Tyrime sulygintos senos kartos sniego valymo sistemos su nauja skaitmeninio valdymo šildymo sistema. Atsižvelgus į gautus rezultatus, pateiktiami pasiūlymai sniego valymo sistemoms efektyvumo didinimui. Tyrimas skirtas sistemų optimizavimui ir elektros energijos vartojimo mažinimui. / Point heating systems, used by SC „Lietuvos gelezinkeliai“, have to warrant safe and reliable train traffic. It is designed to melt ice which is between point’s spike and frame rail and accomplish heating elements’ and other system parts monitoring and control according the stated parameters. At present the snow blowing system use a lot of electrical energy, the research is dedicated to optimize the systems and to reeducated use of electrical energy.

Šiais laikais sunku įsivaizduoti namus be bendram vartojimui skirto šilto vandens prieigos. Namuose, kurie nėra prijungti prie miesto vandentiekio infrastruktūros šiltas vanduo paruošiamas vietiniuose vandens šildytuvuose. Lietuvoje dažnai naudojami kombinuoti vandens šildytuvai. Šilto vandens paruošimui jie gali naudoti elektros energiją, arba centrinės šildymo sistemos šilumą. Deja tokie šildytuai dažniausiai negali automatiškai pasirinkti optimaliausio energijos šaltinio. Dėl to gaunami prasti ekonominiai rodikliai ir be reikalo švaistoma energija. Šio darbo tikslas yra kombinuoto vandens šildytuvo modernizacija sukuriant paprastą, tačiau galingą valdiklį, suteikiantį, jo vartotojui, galimybę automatizuoti šilto vandens paruošimo sistemos darbą, taip pagerinant ekonominius ir ergonominius pastato rodiklius. / In modern day it is very hard to imagine household without access to general purpose hot water. In buildings, with no access to centralized water distribution system, hot water is prepared in domestic water heaters or boilers. One of the most common types of water heaters in Lithuania is combined water heater. For hot water preparation it can use either electric power or heat from domestic heating system. However these heaters rarely have any capability to automatically choose energy source so this results in poor economy and useless energy losses. The goal of this work is modernization of combined water heater system by creation of simple yet powerful controller, capable of giving its user ability to automate control of water heating system, improve economy and comfort.

The aim of this study is to examine the effect of heat and cold on the characteristics of skeleton muscles. 24 persons of different age and attitude to sport, men and women, have been examined (12 - using passive heating, 12 - using passive cooling). The rates of vertical jumps were registered (force, power, speed, height of jumps). The rates have been registered before and after cooling and heating procedures. Jumps with and without springing squats with angles of 90 and 135 degrees have been made. After the parameters were recorded, leg mucles were heated in 44 degrees water for 45 minutes or cooled two times in 15 degrees water for 15 minutes with 10 minutes break. Obtained results showed, that the contractile features of sceleton muscles after heating changed differently, the significant improvement of power of muscles was observed, the force of the contraction was stable. After reducing temperature the features of skeletal muscles (force, power, speed) have notably deteriorated. Slow muscle fibres showed greater response to the heating. The increment of power has been noticed. Faster and slower muscle fibres reacted equally to the cooling contraction speed and power have greatly reduced. The usage of elastic energy have not changed either at lower or higher temperatures. When applying physiotherapy means, such as heating or cooling, one has to take into account the dependence of contractile properties of the muscle on the temperature.

