Wool Substrate Research Articles

Effect of Salicylic Acid and Calcium on Growth, Yield, and Fruit Quality of Pepper (Capsicum annuum L.) Grown Hydroponically

The aim of this study was to investigate the effects of spraying plants with 0.03% salicylic acid (SA), 0.7% calcium nitrate (Ca), and 0.03% salicylic acid together with 0.7% calcium nitrate (SA + Ca) on plant growth, yield, and fruit quality of peppers grown in a mineral wool substrate. The control plants were sprayed with water (C). Two red-fruited sweet pepper cultivars were used in the study: ‘Aifos’, and ‘Palermo’, which produce fruits characterized by different shapes. Biometric measurements of the plants showed a higher growth rate of pepper plants when SA and Ca were applied foliarly compared to the control. Plants treated simultaneously with SA and Ca were characterized by the highest steady-state fluorescence yield [Fs]. The relative chlorophyll content of pepper leaves was also higher in plants sprayed with SA, Ca, and SA + Ca than in plants in the control. The analysis of pepper yield showed in both cultivars the effect of foliar treatment of plants with SA and Ca and SA + Ca on increasing pepper resistance to the occurrence of Ca deficiency on pepper fruit (Blossom end rot). Pepper fruits harvested from plants treated with SA, Ca, and SA + Ca had more juicy flesh.

Effect of lignite substrate compared to mineral wool and supplementary lighting with HPS and LED on growth, plant photosynthetic activity, yield and fruit quality of greenhouse cucumber

The substrate in hydroponic cultivation is one of the basic factors for proper plant growth, and current environmental trends suggest replacing the previously used mineral wool with organic substrates. Light is also essential for proper plant growth, which is why LEDs (Light Emitting Diode) are increasingly used to provide plants with supplementary light, allowing, among other things, to control the spectral composition. The aim of this study was to determine the effect of lignite substrate and LED supplementary lighting on morphological and physiological parameters as well as quality and yield of cucumber (Cucumis sativus L.) in hydroponic cultivation compared to the cultivation in mineral wool substrate. Lignite mats applied in cultivation with LED supplementary lighting had a beneficial effect on cucumber plant growth and development and plant nutrition in Fe, K, P, Ca, Mg and Zn compared to cultivation in mineral substrate and HPS supplementary lighting. The combination of LED lighting and lignite mats also improved the physiological parameters of the cucumber plants, as well as fruit hardness. Fruits harvested from plants grown in lignite substrate and supplemented with LEDs had the lowest nitrate content and increased TSS value, as well as increased fruit firmness.

Room acoustics of Mycelium Textiles: the Myx Sail at the Danish Design Museum

Abstract Taking the Myx Sail displayed at the Danish Design Museum as a case study, this article investigates the room acoustics of an architectural installation made of Mycelium Textiles. Mycelium Textiles represent a novel typology of mycelium-based composites (MBC). The Myx Sail absorbers are grown on a composition of different layers of plant fibres combining woven jute textile with hemp mat and loose wood wool substrate enhancing the mechanical and acoustic properties of the composite. Two complementary acoustic tests were conducted to measure the absorbing properties of the mycelium material and its effects on the acoustics of the exhibition hall. The results show that the sail acts effectively as an acoustic absorber especially in higher range of frequencies, reducing the reverberation time and improving speech intelligibility. The effect of the sail on the overall room acoustics is especially effective, if the sound source is placed directly underneath the sail. The results of a complementary survey amongst visitors on their subjective perception of comfort and well-being however indicate that the degree to which a grown surface (and by extension, a grown building) is perceived positively or negatively depends on the relationship the individual has with Nature.

