POSSIBILITIES FOR USING SOLAR ENERGY TOHEAT LOCAL WARMING OF NEW BORN PIGLETS

The optimum air temperature in a pigsty for sows is 16-18 °C, but during the first days of new born piglets life the temperature in their lairs ought to be 32...34 °C. Therefore the local warming for piglets is installed. The goal o f the investigation was to measure the intensity o f heat irradiation under different lands of infra-red heaters, more often used on Latvia farms. An autonomous infra-red piglet warming systems have been developed. The experiment has showed, that during the first days of piglets life the heater should be kept at the high, so that the irradiated area 0.3— 0.4 m has been. Gradually heaters have to be lifted up 3-4 times while the warming area is 0.6-0.7 m2 in 40-45 days, when piglets are weaned. The temperature in a lair has to be regulated by change o f electric power o f the heater. Several constructions of voltage regidators are worked out, which are able to ensure the temperature on the warmed surface automatically or manually, depending on the temperature in a pigsty and live mass of piglets. The automatic power regulation o f the heaters decreases the consumption of electric energy more than 2 times

BIOFUEL FOR NATURE PROTECTION

Energy sector has been one o f the most important priorities since reestablishment o f the independence o f Latvia. The deficiency o f energy resources in Latvia has created a need to assess all the possibilities to utilize all the local enrgy resources, including the biological ones, to motivate the trends in the development of energetics in Latvia. Therefore data have been collected, calculations made and possibilities analysed to replace the imported energy resources. From the renewable energy in Latvia there are used the wind, solar, hydraulic and bioenergy. A biofuel programme has been worked out in Latvia. It is envisaged to develop the production of ethanol and rape oil for vehicle engines. For this purpose an arable area of 288 thousand ha is needed. A huge non-utilised reserve in Latvia is methane fermentation of organic agricultural and municipal residue and sewage from food industry. It is calculated that about 170 million m3 biogas can be obtained in Latvia. Implementation of the fuel programme will stimulate Latvia’s economy

Impact of forest management regimes on the development of forest successions in the territory of Gauja national park in the period from 2020 to 2520

Maģistra darbs veltīts Gaujas nacionālā parka meža sukcesijas procesa izpētei nākamo 500 gadu periodā, ņemot vērā atšķirīgus apsaimniekošanas režīmu scenārijus. Meža sukcesijas modelēšana veikta ar LANDIS II meža simulācijas modeli, kas pirmo reizi Latvijā aprobēts un šī darba ietvaros validēts. Iegūtie simulācijas rezultāti analizēti Fragstats modeļos, secinot, ka apses, blīgznas un baltalkšņa sastopamība ainavā ir atkarīga no traucējuma klātesamības, savukārt egle mazina citu sugu izplatību. Pašreiz esošā koku sugu sabiedrība ir seriāla sabiedrība un tā vērtējama kā ekoloģiski nestabila, tā nepārtraukti mainās noteiktās attīstības trajektorijās, tiecoties sasniegt egles monodominantu audzi kā klimaksa sabiedrību. Līdz ar to dabiskošanās process samazina koku sugu daudzveidību, turpretim mežsaimnieciskā darbība palielina koku sugu skaitu un daudzveidību, kas ir seriālo sabiedrību indikators. Secināts, ka tagadnes nosacījumi Gaujas nacionālajā parkā dabas lieguma zonā ir efektīvi, lai veicinātu meža ainavas dabiskošanos, turpretim Gaujas nacionālā parka stingrā režīma zonā tie nav efektīvi, lai nodrošinātu dabiskošanās procesus.The Master's thesis is dedicated to exploring the forest sukcession process of Gauja National Park over the next 500 years, taking into account different scenarios for management regimes. Forest succession modelling has been performed with a LANDIS II forest simulation model, which has been used for the first time in Latvia and has been validated in the framework of this work. The results of the simulation have been analysed in the Fragstat models, concluding that the occurrence of Populus tremula, Salix caprea and Alnus incana in the landscape depends on the presence of the disturbance, while the Picea abies reduces the prevalence of other species. The current community of tree species is a serial community and is considered to be ecological unstable, and it is constantly changing in certain developmental pathways to reach the growth of monodominants as a society of climax. Consequently, the naturalness reduces the diversity of tree species, whereas forestry activity increases the number and diversity of tree species, which is an indicator of serial community stage. It is concluded that the present conditions in the nature protection zone of the Gauja National Park are effective in promoting the naturalness of the forest landscape, whereas in the strict regime zone of the Gauja National Park they are not effective in ensuring the naturalness

