The direct carbon fuel cell technology provides excellent conditions for conversion of chemical energy of carbon-containing solid fuels directly into electricity. The technology is very promising since it is relatively simple compared to other fuel cell technologies and accepts all carbon-reach substances as possible fuels. Furthermore, it makes possible to use atmospheric oxygen as the oxidizer. In this paper the results of authors' recent investigations focused on analysis of the performance of a direct carbon fuel cell supplied with graphite, granulated carbonized biomass (biocarbon), and granulated hard coal are presented. The comparison of the voltage-current characteristics indicated that the results obtained for the case when the cell was operated with carbonized biomass and hard coal were much more promising than those obtained for graphite. The effects of fuel type and the surface area of the cathode on operation performance of the fuel cell were also discussed.
Twenty-eight two-, three-, four-, and five-component amine mixtures have been evaluated as possible activators of CO2 absorption into aqueous carbonate/bicarbonate solutions. Measurements were per- formed using a pressure autoclave with a sparger at conditions close to industrial ones. On the basis of these results, a formula for a new, more efficient amine activator named INS13 was developed. The activator was tested both in a pilot plant and on an industrial scale in an ammonia plant producing 300 tons/day of ammonia. Activator INS13 was applied in a number of ammonia plants in Poland and abroad.
In the present paper, the one-dimensional model for heat and mass transfer in fixed coal bed was proposed to describe the thermal and flow characteristics in a coke oven chamber. For the purpose of the studied problem, the analysis was limited to the calculations of temperature field and pyrolytic gas yield. In order to verify the model, its theoretical predictions for temperature distribution during wet coal charge carbonization were compared with the measurement results found in the literature. In general, the investigation shows good qualitative agreement between numerical and experimental data. However, some discrepancy regarding the temperature characteristics at the stage of evaporation was observed.
“Soon we will be able to fit the contents of the Encyclopedia Britannica on a head of a pin,” the famous physicist Richard Feynman argued back in the 1960s. Perhaps even he would be amazed at the possibilities now offered by carbon nanotubes, several hundred thousand times tinier than a pin. Their amazing properties have been exploited in an integrated circuit developed at the Karlsruhe Institut für Technologie.
A sediment core (LS-1) collected from Long Lake in King George Island, South Shetland Islands (West Antarctica) was analyzed for a variety of textural, geochemical, isotopic and paleontological properties together with 14C age dates. These data combined with published records of other studies provide a detailed history of local/regional postglacial paleoproductivity variation with respect to terrestrial paleoclimate change. The lithologic contrast of a lower diamicton and an upper fine-grained sediment demonstrates glacial recession and subsequent lake formation. The upper fine-grained deposit, intercalated by mid-Holocene tephra-fallout followed by a tephra gravity flow, was formed in a lacustrine environment. Low total organic carbon (TOC) and biogenic silica (Sibio) contents with high C/N ratios characterize the diamicton, whereas an increase of TOC and Sibio contents characterize the postglacial lacustrine fine-grained sediments, which are dated at c. 4000 yrBP. More notable are the distinct TOC maxima, which may imply enhanced primary productivity during warm periods. Changes in Sibio content and δ13C values, which support the increasing paleoproductivity, are in sympathy with these organic matter variations. The uniform and low TOC contents that are decoupled by Sibio contents are attributed to the tephra gravity flows during the evolution of the lake rather than a reduced paleoproductivity. A very recent TOC maximum is also characterized by high Sibio content and δ13C values, clearly indicating increased paleoproductivity consequent upon gradual warming across King George Island . Comparable with changes in sediment geochemistry, the occurrence and abundance of several diatom species corroborate the paleoproductivity variations together with the lithologic development. However, the paleoclimatic signature in local terrestrial lake environment during the postglacial period (for example the Long Lake) seems to be less distinct, as compared to the marine environment.
The transition to a zero-carbon economy is the inclusive growth story of the twenty-first century. It needs to be managed with effective and cohesive policies, whilst recognizing that sustainable development, inclusive growth and climate action are interwoven and mutually supportive.