Surface characteristics of phenolic resin coatings

Phenolic resins are commonly used as polymer binders for metal, paper and mineral wool substrates. For such applications, mechanical, adhesive and thermal properties are considered most important, and the effect of synthesis and structural parameters on such end-use characteristics are well-documented. However, surface characteristics of cured phenolic resins can be equally relevant and are often overlooked. Widely used resins are phenol-urea-formaldehyde (PUF) and phenol-formaldehyde (PF). It is believed that the inherent chemistry and curing procedure of these resins result in coatings with distinct surface properties and wettability. To gain more insight into surface characteristics such as morphology, chemical composition and wettability of cured PUF and PF resins, different binder formulations were applied on glass substrates and subsequently characterised by Scanning Electron Microscopy (SEM), Contact Angle Goniometry (CAG) and X-Ray Photoelectron Spectroscopy (XPS). The effect of catalyst, chemical composition and curing conditions on surface characteristics of various PUF and PF coatings were investigated. The curing temperature was found to have a strong influence on surface properties; curing at 200 °C yields a surface with varying degrees of oxidation, differences in linkages between phenolic and urea species, and a lower overall nitrogen content in case of urea-containing coatings, resulting in stronger fluctuations in water-wettability compared to surfaces hardened at lower temperatures.

Effect of lignite substrate and supplementary lighting and packaging type on post-harvest storage quality of cucumber fruit

Cucumber is an economically important vegetable grown all over the world. Consumers demand that high-quality cucumber fruit is available throughout the year. The aim of this study was to evaluate the effects of growing conditions such as lignite substrates and assimilation lighting in hydroponic cultivation and storage methods on the quality and post-harvest shelf life of greenhouse cucumber fruit. Cucumber fruit quality was analysed from harvest through cold storage and simulated trading conditions.Plants were grown in lignite and mineral wool growing mats. Sunlight supplementation was carried out using sodium and LED lamps. Post-harvest fruit were packed in plastic crates, cardboard boxes or plastic bags and stored in a cold store (5 days) and under simulated trading conditions (10 days - 5 days in a cold store and another 5 days at 22 ᵒC). The weight loss of cucumber fruit during storage was determined depending on the combination. After fruit harvest, after fruit storage in the cold store and after 10 days of storage under simulated trading conditions, fruit hardness, dry matter content, TSS, nitrate content of cucumber fruit were studied and sensory evaluation of fruit quality was carried out.Fruit from plants grown in lignite substrate had lower weight loss during storage and significantly higher TSS (total soluble solids) and dry matter content. They also had a lower nitrate content compared to fruit harvested from plants grown in mineral wool substrate. Furthermore, the best sensory parameters were found in fruit from plants grown in lignite substrate under LED lighting. It was also found that PE film packaging reduced the weight loss of fruit during transport and storage, and that fruit removed from the film and placed in a cardboard box lost weight more slowly compared to the other packaging tested.

Changes in the microbial community after vaginal fluid exposure in different simulated forensic situations

If vaginal fluid is found on clothing or on the body of the suspect, it may indicate the occurrence of sexual assault. Therefore, it is important to collect the victim's vaginal fluid at different sites from the suspect. Previous studies have revealed that fresh vaginal fluids can be identified based on 16S rRNA gene sequencing data. However, the influence of environmental factors on the stability of microbial markers must be investigated before being used in forensic practice. We collected vaginal fluid from nine unrelated individuals and placed each individual of vaginal swab on five different substrates. A total of 54 vaginal swabs were analyzed using 16S rRNA on the V3-V4 regions. Then, we constructed a random forest model including the samples of all vaginal fluids in this study and the other four types of body fluids in our previous studies. The alpha diversity of vaginal samples increased after exposure to the substrate environment for 30 days. The dominant vaginal bacteria were Lactobacillus and Gardnerella, which remained relatively stable after exposure, with Lactobacillus being the most abundant in all substrates, while Gardnerella was more abundant in other substrates than in the polyester fiber substrate. Except for bed sheets, Bifidobacterium significantly declined when placed on other substrates. Rhodococcus and Delftia from the substrate environment migrated to the vaginal samples. Rhodococcus was abundant in polyester fibers, and Delftia was abundant in wool substrates, while those environmental bacteria were all in low abundance in bed sheets. Overall, the bed sheet substrates showed a good retention capacity for the dominant flora and could reduce the number of taxa migrated by the environment compared with the other substrates. Both fresh and exposed vaginal samples of the same individuals could mostly be clustered and clearly distinguished from different individuals, showing the potential of individual identification, and the confusion matrix value of body fluid identification for vaginal samples was 1. In summary, vaginal samples placed on the surface of different substrates retained their stability and demonstrated good application potential for individual and body fluid identification.

