Search

The automotive upholstery industry, which processes bovine leathers, has struggled with vast amounts of solid waste, of which the majority are fractions, such as shavings and splits and offcuts, both containing chromium (Cr) and free of Cr. In this work, a novel leather waste-to-fertiliser approach has been tested: four lightly processed (incubation with effective microorganisms) and three aggressively processed (using pyrolysis or hydrolysis processes) tanned leather waste fractions were used. They were applied as organic nitrogen-based fertilisers in two separate glasshouse experiments, consisting of four subsequent harvests, under spring–autumn conditions in northern Poland. The Cr stressing effect caused by bovine shavings containing Cr and splits and offcuts containing Cr stimulated an increase in ryegrass growth after 30 days, providing twice the dry matter yield than bovine shavings free of Cr and splits and offcuts free of Cr, then (after 90 and 120 days) it inhibited growth. The Monod kinetics model was developed using the best fitting procedure (R2 > 0.94) for the efficiency of internal N use in ryegrass for the lightly processed fractions of tanned leather-waste fractions and each harvest. In the case of the processed leather waste-fractions, the relation was quasi linear, evidencing less growth inhibition and no over-fertilisation effects. The acid hydrolysate of bovine shavings containing Cr showed the best performance, reaching a relative agronomic effectiveness (RAE, N utilization-based) equal to 89%, 95%, 19%, and 38% for 30, 60, 90, and 120 days, respectively, and 71% in total. For the lightly processed fractions, it was lower than 12%. The future perspective should focus on steps including scaling up the tests to field conditions; transportation, storage, and application methods; effectiveness for other crops; usage in crop rotation systems; environmental impact assessment; production carbon footprint; commercial potential; and optimizing the production processes. [ABSTRACT FROM AUTHOR]

In this study, alternative uses for lignocellulosic waste by considering them a source of eco-friendly and renewable energy generation with the application of the anaerobic digestion of treated and untreated waste for biogas and biohydrogen generation were investigated. The diluted sulfuric acid method was used for both the substrates and inoculum. Hydrogen production was absent when untreated spent coffee grounds (SCG) and alcohol waste (AW) were both used with the inoculum at pH 5.5 and pH 7.5. Meanwhile, the highest biogas yield of 320 dm3 kg V.S−1 was obtained when using AW at pH 7.5, with a 190 dm3 kg V.S−1 yield of methane. Instead, hydrogen production was observed when initially 4% (w/v) and 6% (w/v) SCG-containing hydrolysates were used as the substrates at pH 5.5, yielding 2.9 ± 0.09 dm3 kg V.S−1 and 3.85 ± 0.12 dm3 kg V.S−1, respectively. The further optimization of pretreatment technologies and pH control could lead to increased and prolonged hydrogen production. [ABSTRACT FROM AUTHOR]

Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is, however, under-recognized that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing, and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization, or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical–chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective. [ABSTRACT FROM AUTHOR]

The role of the addition of nitrogen to the discharge plasma of CO lasers on thermodynamic properties and composition of the laser active medium is discussed here. It is shown that nitrogen addition improves laser characteristics and changes the composition of the laser active medium. The addition of nitrogen significantly decreases CO dissociation level and concentrations of C atoms created in plasma-chemical reactions of laser discharge. [ABSTRACT FROM AUTHOR]

The objective of this work was to determine the potential of chicken manure as a substrate for biogas production after pretreatment. The effects of removing excess nitrogen from chicken manure by water extraction in a temperature range from 20 °C to 60 °C to increase methane production were investigated. The dynamics of the process and efficiency of biogas production were also analyzed. As a result of manure fermentation after pretreatment, 16 to 45% more biogas and 18 to 39% more methane were obtained compared to manure without pretreatment. The effect of extraction was to increase the ratio of carbon to nitrogen by 2–2.7 times, which contributed to increasing biogas efficiency. The proposed method seems to be a promising enhancing of biogas and methane production in comparison with raw chicken manure. Biomass in the form of chicken manure is a promising substrate for biogas production, due to the constantly growing poultry meat production as well as environmental aspects such as reducing gas emissions from manure into the atmosphere. [ABSTRACT FROM AUTHOR]

