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EN
Phytolith-occluded carbon (PhytOC) is highly stable, and constitutes an important source of long-term C storage in agrosystems. This stored carbon is resistant to the processes of oxidation of carbon compounds. In our research phytolith content in barley (Estonia) and oat (Poland) grain and straw was assessed at field trials, with Si as a liquid immune stimulant OPTYSIL and compost fertilisation. We showed that cereals can produce relatively high amounts of phytoliths. PhytOC plays a key role in carbon sequestration, particularly for poor, sandy Polish and Estonian soils. The phytolith content was always higher in straw than in grain regardless of the type of cereals. The phytolith content in oat grains varied from 18.46 to 21.28 mg∙g-1 DM, and in straw 27.89-38.97 mg∙g-1 DM. The phytolith content in barley grain ranged from 17.24 to 19.86 mg∙g-1 DM, and in straw from 22.06 to 49.08 mg∙g-1 DM. Our results suggest that oat ecosystems can absorb from 14.94 to 41.73 kg e-CO2∙ha-1 and barley absorb from 0.32 to 1.60 kg e-CO2∙ha-1. The accumulation rate of PhytOC can be increased 3-fold in Polish conditions through foliar application of silicon, and 5-fold in Estonian conditions. In parallel, the compost fertilisation increased the phytolith content in cereals.
EN
This paper presents the investigations and performance analysis of monofacial and bifacial crystalline silicon solar cells with PC1D simulation software. The fundamental limitation in the monofacial solar cell’s performance is its inability to absorb all the incoming solar radiation since the albedo effect (ground-reflected light that can be captured by the rear of the solar cell) is often neglected. So, the efficiency of the monofacial cell will be lower due to poor and incomplete optical absorption. Bifaciality helps to enhance the capturing of light in the solar cell, which means that the rear of the cell is exposed to solar radiation to produce electrical power. The primary focus of our work is to determine which solar cell offers better device performance and conversion efficiency by analyzing various parameters of the solar cell like surface texturing, emitter doping, bulk doping, minority carrier lifetime, bulk and surface recombination rates, front and rear reflectance, among other parameters. The other parameters are maintained at an optimal range to achieve the highest conversion efficiency. Our work has shown that the bifacial solar cell can be as efficient as 28.15%, which is much better than the 22.65% efficiency of the monofacial solar cell.
EN
Changes in the resistance of single crystals of p-type conductivity silicon under the action of mechanical loading were investigated in this research. Also, non-irradiated and pre-irradiated X-rays experimental samples were studied. It was found that at small deformation values when they are at the initial stage of the action of elastic deformation, a section forms and increases, on which the resistance practically does not depend on the applied mechanical load. In irradiated crystals, at small deformation values, electron generation processes dominate, which then recombine with the main carriers – holes. The consequence of such processes is the appearance of a maximum increase in electrical resistance at the initial stage of elastic deformation of experimental samples irradiated with X-rays. Charge carrier generation processes begin to dominate with further deformation. Such processes occur as a result of the release of acceptor centers from other complex defects, which are destroyed during the deformation of the Si crystal and captured by mobile dislocations. Thus, the processes of generation of charge carriers prevail over the processes of gettering and, accordingly, a mechano-stimulated decrease in the electrical resistance of p-Si samples occurs.
EN
In view of the disadvantages of the existing electrostatic separation process of decommissioned photovoltaic modules, which can only achieve the separation of fine silicon wafers and glass and has high energy consumption, a new process to solve the efficient dry separation of coarse silicon wafers and glass in decommissioned photovoltaic modules is proposed- the vibration separation method. Based on the theoretical analysis of the vibration separation of flaky silicon wafer and polyhedral glass particles, the effects of feed size, feed amount, vibration voltage, vibration frequency, horizontal inclination angle and longitudinal inclination angle on the product indexes of wafer and glass separation were investigated by single factor experiment. The optimal experimental conditions were obtained as follows: feed particle size +0.83mm, feed amount 0.15 t/h, vibration voltage 190 V, vibration frequency 48 Hz, horizontal inclination Angle 8°, longitudinal inclination Angle 3°. Under this optimized condition, the content of metal Si in the obtained silicon wafer product is 84.47%, the recovery rate of is 83.73%, the content of impurity SiO2 is 1.09%, and the content of SiO2 in the obtained glass product is 65.69%, and the recovery rate is 98.95%, the impurity metal Si content is 0.56%. This study provides a research idea for the industrial separation of silicon wafers and glass from decommissioned photovoltaic modules.
