| 1. |
- Anuradha, Chandrasekar, et al.
(författare)
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Losses and Efficiency Calculation for Multi-Port Converter
- 2022
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Ingår i: AIP Conference Proceedings. - : AIP Publishing. - 1551-7616 .- 0094-243X. ; 2516
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Konferensbidrag (refereegranskat)abstract
- In this paper, a multi-port non-isolated SEPIC converter is analysed for integrating with the renewable energy source and also losses and efficiency are calculated. The proposed converter utilizes a single stage power conversion, thereby providing higher energy efficiency. The proposed structure comprises of a combination of Pulsating Voltage Cells (PVC) and Pulsating Voltage Source Cell (PVSC) on the input side and a Pulsating Voltage Load Cell (PVLC) on the output side. The two topologies involved are Multi Input Single Output (MISO) and Multi Input Multiple Output (MIMO) which are bidirectional. The efficiency of the proposed multi-port converter has been calculated by determining the switching stress of the power electronic switches used. The proposed multi-port SEPIC converter considers the entire system to be a single-stage converter, and promises higher energy efficiency.
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| 2. |
- Ashyraliyev, Maksat, et al.
(författare)
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A note on the hyperbolic-parabolic identification problem with nonlocal conditions
- 2021
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Ingår i: AIP Conference Proceedings. - : AIP Publishing. - 0094-243X .- 1551-7616. ; 2334
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Tidskriftsartikel (refereegranskat)abstract
- In the present paper, we study a source identification problem for hyperbolic-parabolic equation with nonlocal conditions. The stability estimates for the solution of this source identification problem are established. Furthermore, we construct the second order of accuracy difference scheme for the approximate solution of the problem under consideration. The stability estimates for the solution of this difference scheme are presented.
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| 3. |
- Ashyraliyev, Maksat, et al.
(författare)
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On the source identification problem for hyperbolic-parabolic equation with nonlocal conditions
- 2021
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Ingår i: AIP Conference Proceedings. - : AIP Publishing. - 0094-243X .- 1551-7616. ; 2325
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Tidskriftsartikel (refereegranskat)abstract
- In the present paper, we establish the well-posedness of an identification problem for determining the unknown space-dependent source term in the hyperbolic-parabolic equation with nonlocal conditions. The difference scheme is constructed for the approximate solution of this source identification problem. The stability estimates for the solution of the difference scheme are presented.
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| 4. |
- Chaudhary, Shilpi, et al.
(författare)
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Adsorption of 3-(triethoxysilyl)propionitrile on a rutile TiO2(110) surface : An X-ray photoelectron spectroscopy study
- 2020
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Ingår i: DAE Solid State Physics Symposium 2019. - : AIP Publishing. - 1551-7616 .- 0094-243X. - 9780735420250 ; 2265
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Konferensbidrag (refereegranskat)abstract
- The adsorption of 3-(triethoxysilyl)propionitrile (TESP) on a reduced rutile TiO2(110) surface has been investigated using synchrotron-based X-ray photoelectron spectroscopy in ultrahigh vacuum (UHV). We have studied TESP adsorption on two surface preparation of rutile TiO2 (110) to explore the role of surface defects. In the first preparation, the adsorption of TESP was studied on reduced TiO2 (110) surface at room temperature. In the second experiment TESP was adsorbed on the oxygen-treated TiO2 surface to quench the oxygen vacancies generated by UHVannealing of the TiO2 crystal. The molecular footprints of the TESP molecules confirms the adsorption on both types of TiO2(110) surfaces. In the case of the reduced surface, temperature-dependent XPS measurements show the thermal stability of TESP molecules up to 600 °C. The comparison of the nitrogen and carbon lineshapes for both preparations suggests different adsorption geometries on the reduced and oxygen-dosed surfaces. To the best of our knowledge, the UHV preparations and measurements of TESP adsorption on rutile TiO2 (110) in the present study are reported for the first time.
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| 5. |
- Ewaid, Salam H., et al.