To improve the in situ soil stabilization, different chemical additives are used (ion exchange compounds, additives based on H2SO4 or vinyl polymers, and organic additives using lignosulfonates). One interesting alternative is the production of additives from various waste materials. The extensive testing of waste-based blends with soil was performed; the mechanical (unconfined compressive strength (UCS)) and hydraulic (capillary rise, water absorption, and frost resistance (FR)) soil properties were measured. The optimization process led to obtaining additive compositions ensuring high strength and sealing properties: by-pass ash from the ceramics industry, waste H2SO4, pyrolytic waxes/oils from waste mixed plastics, waste tires and HDPE, and emulsion from chewing gum waste. For sandy soil, the following additives were the most promising: emulsion from pyrolytic wax (EPW) from waste PE foil (WPEF) with the addition of waste H2SO4, pyrolytic-oil emulsion from waste tires, EPW from waste mixed plastics with the addition of "by-pass" waste ash and NaOH, EPW from WPEF with the addition of NaOH, and EPW from WPEF reaching up to 93% FR, a 79.6% 7-day UCS increase, and a 27.6% of 28-day UCS increase. For clay: EPW from WPEF with the addition of NaOH, EPW from WPEF with the addition of waste H2SO4, and solely EPW from WPEF reaching up to 7.5% FR, an 80.7% 7-day UCS increase, and a 119.1% 28-day UCS increase. [ABSTRACT FROM AUTHOR]

The main purpose of this research was to determine the chemical composition of deposits in gas engines fuelled by coal mine methane (CMM), as well as its dependence on the place of collection. This composition was compared with that for deposits formed in biogas-powered engines. It was also found that the chemical composition of deposits varies depending on the place of their formation in the engine and on the gaseous fuel used. The dominant mineral deposits found in gas engines fuelled by CMM contained Ca, Zn, P, and S, which originate from oil additives. The Al, Cr, Cu, Ti, and Fe elements present in the tested samples are related to the wear of the engine under normal operation. The remaining trace elements can originate as impurities from the air. [ABSTRACT FROM AUTHOR]

This paper compares a traditional district heating (DH) system with a low temperature DH system based on a combined heat and power (CHP) system using Organic Rankine Cycle (ORC). Both systems supply the same amount of heat, but it is shown that the system based on CHP using ORC is more effective and uses less fuel. This in turn results in less carbon dioxide emissions. The most advantageous configuration improving the real efficiency of the ultra-low temperature heating system seems to be a system combining a central heat pump and a station based on modern ORC technology which also provides an independent (off grid) electricity supply. • Analytical model of low temperature district heating supplied by CHP ORC is shown. • Electrical energy from ORC is used to supply DH pumps and heat domestic hot water. • Such DH system is more effective and it uses less fuel than traditional (3G) one. • Such DH systems emits less CO 2 and no external electricity is required. • The novelty includes also more flexible response to changing heat and cool demand. [ABSTRACT FROM AUTHOR]

Municipal landfills generate a significant amount of high-energy biogas, which can be used as a renewable gaseous fuel. However, it is necessary to improve the quality of this biogas due to the presence of various chemical compounds. The most common pollutants in landfill biogas include volatile compounds of silicon, sulphur, phosphorus and chlorine. The aforementioned elements, as well as other metals, were found both in the deposits and in the engine oil. The paper presents detailed characteristics of the solid residues formed in selected parts of gas engines powered by landfill biogas. Its elemental composition and morphology were investigated in order to determine the structure and influence of these deposits. In order to better understand the observed features, selected analyses were also conducted for biogas, engine oil and the condensate generated during biogas dewatering. It was found that the content of individual elements in samples collected from the same part of the gas engine but sourced from various landfills vary. The occurrence of elements in deposits, e.g., Mg, Zn, P and Cr, depends on the location of sampling sites and the type of engine. It was also observed that the deposits formed in parts that come into contact with both biogas and engine oil contain Ca or Zn, which can be related to biogas pollutants as well as different oil additives. The presence of Al, Fe, Cu, Cr, Sn or Pb in selected motor oil samples can be explained by the penetration of metallic abrasives, which confirms the abrasive properties of the formed deposits. The analysis of the characteristic deposits may contribute to the selection of an appropriate landfill biogas purification technology, thus reducing the operating costs of energy cogeneration systems. Finally, we highlight challenges for biogas purification processes and anticipate the direction of future work. [ABSTRACT FROM AUTHOR]

Carbon nitride materials have received much attention due to their excellent tribological, mechanical and optical properties. It was found that these qualities depend on the N/C ratio; therefore, the possibility to control it in situ in the sputtered film is of high importance. The plasma-electron spectroscopy method based on the Penning ionization process analysis is developed here to control this ratio in CNx films produced by plasma-sputtering in a pulsed-periodic regime of glow discharge. The electron energy distribution function is determined by the means of a single Langmuir probe placed in the center of the discharge tube. The mixture N2:CH4:He was used in the process of sputtering. The applied concentrations of CH4 varied in the range of 2–8%, and He concentration was 80–90%. The gas pressure in the discharge tube used for sputtering varied between 1 and 10 Torr, and the current was between 10 and 50 mA. It was shown that the proposed method enables the extraction of information on the composition of the surface layer of the investigated film and the development of an on-line inspection, without extracting the film from the sputtering chamber. [ABSTRACT FROM AUTHOR]

