| 1. |
- Ahvenniemi, Esko, et al.
(författare)
-
Recommended reading list of early publications on atomic layer deposition-Outcome of the "Virtual Project on the History of ALD"
- 2017
-
Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 35:1
-
Forskningsöversikt (refereegranskat)abstract
- Atomic layer deposition (ALD), a gas-phase thin film deposition technique based on repeated, self-terminating gas-solid reactions, has become the method of choice in semiconductor manufacturing and many other technological areas for depositing thin conformal inorganic material layers for various applications. ALD has been discovered and developed independently, at least twice, under different names: atomic layer epitaxy (ALE) and molecular layering. ALE, dating back to 1974 in Finland, has been commonly known as the origin of ALD, while work done since the 1960s in the Soviet Union under the name "molecular layering" (and sometimes other names) has remained much less known. The virtual project on the history of ALD (VPHA) is a volunteer-based effort with open participation, set up to make the early days of ALD more transparent. In VPHA, started in July 2013, the target is to list, read and comment on all early ALD academic and patent literature up to 1986. VPHA has resulted in two essays and several presentations at international conferences. This paper, based on a poster presentation at the 16th International Conference on Atomic Layer Deposition in Dublin, Ireland, 2016, presents a recommended reading list of early ALD publications, created collectively by the VPHA participants through voting. The list contains 22 publications from Finland, Japan, Soviet Union, United Kingdom, and United States. Up to now, a balanced overview regarding the early history of ALD has been missing; the current list is an attempt to remedy this deficiency.
|
|
| 2. |
- Etula, Jarkko, et al.
(författare)
-
Room-Temperature Micropillar Growth of Lithium-Titanate-Carbon Composite Structures by Self-Biased Direct Current Magnetron Sputtering for Lithium Ion Microbatteries
- 2019
-
Ingår i: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 29:42
-
Tidskriftsartikel (refereegranskat)abstract
- Here, an unidentified type of micropillar growth is described at room temperature during conventional direct-current magnetron sputtering (DC-MS) deposition from a Li4Ti5O12+graphite sputter target under negative substrate bias and high operating pressure. These fabricated carbon-Li2O-TiO2 microstructures consisting of various Li4Ti5O12/Li2TiO3/LixTiO2 crystalline phases are demonstrated as an anode material in Li-ion microbatteries. The described micropillar fabrication method is a low-cost, substrate independent, single-step, room-temperature vacuum process utilizing a mature industrial complementary metal-oxide-semiconductor (CMOS)-compatible technology. Furthermore, tentative consideration is given to the effects of selected deposition parameters and the growth process, as based on extensive physical and chemical characterization. Additional studies are, however, required to understand the exact processes and interactions that form the micropillars. If this facile method is further extended to other similar metal oxide-carbon systems, it could offer alternative low-cost fabrication routes for microporous high-surface area materials in electrochemistry and microelectronics.
|
|
| 3. |
- Garthwaite, Taru, et al.
(författare)
-
Associations of sedentary time, physical activity, and fitness with muscle glucose uptake in adults with metabolic syndrome
- 2022
-
Ingår i: Scandinavian Journal of Medicine and Science in Sports. - West Sussex : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 33:3, s. 353-358
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of the study was to investigate the associations of sedentary time, physical activity, and cardiorespiratory fitness with skeletal muscle glucose uptake (GU). Methods: Sedentary time and physical activity were measured with accelerometers and VO2max with cycle ergometry in 44 sedentary adults with metabolic syndrome. Thigh muscle GU was determined with [18F]FDG-PET imaging. Results: Sedentary time (β = −0.374), standing (β = 0.376), steps (β = 0.351), and VO2max (β = 0.598) were associated with muscle GU when adjusted for sex, age, and accelerometer wear time. Adjustment for body fat-% turned all associations non-significant. Conclusion: Body composition is a more important determinant of muscle GU in this population than sedentary time, physical activity, or fitness. © 2022 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.
|
|
| 4. |
- Garthwaite, Taru, et al.