Ekonomiškai temperatūrą valdanti sistema turi tiekti šilumą ten kur tuo metu ji yra reikalingiausia ir minimaliai sumažinti ją ten kur ji nėra reikalinga. Tačiau bet kuriai temperatūros valdymo sistemai, tam, kad ji optimaliai valdytų temperatūrą reikalinga žinoti kokia temperatūra yra realiu laiku strategiškai svarbiuose patalpos taškuose. Našus ir greitas temperatūrinės informacijos surinkimas iš įvairių patalpų yra svarbus dalykas ne tiktai šildymo, vėdinimo, kondicionavimo procesams, bet taip pat gali būti naudojama kaip apsauga nuo gaisro. Tačiau iškyla problema – kaipgi stebėti visas temperatūras realiu laiku ir vienoje vietoje? Taigi pagrindinis darbo tikslas yra sukurti temperatūros stebėjimo sistemą, kuri yra sudaryta iš techninės ir programinės įrangos, būtų lengvai įdiegiama ir pritaikoma įvairioms patalpomis arba technologiniams procesams. Ši systema bus paprasta ir nebrangi, tačiau funkcionalumu nenusileis sudėtingoms programoms. Šiame darbe buvo išanalizuota jau egzistuojanti temperatūros stebėjimo sistemų programinė įranga, pabrėžiant jos privalumus ir tr��kumus. Atsižvelgiant į analizės rezultatus, buvo sukurta temperatūros stebėjimo sistemos projektas. / Smart house system, which economically controls temperature, has to supply heating where it necessary at this time and reduce to minimum where it is not necessary. To control temperature optimally, every temperature control system has to know what temperature is in the real time at strategically important room places. Efficient and fast collection of temperature information from various house places is a matter of substance not even in processes of heating, ventilation and air conditioning but also can be used as a preventive mean from fire. But there is a main problem – how to know and observe all temperatures in real time, in one place? So the main aim of research is to design temperature monitoring system, which consists of hardware and software, would be easy installation, adapted for various accommodations or technological processes. This system would be simple and cheap, with it’s functionality would be equal with another sophisticated systems. It was analyzing properly existing temperature monitoring systems’ software at this work and marked its’ merits and demerits. It was created temperature monitoring system project.

Išstudijavus mokslinius literatūros šaltinius, pastebėta, kad kūno temperatūros, o tuo pačiu ir raumens vidinės temperatūros padidėjimas sukelia daug fiziologinių reakcijų žmogaus organizme, tačiau vis dar mažai darbų, nagrinėjančių aklimacijos (aklimacija �� tai dirbtinėse sąlygose (laboratorijoje) sukelta ilgalaikė aklimatizacija) hipertermijai, sukeltos dirbtiniu būdu, poveikį žmogaus fiziologinių rodiklių kaitai, raumens išvystomai maksimaliai valingai jėgai. Nepavyko rasti duomenų kaip maksimalios valingos jėgos metu keičiasi raumenų elektrinis aktyvumas, priklausantis nuo aklimacijos hipertermijai. Pagrindinis šio darbo tikslas buvo nustatyti ir įvertinti dirbtinės aklimacijos hipertermijai poveikį �����mogaus organizmui. Uždaviniai: Nustatyti ir įvertinti žmogaus fiziologinių rodiklių (rektalinę, odos bei kūno temperatūras, fiziologinį stresą, netenkamą kūno svorį, širdies susitraukimų dažnį ir šiluminį stresą) kaitą aklimacijos hipertermijai laikotarpyje: prieš pasyvų šildymą, šildymo metu ir po šildymo; nustatyti aklimacijos hipertermijai poveikį raumenų atsparumui nuovargiui; nustatyti aklimacijos hipertermijai poveikį raumenų centriniam aktyvacijos koeficientui; nustatyti ir įvertinti aklimacijos hipertermijai poveikį šlaunies raumens elektriniam aktyvumui. Šio tyrimo metu iš viso buvo atliekami aštuoni tyrimai — vienas kontrolinis ir septyni hipertermiją sukeliantys eksperimentiniai. Eksperimentiniai nuo kontrolinio skyrėsi pasyviu kojų pašildymu (tiriamieji... [toliau žr. visą tekstą] / Firstly, it is important to emphasize that the research of different scientific articles and other sources of information has proved that the increment of temperature in the man’s body as well as the inner muscle causes many physiologic reflexes in human’s organism. However not many research projects analyzing the impact of the acclimation (In vitro(in laboratory) related long term acclimatization) to hyperthermic environment, created in imitative way, neither on the fluctuation of man’s vital functions nor on the maximum voluntary muscle strength, could be found. Secondly, it should be noted, that none of the above mentioned sources provided the information on the change of muscle electric activity at the moment of its maximum voluntary strength. Therefore, the main purpose of this research was to establish and measure the influence of the imitative acclimation of hyperthermia on the man’s body. The main tasks of the project were to observe and evaluate the change of man’s physiological functions (rectal, skin and body temperature, physiologic stress, weight loss, heart rate and thermic stress) during the acclimation to hyperthermia process: before passive heating, during the heating time and after it; to establish the impact of acclimation to hyperthermia on the maximum voluntary force as well as on the maximum activation rate; to establish and measure the impact of the acclimation to hyperthermia on the muscle electrical activity. In order to achieve the desired... [to full text]