In Poland lignocellulose wastes constitute about 43% of municipal waste (∼4 417 Gg). Anaerobic and/or dark fermentation are sustainable methods of lignocellulosic waste-management and contribute greatly to ever increasing demand for energy and products. This paper presents the results of the theoretical potential of methane and hydrogen yields from lignocellulosic wastes. Also, state-of-the-art methods in the field of lignocellulose fermentation as well as its development and pretreatment are discussed. The main reason for applying pretreatment is the decomposition (decrystallization) of cellulose and hemicellulose and cleavage of polymers into monomers, which may be more easily digested by bacteria in DF and AD fermentation processes. At current price levels the cheapest methods are basic and acidic pretreatments. Acidic pretreatment is very efficient (especially using sulfuric acids), solubilizing up to 80% of lignocellulose, but strong acids produce inhibitors and are highly corrosive. Alkaline pretreatment is a competitive and even more efficient (>80%) method to acidic pretreatment especially for some rigid materials that acid cannot solubilize. Oxidative pretreatment is usually expensive but can support the sacharisation process by either alkaline or acidic methods; in the case of NMMO efficiency reaching 82%. Ion-liquid pretreatment is selective (almost 100% sacharisation) but very costly and is too expensive for hydrogen production. The last methods can be profitable if some valuable by-products results. An efficient chemical pretreatment should be preceded by physical comminution e.g. mechanical which is the cheapest one. • Efficient anaerobic and/or dark fermentation of lignocellulose requires substrate pretreatment. • Acidic pretreatment -very popular and efficient but strong acids produce inhibitors and are strongly corrosive. • Designed pretreatment technique should prevent the corrosion stress. • Alkaline pretreatments are the cheapest (but polluting) while ionic and oxidants pretreatments are the most expensive. [ABSTRACT FROM AUTHOR]

The dark fermentation (DF) of organic textile (e.g. cotton) wastes is discussed in this paper. The influence of micro-aeration on hydrogen and methane production is studied. Fermentation was carried out under the following conditions: load 5 g VSS/L (Volatile Suspended Solids), the pH was varied in the range from 6.23 to 7.8; oxygen was added in small quantities. The oxygen flow rates (OFRs) were varied between 1 and 4.6 mL/h. The highest yields of methane (0.78 L/g VSS) were obtained under anaerobic conditions and neutral pH (7.54), while the production of hydrogen (1.1 mL/g VSS) peaked under an oxygen flow rate of 4.6 mL/h and a pH value of 6.4. Hydrogen and methane yield and the peak days of their production from various substrates (such as cotton waste, sour cabbage, wheat straw, and potato wastes) were compared and discussed. Cotton waste is a potential source of methane, but is substantially less efficient than potato waste. • Microaeration influence hydrogen and methane production differently. • There is an optimal oxygen flow rate for hydrogen production. • As increased microaeration leads to decreased methane production. • Cotton waste is a potential source of methane, although substantially less productive (or cost effective) than potato waste. [ABSTRACT FROM AUTHOR]

Abstract All over the world the number of people suffering from diabetes and related complications is drastically growing. Therefore, the need for accurate, reliable and stable sensor for monitoring of glucose in human body fluids is becoming highly desirable. In this work we show that material composed of gold layers deposited onto TiO 2 nanotubes (NTs) formed onto the flexible Ti foil exhibits great response toward glucose oxidation and can be successfully used as electrodes in non-enzymatic and non-invasive electrochemical sensors. TiO 2 NTs have been prepared via anodization process followed by calcination at 450 °C in order to ensure formation of anatase crystalline phase. Next, gold layers (up to 100 nm) have been deposited on the NTs by means of the magnetron sputtering. The SEM imaging confirmed presence of the well-aligned nanotubes and preservation of their initial architecture after metal deposition for Au thicknesses up to 50 nm. Basing on electrochemical results in the presence of glucose in neutral and alkaline solutions, the optimal Au thickness was found to ensure both the best response and cost-effectiveness. The detection limit of 50 μM and sensitivity of 45 μA/cm2mM obtained under neutral conditions confirm that prepared material can be used for glucose detection at levels typical for blood, urine or saliva. Moreover, the proposed electrodes exhibit great tolerance to extensive exploitation and multiple bending. Graphical abstract Unlabelled Image Highlights • Flexible material prepared via facile approach for non-enzymatic glucose sensing • Au-TiO 2 heterostructures show great activity toward glucose oxidation. • Possibility of material exploitation in neutral and alkaline environment • Selectivity and sensitivity of material satisfy demands for glucose sensors. • Proposed electrodes are resistant to the multiply mechanical deformation. [ABSTRACT FROM AUTHOR]