EN
The aim of the research was to modify the surface layer of flakc iron by laser alloying with composition of elements: Si and Co and the evaluation of the obtained effects (regarding the changes in the surface layer microstructure and its chosen properties). In the first part, the treatment consist on covering the cast iron surface with the alloying composition layer, and in the second part – heating of this surface with laser beam using molecutar laser. The treatment effects were estimated with: SEM, EDS, hardness tester, nanoindentalion tester and surface profile device. Il was started (among others), that the alloyed zone in the surface layer flake iron after performed laser treatment was gained and it was characterized by following features (in comparison to the core material): fine and homogencous microstructure with some similarities to the hardened white cast iron, presence of Co and increased amount of Si. lt was noticed that such properties as hardness and Young's modulus have been increased.
EN
This paper presents the results of a structure study of a dispersion composite on a silicone matrix with a filler in the form of multi-walled carbon nanotubes (MWCNTs). The study aims to determine the effect of the filler on the composite mechanical properties and electrical conductivity. Materials that are electrically conductive and exhibit high mechanical properties can find applications in high-strain sensors. During the study, the characteristic properties of the susceptible materials, silicone alone and silicone with different filler contents (4%, 6%, and 8% by weight), were determined after curing. Microscopic observations were performed to assess the influence of carbon fillers on the material structure and to determine the level of homogeneity of the material. Examination of mechanical properties facilitated the determination of the Shor A hardness (ShA), stiffness, and Poisson’s ratio of the cured composites, depending on the nanotubes’ content. In parallel with the study of mechanical properties, the effect of loading, and the associated deformation of the samples, on the conductivity of the composite was investigated. Based on the results obtained, a discussion was carried out on the type of conductivity characteristic of silicone with different filler content as well as depending on the level of deformation of the samples.
PL
Rozwój przemysłu produkcji urządzeń i komponentów dla zeroemisyjnych OZE to podstawa przyszłego bezpieczeństwa surowcowego, technologicznego i energetycznego kraju. W szczególności dotyczy to fotowoltaiki, której rola na rynku energii rośnie i która zwiększa bezpieczeństwo energetyczne oraz środowiskowe, ale ma też potencjał do poprawy bezpieczeństwa surowcowego i technologicznego.
EN
The effect of post-process aging on the microstructure and mechanical properties of multi-pass friction stir processed (FSPed) Al-4.5Cu alloy containing Si (1, 3, and 5 wt.%) was studied. According to the results, adding Si improved the fluidity and decreased the porosity content of the alloy. The addition of Si up to 3 wt.% also enhanced the mechanical properties. However, further addition of Si up to 5 wt.% impaired the tensile properties. Applying the first pass of FSP improved the tensile strength and fracture strain of the alloy containing 3 wt.% Si by 25 and 125%, respectively. However, the second and fourth pass of FSP substantially improved the fracture strain, but deteriorated the hardness and tensile strength of the alloy containing 3 wt.% Si. Post-FSP aging at 180 °C for 8 h significantly improved the mechanical properties. For instance, compared to the as-cast condition, the hardness, tensile strength, fracture strain, and toughness of post-aged four-pass FSPed Al-4.5Cu-3Si alloy increased by 107, 108, 175, and 310%, respectively. According to the fractography results, the fracture surface morphology of Al-4.5Cu-3Si alloy changed from a quasi-cleavage mode in as-cast condition to a ductile-dimple fracture mode after post-FSP aging.
9
Content available remote The history of introducing the silicones in Poland
EN
The present elaboration presents a fragment of the history of developing and implementation of the manufacturing technology and application of silicones in Poland. At present, the silicones are already well known in Poland not only for plumbers or producers of windows, restorers of monuments and physicians but also for the users of cosmetics or baby pacifiers. Market-oriented economy and prices decide on the choice of the supplier. Undertaking the studies and a small-scale production about 70 years ago has contributed to their wide utilization and benefits for the economy.