The majority of physiological processes and various other processes taking place in the body are closely related to changes in body temperature (Shellock & Prentince, 1985; Bennett, 1990). The temperature of the human body is constant throughout one’s life. It is approximately 37ºC and it constantly adjusts itself to changes in environment, relative air humidity, the level of radiation, atmosphere pressure and thermo isolation. During long-term physical load, in case of illness or in conditions of extreme body temperature may be in the range from 32ºC to 40ºC or even more (Wilmore & Costill, 2004). It could be hypothesized therefore that the muscle warmed prior to the load to be undertaken, when the leg is extended and flexed in the knee joint at high (500, 450o / s) and average (180o / s) speed depending on gender will increase muscle force and muscle capacity to a greater extent than the cooled muscle, but after lowering the temperature muscle resistance to fatigue will increase. Though considerable research has been done already certain questions still remain to be cleared up, namely: 1. how warming affects muscle fatigue and recovery of female knee extensors and flexors when the leg is being flexed and extended in the knee joint at the fixed 500o / s speed; 2. how muscle contraction function of female and male knee extensors and flexors depends on temperature when the leg is being flexed and extended in the knee joint at the fixed 450o / s and 180o / s peed. Though there... [to full text]

Žmogaus adaptacija prie karščio yra visapusiškai nagrinėjama ir plati problema (Hori, 1978). Literatūroje gausu tyrimų, nagrinėjančių hipertermijos poveikį neuroraumeninei funkcijai po fizinių pratimų karštyje (Nybo & Nielsen, 2001) ar pasyvaus šildymo (Thomas et al., 2006; Todd et al., 2005). M. M. Thomas et al. (2006) nustatė, kad pasyvaus šildymo metu, padidinus vidinę kūno temperatūrą iki 39,5 oC, sumažėja maksimali izometrinė pėdos lenkiamųjų raumenų jėga ir tai įtakoja raumenų aktyvacijos iš CNS sumažėjimas. Anksčiau atlikti tyrimai patvirtina, kad aukšta organizmo vidinė temperatūra paveikia CNS ir jos galimybę aktyvuoti dirbančius raumenis (Nybo & Nielsen, 2001; Todd et al., 2005). Organizmui aklimuojantis prie karščio, sumažėja TREKT, ŠSD, FSI ir padidėja prakaitavimas, kas lemia mažesnį fiziologinį-terminį stresą hipertermijos sąlygomis (Brazaitis ir kt., 2009; Brazaitis ir Skurvydas, 2010), tačiau sunku rasti tyrimų, nagrinėjančių kaip tai paveikia neuroraumeninę funkciją. M. Brazaitis ir A. Skurvydas (2010) nustatė, kad po 7 pasyvaus šildymo procedūrų (~44 oC vandenyje po 45 minutes), kurios buvo vykdomos kas antrą dieną 2 savaičių laikotarpyje, organizmas aklimavosi prie karščio, bet tai nepaveikė centrinio ir periferinio nuovargio MVJ-2min izometrinio krūvio metu hipertermijos sąlygomis. Mūsų atliktame tyrime buvo naudota unikali pasyvaus šildymo metodika (siekiama TREKT padidinti iki 39,5 0C, maksimalus šildymo procedūros laikas 120 min., šildymo procedūros... [toliau žr. visą tekstą] / Human adaptation to heat is comprehensive of a broad problem (Hori, 1978). The literature is rich in research of analyzing the influence of hyperthermia on neuromuscular function, after exercising in the heat (Nybo & Nielsen, 2001) or passive heating (Thomas et al., 2006; Todd et al., 2005). M. M. Thomas et al. (2006) ascertained that the increase to 39,5 oC of core temperature in passive heating, reduces maximal isometric force of plantar flexors and this is influence of the reduction on voluntary muscle activation from CNS. Earlier studies show, that high core temperature affects CNS and its ability to activate working muscles (Nybo & Nielsen, 2001; Todd et al., 2005). Heat acclimation occurs with reduced rectal temperature, heart rate, physiological strain index and increased sweat rate, which causes reduction in physiological-thermal stress in the hyperthermia (Brazaitis ir kt., 2009; Brazaitis ir Skurvydas, 2010), but it is difficult to find studies how this affects the neuromuscular function. M. Brazaitis & A. Skurvydas (2010) found out that after 7 passive heating procedures (in ~44 oC water, 45 minutes each), which was carried out every second day for two weeks, heat acclimation occurred, but did not change the central and peripheral fatigue during a 2-min MVC in hyperthermia. In our study, we used the unique passive heating technique (we tried to elevate rectal temperature to 39,5 0C, maximal passive heating time was 120 min., 16 days of passive heating procedure... [to full text]

Main goal of this work is to establish background for improvement of forecasting and planning of heat market for district heating through defining functional relations between heat consumption versus internal and external factors.

