moisture content
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The investigation of the effect of moisture on the release and enrichment of heavy metals during pyrolysis of municipal solid waste is essential. This is important owing to: (i) the increasing amount of metals in the solid product of pyrolysis beyond the normalised level; (ii) the effect of moisture on the overall cost of pyrolysis process; and (iii) the utilisation of pyrolysis products. Seven metals were selected for evaluation: arsenic, cadmium, chromium, mercury, nickel, lead, and vanadium. Pyrolysis experiments were conducted in a steel retort at 650 °C. The municipal solid waste samples with moisture contents of 0, 30, and 65 wt% were investigated. The relative enrichment index and release of heavy metals were evaluated individually for liquid and solid fractions. A consistent trend was observed for the majority of metals investigated. Reductions of relative enrichment index and release, i.e. an increase of volatility, were observed for arsenic, chromium, cadmium, nickel, and vanadium, with an increase of municipal solid waste moisture. Whereas divergent results were obtained for lead and mercury. The effect of moisture on the relative enrichment index and release was greater at 65 wt% moisture than at 30 wt% for lead, and more remarkable at 30 wt% than at 65 wt% for mercury.
- MeSH
- arsen chemie MeSH
- spalování odpadů * MeSH
- těžké kovy chemie MeSH
- tuhý odpad analýza MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Experimentální studie sledovala vlastnosti bukálních mukoadhezivních filmů (tloušťka, hmotnost, hmotnostní stejnoměrnost aobsah vlhkosti ve filmech) připravených metodou odpařování rozpouštědla. Filmy obsahovaly buď jeden mukoadhezivní polymer (hyaluronát sodný odvou různých molekulových hmotnostech nebo sodná sůl karboxymethylcelulosy), případně kombinaci uvedených polymerů. Jako nejdůležitější parametr hodnocení filmů se zvolil obsah vody v bukálních mukoadhezivních filmech. Obsah vody byl ovlivněn jak molekulovou hmotností hyaluronátu sodného, tak také poměrem jednotlivých mukoadhezivních polymerů ve složení bukálních filmů. Složení filmů ovlivňuje také ostatní kvalitativní parametry filmů.
Characteristics of the buccal mucoadhesive films (film thickness, film weight, uniformity of mass and moisture content) prepared by solvent casting method were tested in this experimental study. The formulations consisted either of one mucoadhesive polymer (sodium hyaluronate of two different molecular weights and sodium carboxymethylcellulose) or combinations thereof. On the basis of the aforementioned tests, it was determined that water content was influenced by the molecular weight of sodium hyaluronate as well as by the ratio of mucoadhesive polymers in the composition. The composition of the films influences also other tested parameters.
BACKGROUND: Chickpea (Cicer arietinum L.) is a widely cropped pulse and an important source of proteins for humans. In Mediterranean regions it is predicted that drought will reduce soil moisture and become a major issue in agricultural practice. Nitrogen (N)-fixing bacteria and arbuscular mycorrhizal (AM) fungi have the potential to improve plant growth and drought tolerance. The aim of the study was to assess the effects of N-fixing bacteria and AM fungi on the growth, grain yield and protein content of chickpea under water deficit. RESULTS: Plants inoculated with Mesorhizobium mediterraneum or Rhizophagus irregularis without water deficit and inoculated with M. mediterraneum under moderate water deficit had significant increases in biomass. Inoculation with microbial symbionts brought no benefits to chickpea under severe water deficit. However, under moderate water deficit grain crude protein was increased by 13%, 17% and 22% in plants inoculated with M. mediterraneum, R. irregularis and M. mediterraneum + R. irregularis, respectively. CONCLUSION: Inoculation with N-fixing bacteria and AM fungi has the potential to benefit agricultural production of chickpea under water deficit conditions and to contribute to increased grain protein content. © 2017 Society of Chemical Industry.
