Search results for "kuumuus"
showing 3 items of 3 documents
Engineering thermal conductance using a two-dimensional phononic crystal
2014
Controlling thermal transport has become relevant in recent years. Traditionally, this control has been achieved by tuning the scattering of phonons by including various types of scattering centres in the material (nanoparticles, impurities, etc). Here we take another approach and demonstrate that one can also use coherent band structure effects to control phonon thermal conductance, with the help of periodically nanostructured phononic crystals. We perform the experiments at low temperatures below 1 K, which not only leads to negligible bulk phonon scattering, but also increases the wavelength of the dominant thermal phonons by more than two orders of magnitude compared to room temperature…
Endocrine effects of sauna bath
2020
Sauna bath brings about numerous acute changes in hormone levels, partly akin to other stressful situations, partly specific for sauna. Norepinephrine increases in those accustomed to sauna bath. Sweating increases the production of antidiuretic hormone, and the renin-angiotensin system becomes activated. Of the anterior pituitary hormones, growth hormone (GH) and prolactin (PRL) secretion is increased. Also β-endorphin has been frequently reported to increase, whereas the responses of ACTH and cortisol are variable, probably depending on the type of sauna exposure. Sperm production decreases in particular in sauna-naïve men, but reduced fertility has not been associated with regular sauna …
Aerobic wastewater treatment under high and varying temperatures : thermophilic process performance and effluent quality
2003
Tuottavassa teollisuudessa, esimerkiksi paperin ja massan valmistuksessa, muodostuvat kuumat prosessi- ja jätevedet tyypillisesti viilennetään ennen niiden biologista käsittelyä. Juhani Suvilammen väitöstutkimus osoittaa, että jätevesiä voidaan käsitellä myös korkeissa lämpötiloissa, mistä on monia etuja.Tutkimuksen tuloksia voidaan hyödyntää kuumien jätevesien biologisessa aerobisessa käsittelyssä ja erityisesti metsäteollisuuden vesikiertoja suljettaessa. Tutkittu prosessi on aikaisempaa yksinkertaisempi, koska lämmönvaihtimien tarve pienenee. Käsittely on siten kustannustehokkaampi ja toiminnaltaan varmempi. Lämpötilan noustessa reaktionopeudet kasvavat, joten prosessi voidaan toteuttaa …