Control of the concentration of the macroelement phosphorus in the substrate when growing tomatoes in protected soil conditions

Although most tomatoes are grown in open ground, their cultivation in glass greenhouses or tunnel-typegreenhouses covered with plastic film is becoming more common to supply local markets with fresh fruit. In closed soil, mainly tall varieties of tomatoes are grown. They make it possible to use the area of greenhouses as efficiently as possible and get rich harvests. Tomatoes grown in greenhouses can be stored for 11 months, unlike those grown in open ground. Tomatoes are usually harvested unripe and ripen during transportation or on store shelves. Different types of tomatoes grown in greenhouses tend to have a longer shelf life, better taste and higher market value than those grown in the open field. Usually, plants are attached to the supports with a single wire, while the extra side shoots (stepchildren) are removed so that only one stem remains. The height of the tomato bushes can be gradually reduced for convenience immediately after the ripening of the first bunches of tomatoes. Shoots and inflorescences are removed to increase the length of the tomato bush, the number of fruits on it and their weight in order to meet the needs of the market. Taste, color, shape and texture are extremely important criteria for evaluating the quality of fresh tomatoes. Also, the fruits must be clean and contain no signs of decay or disease. Fresh tomatoes should be uniform in shape, symmetry and size. They should have a bright and uniform color, not contain green shoulders, spots and characteristic signs of immaturity. High concentrations of carbon dioxide (600–1000 ppm) are maintained in greenhouses to improve the process of photosynthesis, growth rate and yield. This practice is very common in low yield regions and intensive agricultural production systems. Although planting tomatoes in soil in tunnel-type greenhouses is still quite common, most intensive-type green-house tomato varieties are grown on substrates such as mineral wool. Fertigation provides adequate nutrient supply and eliminates most of the factors associated with heavy soil characteristics that are difficult to control. Growing tomatoes in greenhouses requires the use of a significant amount of water. To feed tomatoes, their producers also need to take into account the mass and degree of solubility of mineral fertilizers in water. Some elements or compounds present in irrigation water can affect the growth of plants, which is why there is a need to control their level. The paper investigates the influence of the concentration of the macroelement phosphorus in the mineral wool substrate on the growth and development of the Rosaletta (pink) tomato crop during the period of mass fruiting in protected soil conditions. It was established that the photoelectrocolorimetric method for determining the phosphorus content in mineral wool hoods is quite sensitive, simple and recommended for use in serial analyses. The determined average value of the phosphorus macroelement content (50.0 mg/l) turned out to be higher than that required for growing tomatoes in the period of mass fruiting. Controlling the phosphorus content allows you to significantly prevent tomato diseases and obtain high-quality crops.

Influence of substrate and nutrient solution on biometric performance and net productivity of garden strawberry seedlings photosynthesis under photoculture conditions

The effect of substrate and nutrient solution on biometric parameters and net photosynthesis productivity of strawberry seedlings of the White Swede variety obtained in vitro under light culture conditions at irradiation power of 126.8 and 172.3 mmol/m2/s was investigated. The highest seedlings with a horn diameter of 0.8 cm were obtained in variants using a mineral wool substrate and nutrient solutions at an irradiation power of 126.8 mmol/m2/s. The irradiation power of 172.3 mmol/m2/s contributed to the largest number of leaves in the variants MV+ PR and MV + 1 MS of 10.0 ± 0.5 pcs. in both cases, and the active development of the assimilation area of the leaves. The irradiation power of 126.8 mmol/m2/s and the use of a nutrient solution contributes to the better development of the root system. The net photosynthesis productivity on an organic substrate using a nutrient solution (CS+1 MS) is 1.5-2.5 times higher than when using an organic substrate filled with fertilizers (GT+water). The net photosynthesis productivity of the leaf apparatus of seedlings grown on a mineral wool substrate at an irradiation power of 126.8 mmol/m2/s was in the range from 0.27 to 0.33 mg/cm2/day, and at an irradiation power of 172.3 mmol/m2/s - in the range from 0.23 to 0.29 mg/ cm2/day.