(författare)
-
Standing is associated with insulin sensitivity in adults with metabolic syndrome
- 2021
-
Ingår i: Journal of Science and Medicine in Sport. - Chatswood : Elsevier. - 1440-2440 .- 1878-1861. ; 24:12, s. 1255-1260
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To determine how components of accelerometer-measured sedentary behavior (SB) and physical activity (PA), and fitness are associated with insulin sensitivity in adults with metabolic syndrome. Design: Cross-sectional. Methods: Target population was middle-aged (40–65 years) sedentary adults with metabolic syndrome. SB, breaks in SB, standing, and PA were measured for four weeks with hip-worn accelerometers. VO2max (ml/min/kg) was measured with maximal cycle ergometry. Insulin sensitivity was determined by hyperinsulinaemic-euglycaemic clamp (M-value) and fasting blood sampling (HOMA-IR, insulin). Multivariable regression was used for analyses. Results: Sixty-four participants (37 women; 58.3 [SD 6.8] years) were included. Participants spent 10.0 (1.0) h sedentary, 1.8 (0.6) h standing, and 2.7 (0.6) h in PA and took 5149 (1825) steps and 29 (8) breaks daily. In sex-, age- and accelerometer wear time-adjusted model SB, standing, steps and VO2max were associated with M-value (β = −0.384; β = 0.400; β = 0.350; β = 0.609, respectively), HOMA-IR (β = 0.420; β = −0.548; β = −0.252; β = −0.449), and insulin (β = 0.433; β = −0.541; β = −0.252; β = −0.453); all p-values < 0.05. Breaks associated only with M-value (β = 0.277). When further adjusted for body fat %, only standing remained significantly associated with HOMA-IR (β = −0.381) and insulin (β = −0.366); significance was maintained even when further adjusted for SB, PA and fitness. Light and moderate-to-vigorous PA were not associated with insulin sensitivity. Conclusions: Standing is associated with insulin sensitivity markers. The association with HOMA-IR and insulin is independent of adiposity, PA, SB and fitness. Further studies are warranted, but these findings encourage replacing sitting with standing for potential improvements in insulin sensitivity in adults at increased type 2 diabetes risk. © 2021 The Authors.
|
|
| 5. |
- Haapala, Eero A., et al.
(författare)
-
Association between cardiorespiratory fitness and metabolic health in overweight and obese adults
- 2022
-
Ingår i: Journal of Sports Medicine and Physical Fitness. - Turin : Edizioni Minerva Medica. - 0022-4707 .- 1827-1928. ; 62:11, s. 1526-1533
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cardiorespiratory fitness (CRF) has been inversely associated with insulin resistance and clustering of cardiometabolic risk factors among overweight and obese individuals. However, most previous studies have scaled CRF by body mass (BM) possibly inflating the association between CRF and cardiometabolic health. We investigated the associations of peak oxygen uptake (V?O2peak) and peak power output (Wpeak) scaled either by BM-1, fat free mass (FFM-1), or by allometric methods with individual cardiometabolic risk factors and clustering of cardiometabolic risk factors in 55 overweight or obese adults with metabolic syndrome. METHODS: VO2peak and Wpeak were assessed by a maximal cycle ergometer exercise test. FFM was measured by air displacement plethysmo- graph and glucose, insulin, HbA1c, triglycerides, and total, LDL, and HDL cholesterol from fasting blood samples. HOMA-IR and metabolic syndrome score (MetS) were computed. RESULTS: VO2peak and Wpeak scaled by BM-1 were inversely associated with insulin (β=-0.404 to -0.372, 95% CI: -0.704 to -0.048), HOMAIR (β=-0.442 to -0.440, 95% CI: -0.762 to -0.117), and MetS (β=-0.474 to -0.463, 95% CI: -0.798 to -0.127). Other measures of CRF were not associated with cardiometabolic risk factors. CONCLUSIONS: Our results suggest that using BM-1 as a scaling factor confounds the associations between CRF and cardiometabolic risk in overweight/obese adults with the metabolic syndrome. © 2022 EDIZIONI MINERVA MEDICA.
|
|
| 6. |
- Hartmann, Sean J., et al.
(författare)
-
Electrochemical Properties of Nitrogen and Oxygen Doped Reduced Graphene Oxide
- 2020
-
Ingår i: Energies. - : MDPI. - 1996-1073. ; 13:2
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon nanostructures are promising electrode materials for energy storage devices because of their unique physical and chemical properties. Modification of the surface improves the electrochemical properties of those materials because of the changes in morphology, diffusion properties, and inclusion of additional contributions to redox processes. Oxygen-containing functional groups and nitrogen doped into the carbon matrix significantly contribute to the electrochemical behavior of reduced graphite oxide (RGO). In this work, RGO was synthesized during hydrothermal treatment of graphite oxide with a hydrazine sulfate aqueous solution. Different amounts of hydrazine sulfate were used to synthesize RGO with different nitrogen contents in the structure, and the same synthesis conditions made it possible to obtain a material with a similar composition of oxygen-containing functional groups. The materials with different nitrogen concentrations and similar amounts of oxygen were compared as electrode materials for a supercapacitor and as a negative electrode material for a Li-ion battery. It was shown that the presence of oxygen-containing functional groups has the greatest influence on the behavior and efficiency of supercapacitor electrode materials, while nitrogen atoms embedded in the graphene lattice play the largest role in lithium intercalation.
|
|
| 7. |
|
|
| 8. |
- Iurchenkova, Anna A., 1997-, et al.