Water samples were collected at 12 oceanographic stations from six standard depths ranging from 0 to 100 and 150 m. The number of bacteria and concentration of organic components were expressed in adequate units per 1 litre of sea water and in the form of the integrated values for the whole water column under I m2 of sea of organic components were expressed in adequate units per 1 litre of sea water and in the form of the integrated values for the whole water column under 1 m2 of sea surface. Total numbers of bacteria (TC) ranged from 0.16 to 7.31 x 107/1 and 1.74 — 5.67 x 10, 2/m2 saprophytic bacteria (CFU) 0.10 — 46.85 x 103/1 and 0.62 — 27.7x 108/m2. contents of particulate organic carbon (РОС) 0.02 — 0.25 mg/1 and 3.5 — 20.0 g/m2 dissolved organic carbon (DOC) 0.07 — 3.02 mg/1 and 53.5 — 207.9 g/m2, dissolved free amino acids (DFAA) 0 — 1.8965 μmol/1 and 2.7 -151.5 mmol/m2, dissolved combined amino acids (DCAA) 0 2.9366 μmо1/1 and 16.5— 163.5 mmol/m2, particulate combined amino acids (PCAA) 0 — 3.0215 μmо1/1 and 3.7 — 249.0 mmol/m2. Total numbers of bacteria and РОС, DOC and DCAA concentrations, widely differentiated in the investigated area, were on the average much lower than the values obtaine in previous years. The saprophytic bacteria content and DFAA and PCAA concentrations were at a similar level to that in the past years. Higher TC and CFU values were observed in the areas with high concentrations of phytoioplankton to the NW of Anvers I. and around Clarence I.
A year-round (3 March 1994 - 28 February 1995) phytoplankton study in Admiralty Bay revealed nanoplankton flagellates (< 20 μm) to be the major algae of the plankton, both in terms of cell numbers and carbon biomass. Their quantities fluctuated widely thoroughly the year showing several peaks, in May, April, December and January. Summer maximum of the group in December was mainly due to Cryptophyceae (4.9 x 106 cells l-1; 98.0 μg C 1-1) and Prasinophyceae (7.3 x 105 cells -1; 33.5 μg C -1). Diatoms were usually scarce (max. 6.8 x 105 cells -1; 7.82 p:g C 1-1) and were dominated by small species of Thalassiosira and by Nitzschia spp. (Pseudonitzschia); the domination structure somewhat differed from that observed in Admiralty Bay in the summer of 1977/78. Algal peaks were related to the surface water (4 m depth) temperature rise from +0.16 to +1.71˚C. Summer phytoplankton maxima were about 5-fold greater than those recorded in the summer of 1977/78.
Studies on the quantity and distribution of organic carbon (DOC and РОС) in the water of the Admiralty Bay were conducted between 20 December 1978 and 15 February 1979. The С org. content ranged from 1.62 to 3.22 mg 1-1 for DOC and from 0.22 to 0.65 mg x 1-1 for РОС. Maximal DOC amounts were observed at the depth 25—50 m (on average about 2.50 mg x 1-1 ) and in chosen regions of surface waters of the Admiralty Bay, among others, in the vicinity of a large penguin colony. Mean content of DOC in waters of the Admiralty Bay (about 2.26 mg x 1-1 ) is lower as compared to mean DOC content in waters of the Bransfield Strait (about 4.12 mg x 1-1).
The authors established the chemical and phase compositions of grain fractions of the magnesia carbon scrap disintegrated using industrial cone crushers. The investigations included chemical and XRD analyses and optical investigations. The contents of admixtures: SiO2, CaO, Fe2O3 and Al2O3 increase with the decreasing size of the scrap grain fractions, whereas the C/S ratio decreases in finer and finer fractions due to changes of the phase composition. These relations are caused by the presence of low-fusible silicate phases, characterized by their cleavage and brittleness. Such phases were mainly derived from the graphite ash containing a high silica content. The scrap after removing its finest grain fractions can be recycled and utilized for producing the magnesia-carbon refractory materials. However, the finest grain fractions may be used, e.g. as a component of gunite mixes. Many years of experience collected by the ArcelorMittal Refractories Ltd., Krakow, Poland in the field of refractory scrap utilization has also been presented.