Sources of nitrous oxide emissions from hydroponic tomato cultivation: Evidence from stable isotope analyses.

Hydroponic vegetable cultivation is characterized by high intensity and frequent nitrogen fertilizer application, which is related to greenhouse gas emissions, especially in the form of nitrous oxide (N2O). So far, there is little knowledge about the sources of N2O emissions from hydroponic systems, with the few studies indicating that denitrification could play a major role. Here, we use evidence from an experiment with tomato plants (Solanum lycopersicum) grown in a hydroponic greenhouse setup to further shed light into the process of N2O production based on the N2O isotopocule method and the 15N tracing approach. Gas samples from the headspace of rock wool substrate were collected prior to and after 15N labeling at two occasions using the closed chamber method and analyzed by gas chromatography and stable isotope ratio mass spectrometry. The isotopocule analyses revealed that either heterotrophic bacterial denitrification (bD) or nitrifier denitrification (nD) was the major source of N2O emissions, when a typical nutrient solution with a low ammonium concentration (1-6 mg L-1) was applied. Furthermore, the isotopic shift in 15N site preference and in δ18O values indicated that approximately 80-90% of the N2O produced were already reduced to N2 by denitrifiers inside the rock wool substrate. Despite higher concentrations of ammonium present during the 15N labeling (30-60 mg L-1), results from the 15N tracing approach showed that N2O mainly originated from bD. Both, 15N label supplied in the form of ammonium and 15N label supplied in the form of nitrate, increased the 15N enrichment of N2O. This pointed to the contribution of other processes than bD. Nitrification activity was indicated by the conversion of small amounts of 15N-labeled ammonium into nitrate. Comparing the results from N2O isotopocule analyses and the 15N tracing approach, likely a combination of bD, nD, and coupled nitrification and denitrification (cND) was responsible for the vast part of N2O emissions observed in this study. Overall, our findings help to better understand the processes underlying N2O and N2 emissions from hydroponic tomato cultivation, and thereby facilitate the development of targeted N2O mitigation measures.

The role of magnesium ions for the growth and development of tomatoes when growing in protected soil conditions

Tomato is one of the main and popular vegetable crops not only in Ukraine, but throughout the world. According to the Food and Agricultural Organization (FAO), tomatoes occupy the first place in the world in terms of cultivated areas among all vegetables — more than 4 million hectares. In Ukraine, about 93,000 hectares — about 24% of the total area under vegetables — are devoted to this culture. With the advent of high-intensity technologies with the use of drip irrigation systems, tomato yields of 120–140 t/ha in open ground, and more than 50 kg/m2 in sheltered ground, became real. Nowadays, the method of small-volume hydroponics with the use of drip irrigation is becoming more and more widespread in greenhouse farms. As a substrate, special materials are used — mineral wool, coconut, peat, etc. The selected substrate functions as a medium for the roots, feeding is carried out by supplying a fertilizer solution. When growing on a substrate, it is necessary to dose fertilizers very accurately and provide plants with a sufficient amount of nutrients. The paper investigates the effect of the concentration of the macroelement magnesium in the mineral wool substrate on the growth and development of the Campari (cocktail) tomato culture in protected soil conditions. It was established that the photoelectrocolorimetric method for determining the magnesium content in mineral wool hoods is quite sensitive, simple, and recommended for use in serial analyses. The determined content of magnesium salts (72.0 mg/l) turned out to be insufficient for growing tomatoes in the period of mass fruiting. Controlling the magnesium content allows you to significantly prevent tomato chlorosis and obtain high-quality crops.