The phase conversion from amorphous into crystalline one in the selected area of as-anodized titania nanotubes was achieved via laser treatment. The optimized processing parameters enable fast, one-minute crystallization of titania within an area limited by a shadow mask and without any morphology damage of ordered TiO 2 tubular film. The laser annealed titania nanotubes could be easily overgrown by a conducting polymer without any additional activation procedure. The organic matrix infiltrated down to the titanium substrates as was revealed on the basis of depth profile of elemental composition recorded using X-ray photoelectron spectroscopy technique performed under the etching mode. Obtained inorganic-organic composite exhibits a doubling of its colour depending on the applied potential and high contrast electrochromic properties were verified. [ABSTRACT FROM AUTHOR]

Hydrogen is an important raw material for chemical industry and feasible renewable energy carrier that could replace fossil fuels. However, the specie seldom exists in a form of pure H 2 . Therefore, to obtain hydrogen in volumes suitable to be used as a raw material it is necesary to decompose hydrogen-rich compounds. The carbohydrate-rich biomass can be an important source of hydrogen by applying the process of dark fermentation. In this paper potential ways of hydrogen production from organic wastes (biomass) by means of dark fermentation are reviewed and discussed. The bacteria used for dark fermentation are enlisted, characterized and compared. The pretreatment processes and various reactor designs are analyzed and discussed. The hydrogen separation by membrane method (which can provide the most pure hydrogen) are presented. The paper describes recent achievements in optimizing parameters, conditions and reactors used to industrialize dark fermentation. [ABSTRACT FROM AUTHOR]

This paper presents a newly developed dermatological laser (with a central wavelength 975 nm) for application in therapies requiring deep penetration of tissue, e.g., cutaneous (dermal) neurofibroma (von Recklinghausen disease) and hemangiomas. This laser can work either in pulses or continues wave mode. Laser radiation is transmitted toward the application region by optical fiber with a diameter of 0.6 mm. The compact design of the laser facilitates its transport and increases the comfort of use. [ABSTRACT FROM AUTHOR]

Carbon nanotubes due to their catalytic properties are a promising alternative to platinum counter electrodes (CE) for dye-sensitized solar cells (DSSC). In this study, counter electrodes were made from double-walled carbon nanotube (DWCNT) ink using the spray printing technique and afterwards they were thermally treated at temperatures ranging from 120 to 300 °C. Morphology and structure was studied using scanning electron microscopy and Raman spectroscopy. DSSCs were constructed from titanium-dioxide photoanodes and DWCNT counter electrodes cured at various temperatures. The current-voltage characteristics of DSSCs and their impedance spectra recorded under illumination have been studied and compared. The photoconversion efficiency (PCE) of the solar cell reached a maximum value of 4.59% when the carbon layer was thermally treated at 300 °C and is 16% higher than that registered for devices with a standard platinum counter electrode. [ABSTRACT FROM AUTHOR]

Skin lesions are commonly treated using laser heating. However, the introduction of new devices into clinical practice requires evaluation of their performance. This study presents the application of optical phantoms for assessment of a newly developed 975-nm pulsed diode laser system for dermatological purposes. Such phantoms closely mimic the absorption and scattering of real human skin (although not precisely in relation to thermal conductivity and capacitance); thus, they can be used as substitutes for human skin for approximate evaluation of laser heating efficiency in an almost real environment. Thermographic imaging was applied to measure the spatial and temporal temperature distributions on the surface of laser-irradiated phantoms. The study yielded results of heating with regard to phantom thickness and absorption, as well as laser settings. The methodology developed can be used in practice for preclinical evaluations of laser treatment for dermatology. [ABSTRACT FROM AUTHOR]

Abstract: In the paper the mechanical, optical and electrical parameters of transparent conductive layers (TCLs) made of carbon nanotubes and metal conductive oxides are explored and compared. All investigated materials are deposited on transparent, flexible polymer foils used for solar cell applications. Obtained results are compared with available parameters of rigid transparent conductive oxides (TCOs) as well as literature reports about Indium–Tin Oxide (ITO) on flexible substrates. Presented paper is a report from the preliminary stage of a new flexible solar cell construction. [Copyright &y& Elsevier]

