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Mūsdienīgu loģistikas tehnoloģiju pielietojums tranzīta kravu pārvadājumu attīstībai Latvijā
No full textŠajā darbā tiek piedāvātas jaunas loģistikas tehnoloģijas, lai attīstītu tranzīta kravu pārvadājumus Latvijā. Tranzīta kravu piesaistīšana ir saistīta ar jaunas sistēmas izveidi, kurā mijiedarbojas transports un loģistika, un tā tiek balstīta gan uz eksistējošās transporta infrastruktūras modernizāciju, gan uz
jaunas loģistikas pieejas ieviešanu.
Šie pasākumi ļaus izveidot jaunu transporta un loģistikas nozari, kurā tiks iekļautas šādas daļas: multimodālais transports, mūsdienīgi termināļi, kravu ekspedīcija, kas ļaus realizēt kombinētos kravu pārvadājumus
Kravas autotransporta līdzekļu sastāvu ceļu satiksmes negadījumu rašanās risku ietekmējošo parametru analīze
No full textPētījuma mērķis ir noteikt sakarību starp kravas autotransporta līdzekļu sastāvu ceļu satiksmes negadījumu notikšanas varbūtību un divjoslu vienas brauktuves autoceļu ģeometriskajiem un transporta plūsmas parametriem. Izmantojot Vuonga testu, savstarpēji salīdzināti Puasona, negatīvais binominālais (NB), Puasona ar nuļļu ietekmi (ZIP) un negatīvais binominālais ar nuļļu ietekmi (ZINB) regresijas modeļi. Par atbilstošāko izvēlēts ZINB matemātiskās prognozēšanas modelis. Izstrādāts matemātiskais prognozēšanas modelis, izmantojot izvēlēto teorētisko regresijas sadalījumu
Derivation of Use Cases from the Topological Computation Independent Business Model
No full textIn Model Driven Architecture (MDA), business requirements for the information system are described in a Computation Independent Model (CIM), which additionally can describe knowledge of the business, and structure and behavior of both business and supporting information system. In object-oriented software development requirements are described by use cases. Use cases and identification of them are informal and application-oriented. Goal-based approaches provide a more systematic way for discovering use cases from informal knowledge about a system. The main and very important difference of the approach suggested in this chapter is that we ground our domain analysis on a mathematical engineering model, Topological Functioning Model. It is a formal holistic computation independent business model, whose characteristics help in avoiding challenges in functional requirements caused by non-systematic approaches and fragmental nature of use cases, namely, completeness, traceability and compliance with the problem domain
Corporate Social Responsibility (CRS) in Business Practisies of the Companies: Problems and Possibilities
No full textCorporate Social Responsibility (CRS) is concept in the theoretical literature have different definitions, concepts and approaches. In business environment CSR is known term, but at the same time this concept also have different understandings and as well as different levels of realization
Topological Modeling and Arrow Diagram Logic Formalism Application for Software Development
No full textProblem domain analysis and modeling problems are discussed in the paper. The main problem of the object-oriented approach is its direction not to the problem domain, but to the application domain analysis and modeling. There is no formal connection between system functioning (dynamics) and a structure (static). Topological modeling is a convenient formal and comprehensive way to describe a problem domain in mathematical terms and to transform a system functioning model into a system structure model (class diagram). Sketch approach is a formal comprehensive way to precise a description of system class relations. The comparison of these two approaches and a small example of its application to the system modeling are given in the paper
Impact of External Factors on Humidity Migration Processes in Walls Made from Autoclaved Aerated Concrete
No full textThe paper is devoted to the analysis of humidity migration and heat transfer
processes in walls made from new generation of autoclaved aerated concrete
blocks. The paper gives experimental results of humidity migration and heat
transfer processes in new generation of autoclaved aerated concrete walls as well
as measurements of climatic data during the experiment. Analyzing experimental
data, the model for climatic data evaluation in Baltic Sea states was created and
tested. The influence of new generation of autoclaved aerated concrete wall
finishing materials on the drying process of the wall was also studied in this
paper
Generation of Algal Biomass for Biogas Production: Energetic and Environmental from a Life Cycle Assessment (LCA) Perspective
No full textIn fact, algae represent an interesting alternative to the production of first or second generation biofuels, thanks to an high photosynthetic yield and hence, a lower land competition with food production and a better control of ground emissions. In addition, the ability to use CO2 directly from industrial emissions as a resource of carbon for the growth of microalgae is a promising feature for fluegas mitigation. Hence if used as an interface between biowaste and energy production, macroalage allows direct utilization of biowaste and, at the same time transforms negative environmental externalities into positive ones. A Life cycle assessment (LCA) is fundamental in order to optimize the overall process from the environmental point of view, addressing the attention on the environmental “hot spots” of the process. The LCA methodology is one of the best suitable instruments for understanding the environmental benefits and the share of non-renewable sources still needed for the process.