Stone Wool Substrate Cover Incision Impacts on the Root-Zone Water Content, Temperature, and Yield of Tomato Cultures.

Standardized cultivation systems are crucial for establishing reproducible agronomic techniques. Especially stone wool-based cultivation is governed by standardized specifications and provides a controllable root-zone environment. However, the effects of stone wool cover incision on root-zone variability have rarely been studied. Therefore, in this study, we focused on the effect of the stone wool cover incision method on environmental variations and their subsequent effects on tomato plant productivity. Stone wool slab plastic covers represent a core component of this substrate system that can potentially affect the performance of water control techniques. We designed a cover incision method to create four different levels of drainage performances that were tested by cultivating tomato plants (Solanum lycopersicum “Dafnis”). The water content, root-zone temperature, and dissolved oxygen were measured and analyzed relative to the tomato yield. We found that the incision level with the lowest drainage performance showed a lower air-root zone temperature correlation slope than those of slabs with favorable drainage conditions. Furthermore, these slabs had low dissolved oxygen levels (3.2 mg/L); nevertheless, the tomatoes grown in the slabs with incision level showing the lowest drainage performance had greater fruit yield (6,748 g/plant) than those in the slabs with favorable drainage conditions (6,160 g/plant). Furthermore, the normalized yield separation timing between treatments coincided with the hotter air temperature (27°C average) periods. We noted that manipulating the cover incision process consequently entailed variations in the correlation slope between the air temperature and root-zone temperature in the substrate. Our results reveal another trade-off relationship in the conventional perspective on the drainage performance effects and provide insights into further optimization of crop production and water use in the stone wool-based system.

Continuous self-crimped micro-nanofiber via one-step electrospinning

Micro-nanofiber with crimped structure can be promising in advanced functional application, but its preparation method is still challenged by complex processing, uncontrollable structure and elusive formation mechanism. Herein, a novel continuous self-crimped micro-nanofiber forming method is developed by one-step electrospinning. Through morphological observation, crystal characterization, electrical-performance measurement, mathematical simulation and mechanical analysis, it is shown that the trigger of crimp of polystyrene (PS) electrospinning fiber deposited on wool substrate is the comprehensive differences in diameter size, dielectric constant and electrical conductivity between them and the gap width between substrate fibers. Additionally, the degree of crimp can be adjusted by combining position and form. The theoretical model of multiple forces is established to explain the forming mechanism of crimp, which is further validated by experimental results. Conclusively, this work offers a facile means to inspire crimping of various specific fibers, which can endow them with functional application potentials in wide field.

Experimental investigation of summer thermal performance of the green roof system with mineral wool substrate

Green roof systems have become an important part in creating sustainable cities. They can provide a wide range of economic, environmental, and social benefits. The goal of this research was to quantify the thermal performance improvements from a green roof with mineral wool substrate installed on a school building in a humid subtropical climate. In-situ measurements during a summer period included heat fluxes through the green and reference roof, vertical temperature profile through both roofs, the local air temperature above roofs, and local meteorological parameters. Furthermore, the summer thermal performance of green and reference roof and the green roof cooling effect were evaluated concerning meteorological parameters using the Pearson correlation analysis. The results indicate that the green roof layers have improved thermal performance of the roof with respect to reduced conductive heat flow by 57% and delayed heat transfer. The maximum and averaged reference roof to green roof outdoor surface temperature difference was 27.5 °C and 5.5 °C, respectively. It was found that ambient temperature and relative humidity have a dominant role on the thermal performance of the green and reference roof, while solar radiation and ambient temperature present the key meteorological determinants of the green roof cooling effect.