(författare)
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Acute toxicity of the water chlorinationbyproduct (chloroform) in male mice
- 2020
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Ingår i: AIP Conference Proceedings. - USA : American Institute of Physics (AIP). - 0094-243X .- 1551-7616. ; 2290:1
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Tidskriftsartikel (refereegranskat)abstract
- Drinking water disinfection has been one of the biggest advances in public health. However, animal studies have suggested that when tested at high concentrations, certain disinfection byproducts disinfection (DBPs) in drinking water can cause an increased incidence of cancer and reproductive effects. In this study, sixty male white mice were kept under the laboratory conditions, divided into six exposure groups and administrated with single oral dose 0, 50, 300, 700, 1000 or 1500 mg/kg BW chloroform dissolves in corn oil as a vehicle. Clinical observations and gross pathologic examination made after dosing on surviving died, and animals that were killed on the 7th day. At end of 14 days, animal weights were recorded, liver and kidneys removed, weigh and examined with the naked eye then it was fixed in 10% Neutral Buffered Formalin (NBF), transfer to 70% ethanol and included in paraffin. Tissue parts were cut 4-5 μm soiled with hematoxylin and eosin. Clinical signs observed at high doses consisted of behavioral effects, reduced body weight, livers and kidneys were congested, enlarged and their weights increased. Liver damage was characterized mainly through centrilobular necrosis and massive necrosis at higher doses. The kidney damage containing raised kidney weight, inflammation, renal cell proliferation and proximal tubular necrosis. Lethal dose causes death in 50% of exposed animals (LD 50) value calculated by the probit analysis was 550 mg/kg Body Weight (BW).
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| 6. |
- Hamid, Akram Abdul, et al.
(författare)
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Choice of Indoor Standard in Hygrothermal Simulations of External Walls – Three Swedish Case Studies
- 2023. - 1
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Ingår i: AIP Conference Proceedings. - 0094-243X. ; 2918
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Konferensbidrag (refereegranskat)abstract
- When assessing the moisture damage risks of different external wall designs using hygrothermal simulation software, the user of said software can choose between different inputs for the determination of the indoor climate. This paper aims to compare results from field measurements in three Swedish buildings using different standards available in a widely used commercial hygrothermal simulation software, WUFI Pro. In this project, field measurements on external walls were conducted before the implementation of interior insulation. Measurements were conducted indoors, outdoors, and on the exterior and interior surfaces of the external walls. Comparing measurement and simulation results shows that on-site measurements give more accurate modelling of an existing external wall. However, the results also show that, when needed, any of the current standards can be used as replacements for actual measurements regarding indoor air temperature. The comparisons show that the most accurate results regarding the relative humidity are generated when ASHRAE Standard 160 is applied with an intermediate approach and a higher air change rate than in the nominal case. However, several parameters must be known for such an approach, such as the actual air change rate and the number of bedrooms. If such parameters are not known, the standard that gives the best fit between measured and simulated relative humidity is EN15026.
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| 7. |
- Hamid, Akram Abdul, et al.
(författare)
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Impact of Added Thermal Insulation on Cold Attics in Apartment Buildings in Temperate Climate – A Review
- 2023. - 1
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Ingår i: AIP Conference Proceedings. - 0094-243X. ; 2918
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Konferensbidrag (refereegranskat)abstract
- Added insulation in cold attics can be an efficient and profitable energy efficiency measure. Simultaneously, added insulation increases the risk of a decreased temperature in the attic, thereby increasing the risk of high relative humidity and moisture damage. This paper collocates and reviews previous publications that deal with the impact of added insulation on attics as a renovation measure. This is done by systematically searching for publications relevant to tempered climate, specifically Swedish climate. Furthermore, the review aims to categorize and review existing literature in order to synthesize the examined impact of additional insulation of cold attics regarding the potential for energy reduction, the impact on risks for moisture damage, and the impact on indoor environmental quality. Results from the literature review show that the measure reduces the energy use of buildings and emissions. Furthermore, the measure is shown to be a profitable measure, especially in combination with other measures. However, previous publications also show that with increased insulation, the risk for moisture damage also increases, but that supplemental measures can be taken in order to reduce such a risk.
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| 8. |
- Hamid, Akram Abdul, et al.