Measurements of CO2 concentrations in soil air were taken in the summer seasons of 1998 and 2001 in SW Spitsbergen. The measurements were carried out in three small non-glaciated catchments in the Hornsund region close to the Polish Polar Station. The preliminary measurements were made using a Dräger's pump and ampules which contained an alkaline absorbent (1998). Later (2001), a new more accurate apparatus which uses a gravimetric method was tested. A variety of different geographical situations was chosen for the CO2 measurements. These included areas which differed in respect of the local hydrology, terrain relief, exposure to solar radiation, distance from the sea and quantity of seabird excrements in the soil. The measured concentrations of soil CO2 varied between 0.05 and 0.3% (with one exceptionally high value close to 0.5%). Owing to the local conditions, the differences between CO2 concentrations seem closely to relate to the specific properties of each catchment. Much of the biogenic CO2 present in water that circulates in tundra catchments which have a limestone foundation becomes involved in the dissolution of that limestone. In July 2001, about 40% of the CO2 was used in the dissolution of the carbonate rocks (30.3 kg/km2 month), the “free” CO2 being transported to the sea at Isbjřrnhamna Bay (40.4 kg/km2 month). In contrast, the water flowing through acidic rocks are rich in “free” CO2. The concentrations of dissolved and transported HCO3– ions from the polar catchments are closely correlated with variations in the daily production of biogenic CO2.
Operational Transresistance Amplifier (OTRA) has been a topic of great interest recently. OTRA has proved itself to be an appropriate device for the analog applications. As MOS scaling suffers from various problems, carbon nanotube field effect transistor (CNTFET) has came into light as one of the brightest alternative for FET (Field Effect Transistors) based devices. This work has introduced a new CNTFET based OTRA which is capable of realising inverse low pass filter using two OTRAs and few passive elements. CNTFET based OTRA has been designed and simulated at 10nm technology node. The working ability of the designed model has been conformed using HSPICE simulation. It is compared with conventional CMOS based OTRA. The comparative analysis has revealed improvement in various performance parameters. The paper also presents how change in number of carbon nanotube in CNTFETs in OTRA circuit affects the transresistance gain and input impedance. The optimized results are also discussed to improve transresistance gain and input impedance. The paper also dealt with the realisation of inverse low pass filter using proposed CNTFET based OTRA.
The intercalation into interlayer spaces of montmorillonite (MMT), obtained from natural calcium bentonite, was investigated. Modification of MMT was performed by the poly(acrylic acid-co-maleic acid) sodium salt (co-MA/AA). Efficiency of modification of MMT by sodium salt co-MA/AA was assessed by the infrared spectroscopic methods (FTIR), X-ray diffraction method (XRD) and spectrophotometry UV-Vis. It was found, that MMT can be relatively simply modified with omitting the preliminary organofilisation – by introducing hydrogel chains of maleic acid-acrylic acid copolymer in a form of sodium salt into interlayer galleries. A successful intercalation by sodium salt of the above mentioned copolymer was confirmed by the powder X-ray diffraction (shifting the reflex(001) originated from the montmorillonite phase indicating an increase of interlayer distances) as well as by the infrared spectroscopy (occurring of vibrations characteristic for the introduced organic macromolecules). The performed modification causes an increase of the ion exchange ability which allows to assume that the developed hybrid composite: MMT-/maleic acid-acrylic acid copolymer (MMT-co- MA/AA) can find the application as a binding material in the moulding sands technology. In addition, modified montmorillonites indicate an increased ability for ion exchanges at higher temperatures (TG-DTG, UV-Vis). MMT modified by sodium salt of maleic acid-acrylic acid copolymer indicates a significant shifting of the loss of the ion exchange ability in the direction of the higher temperature range (500–700°C).
Among the numerous modern, high-efficiency energy technologies allowing for the conversion of chemical energy of coal into electricity and heat, the Direct Carbon Fuel Cells (DCFC) deserve special attention. These are devices that allow, as the only one among all types of fuel cells, to directly convert the chemical energy contained in solid fuel (coal) into electricity. In addition, they are characterized by high efficiency and low emission of pollutants. The paper reviews and discusses previous research and development works, both around the world and in Poland, into the technology of direct carbon fuel cells with an alkaline (hydroxide) electrolyte.