The miniaturization of devices requires the introduction of a high aspect ratio through patterning in the Damascene copper interconnect process. The high aspect ratio etch process employs hardmasks, such as amorphous carbon, that can withstand high-powered plasma exposure. When an etch hardmask is removed after patterning, the properties of the underlying film can be altered by the effect of plasma exposure during the strip process. In this study, surface properties of SiOC(H) are investigated after an amorphous carbon strip with O2/Ar plasma. Since the low-k film of SiOC(H) structure shows characteristics according to the Si-O internal bonding structure, the Si-O bonding ratio of the ring, network and cage structure was analyzed through Fourier-transform infrared (FT-IR) analysis to measure changes in thin film properties. X-ray photoelectron spectroscopy (XPS) was also used to add reliability to the SiOC(H) film structure. In addition, the end point of the strip process was obtained using an optical emission spectroscopy sensor and variations in thin film characteristics over the plasma exposure time were analyzed. These results revealed the structural modification of the SiCO(H) thin film in the post-etch strip of the amorphous carbon layer (ACL) hardmask. [ABSTRACT FROM AUTHOR]

• Au-Cu nanomosaic onto titanium dimples formation via facile approach. • Shift in the absorbance band maximum for the bimetallic materials from 470 nm to 900 nm. • Combination of Au and Cu metals results in current density almost 15 times higher than for pure Au nanostructures. • Synergistic effect between the Au and Cu can be achieved via simple thermal treatment of sputtered films. Au-Cu nanostructures offer unique optical and catalytic properties unlike the monometallic ones resulting from the specific interaction. Among others, they have the ability to exhibit surface plasmon resonance, electrochemical activity towards the oxygen and hydrogen evolution reaction (OER, HER) as well as improved photoresponse in relation to monometalic but those properties depend highly on the substrate where bimetallic structures are immobilized. In this work, bimetallic gold-copper mosaics over the conducting structured titanium substrate were fabricated via following steps: anodization of Ti foil, chemical etching of as-formed titania resulting in nanodimpled Ti substrate (TiND), sputtering of thin metal layer (Au, Cu) in various sequences, and finally thermal treatment in furnace at 450 °C or 600 °C. The morphology, optical and structural properties were investigated in details and it was shown that both arrangements of metallic films and thermal conditions strongly affect the morphology and optical features. The XPS results confirmed the presence of gold-copper alloys and copper oxide species. Last but not least, the electrochemical activities were verified in 0.1 M NaOH using cyclic voltammetry and linear voltammetry measurements performed in dark and under visible light illumination. Among all investigated materials in both anodic and cathodic regimes bimetallic 5Au/5Cu sample annealed at 450 °C exhibits the highest response towards OER and HER, respectively. This is further boosted by the light with λ > 420 nm. Upon exposure to visible light, the current density for 5Au/5Cu and 5Cu/5Au electrodes reached 1.32 mA cm−2 and 1.26 mA cm−2, respectively, while in the case of monometallic structures the current was below 10 μA cm−2. Both optical and electrochemical behaviour indicate a strong synergistic effect arising within the bimetallic mosaic formed over the TiND. [ABSTRACT FROM AUTHOR]

Thin layers of bismuth vanadate were deposited using the pulsed laser deposition technique on commercially available FTO (fluorine-doped tin oxide) substrates. Films were sputtered from a sintered, monoclinic BiVO4 pellet, acting as the target, under various oxygen pressures (from 0.1 to 2 mbar), while the laser beam was perpendicular to the target surface and parallel to the FTO substrate. The oxygen pressure strongly affects the morphology and the composition of films observed as a Bi:V ratio gradient along the layer deposited on the substrate. Despite BiVO4, two other phases were detected using XRD (X-ray diffraction) and Raman spectroscopy—V2O5 and Bi4V2O11. The V-rich region of the samples deposited under low and intermediate oxygen pressures was covered by V2O5 longitudinal structures protruding from BiVO4 film. Higher oxygen pressure leads to the formation of Bi4V2O11@BiVO4 bulk heterojunction. The presented results suggest that the ablation of the target leads to the plasma formation, where Bi and V containing ions can be spatially separated due to the interactions with oxygen molecules. In order to study the phenomenon more thoroughly, laser-induced breakdown spectroscopy measurements were performed. Then, obtained electrodes were used as photoanodes for photoelectrochemical water splitting. The highest photocurrent was achieved for films deposited under 1 mbar O2 pressure and reached 1 mA cm−2 at about 0.8 V vs Ag/AgCl (3 M KCl). It was shown that V2O5 on the top of BiVO4 decreases its photoactivity, while the presence of a bulk Bi4V2O11@BiVO4 heterojunction is beneficial in water photooxidation. [ABSTRACT FROM AUTHOR]