PL
Artykuł przedstawia fragment historii opracowań i wdrożeń technologii produkcji oraz zastosowań silikonów w Polsce. Obecnie silikony są już dobrze znane w Polsce, nie tylko hydraulikom czy producentom okien, konserwatorom zabytków i lekarzom, ale też użytkownikom kosmetyków czy smoczków. Wolny rynek i ceny decydują o wyborze dostawcy. Podjęcie przed blisko 70. laty badań, niewielkiej produkcji przyczyniły się do ich o szerokiego wykorzystania i korzyści dla gospodarki.
EN
This study investigated the spatial variability of the soil silicon content in relation with topography, parent materials, soil texture, soil organic matter, exchangeable cations and pH. Using the experimental data from two longterm sites in the Forest-Steppe area of Ukraine, the SiO2 content was estimated in 60 samples taken from a soil depth 0–25 cm. The accumulation of SiO2 was significantly greater in the soils formed in footslopes. A content of extractable silicon fraction significantly increased from a sandy loam(366–465 mg•kg-1) to medium(670–697 mg•kg-1) and heavy(506–849 mg•kg-1) textured soils. The highest amount of available silicon content was found in the soils containing: 35.0–39.9% of physical clay fraction (< 0.01 mm dia) in Hrytsiv area – 143.0 ± 46 mg•kg-1 and < 25.0% of physical clay fraction in Khrolyn area – 125.0 ±6 mg•kg-1. A significant relationship was found between pHKCl, P2O5, K2O, Mg and both forms of SiO2. There was almost no correlation between available/ extractable SiO2 and exchangeable Ca and ∑ Ca+Mg. Our studies found the best correlation between extractable SiO2 and spring barley yield (r = 0.651; P = 0.041), as well assoluble SiO2 and corn for grain yield (r = 0.514; P = 0.128). No significant relationships were found for sugar beet, winter wheat, sunflower.
PL
Stopy na bazie glinu ze względu na swoje właściwości znalazły wiele zastosowań i są używane do wyrobu szerokiej grupy produktów – od części karoserii i silników samochodów, przez poszycia i elementy konstrukcyjne samolotów, po części statków kosmicznych.
PL
Rośliny lecznicze stanowią niedoceniany rezerwuar bioaktywnych substancji antybakteryjnych, antygrzybicznych i antypasożytniczych. Prowadzenie kompleksowych i systematycznych badań w zakresie identyfikacji oraz izolacji tych substancji stanowi wyzwanie dla współczesnej nauki.
13
EN
This work aims to confirm that the single-diode model of a monocrystalline cell can be used successfully also for thin-film solar cells when their basic parameters are calculated using the method of changing illumination. The authors describe the experimental procedure, in which I–V curves of thin-film solar cells are measured when illumination levels are changing. In experiments, a fully reflective 500 W solar simulator is used as an excellent broadband white light source, which provides the range of 0.01–10 Sun settings.
EN
This work presents results of comparative studies of the optical absorption coefficient spectra of ion implanted layers in silicon. Three nondestructive and noncontact techniques were used for this purpose: spectroscopic ellipsometry (SE), modulated free carriers absorption (MFCA) and the photo thermal radiometry (PTR). Results obtained with the ellipsometric method are the proof of correctness of the results obtained with the MFCA and PTR techniques. These techniques are usually used for investigations of recombination parameters of semiconductors. They are not used for investigations of the optical parameters of semiconductors. Optical absorption coefficient spectra of Fe+ and Ge+ high energy and dose implanted layers in silicon, obtained with the three techniques, are presented and compared.