Diagenetic carbonate deposits (concretions, cementation bodies and cementstone bands) commonly occur in organic carbon-rich sequence of the Agardhfjellet Formation (Upper Jurassic) in Spitsbergen . They are dominated by dolomite/ankerite and siderite. These deposits originated as a result of displacive cementation of host sediment in a range of post-depositional environments, from shallow subsurface to deep-burial ones. Preliminary results of the carbon and oxygen isotopic survey of these deposits in southern Spitsbergen (Lĺgkollane, Ingebrigtsenbukta, Reinodden, and Lidfjellet sections) show the δ13C values ranging between –13.0‰ and –1.8‰ VPDB, and the δ18O values between –16.0‰ and –7.7‰ VPDB. These results suggest that the major stage of formation of the carbonate deposits occurred during burial diagenesis under increased temperature, most probably in late diagenetic to early catagenic environments. Carbonate carbon for mineral precipitation was derived from dissolution of skeletal carbonate and from thermal decomposition of organic matter.
The organic carbon (OC)-rich, black shale succession of the Middle Triassic Bravaisberget Formation in Spitsbergen contains scattered dolomite-ankerite cement in coarser-grained beds and intervals. This cement shows growth-related compositional trend from non-ferroan dolomite (0–5 mol % FeCO3) through ferroan dolomite (5–10 mol % FeCO3) to ankerite (10–20 mol % FeCO3, up to 1.7 mol % MnCO3) that is manifested by zoned nature of composite carbonate crystals. The d13C (-7.3‰ to -1.8‰ VPDB) and d18O (-9.4‰ to -6.0‰ VPDB) values are typical for burial cements originated from mixed inorganic and organic carbonate sources. The dolomite-ankerite cement formed over a range of diagenetic and burial environments, from early post-sulphidic to early catagenic. It reflects evolution of intraformational, compaction-derived marine fluids that was affected by dissolution of biogenic carbonate, clay mineral and iron oxide transformations, and thermal decomposition of organic carbon (decarboxylation of organic acids, kerogen breakdown). These processes operated during Late Triassic and post-Triassic burial history over a temperature range from approx. 40°C to more than 100°C, and contributed to the final stage of cementation of the primary pore space of siltstone and sandstone beds and intervals in the OC-rich succession.
In this paper, the analysis of carbon footprint values for children’s footwear was conducted. This group of products is characterized by similar small mass and diversity in the used materials. The carbon footprint is an environmental indicator, which is used to measure the total sets of greenhouse gas (GHG) emissions into the atmosphere caused by a product throughout its entire lifecycle. The complexity of carbon footprint calculation methodology is caused by multistage production process. The probability of emission greenhouse gases exists at each of these stages. Moreover, a large variety of footwear materials – both synthetic and natural, give the possibility of the emission of a lot of waste, sewage and gases, which can be dangerous to the environment. The diversity of materials could be the source of problems with the description of their origins, which make carbon footprint calculations difficult, especially in cases of complex supply chains. In this paper, with use of life cycle assessment, the carbon footprint was calculated for 4 children’s footwear types (one with an open upper and three with full uppers). The life cycles of the product were divided into 8 stages: raw materials extraction (stage 1), production of input materials (stage 2), footwear components manufacture (stage 3), footwear manufacture (stage 4), primary packaging manufacture (stage 5), footwear distribution to customers (stage 6), use phase (stage 7) and product’s end of life (stage 8). On these grounds, it was possible to point out the life cycle stages, where the optimization activities can be implemented in order to reduce greenhouse gases emissions. The obtained results showed that the most intensive corrective actions should be focused on the following stages: 3 (the higher emissivity), 4 and 8.
It is estimated that the amount of used car tires in the European Union in 2016 was established at the level of 3,515,000 Mg, which is undoubtedly a problem from the point of view of engineering and environmental protection. An alternative to storing this waste in landfills is their pyrolysis. As a result of thermal decomposition, calorific value products (oil and gas fraction) are obtained, as well as a solid residue, which due to its composition and properties can be processed into a high quality carbon sorbent. For this purpose, various methods of modification of the pyrolyzate are used, both involving physical and chemical activation. This article presents the characteristics of solid residue after the pyrolysis of rubber tires running at a temperature of about 400°C, which included an analysis of chemical composition (XRF and IR), mineralogical composition (XRD, SEM-EDS) and textural characteristics. Additionally, for the purpose of activation, the sample was treated with nitrogen at a temperature of 550°C. The mineralogical analysis showed that the dominant mineral component is carbon. In addition, the presence of quartz, calcite and sphalerite was observed. Analysis of the chemical composition suggests that due to the high carbon content (about 80% by mass) it is possible for a carbon sorbent from the analyzed waste to be obtained. However, previous preliminary studies did not allow a material constituting a substitute for activated carbon to be obtained, because the applied modification only slightly increased the BET specific surface area, which reached the value of approx. 85 m2/g. Based on the analysis of the pore size distribution of the 2 tested samples, it was found to be homogeneous/modal with a micro/mesoporous nature, while the shape of the hysteresis loop suggests the presence of “bottle shape” pores. Due to the relatively high content of zinc, the composition of waste (about 4% of mass), the possibility of recovery of this element should also be considered.
