465 research outputs found
Vesi ja vÀhÀhiilinen talous
TiivistelmÀ. TÀssÀ kandidaatintyössÀ tarkastellaan vesi ja vÀhÀhiilistÀ taloutta. Aihe on todella laaja, joten sitÀ on hieman rajattu. TyössÀ kÀydÀÀn lÀpi mitÀ vesi ja vÀhÀhiilinen talous tarkoittavat, miten vÀhÀhiiliseen talouteen pÀÀstÀÀn ja kuinka vesi liittyy tÀhÀn. Lyhyesti myös esitetÀÀn, mitÀ ovat uusiutuvat energiamuodot ja kuinka niitÀ tuotetaan Suomessa ja kansainvÀlisellÀ tasolla. Vuonna 2018 Suomessa tuotettiin uusiutuvilla energiamuodoilla sÀhköÀ 47 % kokonaissÀhköntuotannosta, pÀÀosin vesi- ja tuulivoimalla. TyössÀ myös perehdytÀÀn Pariisin ilmastosopimukseen, koska se on yksi tÀrkeimmistÀ suunnan nÀyttÀjistÀ kohti vÀhÀhiilistÀ taloutta. Työ on toteutettu kirjallisuusselvityksenÀ.
SekÀ vÀhÀn vettÀ kuluttava, ettÀ vÀhÀhiilinen talous edellyttÀvÀt oikeanlaisten energiamuotojen valitsemista. Molempia talouksia tukevia energiamuotoja ovat ydinvoima, aurinkovoima ja tuulivoima. NÀissÀ kolmessa energiamuodossa on suhteessa tuotettuun energiamÀÀrÀÀn pienet kasvihuonepÀÀstöt, 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
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
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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 (nâ=â55 in the xenon group) or hypothermia treatment alone (nâ=â55 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], Pâ=â.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]; Pâ=â.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]; Pâ=â.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
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