(författare)
-
The effect of the pyrolysis temperature and biomass type on the biocarbons characteristics
- 2023
-
Ingår i: ChemSusChem. - : John Wiley & Sons. - 1864-5631 .- 1864-564X. ; , s. 1-21
-
Tidskriftsartikel (refereegranskat)abstract
- The conversion of biomass and natural wastes into carbon-based materials for various applications such as catalysts and energy-related materials is a fascinating and sustainable approach emerged during recent years. Precursor nature and characteristics are complex, hence, their effect on the properties of resulting materials is still unclear. In this work, we have investigated the effect of different precursors and pyrolysis temperature on the properties of produced carbon materials and their potential application as negative electrode materials in Li-ion batteries. Three biomasses, lignocellulosic brewery spent grain from a local brewery, catechol-rich lignin and tannins, were selected for investigations. We show that such end-product carbon characteristic as functional and elemental composition, porosity, specific surface area, defectiveness level, and morphology strictly depend on the precursor composition, chemical structure, and pyrolysis temperature. The electrochemical characteristics of produced carbon materials are correlate with the characteristics of the produced materials. A higher pyrolysis temperature is shown to be favourable for production of carbon material for the Li-ion battery application in terms of both specific surface area and long-term cycling stability.
|
|
| 9. |
- Jukka-Pekka, Spets, et al.
(författare)
-
Test of Different Anode Electrocatalysts for Direct Glucose Anion Exchange Membrane Fuel Cell
- 2016
-
Ingår i: International Journal of Electrochemical Science. - : Electrochemical Science Group. - 1452-3981. ; 11:6, s. 4219-4230
-
Tidskriftsartikel (refereegranskat)abstract
- Direct glucose anion exchange membrane fuel cell (AEMFC) with near-neutral-state electrolyte of 0.1 M [PO4] (tot) was studied with five different anode electrocatalysts (Pt, PtRu, PtNi, Au, PdAu) at a temperature of 37 degrees C and at a glucose concentration of 0.1 M. The cathode catalyst in each test was Pt supported on carbon (60 wt.%). Four anode electrocatalysts (supported on carbon) had a total metal content of 40 wt.% while the fifth anode material of PtRu had a higher content of 60 wt.%. Moreover, in order to show the influence of the metallic content on the fuel cell performance, anode catalysts with 60 wt.% (Pt) and 10wt.% (PtNi) were tested. The operation of the AEMFC was controlled by means of an in-house-made electronic load with PI-controller (i.e. a feedback controller that has proportional and integral action on control error signal) either at constant current (CC) or at constant voltage (CV). The primary objective was to characterize the Coulombic efficiency (CE) based on the exchange of two electrons and compare the specific energy (Wh kg(-1)) for the direct glucose AEMFC related to the different electrode combinations and electrocatalysts. As a result of these screening tests, two most efficient anode electrodes with Pt and PtNi were selected to be used for further AEMFC studies.
|
|
| 10. |
- Jukka-Pekka, Spets, et al.
(författare)
-
Towards an Efficient Direct Glucose Anion Exchange Membrane Fuel Cell System with Several Electro-Oxidation Units
- 2017
-
Ingår i: International Journal of Electrochemical Science. - : ESG. - 1452-3981. ; 12:5, s. 3697-3708
-
Tidskriftsartikel (refereegranskat)abstract
- This work covers the direct glucose anion exchange membrane fuel cell (AEMFC) with near-neutralstate electrolyte of 0.1 M [PO4] (tot) having two high-performing anode electrocatalysts (Pt and PtNi) at 37 degrees C and at a glucose concentration of 0.1 M. The cathode catalyst in each test was a Pt supported on carbon (60 wt.%). The PtNi/C had a total metal content of 40 wt.% and the Pt/C 60 wt.%. The operation of the AEMFC was controlled by means of an in-house made electronic load with PI-controller (i.e. a feedback controller, which has proportional and integral action on control error signal). There were two primary objectives with this study. At first, to find out how the electrode modifications of the anode (i.e. by increasing the thicknesses of these electrodes by adding extra carbon) affect the Coulombic efficiency (CE, based on the exchange of two electrons) and the specific energy (SPE, Wh kg(-1)) values of the direct glucose AEMFC. Secondly, investigate how a two-stage fuel cell system with two fuel cells concatenated and used one after the other for the electrochemical oxidation of glucose, influence the CE and SPE values. The results show that the modified PtNi anode shows superior results for the AEMFC compared to our earlier results. As for the two-stage fuel cell system, it increased the average electric power (mWh) and SPE when compared to single fuel cell systems except when the higher selective anode catalyst (Pt) was used in the first fuel cell prior to the fuel cell in the second fuel cell containing the lower selective anode catalyst (PtNi).
|
|