The article presents the current state of the CNG market used as an alternative fuel for car engines. Attention was paid to European Union directives requirements and the current state of the directives’ fulfillment. The economic aspect of CNG usage was analyzed and the approximate costs of driving 10,000 km on different fuels in the last four years were presented. The PtG process which uses electric energy (hydrogen production) and carbon dioxide captured from the flue gas for the production of synthetic methane were discussed. The scheme of the SNG plant with the indication of its most important components was presented, and attention was paid to the mutual complementation of PtG technologies with carbon dioxide capture technology. The benefits of synthetic methane production are presented and the use of compressed natural gas to power engines in vehicles has been described. First, the focus was on the single-fuel use of CNG in bus and truck engines, paying particular attention to the ecological aspect of the implemented solutions. It has been shown that the use of compressed natural gas will reduce almost 100% of the particulates emission from the combustion process. The advantages and disadvantages of the alternative fuel supply are given. Next, the aspect of dual-fuel use in diesel engines was analyzed on the example of a smaller engine. The degree of reduction of harmful compounds emission from the combustion process is shown. Finally, attention was paid to the possible scale effect, referring to the number of motor vehicles in Poland.
51 samples from the Middle Triassic black shales (organic carbon−rich silt− stones; up to 4.9% TOC – Total Organic Carbon) from the stratotype section of the Bravaisberget Formation (western Spitsbergen) were analyzed with respect to isotopic composition of pyritic sulphur (34S) and TOC. Isotopic composition of syngenetic py− rite−bound sulphur shows wide (34S from −26‰ to +8‰ VCDT) and narrow (34S from −4‰ to +17‰ VCDT) variation of the 34S in upper and lower part of the section, respec− tively. Range of the variation is associated with abrupt changes in dominant lithology. Wide 34S variation is found in lithological intervals characterized by alternation of black shales and phosphorite−bearing sandstones. The narrow 34S variation is associated with the lithological interval dominated by black shales only. Wide and narrow variation of the #2;34S values suggests interplay of various factors in sedimentary environment. These fac− tors include oxygen concentration, clastic sedimentation rate, bottom currents and bur− rowing activity. Biological productivity and rate of dissimilatory sulphate reduction had important impact on the 34S variation as well. Wide variation of the 34S values in the studied section resulted from high biological productivity and high rate of dissimilatory sulphate reduction. Variable degree of clastic sedimentation rate and burrowing activity as well as the activity of poorly oxygenated bottom currents could also cause a co−occurrence of isotopically light and heavy pyrite in differentiated diagenetic micro−environments. Occurrence of organic matter depleted in hydrogen could also result in a wide variation of the 34S values. Narrow variation of the #2;34S values was due to a decrease of biological productivity and low rate of dissimilatory sulphate reduction. Low organic matter supply, low oxygen concentration and bottom currents and burrowing activity were also responsible for narrow variation of the 34S. The narrow range of the 34S variation was also due to occurrence of hydrogen−rich organic matter. In the studied section the major change in range of the 34S variation from wide to narrow appears to be abrupt and clearly associated with change in lithology. The change of lithology and isotopic valuesmay sug− gest evolution of the sedimentary environment from high− to low−energy and also facies succession from shallow to deeper shelf. The evolution should be linked with the Late Anisian regional transgressive pulse in the Boreal Ocean.