(författare)
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Strategies and Combinations of Measures for Renovations of Swedish Heritage Buildings – A Review
- 2023. - 1
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Ingår i: AIP Conference Proceedings. - 0094-243X. ; 2918
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Konferensbidrag (refereegranskat)abstract
- In order to achieve environmental goals, the impact of the European building stock on the environment needs to be reduced through renovation measures. However, regarding heritage buildings, the choice of measure(s) must simultaneously consider the preservation of cultural and historical values. Besides the impact on such values, energy-efficiency measures can result in increased risks for moisture damage and the diminishment of indoor environmental quality. Furthermore, a measure's impact on a building's environmental print is not self-evident, adding further to the difficulty of choice. This paper synthesizes and reviews existing literature on choosing renovation measures for heritage buildings and literature dealing with choosing the combination of renovation measures. The paper shows that several publications present strategies/ methodologies for the choice of renovation measures for heritage buildings. However, none are holistic, and none detail the choice from a holistic perspective. Furthermore, several publications have investigated the impact of different combinations of measures on older buildings. However, few consider cultural values. Through this literature review, this paper states the need for a holistic approach to choosing renovation measures for heritage buildings.
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| 9. |
- Iarkov, Ilia, et al.
(författare)
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Economic Feasibility of PV Installations for Multifamily Houses in Moscow
- 2023. - 1
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Ingår i: AIP Conference Proceedings. - 0094-243X .- 1551-7616. - 9780735445420 ; 2791:1
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Konferensbidrag (refereegranskat)abstract
- While it is evident that photovoltaic installations are becoming more and more widespread globally, demand for them in the Russian market remains low. Considering recent changes in the legal framework, which are beneficial for households with renewable energy, it is crucial to evaluate photovoltaic installation's economic feasibility for the Russian context, which is evaluated in this article. First, the authors created an hourly electricity consumption profile for a typical Russian multifamily house. Then a PV installation was designed and scaled to reach annual net-zero balance and net-zero balance in July for different ways of installing PV modules. After that, a monthly energy balance, considering underproduction and overproduction of electrical energy, was calculated. Finally the costs of PV electricity were calculated including purchased equipment, costs for installation as well as cost for buying electricity not covered by the PV modules and sold electricity during hours of overproduction. The economical evaluation was performed assuming a 30 year lifetime for the PV installation. It is concluded in this paper that PV installations can be profitable in the Russian market.
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| 10. |
- Johansson, Dennis, et al.
(författare)
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Adopting Real Measurements to a Simulation Model for Indoor Temperature Increase at Reduced Cooling Power to Lower Power Peaks
- 2023. - 1
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Ingår i: AIP Conference Proceedings. - 0094-243X. ; 2918
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Konferensbidrag (refereegranskat)abstract
- Lately there has been an increasing focus on saving peak power in heating systems as a way to lower the environmental load past just saving energy. At the same time, active cooling is becoming increasingly interesting. Sweden has more and more cooling systems with an increase in cooling also in residential buildings. The cooling power is much more expensive than the heating power. Therefore, there is a relative advantage of reducing the cooling instead of heating power, and at the same time the traditional users are accepting over temperatures indoors more than if the temperature becomes too low. Buildings facing renovation as well as new construction will reduce the use of heating, while more cooling power will be needed to cover the lack and future climate scenarios with warmer outdoor temperatures. In this study a simplified simulation model is proposed to simulate the increase in indoor temperature that will occur if cooling power is reduced or switched off to save peak power in the grid and supply system. Considered parameters include the thermal mass of the building and its interior, the heat transmittance, the windows, internal heat gains, ventilations losses and outdoor climate. The simplified model makes it possible to make parametric and Monte Carlo studies to show how the resulting temperature incline varies for different parameters and potential buildings as a foundation for energy companies to create new power control and business models. Results from the simulation model are presented for Swedish outdoor climate together with measurements in 9 buildings. An important conclusion of this study is that the cooling power of a building can be reduced or switched off for a surprisingly long time of up to hours without the indoor temperature rising more than 1 °C, but there is a large variation.
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