It interest to investigate a transformation system coupling the anaerobic digestion of raw algae (for production of biogas and after upgrading methane as biofuel) and the algal production itself. The benefits can be focused also on the recirculation of the liquid fraction of the digestates toward the algal ponds and a significant fertilizers recycling.
The purpose of this paper is to carried out an environmental assessment of the use of biogas from algae as a biofuel for the heat and electricity production on a cogeneration (CHP) unit (40kW) and compares it in case of natural gas/diesel supplies. All the biogas production from algae is reference to the pilot plant in Augusta (Italy) to be implemented within the framework of the FP7 project BioWALK4biofuels.
Environmental and energy analysis will be carried out within the methodological framework of the LCA based on a ‘‘cradle to grave” inventory of emissions and resources consumption.
The chosen method to assess the potential impacts is IMPACT2002+, described in Jolliet et al. (2003).
Data about algal productivity and the methane yield production mainly coming from the project partners and technical literature. In this study, the anaerobic digestion of the marine macroalgae Ulva Prolifera has been taken into account
Simplified Dynamic Life Cycle Assessment Model of CO2 Compression, Transportation and Injection Phase within Carbon Capture and Storage
No full textCarbon capture and storage is significant technology in the limitation of greenhouse gases in the atmosphere worldwide. Carbon
capture and storage consists of four general processes within the system: carbon capture, carbon compression and transport,
carbon injection and carbon storage. All the processes require energy to operate the system and therefore produce additional
amount of carbon dioxide emissions. The energy penalty decreases the efficiency of the plant: the total conditional efficiency of
the CCS system is often characterised as difference between CO2 emissions eliminated by CCS and CO2 emissions produced by
CCS processes. Additionally, CCS is associated with environmental, safety and human consequences because of CO2 leakage
from storage sites and its impact to ecosystems, stability of geological layers and changes in geological properties of formations,
etc. This paper is aimed at the identification and optimisation of costs and the environmental impact categories caused by energy
consumption at a CCS power plant for the realization of carbon compression, pipeline transport and carbon injection phases
Assurance of Automatic Connection of Plastic Details by Machines of Nonstop Operation
No full textIn this article the problem of necessity to search for other ways of improvement of accomplishment quality of the threaded joints from plastic automated assembly, because it is necessary to prevent the process of unscrewing of a threaded joint using higher material inputs
Investigation of Solar Collector's in Latvian Conditions
No full textOutdoor air temperature range in the Baltic region is below average values in Europe. Range of outdoor air temperature in the Baltic region is -3 ºC in winter and +16 ºC in summer. And solar radiation intensity is lower in comparison with the average European values. The average solar radiation intensity reaches 1100 kWh/m2 per year in Baltic region. Therefore, there is a particular need to optimize the solar thermal system in the Baltic region.
Solar collector’s operation methods investigated on the IPE solar energy polygon according different parameters. The most common types of solar collector’s operation were investigated and compared: by the time, by the heat carrier temperature differences of input and output, by the solar radiation intensity and operation control methods in various combinations.
Theoretical and practical advantages and disadvantages of using each control methods were analyzed. Solar collector’s operation system could be regulated in accordance with the solar radiation intensity, by the boiler lower temperatures and by the outdoor air temperature to determine precisely the solar collector efficiency of the parameter changes. This may help to avoid the previous operation systems testing regime deficiencies.
The precision of solar collectors operation depends on the type of operation systems: heat losses and the collector efficiency calculation accuracy, the sensor is accuracy, the time between the regulation regimes, and the range of heat carrier pumps action operation sensors.
Currently, companies that offer solar collectors, offer solar collectors complete set with all necessary equipments for the solar collector connection for hot water supply system, or for home heating operation system by the temperature difference of input and output. And no one of them does not offer solar collectors operation systems by the various parameters