Industrial Policy as a Factor Affecting Competitiveness of Latvia

Bakalaura darba tēma ir „Industriālā politika kā Latvijas konkurētspēju ietekmējošs faktors”. Darba mērķis ir analizēt Latvijas industriālo politiku un tās ietekmi uz valsts konkurētspēju, salīdzināt to ar Somijas industriālo politiku un izstrādāt priekšlikumus tās pilnveidei. Darba pirmajā daļā tiek aplūkota teorija par industriālo politiku un valsts konkurētspēju, otrajā tiek apskatīta Latvijas tautsaimniecība un trešajā daļā tiek analizēta Latvijas industriālās politikas ietekme uz valsts konkurētspēju un veikts salīdzinājums ar Somijas industriālo politiku. Darba rezultātā tika secināts, ka Latvijā īstenotā industriālā politika laika posmā no 2003.-2013. gadam ir veicinājusi Latvijas konkurētspējas palielināšanos, bet tās horizontālā rakstura dēļ, ir bijušas mazas strukturālās pārmaiņas, kuras Somijā tiek veicinātas mērķtiecīgāk.The theme of the bachelor thesis is „Industrial policy as a factor affecting competitiveness of Latvia”. The aim of the work is to evaluate industrial policy of Latvia and its effect on country competitiveness and compare it with industrial policy of Finland. Paper consists of three parts. In the first part author has studied theoretical aspects of industrial policy and country competitiveness. In the second part author has analyzed economy of Latvia and its main indicators. In third part author has analyzed industrial policies of both countries, evaluated their effect on country competitiveness and compared them. In the result, it was found that during 2003-2013 industrial policy of Latvia has promoted overall country competitiveness, but has made little effect on the structure of economy compared to industrial policy of Finland

Effect of vegetation on Auchenorrhyncha communities in calcareous fens in the Maritime lowland

Latvijā kalcifīlajos zāļu purvos bezmugurkaulnieki ir maz pētīti, kā arī cikādes kā taksonomiska grupa Latvijā netiek pētīta. Darba mērķis: noskaidrot kaļķaino zāļu purvu veģetācijas ietekmi uz cikāžu sugu sabiedrībām. Pētījums veikts Piejūras zemienes kalcifīlajos zāļu purvos, ievācot cikādes ar entomoloģisko tīkliņu un nosakot augu sugu projektīvos segumus. Kaļķainajos zāļu purvos konstatētas 27 cikāžu sugas. Latvijas faunai konstatētas četras jaunas sugas: Aphrophora major, Chloriona glaucescens, Ch. smaragdula, Pentastiridius leporinus. No konstatētajām cikāžu sugām purviem raksturīgās sugas ir: Aphrophora major, Pentastiridius leporinus, Delphax crassicornis, Ommatidiotus dissimilis, Sorhoanus assimilis, Paralimnus phragmitis. Zāļu purvos pēc indivīdu skaita dominē polifāgās cikāžu sugas: Lepyronia coleoptrata, Cicadella viridis un Neophilaenus lineatus, bet pēc sugu skaita dominē monofāgās cikāžu sugas. Monofāgās cikāžu sugas dominē pēc sugu skaita, jo purvos dominē grīšļi un parastā niedre un ar šiem augiem barojas liela daļa monafāgo cikāžu sugu. Polifāgās cikāžu sugas dominē pēc indivīdu skaita, jo barība nav populāciju limitējošais faktors. Augu sugu daudzveidība būtiski pozitīvi ietekmē cikāžu sugu skaitu, bet neietekmē populācijas blīvumu. Kopumā korelācijas analīze neparāda būtisku saistību starp cikāžu sugu un saimniekaugu. Monofāgajām cikāžu sugām Chloriona glaucescens, Ch. smaragdula, Pentastiridius leporinus, Paralimnus phragmitis, Delphax crassicornis saimniekaugs parastā niedre nav populāciju limitējošais faktors. Atslēgvārdi: Auchenorrhyncha, cikāžu sabiedrības, kalcifīlie zāļu purvi, saimniekaugi, augu sugu daudzveidība.In Latvia in calcareous fens invertebrates are studied little, and hoppers as taxonomic group nobody investigates in Latvia. The aim of the work is to determine impact of calcareous fens vegetation on hopper species communities. The research was done in calcareous fens of the Maritime lowland, collecting hoppers with entomological net and determining the projective cover of plant species. 27 hopper species collected in calcareous fens. Four new species detected for Latvian fauna: Aphrophora major, Chloriona glaucescens, Ch. smaragdula, Pentastiridius leporinus. Characteristic hopper species for bogs: Aphrophora major, Pentastiridius leporinus, Delphax crassicornis, Ommatidiotus dissimilis, Sorhoanus assimilis, Paralimnus phragmitis. After the number of individuals polyphagous hopper species dominated in fens: Lepyronia coleoptrata, Cicadella viridis and Neophilaenus lineatus, but after the number of species monophagous hopper species dominated. Monophagous hopper species dominate after the number of species, because in fens sedges and common reeds are dominant and a large number of monophagous hopper species feed on these plants. Polyphagous hopper species are dominant after the number of individuals, because food is not limiting factor for population. Plant species diversity had significant positive impact on number of hopper species, but had no impact on population density. Total correlation analysis did not showed significant connection between hopper species and host plant. Host plant common reed is not a population limiting factor for monophagous hopper species Chloriona glaucescens, Ch. smaragdula, Pentastiridius leporinus, Paralimnus phragmitis, Delphax crassicornis. Key words: Auchenorrhyncha, hopper communities, calcareous fens, host plants, plant species diversity