Experiments have been carried out on the influence exerted by Aroclor 1254 upon the photosynthetic production of organic 14C by an assemblage of marine Antarctic diatoms (Thalassiosira sp. 48%, Nitzschia sp. 21%, Chaetoceros sp. 15% and Corethron iriophilum 10%). Samples of various numbers of cells per cm3 of water have been used. Incorporation of 14C02 by the diatoms proved to be proportional to the increased number of cells in the sample only at the lowest levels of concentration in per cm3. Further increase of the level of 14C in diatoms has not been found as number of cells in the sample kept growing. Calculation of brutto photosynthesis has indicated that low concentration of Aroclor 1254 (0,01 to 1 ppm) may stimulate the photosynthetic incorporation of carbon, yet the photosynthetic release of carbon from cells within the photorespiratory process is stimulated to a higher degree. High concentration of Aroclor (1 to 50 ppm) inhibit the brutto assimilation, yet the release of carbon during the photorespiratory process is inhibited to a higher degree. A hypothesis is being considered implying that the relation between the intensity of photosynthesis and intensity of photorespiration may vary according to the rate of concentration of Aroclor.
The general objective of this research has been to identify the factors and conditions of migration of CaCO3 within glaciers and their marginal zones in Svalbard . Special attention has been paid to the cryochemical processes responsible for precipitation of calcium carbonate in icing (naled ice) formed near fronts of polythermal glaciers during winter. Estimates of the importance of those processes in respect of the general mineral mass transfer in the glacier system are attempted here. Field studies concerning the carbonate contents in proglacial sediments and icing fields were carried out in the Werenskioldbreen and the Elisebreen basins (S and NW Spitsbergen respectively). A functional model of CaCO3 migration in a glacier system is proposed which indicates the various paths of the mineral mass flow. Considerations on intensity of glacial processes permitted quantitative estimation of the particular components in respect to the Werenskioldbreen basin. Cryochemical processes do not appear to be of overriding importance in such migration but, clearly, they play a specific role in retaining CaCO3 in the proglacial zone on land. The crystalline forms present in the icings, which have many lattice defects, are very easily re-dissolved or removed by wind.
Using High Performance Liquid Chromatography, concentrations of uric acid in the surface waters of two non-glaciated catchments (Fugle and Dynamisk) on Spitsbergen were measured. Measurements of specific conductivity enabled us to perform tests on the dissolution of the carbonate rocks present in both catchments in both natural and aqueous solutions of uric acid. Samples of calcium urate were made and its water solubility determined. Given a knowledge of concentrations of uric acid, calcium ions and calcium urate solubility product, an estimate of the role of uric acid in the dissolution of carbonate rocks was possible. Uric acid increases the dissolution of carbonate rocks by c. 12.5% in case of the Fugle catchment and 7% in Dynamisk.
Measurements were made of organic fluxes at a coastal sediment at Signy Island , South Orkney Islands, Antarctica , between December 1990 and March 1992. The deposition rate of organic matter to the sediment was measured at the same time with a maximum sedimentation rate of 306 mg C m–2 d–1. The rates of sedimentary organic input were small during winter ice cover, and the organic content of the sediment declined during this period as available organic matter was depleted. Fresh organic input occurred as soon as the sea-ice melted and ice algal biomass was deposited to the sediment; and was sustained during the spring after ice break-up by continued primary production in the water column. The proportion of available carbon in surface sediments was measured during a seasonal cycle using Pseudomonas aeruginosa as an indicator organism over the 0–1 cm depth horizon. Variations in the amount of organic matter deposited to the sediments and the proportion of available carbon were observed during the seasonal cycle. Seasonal variations of benthic activity in this coastal sediment was regulated by the input and availability of organic matter, and not by seasonal water temperature, which was relatively constant between –1.8 and 0.5°C .
The present work has the objective of studying the effect of shot peening with glass microspheres on SAE 1020 steel in its resistance to fatigue. Fatigue tests were carried out by rotary bending with load control and loading on balance in specimens with and without shot peening. A rotation speed of approximately 750 rpm (12.5 Hz) was employed in the fatigue tests. Vickers microhardness tests were performed in order to verify the surface hardening produced by shot peening with glass microspheres. Analysis of the steel surface and fatigue fractures was performed using scanning electron microscopy (SEM). Fatigue tests were performed in order to obtain S-N curves (Wöhler curves). It was observed that shot peening with glass microspheres improved the fatigue strength of the steel at high cycle.