Electrical stimulation has been widely used in the field of sport training or functional rehabilitation to enhance strength training and to assess voluntary muscle activation. Two superimposed techniques can be used: 1) the twitch interpolation technique, which consists of interjecting an electrical stimulus onto the muscle nerve; and 2) the percutaneous superimposed electrical stimulation technique, where the stimulation is applied to the muscle belly. These two superimposed techniques can be used to evaluate the ability to fully activate a muscle. Temperature is important for muscle function. Muscle contraction and relaxation becomes quicker, development of power increasing as the temperature of the body raises. Immoderate temperature of the muscle, as a result, can decrease physical efficiency. However it is unclear how muscle heating can affect superimposed pulse force, therefore our aim was to determine and compare variant temperature affect on additionally activated quadriceps femoris muscle during isometric load. The study was performed at Lithuanian Academy of Physical Education. The subjects were 10 healthy adult men (age 22,1 ± 2,3 years, weight 72,3 ± 4,9 kg, height 178 ± 5,7 cm) who were not actively going in for sports. The study was consisted of two stages. During the first stage subjects were tested under control conditions. During the second stage (was performed after two weeks) subjects were tested, when their muscles were heated. Quadriceps femoris... [to full text]

Darbe projektuojama geoterminė jėgainė, kuri tiekia šiluminę energiją pastatų grupei. Darbą sudaro įvadas, keturi skyriai, išvados ir rekomendacijos bei literatūros sąrašas. Įvade pateikta nagrinėjamos temos problema, aktualumas, darbo tikslai ir uždaviniai bei praktinė darbo vertė. Pirmajame skyriuje pateikiami projektiniai duomenys pastatų grupei Tauragės miesto pavyzdžiu, aprašomi geoterminės energijos tipai bei jos panaudojimas pasaulyje ir Lietuvoje. Antrajame skyriuje analizuojamas Lietuvos geoterminis laukas bei parenkama projektuojamos geoterminės stoties vieta. Analizuojamos UAB „Geoterma“ iškilusios problemos ir nustatomos jų priežastys. Trečiajame skyriuje atliekamas metinio šilumos poreikio modeliavimas bei trijų energijos šaltinių techninis vertinimas kompiuterine programa EnergyPRO. Ketvirtajame skyriuje energijos šaltiniai vertinami ekonominiu ir aplinkosauginiu požiūriu, taip pat atliekama jautrumo analizė bei aprašomos prielaidos, naudotos darbe. Išanalizavus pastatų grupės energijos poreikius, atlikus techninius energijos šaltinių vertinimus ir reikalingus skaičiavimus šilumos gamybos galimybėms įvertinti, teikiamos išvados ir rekomendacijos. Pridedama: trijų energijos šaltinių schemos. Darbo apimtis – 65 p. be priedų, 35 pav., 15 lent., 19 literatūros šaltinių. / There is designed geothermal power plant that supplies thermal energy group of buildings in this paper. The work consists of four chapters, conclusions, recommendations and references. The introduction is about the problem of the topic, the relevance, the work goals, objectives and the practical value of the work. The first chapter provides design details of buildings group using Taurage's city example, describes the types of geothermal energy and its use in the world and in Lithuania. The second chapter analyzes the Lithuanian geothermal area, also the place for designed geothermal station is selected. Analyze the problems encountered in Geoterma company and identify their causes. There is modeling an annual heat demand and performed the three technical evaluation of energy sources with a computer program EnergyPRO. There is assessed the economic sources from energy and environmental point of view in the fourth chapter. As well sensitivity analysis is produced and description of the assumptions used in the workplace. After the analysis of the building group's energy needs and performed technical evaluations and calculations of energy sources necessary to evaluate the heat generation ability, findings and recommendations are provided. Enclosure: energy sources schemes. Working volume - 65 pages without additives, 35 pic., 15 tables, 19 references.