- MeSH
- Bacteria růst a vývoj MeSH
- Cicer chemie růst a vývoj metabolismus mikrobiologie MeSH
- dusík metabolismus MeSH
- fyziologie bakterií * MeSH
- houby růst a vývoj fyziologie MeSH
- mykorhiza fyziologie MeSH
- očkovadla agrotechnická fyziologie MeSH
- rostlinné proteiny analýza metabolismus MeSH
- symbióza MeSH
- voda analýza metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
Sorption isotherms of elecampe (Inula helenium L.) and burdock (Arctium lappa L.) root samples were obtained at 25 °C. Elecampe exhibited hysteresis loop in the range of 0.35-0.90 a(w) , whereas burdock roots showed significant differences between adsorption and desorption isotherms from 0.65 to 0.80 a(w) . Blahovec-Yanniotis was considered to give the best fit over the whole range of a(w) tested. Various parameters describing the properties of sorbed water derived from GAB, Henderson and Blahovec-Yanniotis models have been discussed. Differential scanning calorimetric method was used to measure the glass transition temperature (T (g)) of root samples in relation to water activity. The safe moisture content was determined in 12.01 and 14.96 g/100 g d. b. for burdock and elecampe root samples at 25 °C, respectively. Combining the T (g) line with sorption isotherm in one plot, it was found that the glass transition temperature concept overestimated the temperature stability for both root samples.
- MeSH
- adsorpce MeSH
- Arctium chemie MeSH
- chemické jevy MeSH
- diferenciální skenovací kalorimetrie metody MeSH
- Inula chemie MeSH
- kořeny rostlin chemie MeSH
- skladování potravin metody MeSH
- teoretické modely MeSH
- tranzitní teplota MeSH
- voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
BACKGROUND: There is a general requirement to determine and correlate water content to viability for the standardization of conservation protocols to facilitate effective cryostorage of plant germplasm. OBJECTIVE: This study examined water content as a critical factor to optimize the cryostorage of Allium sativum. MATERIALS AND METHODS: Stem discs were excised from post-harvest, stored bulbs prior to cryopreservation by encapsulation-dehydration and water content was determined gravimetrically. RESULTS: Survival of cryopreserved stem discs was 42.5 %, with 22.5 % exhibiting shoot regrowth following 6 h desiccation. Gravimetric data demonstrated a correlation between water content corresponding with survival / regrowth from desiccated, cryopreserved stem discs. For encapsulated stem discs a 25 % residual moisture and corresponding water content of 0.36 g H2O g(-1) d.wt correlated with maximal survival following ~6.5 h of desiccation. CONCLUSION: The data concurs with the literature suggesting the formation of a stable vitrified state and a 'window' for optimal survival and regrowth that is between 6 - 10 h desiccation. Further studies using differential scanning calorimetry (DSC) are suggested to substantiate these findings.
Dry skin is a common condition that is experienced by many. Besides being particularly present during the cold season, various diseases exist all year round, leading to localized xerosis. To prevent it, the skin is provided with natural moisturizing factors (NMFs). They are small amino acids or derivatives found in the outermost layer of the skin, the stratum corneum (SC). They are often claimed to be highly efficient humectants, increasing the water content to maintain the fluidity of the skin. However, alternative mechanisms have been proposed, suggesting that NMFs themselves may act as lipid mobility amplifiers. This work aims at investigating the role of three NMFs, namely, urea (URE), glycerol (GLY), and urocanic acid/urocanate (UCA/UCO) in SC in silico models, considering two different levels of humidity. Molecular dynamic simulations showed an increase in the diffusion of different lipid components, mainly free fatty acids (FFAs) and ceramide acyl chain moieties, in the presence of either high water content or NMFs. The membrane properties were modified, as seen by an increased thickness and greater lateral stiffness. All NMFs exhibited a similar impact, whereas UCA revealed slight differences according to its charged state. By studying NMF-water intermolecular interactions, we highlighted the role of NMF as a regulator of membrane perturbations while ensuring membrane fluidity. This role allows NMFs to prevent destabilization of the skin membrane in the presence of high water content. This study, performed at an atomistic resolution, highlighted a strong H-bond network between lipids involving mainly ceramides but also all other components. This network can be modified in the presence of a high water concentration or NMFs, resulting in modifications of membrane properties, rationalizing hydration effects.
