Vesi ja vähähiilinen talous

Tiivistelmä. Tässä kandidaatintyössä tarkastellaan vesi ja vähähiilistä taloutta. Aihe on todella laaja, joten sitä on hieman rajattu. Työssä käydään läpi mitä vesi ja vähähiilinen talous tarkoittavat, miten vähähiiliseen talouteen päästään ja kuinka vesi liittyy tähän. Lyhyesti myös esitetään, mitä ovat uusiutuvat energiamuodot ja kuinka niitä tuotetaan Suomessa ja kansainvälisellä tasolla. Vuonna 2018 Suomessa tuotettiin uusiutuvilla energiamuodoilla sähköä 47 % kokonaissähköntuotannosta, pääosin vesi- ja tuulivoimalla. Työssä myös perehdytään Pariisin ilmastosopimukseen, koska se on yksi tärkeimmistä suunnan näyttäjistä kohti vähähiilistä taloutta. Työ on toteutettu kirjallisuusselvityksenä. Sekä vähän vettä kuluttava, että vähähiilinen talous edellyttävät oikeanlaisten energiamuotojen valitsemista. Molempia talouksia tukevia energiamuotoja ovat ydinvoima, aurinkovoima ja tuulivoima. Näissä kolmessa energiamuodossa on suhteessa tuotettuun energiamäärään pienet kasvihuonepäästöt, mutta myös pieni veden tarveWater and low carbon economy. Abstract. The topic of this thesis is water and low-carbon economy. This topic is extensive, so it has been restricted. This thesis focuses on what water and low-carbon economy mean, how to reach low-carbon economy and how water can be associated with this. This thesis also displays what renewable energy sources are and how they are generated in Finland and internationally. In 2018 Finland generated 47 percent of its total electricity production by renewable energy sources, mainly by hydropower and wind power. This thesis also discusses the Paris Climate Agreement, since it is one of the main predecessors towards low carbon economy. This thesis has been carried out as a literature review. The choice of energy sources is essential for reaching an economy that uses little water and carbon. Energy sources that maintain both economies are nuclear power, solar power, and wind power. These three sources of energy have low greenhouse gas emissions in contrast to the amount of energy produced, but also have low water demand

Työnaikaisten siltojen aukkomitoitus

Tiivistelmä. Tämän työn tavoitteena on tehdä selvitys työnaikaisten siltojen aukkomitoituksesta kirjallisuuskatsauksen ja kyselytutkimuksen avulla. Työssä perehdytään Suomessa käytettävään varasiltakalustoon, jota käytetään yleensä väliaikaisena siltana varsinaisen sillan rakentamisen tai sen korjauksen aikana, tilapäisratkaisujen rakenteisiin sekä luonnossa tapahtuviin erikoistilanteisiin, kuten jääpatoihin sekä hyydetulviin. Työn keskivaiheilla avataan aukkomitoituksen periaatteet, ongelmat sekä yleisimmät mitoitusmenetelmät. Työn lopussa esitetään johtopäätökset ja suositukset tulevaa tutkimusta varten. Työnaikaisen sillan aukkomitoituksen määrittelyyn vaikuttaa monia eri tekijöitä. Näitä ovat ympäristötekijät, rakenteelliset ratkaisut sekä ilmastonmuutoksen aiheuttamat ääriolosuhteet. Ympäristötekijät sisältävät vesistön luonteen, kuten alttiuden tulville, mutta myös suppojään esiintymisen. Rakenteelliset ratkaisut ja päätökset vaikuttavat rakentamisen aikana, esimerkiksi kuinka tukirakenteet ja siltaosat suunnataan kohti pysyvää siltaa. Ilmaston lämpeneminen aiheuttaa ääriolosuhteita, jotka johtavat muutoksiin rankkasateiden ja kuivien jaksojen esiintymiseen. Sähköpostikysely työtä varten tehtiin lokakuussa 2022. Sähköposti lähetettiin yhteensä seitsemälle henkilölle, jotka työskentelevät työnaikaisten siltojen parissa, joko suunnittelijoina tai rakennuttajina. Monet vastanneista vastasivat kollegoiden kanssa yhdessä, jolloin vastauksia tuli lopulta yhdeksältä henkilöltä. Kyselyn avulla kartoitettiin työnaikaisen sillan suunnittelun ja rakentamisen ongelmakohdat sekä tarve mahdolliselle ohjeistukselle. Kyselyn tulosten analyysimenetelmänä toimi sisällönanalyysi. Kyselyn perusteella valtaosa henkilöistä on tietoisia tärkeimmistä tekijöistä ja ongelmakohdista työnaikaisten siltojen suunnittelussa hydrologian ja hydraulisen puolen näkökulmista. Samalla selvisi, että työnaikaisen sillan aukkomitoitukseen ei ole Suomessa riittävää ohjeistusta tai opasta. Ohjeistuksen uupuessa lähtötietoja ja menetelmiä joudutaan arvaamaan ja soveltamaan, jolloin aukkomitoituksessa virheen mahdollisuus on suuri.Gap sizing of temporary bridges. Abstract. The aim of this work is to investigate the gap sizing of temporary bridges through a literature review and a questionnaire survey. The work examines the emergency bridge equipment used in Finland. Emergency bridges are usually used as temporary solutions during the construction or mending of the main permanent bridge. They are also used as temporary structures, and during some special natural phenomena, e.g., ice jams and slush floods. In the middle section of the work the principles, problems and most common sizing methods of gap sizing are explained. Conclusions and recommendations for future research are presented at the end of the work. There is a plethora of factors that affect the gap sizing of bridges. These include environmental factors, structural decisions, and extreme weather conditions caused by climate change. Environmental factors include the nature of the body of water such as its susceptibility to flooding, and the occurrence of frazil ice. Structural decisions and solutions have an impact during construction, an example being how the supports and bridge span are directed to the permanent bridge. Global warming causes extreme weather conditions, which result in changes in the occurrence of heavy rain and droughts. An e-mail questionnaire for the work was conducted in October 2022. The e-mail was sent to a total of seven people, who work with temporary bridges as either designers or contractors. Many of the respondents wrote their responses with their colleagues, which meant that in total nine people responded. The questionnaire was used to define the problem areas in the design and construction of temporary bridges, as well as the need for possible guidelines. Content analysis was used as the analysis method for the results of the questionnaire. Based on the questionnaire, the majority of people are aware of the major factors and problem areas in designing temporary bridges, from the hydrologic and hydraulic perspectives. At the same time, it was found that the gap sizing of temporary bridges does not have adequate guidelines or instructions in Finland. In the absence of an overall guide, the initial information must be guessed, and methods adapted. This causes a major chance of error in gap sizin