Biofiber waste derived zwitterionic and photocatalytic dye adsorbent: Switchable selectivity, in-situ degradation and multi-tasking application

Dye wastewater and discarded biofiber have brought huge pressure to sustainable developments of ecology and economy. By utilizing dopamine chemistry and benzophenone mediated “grafting onto” atom transfer radical polymerization (ATRP), this work reported a biomass adsorbent containing discarded wool substrate, photocatalytic PDA coating and zwitterionic polymer brushes for dyes removal. The grafted zwitterionic polymer brushes impart the material with not only high adsorption capacity and rapid adsorption rate, but also switchable adsorption selectivity and pH-controlled regeneration capability. Benefiting from such outstanding adsorption performance and excellent free-standing property, the adsorbent could fulfill diversified needs of both static and dynamic adsorptions. Under daylight, the constructed photocatalytic PDA coating could in-situ degrade the captured pollutant, thus achieving consecutive adsorption-degradation-regeneration utilization. Furthermore, through simple dip-coating and cleaner UV-irradiation techniques, the preparation process could be scaled up. This work contributes to both the upcycling of discarded biofiber waste and the development of advanced biomass adsorbent.

INFLUENCE OF SUBSTRATE TYPES AND WAYS TO ADJUST THEIR AGROCHEMICAL PROPERTIES FOR BIOMETRIC PARAMETERS OF SWEET PEPPER SEEDLINGS

There are some problems of growing plants on pure vermiculite and mineral wool substrates in sheltered ground. It is suggested that the problems arise due to alkalization of substrates. The article presents results of the studies on the influence of preparation methods of peat and vermiculite substrates on biometric parameters of sweet pepper seedlings. The research was carried out in a vegetative experiment established in 2017–2019 in the scientific laboratory of Agrarian Institute of Mordovian State University named after N. P. Ogaryov. Two substrates and four ways of adjustment to their agrochemical properties were studied: 1) watering with a nutrient solution with 5.0 pH; 2) preliminary phosphating of the substrate, followed by watering with a nutrient solution with a pH of 5.0; 3) watering with a nutrient solution with a pH of 4.0; 4) application of nutrients into the soil in reserve, followed by irrigation with tap water with a pH of 5.0. Seedlings were grown in a vegetation chamber with adjustable parameters: daytime air temperature +24...+26, at night + 18...+20 degrees Celsius, illumination - 7 klx. A hydroponic solution was used (modified medium for tomatoes according to Aliev E.A.). Watering was carried out by the method of drainage flooding. It was found that the peat substrate provided the best development of seedlings - the plants were characterized by a greater wet weight (+4.91 g), height (+14 cm), leaf area (+148.1 square centimeters). High alkalization of vermiculite substrate from pH 5.95 to 8.14 was revealed. Better growth of sweet pepper seedlings was ensured by constant acidification of the nutrient solution to 4.0 pH, as well as preliminary phosphating of the substrate and subsequent cultivation at 5.0 pH of the nutrient solution. Preliminary phosphating of the vermiculite substrate resulted in an increase of leaf area by 115.5 square cm, wet biomass - by 5.38 g. Acidifying of the nutrient solution to 4.0 pH had a similar beneficial effect on pepper seedling growth.

Lignite Substrate and EC Modulates Positive Eustress in Cucumber at Hydroponic Cultivation

Hydroponic cultivation using organic, fully biodegradable substrates that provide the right physical properties for plant growth and development is now the future of soilless production. Despite the high productivity and strict control of production conditions in this method, excessive salinity of the substrate often occurs. However, recent research results indicate that salinity at a high enough threshold can improve yield quality, while prolonged exposure to too high EC, or exceeding the safe EC threshold for a given species, leads to reduced quality and reduced or even no yield. The aim of this study was to determine the effect of biodegradable lignite substrate (L) and eustressor in the form of high EC nutrient solution (7.0 dS·m−1) on morphological and physiological parameters, as well as the quality and yield of cucumber (Cucumis sativus L.) in hydroponic cultivation compared to the mineral wool substrate (MW). The MW/high EC combination showed a significant reduction in shoot diameter by nearly 6% compared to the MW/control EC combination. The stomatal conductance (gs) and the transpiration rate (E) were also significantly reduced in this combination. The present study indicates that the effects of eustressor application vary depending on the growing medium used, and more favorable effects in terms of yield quality were obtained using biodegradable lignite substrate. The high EC of nutrient solution combined with lignite substrate (L/high EC) significantly increased in cucumber fruit the content of β-carotene, lutein, chlorophyll a, chlorophyll b and the sum of chlorophyll a + b by 33.3%, 40%, 28.6%, 26.3% and 26.7%, respectively, as compared to MW/high EC combination.