- MeSH
- glycerol * chemie MeSH
- kůže * chemie metabolismus MeSH
- kyselina urokanová chemie metabolismus MeSH
- lidé MeSH
- močovina * chemie MeSH
- simulace molekulární dynamiky * MeSH
- voda * chemie MeSH
- vodíková vazba * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Spent coffee ground (SCG) is an environmental nuisance material, but, if appropriately processed it can be converted into pellets, and thus, used as an energy source. The moisture content of the final product should be below 10%, to ensure safe storage, and elimination of microorganism growth (particularly moulds). The present study aims to identify the optimal drying process for removing moisture from SCG and to investigate changes to the composition of SCG due to drying, at temperatures around 75 °C, so that the dried SCG to qualify as renewable energy source. Three drying processes were employed for SCG drying (with initial moisture content of about 65%): oven drying, solar drying and open air sun drying, while SCG samples were placed in aluminium trays with thicknesses of 1.25, 2.5 and 4 cm. Based on the experimental results for SCG samples with thickness 2.5 cm, the open air sun drying process required 10 h to reach final moisture content of 37%, while solar drying achieved 10% moisture content in 10 h and oven drying achieved 7% moisture content in 6 h. The solar drying process proved as the most advantageous, due to low energy requirements and adequate quality of dried SCG. Also, experiments indicated that SCG storage at "normal room conditions" resulted to equilibrium moisture content in SCG of 8%, regardless of the initial moisture content. Furthermore, instrumental analyses of the SCG, revealed changes to its composition for a number of chemical groups, such as aldehydes, ketones, phytosterols, alkaloids, lactones, alcohols, phenols, pyrans and furans, among others. It was also identified that the SCG colour was affected due to the drying process.
- MeSH
- fenoly MeSH
- káva * MeSH
- obnovitelná energie MeSH
- teplota MeSH
- vysoušení * MeSH
- Publikační typ
- časopisecké články MeSH
One of the complications of "diabetes mellitus" is termed diabetic foot syndrome, the first symptoms of which include changes in the skin's condition and properties. The skin becomes dehydrated, dry, and prone to excessive formation of the horny layer, its barrier function becoming weakened. This function can be restored by applying suitable cosmetic excipients containing active substances. The aim of this study was to evaluate and compare the effects of commercially available cosmetic products (CPs) designed for the care of diabetic foot, through a group of selected volunteers using noninvasive bioengineering methods. Statistical surveys (p < 0.05) evaluated these CPs as regards to their hydration effect and barrier properties. Special attention was devoted to CPs with the declared content of 10% urea, and that the influence of this preparation's ability to hydrate and maintain epidermal water in the epidermis was confirmed.
- MeSH
- aplikace kožní MeSH
- diabetická noha patologie MeSH
- dospělí MeSH
- epidermis účinky léků metabolismus patologie MeSH
- glycerol aplikace a dávkování chemie MeSH
- kosmetické přípravky aplikace a dávkování chemie MeSH
- kožní absorpce MeSH
- lidé středního věku MeSH
- lidé MeSH
- močovina aplikace a dávkování chemie MeSH
- permeabilita MeSH
- pomocné látky aplikace a dávkování chemie MeSH
- voda metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Orodispersible films are an innovative dosage form. Their main advantages are the application comfort and the possibility of personalization. This work aimed to evaluate the influence of different drying times on the properties of orodispersible films of various thicknesses, prepared in two different semisolid extrusion 3D printing setups. In the first experiment, drying times were dependent on the overall print time of each batch. In the second setup, the drying time was set equal according to the longest one. The evaluated parameters were films' weight uniformity, thickness, moisture content, surface pH, disintegration time, hardness, and tensile strength. Upon statistical comparison, significant differences in the moisture content were found, subsequently affecting the disintegration time. Moreover, statistically significant differences in films' mechanical properties (hardness, tensile strength) were also described, proving that moisture content simultaneously affects film plasticity and related properties. In conclusion, a mutual comparison of the manufactured orodispersible films showed that the drying time affects their physical and mechanical properties. The in-process drying setup was proved to be sufficient while allowing quicker manufacturing.
- Publikační typ
- časopisecké články MeSH