EN
The effect of multi-pass multi-directional forging (MDF) on the microstructure and mechanical properties of Zn–22Al–xSi (X = 4 and 8 wt. %) alloy, also known as SiP/ZA22 composite, was investigated. MDF process was applied at 100 °C for one, three, and five passes with the strain of 0.47 per pass. According to the results, MDF refined and homogenized the composites microstructure so that the average size of primary Si (SiP) particles reduced from 25.0 µm and 30.4 µm in as-cast ZA22-4Si and ZA22-8Si composites to about 6.2 µm and 7.3 µm in five-pass MDFed condition, respectively, and their distribution shifted to the smaller size range. Mechanical properties tests revealed that multi-pass MDF has softened the investigated composite. For instance, the hardness, tensile strength, and shear strength of ZA22-4Si composite reduced from 83 HV, 280 MPa, and 165 MPa in as-cast condition to about 58 HV, 160 MPa, and 118 MPa in the five-pass MDFed sample, respectively. This is while its fracture strain increased from 15% to about 40% with the strain rate of 1.2 × 10–3 s−1.
16
Content available remote SiN/SiO2 passivation stack of n-type silicon surface
EN
The SiN/SiO2 stack is widely used to passivate the surface of n-type monocrystalline silicon solar cells. In this work, we have undertaken a study to compare the stack layer obtained with SiO2 grown by both rapid thermal and chemical ways to passivate n-type monocrystalline silicon surface. By varying the plateau time and the plateau temperature of the rapid thermal oxidation, we determined the parameters to grow 10 nm thick oxide. Two-step nitric acid oxidation was used to grow 2 nm thick silicon oxide. Silicon nitride films with three refractive indices were used to produce the SiN/SiO2 stack. Regarding this parameter, the minority carrier lifetime measured by means of QSSPC revealed that the refractive index of 1.9 ensured the best passivation quality of silicon wafer surface. We also found that stacks with nitric acid oxidation showed definitely the best passivation quality. In addition to produce the most efficient passivation, this technique has the lowest thermal budget.
EN
Results of the ab initio molecular dynamics calculations of silicon crystals are presented by means of analysis of the velocity autocorrelation function and determination of mean phonon relaxation time. The mean phonon relaxation time is crucial for prediction of the phonon-associated coefficient of thermal conductivity of materials. A clear correlation between the velocity autocorrelation function relaxation time and the coefficient of thermal diffusivity has been found. The analysis of the results obtained has indicated a decrease of the velocity autocorrelation function relaxation time t with increase of temperature. The method proposed may be used to estimate the coefficient of ther-mal diffusivity and thermal conductivity of the materials based on silicon and of other wide-bandgap semiconductors. The correlation between kinetic energy fluctuations and relaxation time of the velocity autocorrelation function has been calculated with the relatively high coefficient of determination R2 = 0.9396. The correlation obtained and the corresponding approach substantiate the use of kinetic energy fluctuations for the calculation of values related to heat conductivity in silicon-based semiconductors (coefficients of thermal conductivity and diffusivity).
EN
The calculation method of the molecular dynamics has been applied to study the correlation of the kinetic energy fluctuations and the relaxation time of the velocity autocorrelation function and the phonon relaxation time in a crystal. On the basis of the molecular dynamics data for silicon crystal obtained at different temperatures in the range 200 K – 1000 K the correlation between the kinetic energy fluctuations and the relaxation time of the velocity autocorrelation function has been calculated with the relatively high coefficient of determination R2 = 0.9396. The correlation obtained and the corresponding approach substantiate a use of the kinetic energy fluctuations for the calculation of values related to the heat conductivity in the silicon based semiconductors (coefficients of thermal conductivity and diffusivity).
PL
Obliczeniowa metoda dynamiki molekularnej została zastosowana do badania korelacji fluktuacji energii kinetycznej i czasu relaksacji autokorelacyjnej funkcji prędkości i czasu relaksacji fononów w krysztale. Na bazie danych dynamiki molekularnej kryształu krzemu otrzymanych w różnych temperaturach w zakresie 200 K – 1000 K została obliczona korelacja fluktuacji energii kinetycznej i czasu relaksacji autokorelacyjnej funkcji prędkości, która cechuje się stosunkowo wysokim współczynnikiem determinacji R2 = 0.9396. Otrzymana korelacja uzasadnia zastosowanie fluktuacji energii kinetycznej do badań obliczeniowych wielkości powiązanych z przewodnością cieplną półprzewodników na bazie krzemu (współczynniki przewodności i dyfuzyjności cieplnej).