An influence of vegetation on hopper (Auchenorrhyncha) communities` structure in the Apšuciems calcareous fen

Darba mērķis ir noteikt veģetācijas ietekmi uz cikāžu sabiedrībām un to struktūru Apšuciema kaļķainajā zāļu purvā. Pētījuma vieta atrodas Apšuciema zāļu purvā, Engures novadā. Cikāžu paraugi ievākti un veģetācija noteikta 57 parauglaukumos. Cikāžu sabiedrību struktūra ir heterogēna, veidojas sabiedrību izmaiņu, līdzības gradients. Visaugstākā cikāžu daudzveidība, sugu un indivīdu skaits sastopams ekotonā, un to būtiski pozitīvi ietekmē augu sugu skaits un daudzveidība. Subdominantās sugas fiziski sadala purva teritoriju. Retākās sugas izplatītas galvenokārt ekotonā. Konstatēta atsevišķu cikāžu sugu izplatības atkarība no barības auga izplatības. Visnegatīvāko ietekmi uz cikāžu sabiedrībām rada dižā aslape. Zilganā molnija un parastā niedre uz dižās aslapes fona cikāžu sabiedrības ietekmē pozitīvi.The aim of the work is to determine the influence of vegetation on hopper communities and their structure in Apšuciems calcareous fen. Study location is in Apšuciems fen, Engure region. Hoppers sampled and vegetation detected in 57 sampling sites. Hopper community structure is heterogenous, gradient of communities changes and gradient of similarity are forming. Highest hopper diversity, number of species and number of individuals are found in ecotone, and number of plant species and plant diversity have significant positive influence on them. Subdominant species physically divide territory of fen. Rarest species are mainly found in ecotone. Some hopper species distribution depending on food plant ditribution was detected. Cladium mariscus had negative influence on hoppers communities. Molinia caerulea and Phragmites australis, on the background of C. mariscus, have a positive influence on hopper communities

Socio-Biological Considerations of Integrity of Visual Image (Abstract)