Novel Graphene Wool Gas Adsorbent for Volatile and Semivolatile Organic Compounds.

Volatile and semivolatile organic compounds in ambient air and occupational settings are of great concern due to their associated adverse human health and environmental impacts. Novel graphene wool samplers have been developed and tested to overcome limitations of commercially available sorbents that can only be used once and typically require solvent extraction. Graphene wool (GW) was synthesized by non-catalytic chemical vapor deposition with optimized conditions, resulting in a novel fibrous graphene wool that is very easy to manage and less rigid than other forms of graphene, lending itself to a wide range of potential applications. Here, the air pollutant sampling capabilities of the GW were of interest. The optimal packing weight of GW inside a glass tube (length 178 mm, i.d. 4 mm, o.d. 6 mm) was investigated by the adsorption of vaporized alkane standards on the GW, using a condensation aerosol generator in a temperature-controlled chamber and subsequent detection using a flame ionization detector. The optimized GW packing density was found to be 0.19 mg mm–3 at a flow rate of 500 mL min–1, which provided a gas collection efficiency of >90% for octane, decane, and hexadecane. The humidity uptake of the sampler is less than 1% (m/m) for ambient humidities <70%. Breakthrough studies showed the favorable adsorption of polar molecules, which is attributed to the defective nature of the graphene and the inhomogeneous coating of the graphene layers on the quartz wool, suggesting that the polar versus non-polar uptake potential of the GW can be tuned by varying the graphene layering on the quartz wool substrate during synthesis. Oxidized domains at the irregular edges of the graphene layers, due to a broken, non-pristine sp2 carbon network, allow for adsorption of polar molecules. The GW was applied and used in a combustion sampling campaign where the samplers proved to be comparable to frequently used polydimethylsiloxane sorbents in terms of sampling and thermal desorption of non-polar semivolatile organic compounds. The total alkane concentrations detected after thermal desorption of GW and PDMS samplers were found to be 17.96 ± 13.27 and 18.30 ± 16.42 μg m–3, respectively; thus, the difference in the alkane sampling concentration between the two sorbent systems was negligible. GW provides a new, exciting possibility for the monitoring of organic air pollutants with numerous advantages, including high sampling efficiencies, simple and cost-effective synthesis of the thermally stable GW, solvent-free and environmentally friendly analysis, and, importantly, the reusability of samplers.

Study of the Dyeing Properties of Annatto and Ultrafiltrated Annatto as Colourants for Natural Fibres

ABSTRACT Cotton and wool fabrics have been dyed in the absence of mordants with annatto and ultrafiltrated annatto powder. Τhe optimum dyeing conditions were determined as far as the quantity of salt and dyebath pH are concerned. The dyeing properties of annatto and ultrafiltrated annatto were studied by monitoring the dye uptake in various time intervals and temperatures of dyeing. The adsorption isotherms for both annatto and ultrafiltrated annatto were studied. It was found that adsorption of annatto on cotton follows a BET-type adsorption isotherm indicating a multilayer formation of molecules onto cotton, whereas the adsorption of ultrafiltrated annatto follows a Freundlich-type monolayer adsorption. Adsorption of both annatto and ultrafiltrated annatto on cotton occurs through the formation of Van der Waals forces between annatto molecules and cotton substrate. The adsorption on wool of both annatto and ultrafiltrated annatto follows a Freudlich-type adsorption isotherm indicating a monolayer formation occurring between the positively-charged wool substrate and the negatively-charged annatto molecules. The dyeing behavior of natural annatto resembles that of the synthetic direct and acid dyes commonly applied for dyeing cotton and wool. Thus, annatto and ultrafiltrated annatto can successfully replace the synthetic yellow dye component in the dyeing of cotton and wool fibers.

