the years 1967 - 2016 from 10 countries including; Brunei Darussalam, Cambodia, Indonesia, Laos PDR, Malaysia, Myanmar, Philippines, Singapore, Thailand and Vietnam which are the member of ASEAN. This research uses the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method and the data used for the mentioned countries include the following criteria; total agricultural production value of the land, self-sufficiency of animal products criteria, self-sufficiency of crop products criteria, rural population rate, greenhouse gas emissions from agriculture, and value of foreign trade in agricultural products. The result of proximity coefficients calculated with the TOPSIS method, which according to the number of proximity and maximum benefit analysis should be done according to the order of preference. It is stated that Thailand, Philippines and Indonesia were the most successful countries in the agricultural policy performance in 1967. As for last decades, Malaysia became the most successful country in agricultural policy performance. We can infer from the results that Malay industrial sector triggered the agricultural sector by supplying financial investment atmosphere.
Afficher plus [+] Moins [-]Green Transportation in the Šiauliai Regional Companies
2021
Beniušienė, Ineta | Jankauskienė, Aida
A relevant and practical research object is analysed in the article – the implementation resolution of green transportation and the benefits of using such means. In this article, object is analysed from the interdisciplinary position, i.e. from the perspective of transportation, one of the logistical subsystems, and sustainable environment. The transportation department is undoubtedly an important guarantor of economic and industrial development. Despite the worldwide importance of transportation in everyday activities, the transportation also poses the risk for human health and life quality, for it is one of the biggest consumer of oil products and significantly contributes towards air pollution. Despite many theoretical and empirical researches, Šiauliai region still lacks an approach towards the implementation possibilities and studies revealing the benefits of green transportation. A comparative analysis has been performed by using the survey data, collected from 402 workers, responsible for transportation, working for Šiauliai regional companies. According to the results of the research for implementation situations of green transport in Šiauliai regional companies, the representatives of regional companies understand the importance of green transport, and more and more companies aim to reduce the environmental risk and to become more competitive. Integrated transportation by combining several means of transport, cargo consolidation by combining small orders and big orders, and ecological driving are the green transportation measures implemented most in regional companies. The typical benefits of green transport are increased environmental friendliness and improved relationship with consumers.
Afficher plus [+] Moins [-]Awareness of Integrated Soil Fertility Management Practices in the Savelugu Municipal of the Northern Region of Ghana
2020
Abukari, Ammal | Abukari, Rahamatu
In sub-Saharan Africa intensifying small-scale farming is essential in addressing poverty related issues in rural communities and the degradation of natural resources. Integrated Soil Fertility Management (ISFM) are the best practices used to improve the productivity of crops whilst maximizing agronomic efficiency of inputs applied and hence contributing to sustainable intensification. ISFM usually include the appropriate use of inorganic fertilizer and organic resources, good agronomic practices and appropriate use of germplasm. The survey was carried-out on the awareness of Integrated Soil Fertility Management practices in the Savelugu Municipal of Northern Ghana to study the awareness of integrated soil fertility management practices amongst farmers through the administration of questionnaires. A multistage method of sampling was used in selecting thirty (30) respondents randomly from five (5) selected communities namely Jana, Yapalsi, Diari, Nabogu and Gushie to make up a total sample size of 150 respondents. Frequency distribution and percentages were used to represent the data. Correlation analysis was used to test for the relationship between awareness, educational level and household size. The survey showed that majority of the respondents at ages between 21 and 30 years were married and majority with household size of 3 to 5 as well as primary and secondary education. Farming activities were carried-out by hand (80%). Majority of the respondents (43.3%) were informed about ISFM through demonstrations and 20% of the farmers apply inorganic fertilizer. About 85.5% of the respondents were aware of ISFM. The research also revealed that ISFM improves production and supports finances of respondents. The assessment of respondents’ perception of ISFM revealed a positive agreement of the effect of ISFM on soil health as well as improved production. In conclusion, it is thus suggested that it is needful for the involvement of the government on the adoption of ISFM via Non-Governmental Organisations (NGOs) locally and or internationally for a suitable advancement and to guarantee a sustainable environment with a world-wide corporation for improvement.
Afficher plus [+] Moins [-]Backwardness of Central and Eastern Europe as a Heritage of the Soviet Period
2020
Ancans, Sandris
The economy of Latvia lags behind economically developed nations approximately fourfold in terms of labour productivity in the tradable sector, which is the key constituent of a modern economy, thereby affecting future sustainable development in the entire country, including the rural areas. The economic backwardness is characteristic of the entire Central and Eastern Europe. This is the heritage of a communist regime that lasted for about half a century and the economic system termed a (centrally) planned economy or a command economy. However, such a term for the communist-period economy is not correct, as it does not represent the purpose it was created for. Accordingly, the paper aims to assess the effect of the communism period on the economic backwardness of the Central and Eastern European region of the EU. A planned economy that existed in all communist countries, with the exception of Yugoslavia, was not introduced to contribute to prosperity. It was intended for confrontation or even warfare by the communist countries under the guidance of the USSR against other countries where no communism regime existed, mostly Western world nations with their market economies. For this reason, it is not correct to term it a (centrally) planned economy or a command economy; the right term is a mobilised (war) economy. An extrapolation of a geometric progression for GDP revealed that during the half a century, Latvia as part of the USSR was forced to spend on confrontation with the West not less than EUR 17 bln. (2011 prices) or approximately one gross domestic product of 2011. The research aim of the paper is to assess the effect of the communism period on the economic backwardness of the Central and Eastern European region of the EU.
Afficher plus [+] Moins [-]The Effect of separated Expansion Chamber Parameters on Exhaust Pressure Oscillations in Single Cylinder Motorcycle Engine
2020
Banis, Kārlis
This paper investigates the effect of separated exhaust expansion chamber parameters on pressure oscillations in spark-ignited internal combustion (IC) gasoline engines. It is known that exhaust expansion chambers are becoming increasingly more popular among both – original equipment (OE) and aftermarket equipment (AE) exhaust system manufacturers for performance-oriented motorcycles equipped with mainly single cylinder engines, but the companies are reluctant to reveal any detailed principles of operation of the mentioned expansion chambers. The subject of this research is the type of expansion chamber (separate) as used on performance-oriented motorcycles, particularly its’ effect on exhaust pressure pulsations as different chamber volumes, locations and passage sizes are tested. Time-dependent computational fluid dynamics (CFD) analysis was carried out in Solidworks Flow Simulation environment on a simplified exhaust header pipe model imitating engine operation at full load and steady speed. Honda CRF450R motorcycle engine was used as the example and fully defined using a 1D engine performance calculator software to determine the combustion chamber pressure and exhaust valve lift at any given crankshaft position. Volume flow rate of exhaust gasses at the header pipe inlet was calculated based on engine parameters and operating speed. The average pressure values with respect to physical time were measured and graphed across the header pipe inlet cross-section. Eight different header pipe and exhaust expansion chamber combinations were modelled, tested, and results compared at low, medium and high engine speeds. It was found that the presence of exhaust expansion chamber tends to dampen the amplitude and decrease the frequency of pressure oscillations generated at the opening of the exhaust valve(s). Observations show that the addition of an expansion chamber as per design of performance-oriented motorcycles helps to decrease the negative effect of engine tuning while also dampening the positive effect.
Afficher plus [+] Moins [-]