Cilvēka vizuālais tēls iemanto apjomīgu sociāli bioloģiskās informācijas daudzumu. Tas norāda uz dzimumu, vecumu, rasi, veselības stāvokli, auglību, hormonu līmeni un pat uz paredzamo uzvedību un dzīves ilgumu. Tā ir būtiska privātā informācija, kas ikdienā nav aizsargāta un kas ir eksponēta apkārtējiem. Latvijā katrs trešais skolēns saskaras ar mobingu, un tas ir viens no augstākajiem rādītājiem starp Ekonomiskās sadarbības un attīstības organizācijas valstīm. Piemēram, visticamāk, tieši mobings bijis par iemeslu 16 gadu veca puiša pašnāvībai, kas notika 2019. gadā. Zināms, ka pašnāvība ir sociālās atstumtības rezultāts, un Latvijā ir trešais lielākais pašnāvību izdarījušo cilvēku skaits Eiropas Savienībā. Rakstā tiek analizēta vizuālā tēla sociāli bioloģiskā koncepcija, sniegti argumenti tā aizsardzībai un nozīmīgumam sabiedrībā kopsakarā ar spēkā esošajām tiesību normām un judikatūru. Nobeigumā ir priekšlikums, kas attiecināms uz likumprojektu “Sejas aizsegšanas ierobežojuma likums”, kā arī uz sejas atpazīšanas videonovērošanas sistēmas iespējamu ieviešanu.Visual image of a man is a considerable amount of socially biological information. This includes gender, age, race, health, fertility, hormone levels, even behavior, and life expectancy. It is essentially private information that is not protected day-to-day basis and is rather exposed to the surrounding individuals. In Latvia, every third pupil faces bullying, which is one of the highest rates among OECD countries. For example, in 2019, it was more likely that bullying had been the reason for suicide of a 16-year-old boy. It is known that suicide is the result of social exclusion, and Latvia possesses the third largest number of people who have committed suicide in the European Union. The article analyses socio-biological concept of visual image, arguments for its protection and its importance in society, compliance with existing legal provisions and case law. A proposal has been made for the establishment of legal provisions relating to the draft of the Facial Masking Limitation Law, as well as for the possible introduction of a facial recognition video surveillance system

Portrait Characteristics and Activity of Cyber Paedophiles in the P2P System DC++ at National and Regional Level

Līdz ar epidemioloģisko drošības pasākumu ieviešanu COVID-19 infekcijas izplatības ierobežošanā plašsaziņas līdzekļos tiek ziņots par pieaugošu interesi par pornogrāfiju. Diemžēl aktualizējas interese arī par bērnu pornogrāfisko materiālu, kas saskaņā ar virkni tiesību aktu ir aizliegta. Krimināllikuma 166. panta otrajā daļā ir noteikts, ka par šīs informācijas aprites noteikumu pārkāpumiem, tostarp glabāšanu, soda ar brīvības atņemšanu uz laiku līdz trīs gadiem. Šī pētījuma mērķis ir noteikt kiberpedofilu aktivitāšu esamību datu apmaiņas platformā DC++ un raksturot potenciālo kiberpedofilu personības profilu, analizējot faktiskās situācijas problēmas nacionālā un reģionālā mērogā. Lai realizētu darba mērķi, tika izvirzīti divi darba uzdevumi: 1) novērtēt nacionālā un reģionālā mēroga ietekmi uz bērnu pornogrāfiskā materiāla apriti datu apmaiņas platformā DC++, 2) noteikt tipiskā kiberpedofila portretu, raksturojot DC++ lietotāju, kas veic bērnu pornogrāfiskā materiāla lejupielādi, aktivitātes un pieejamo informāciju par tiem. Šajā darbā izmantotās zinātniskās pētniecības metodes: empīriskā datu vākšanas metode, statistiskā datu apstrādes metode, sintēzes metode, novērojuma metode un salīdzinošā metode. No iegūtajiem datiem secināts, ka bērnu pornogrāfiskā materiāla glabāšanas kriminalizēšanai valstī ir būtiska ietekme uz šajā valstī esošo lietotāju aktivitātēm datu apmaiņas sistēmā DC++ un tās tiek ierobežotas. Starptautiskie un reģionālie tiesību akti ir efektīvs veids cīņai ar bērnu pornogrāfiskā materiāla apriti, taču tie negarantē pilnīgu problēmu atrisināšanu – tā tas ir novērots Rumānijas gadījumā, kur ir salīdzinoši augsta aktivitāte. Noskaidrots, ka tipiska DC++ platformas lietotāja vecums ir lielāks par 35 gadiem un tas ir vīrietis, kas strādā algotu darbu. Viņam vienlaikus ir arī citas parafiliskas intereses.With the introduction of epidemiological security measures to limit the spread of COVID-19 infections, adult interest in pornography is reported in the media. Unfortunately, there is also a renewed interest in child sexual abuse material, which is illegal under several laws. In Latvia, according to the second paragraph of Section 166 of the Criminal Law, for a person handling of such materials the applicable punishment is the deprivation of liberty for a period of up to three years. The aim of this study is to identify the existence of cyber paedophile activities in the peer two peer (P2P) system Direct Connect DC++ and to characterise the personal profiles of potential cyber paedophiles by analysing the actual problems at national and regional level. In order to realise the objectives of the work, two tasks have been identified: 1) to assess the national and regional impact on the circulation of child sexual abuse material on the P2P system DC++; 2) to define a portrait of the typical cyber paedophile, describing the activities and available information of P2P system DC++ about system users. The scientific research methods used in this work are: the empirical data collection method, the statistical data processing method, the synthesis method, the observation method, the comparative method. It has been concluded that the criminalisation of the storage of child sexual abuse material in a given country has a significant impact on the activities of users in that country in the DC++ system. International and regional legislation is an effective way of combating the circulation of child sexual abuse material, but it does not guarantee full resolution of the problems, such as the case observed in Romania, which has a relatively high activity. The typical user age of the DC++ system has been found to be more than 35 years, an employed mail. At the same time, he also has other paraphilic interests