Natural Dyeing of Cellulose and Protein Fibers with the Flower Extract of Spartium junceum L. Plant.

In this study, the natural dye was extracted from Spartium junceum L. (SJL) flowers and applied on cellulose (cotton) and protein (wool) fabric. Fabrics were pre-mordant with alum prior to the dyeing process. Considering the global requirements on zero waste and green policy, the dyeing process was intended to be as much as possible environmentally friendly but still effective. Therefore, mordant concentration was optimized due to the reduction of the negative impact. The efficiency of the dyeing process was investigated by examination of fabrics’ color characteristics and colorfastness to washing properties. In this paper, we have proved that the extracted dye from Spartium junceum L. is an acidic dye (mordant dye) which is more applicable for the treatment of wool fabrics. In this paper, it was proved that phytochemicals responsible for coloring are part of the flavonoids group. The UV absorption spectra of extracted dye show 4 bands in the region of λmax 224, 268, 308 and 346 nm which are ascribed to bands characteristic for flavonoids. Wool fabric pre-mordant with 3% alum and dyed shows great chromatic (C*) properties where C* value is in a range from 47.76 for unwashed samples to 47.50 for samples after 5 washing cycles and color hue (h°) is in a range 82.13 for unwashed samples to 81.52 for samples after 5 washing cycles. The best result regarding the colorfastness properties is shown by the wool sample treated with 3% alum after 5 washing cycles (total difference in color (Delta E*) = 0.87). These results confirm that metal (Al) from alum mordant make strong chemical bonds with wool substrate and dye since Delta E* values decrease in comparison to Delta E* values of the cotton samples treated the same way. The results revealed it is possible to reduce the concentration of mordant up to 3% and obtain satisfactory results regarding the colorfastness. Nevertheless, future research will go in the direction of replacing synthetic mordant with a more environmentally friendly one.

Growth, Yield and Quality of Sweet Pepper Fruits Fertilized with Polyphosphates in Hydroponic Cultivation with LED Lighting

The aim of this study was to investigate the effect of phosphorus application in the form of polyphosphates on the yield and quality of sweet pepper fruits grown with LED (light-emitting diodes) assimilation lighting. Phosphorus is absorbed by the root system of plants mainly in the form of orthophosphates ions. The availability of phosphorus depends, among other things, on the pH of the substrate and the temperature. Two cultivars of sweet pepper with red fruits were tested in hydroponic cultivation on a mineral wool substrate. The plants were fertilized with one of three schedules, each of the same concentration of components, but differing only in the form of the applied phosphorus: polyphosphates (PP) and orthophosphates (OP). In the experiment, stem length extensions and number of leaves, chlorophyll concentration in leaves and fluorescence of the chlorophyll in a leaf were measured. The number and weight of fruits in total as well as marketable and non-commercial fruits with symptoms of dry rot (BER—blossom end rot) were studied. The concentration of dry matter and selected chemical components in fruits were examined and the sensory quality of fruits was evaluated using the QDA (Quantitative Description Analysis) method. The nutrient status of the pepper plants was also examined. Polyphosphates used in the medium increase the activity of photosynthetic apparatus of leaves and have a positive effect on the share of marketable yield of the total yield in the cultivar susceptible to BER. Fertigation in hydroponic cultivation with medium containing 30% phosphorus in the form of polyphosphates increased the uptake of calcium in pepper plants growing with LED lighting. The pepper cultivars tested differ in, among other things, the susceptibility to BER and the quality attributes of the fruit.