Modeling optical constants from the absorption of organic thin films using a modified Lorentz oscillator model

Optical constants of organic thin films can be evaluated using the Lorentz oscillator model (LOM) which fails to fit inhomogeneously broadened absorption of highly concentrated molecular films. In modified LOM (MLOM), the inhomogeneous broadening is implemented through a frequency-dependent adjustable broadening function. In this work, we evaluate the optical constants of rhodamine 6G doped poly-vinyl alcohol thin films with varying doping concentration (including also extensively high concentrations) using MLOM, which outperforms LOM by showing a better agreement with the experimental results. Our proposed method provides a way to accurately determine optical constants of isotropic organic thin films only from their absorption spectra without spectroscopic ellipsometry.Peer reviewe

Preparation and execution of teeth clenching and foot muscle contraction influence on corticospinal hand-muscle excitability

Contraction of a muscle modulates not only the corticospinal excitability (CSE) of the contracting muscle but also that of different muscles. We investigated to what extent the CSE of a hand muscle is modulated during preparation and execution of teeth clenching and ipsilateral foot dorsiflexion either separately or in combination. Hand-muscle CSE was estimated based on motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) and recorded from the first dorsal interosseous (FDI) muscle. We found higher excitability during both preparation and execution of all the motor tasks than during mere observation of a fixation cross. As expected, the excitability was greater during the execution phase than the preparation one. Furthermore, both execution and preparation of combined motor tasks led to higher excitability than individual tasks. These results extend our current understanding of the neural interactions underlying simultaneous contraction of muscles in different body parts.Peer reviewe

Effect of Inhaled Xenon on Cerebral White Matter Damage in Comatose Survivors of Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial

IMPORTANCE: Evidence from preclinical models indicates that xenon gas can prevent the development of cerebral damage after acute global hypoxic-ischemic brain injury but, thus far, these putative neuroprotective properties have not been reported in human studies. OBJECTIVE: To determine the effect of inhaled xenon on ischemic white matter damage assessed with magnetic resonance imaging (MRI). DESIGN, SETTING, AND PARTICIPANTS: A randomized single-blind phase 2 clinical drug trial conducted between August 2009 and March 2015 at 2 multipurpose intensive care units in Finland. One hundred ten comatose patients (aged 24-76 years) who had experienced out-of-hospital cardiac arrest were randomized. INTERVENTIONS: Patients were randomly assigned to receive either inhaled xenon combined with hypothermia (33°C) for 24 hours (n = 55 in the xenon group) or hypothermia treatment alone (n = 55 in the control group). MAIN OUTCOMES AND MEASURES: The primary end point was cerebral white matter damage as evaluated by fractional anisotropy from diffusion tensor MRI scheduled to be performed between 36 and 52 hours after cardiac arrest. Secondary end points included neurological outcome assessed using the modified Rankin Scale (score 0 [no symptoms] through 6 [death]) and mortality at 6 months. RESULTS: Among the 110 randomized patients (mean age, 61.5 years; 80 men [72.7%]), all completed the study. There were MRI data from 97 patients (88.2%) a median of 53 hours (interquartile range [IQR], 47-64 hours) after cardiac arrest. The mean global fractional anisotropy values were 0.433 (SD, 0.028) in the xenon group and 0.419 (SD, 0.033) in the control group. The age-, sex-, and site-adjusted mean global fractional anisotropy value was 3.8% higher (95% CI, 1.1%-6.4%) in the xenon group (adjusted mean difference, 0.016 [95% CI, 0.005-0.027], P = .006). At 6 months, 75 patients (68.2%) were alive. Secondary end points at 6 months did not reveal statistically significant differences between the groups. In ordinal analysis of the modified Rankin Scale, the median (IQR) value was 1 (1-6) in the xenon group and 1 (0-6) in the control group (median difference, 0 [95% CI, 0-0]; P = .68). The 6-month mortality rate was 27.3% (15/55) in the xenon group and 34.5% (19/55) in the control group (adjusted hazard ratio, 0.49 [95% CI, 0.23-1.01]; P = .053). CONCLUSIONS AND RELEVANCE: Among comatose survivors of out-of-hospital cardiac arrest, inhaled xenon combined with hypothermia compared with hypothermia alone resulted in less white matter damage as measured by fractional anisotropy of diffusion tensor MRI. However, there was no statistically significant difference in neurological outcomes or mortality at 6 months. These preliminary findings require further evaluation in an adequately powered clinical trial designed to assess clinical outcomes associated with inhaled xenon among survivors of out-of-hospital cardiac arrest. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00879892

Grain boundary corrosion in TiO2 bone scaffolds doped with group II cations

A pH drop during the inflammatory phase during bone regeneration can cause corrosion in TiO2 bone scaffolds and the loss of compressive strength. Corrosion as ion leaching and dissolution is confined to grain boundaries. Cationic doping of TiO2 showed to increase the compressive strength but increased the amount of impurities in grain boundaries as well. Therefore, this study showed the different grain boundary formation for Ca, Sr and Mg doped scaffolds and their corrosion behavior. After corrosion, the amorphous phase in grain boundaries was dissolved in all doped scaffolds. Differences occurred due to the formation of an additional crystalline phase in Sr doped scaffolds. The presence of an amorphous and crystalline phase led to an inhomogeneous dissolution in grain boundaries and a significant decrease in compressive strength already after 4 h in contact with an acidic environment. Released ions did not show any cytotoxic effect on hASCs. Mg doped TiO2 scaffolds led to sig- nificant increased osteogenic differentiation.(undefined)info:eu-repo/semantics/publishedVersio

Prevention of Biomaterial Infection by Pre-Operative Incubation with Human Cells

Background: Cells of tissues and biofilm forming bacteria compete for the living space on the surface of an implant. We hypothesized the incubation of the implant (titanium, polydimethylsiloxane, and polystyrene surface) with human cells before implantation as a strategy to prevent bacterial adhesion and biofilm formation. Methods: After 24 hours of incubation with human osteogenic sarcoma SaOS-2 cells (1x10(5) cells/mL), the materials were incubated for 4.5 hours or two days with Staphylococcus aureus in serial 1:10 dilutions of 10(8) colony-forming units/mL. The bacterial adherence and biofilm biomass on materials pre-incubated with SaOS-2 cells were compared with our previous results on materials incubated only with bacteria or in simultaneous co-culture of SaOS-2 cells and S. aureus. Fluorescent microscopy and crystal violet stain were used. The number of viable SaOS-2 and bacterial cells present was tested using colorimetric methods (MTT, LDH) and drop plate method, respectively. Results: The pre-treatment with human cells was associated with a reduction of bacterial colonization of the biomaterial at 4.5 hours and 48 hours compared with the non-pre-treated materials. The presence of bacteria decreased the number of viable human cells on all materials. (Supplementary Fig. 1; see online supplementary materials at www.liebertpub.com/sur). Conclusions: These results suggest that the pre-operative incubation of prostheses with host cells could prevent infection of biomaterials.Peer reviewe