The Effects of Air-Entraining Agent on Fresh and Hardened Properties of 3D Concrete

Three-dimensional concrete printing (3DCP) is becoming more common in the construction industry nowadays; however, the aspect of durability of printed concrete is not well-studied yet. Frost resistance is a very important factor for durability of concrete structures located in northern regions. Since air-entraining agents (AEAs) are widely used in conventional concrete, this paper focuses on exploring the potential of using AEAs in 3D concrete as well—the main objective is to determine how it affects fresh and hardened properties, including frost resistance of 3D concrete. Three different mixes were printed and cast—the dry mix consisted of ordinary Portland cement (OPC), limestone filler (LF), sand, as well as viscosity modifying agent (VMA) and superplasticizer (SP). Two mixes contained different amounts of AEA, the third one was used as reference. First, fresh state properties were tested—air content, density, and mini cone flow test. Second, 28-day compressive and flexural strength tests were carried out; bulk and particle densities were also determined. Next, both cast and printed concrete samples were subject to freeze–thaw cycles according to provisions of CEN/TS 12390-9, mass loss due to surface scaling was determined for each sample. As a result, printed concrete samples containing AEA in the amount of 0.06% of binder mass showed the highest frost resistance—addition of AEA decreased both flexural and compressive strength of this printed concrete mix by 30–40%. To conclude, the obtained results give an insight of how addition of AEA to printed concrete mix affects its properties both in long and short term. Further research of certain aspects, for instance, the air void system and pore distribution is needed to gain a deeper understanding on how to increase durability of 3D concrete

The Effects of Air-Entraining Agent on Fresh and Hardened Properties of 3D Concrete

Three-dimensional concrete printing (3DCP) is becoming more common in the construction industry nowadays; however, the aspect of durability of printed concrete is not well-studied yet. Frost resistance is a very important factor for durability of concrete structures located in northern regions. Since air-entraining agents (AEAs) are widely used in conventional concrete, this paper focuses on exploring the potential of using AEAs in 3D concrete as well—the main objective is to determine how it affects fresh and hardened properties, including frost resistance of 3D concrete. Three different mixes were printed and cast—the dry mix consisted of ordinary Portland cement (OPC), limestone filler (LF), sand, as well as viscosity modifying agent (VMA) and superplasticizer (SP). Two mixes contained different amounts of AEA, the third one was used as reference. First, fresh state properties were tested—air content, density, and mini cone flow test. Second, 28-day compressive and flexural strength tests were carried out; bulk and particle densities were also determined. Next, both cast and printed concrete samples were subject to freeze–thaw cycles according to provisions of CEN/TS 12390-9, mass loss due to surface scaling was determined for each sample. As a result, printed concrete samples containing AEA in the amount of 0.06% of binder mass showed the highest frost resistance—addition of AEA decreased both flexural and compressive strength of this printed concrete mix by 30–40%. To conclude, the obtained results give an insight of how addition of AEA to printed concrete mix affects its properties both in long and short term. Further research of certain aspects, for instance, the air void system and pore distribution is needed to gain a deeper understanding on how to increase durability of 3D concrete