PL
W ramach technologii fotowoltaicznych wyróżniamy obecnie trzy generacje. Pierwsza z nich to ogniwa z mono- i polikrystalicznego krzemu (c-Si), druga obejmuje ogniwa wykonane na bazie technologii cienkowarstwowej, zarówno z krzemu amorficznego (a-Si), jak i diseleneku indowo-miedziowo-galowego (CIGS), tellurku kadmu (CdTe) oraz arsenku galu (GaAs). Trzecia generacja to najnowsze technologie, takie jak: organiczne ogniwa słoneczne, ogniwa uczulane barwnikami czy ogniwa hybrydowe. Przyjmuje się, że średnia długość życia modułu fotowoltaicznego wynosi około 17 lat, co w połączeniu ze wzrastającym zainteresowaniem technologią fotowoltaiczną wiąże się ze zwiększona ilością odpadów, trafiających na składowiska. Oszacowano, że w 2026 roku liczba odpadowych modułów fotowoltaicznych osiągnie 5 500 000 ton. Będą to zarówno pozostałości po procesie produkcji, elementy uszkodzone podczas użytkowania oraz zużyte moduły fotowoltaiczne. Rozwój technologii fotowoltaicznych prowadzi również do doskonalenia istniejących i badań nad opracowaniem nowych metod recyklingu, dostosowanych do procesów produkcji modułów. W pracy zaprezentowano stan wiedzy na temat opracowanych technologii recyklingu modułów, wykonanych z krystalicznego krzemu oraz modułów cienkowarstwowych. Przedstawiono wyniki badań własnych nad procesem delaminacji modułów oraz roztwarzania elementów ogniw wykonanych w obu technologiach. W wyniku przeprowadzonych badań określono minimalną temperaturę, która powinna zostać zastosowana podczas dekompozycji materiału laminującego. U dowodniono, że folie wykonane przez różnych producentów ulegają procesom delaminacji w różnym stopniu, co może być spowodowane różnicami w stopniu usieciowana i stosunkowi polietylenu do polioctanu winylu. Przy wykorzystaniu metody trawienia sekwencyjnego podczas usuwania metalizacji można odzyskać nawet 1,6 kg srebra na 1 t połamanych mono- i polikrystalicznych ogniw krzemowych.
EN
At present we divide photovoltaic technologies into three generations. The first generation are monoand polycrystalline silicon solar cells (c-Si), the second one includes thin film technology both amorphous silicon (a-Si) and copper-gallium-indium diselenide (CIGS), cadmium telluride (CdTe), or gallium arsenide (GaAs). The third generation are newest technologies such as: organic solar cells, cells sensitized with dyes or hybrid cells. It is assumed that the average lifespan of the module is about 17 years, which in addition with the growing interest in solar technology results in an increasing amount of electronic waste in the land fields. I t has been estimated that in 2026, the number of waste photovoltaic modules will reach 5,500,000 tons. These will include both residues from the production process, components damaged during usage and end of life solar modules. Advanced photovoltaic technologies lead to the research and development of new methods of recycling adapted to the production processes. The article presents the state of knowledge regarding recycling technologies for modules from crystalline silicon and thin films. The results of own research of the delamination process and the recovery of cells elements in both technologies are introduced. As a result of the tests, the minimum temperature which should be used during the decomposition of the laminating material was determined. I t has been proven that foil made by different manufacturers is processed in varying degrees. That might be caused by differences in the cross-link degree and the ratio of polyvinyl acetate. U se of the sequential etching method to remove metallization, provides a possibility to recover up to 1.6 kg of silver per 1t of broken mono- and polycrystalline silicon cells.
EN
The world economy needs new breakthrough in the technological and material efficiency and costs in the manufactured solar cells. The authors present new studies on triple junction photo voltaic structures using nano-technological solutions. The system of the amorphous a-Si:H sandwich with the scattered light particles, the plasmonic nano Si in the a-Si:H matrix structure and the silicon-germanium sandwich on the multi ZnO layer electrode- reflector was made and studied in detail.
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