Durability of alternative cementitious binders

Over the past few decades, various alternative binders have been developed and explored, as result of growing global pressure to reduce greenhouse gas emissions and energy use related to Portland cement production. However, wider commercial adoption of the new binders is often hindered by the lack of data on their long-term properties and durability. During their lifetime, binder materials come in contact with various aggressive solutions or conditions with deteriorating effects. Durability assessment of alternative binders is complicated by wide variety of their compositions and lack of standardized procedures, as test parameters used to determine durability of Portland cement are not always suitable for the newly developed binders. In this work, an overview of the testing procedures used and the results obtained when alternative binders, such as alkali activated materials and high volume fly ash binders, were subjected to various aggressive solutions, will be given

An Estimate of Penetration Depth of Rigid Rods Through Materials Susceptible to Microcracking: Part 2 – Validation and Parameter Sensitivity

A simple, approximate model aimed at estimating the penetration depth of slender rigid projectiles into massive targets made of quasibrittle solids is proposed in the companion article [1]. The key ingredient for that novel analytical approach—namely, the functional dependence of the radial traction at the cavity surface on the radial velocity of the cavity expansion—is provided by postprocessing of results of particle dynamics simulations. In this article, this model is validated using experimental results on the depth of penetration of long (virtually rigid) projectiles into Salem limestone targets. Salem limestone is a typical example of quasibrittle materials with random, discontinuous and heterogeneous micro/meso structure, inherently predisposed to microcracking, which is attributed to their inferior tensile strength. Such materials are known for their pronounced scatter of experimental data. This inherent stochasticity is explored in this paper through a comparative analysis of key model input parameters; primarily, the indirect (uniaxial) tensile strength and the coefficient of friction

Changes in sesquiterpene lactones levels in lettuce due to biofertiliser application and their impact on taste

Sesquiterpene lactones play various roles in plants, including allelopathy, antimicrobial activity, and protection against stressors. Higher concentrations of lactones are found in milky latex compared to leaves. Lactones contribute to the bitter taste of lettuce, balance human nutrition, and offer pharmaceutical benefits. This study aimed to examine the effect of biofertilisers on the sesquiterpene lactones content and overall taste of lettuce. Six Rijk Zwaan lettuce cultivars ('Kiribati', 'Murai', 'Aquino', 'Gaugin', 'Aleppo', and 'Carmesi') were grown in fertile soil using two biofertilisers (EM Aktiv and Vital Tricho), and a combination of the two during three successive growing seasons (autumn, winter, and spring). Preliminary UPLC-MS analysis of latex collected in autumn from all cultivars showed the presence of lactucin, deoxylactucin derivate, lactucopicrin, and lactucopicrin oxalate, with the lactucopicrin derivate being the prevailing form of sesquiterpene lactones. Concerning edible parts, the red cultivar 'Carmesi' exhibited the highest level of lactucopicrin (0.37 mg/g DW), with lactucopicrin being the predominant lactone in the autumn trial. Applying EM Aktiv and Vital Tricho alone resulted in significantly higher dihydrolactucopicrin content, while the combination of the two fertilisers led to significantly enhanced levels of all lactones. The results of the sensory analysis showed an overall taste score of 2.83-3.08 using a five-way hedonic scale. Cultivar and biofertiliser did not affect the overall taste, while a more pleasant taste was reported in winter/spring trials. Correlation coefficients revealed a negative impact of higher levels of lactucopicrin on overall taste (r=-0.16*), suggesting a less bitter taste was associated with a lower concentration of this compound. Three-way ANOVA showed that the cultivar, fertiliser, and season jointly affected all of the tested parameters, indicating the need to consider multiple factors. Our findings are significant for applied and sustainable agriculture, showing that biofertilisers can affect lactones content and, at the same time, contribute to consumer acceptance of different cultivars regarding taste

Interclonal Variation in Heavy Metal Accumulation Among Poplar and Willow Clones: Implications for Phytoremediation of Contaminated Landfill Soils

In this study, five poplar clones (Populus deltoides cl. PE19/66, cl. S1-8, cl. 135/81, and Populus × euramericana cl. I-214, cl. Pannonia) and two white willow clones (Salix alba cl. 380, cl. 107/65-9) were tested in pot trials. The aim was to evaluate their potential for phytoextraction of nine heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in three substrates, two based on soil from landfills near Belgrade and Novi Sad, and one control treatment based on nursery soil. The shoot content of all analyzed heavy metals was the highest in the BG substrate with the highest content of heavy metals and the lowest in the control substrate. White willow clone 107/65-9 achieved the highest accumulation of Cd, Cr, Fe, Ni and Pb and along with another willow clone 380 is found to act as generalists. Poplar clones performed more as specialists: I-214 and Pannonia for copper, PE 19/66 for manganese and S1-8 for nickel and zinc. Considerable differences among examined clones in heavy metal accumulation and reaction to substrates should be taken into consideration in further pot and field trials as well as in phytoremediation projects on landfills

Multifunctional reusable Ag-decorated ZnO nanostructured photocatalyst obtained by green synthesis

This work examined an environmentally friendly precipitation method for preparing zinc oxide decorated with silver using chitosan as a non-toxic reducing agent. The obtained powders were characterized in detail by XRPD, FESEM, HRTEM/SAED, PSD, and UV–VIS techniques. Ag/ZnO samples contained wurtzite spherical nanoparticles with an average crystallite size of about 25 nm and cubic Ag distributed on the surface. Compared to the unmodified ZnO, modification with Ag increased absorption of the visible light regarding the formation of additional charge carriers, i.e. hot electrons, due to the surface plasmon resonance effect. The recyclable Ag/ZnO photocatalyst with an optimal content of 1.5 mol. % of Ag, was successfully applied under simulated solar light for the degradation of four industrial dyes: Reactive Orange 16, Mordant Blue 9, Acid Green 25, and Ethyl Violet. High repeatability and reproducibility were confirmed. The kinetics and full mechanism of the photodegradation process through the simultaneous and synergistic influence of light-harvesting Ag and ZnO were also suggested

The intra-Mesozoic bauxite-bearing truncations of the peri-Neotethyan realm (Dinarides/Vardar Zone): A multidisciplinary approach shedding new light on the Neocimmerian event

Once coupled with global eustatic levels, bauxites, breccias, unconformities, and hiatuses are significant markers of compressional geodynamics. Most Balkan intra-Mesozoic bauxites, embedded within widespread Triassic carbonate parental sequences, are dominantly distributed in the tectonically exhumed broader Neotethyan realm (Dinarides s.l.). The same mid-Mesozoic stratigraphic interval within the Vardar Zone contains fewer bauxites (East Vardar Zone), exposing abundant corresponding depositional truncations, with occasional nappe stacking configuration and metamorphism. This study, which initially acquired data from a large number of mid-Mesozoic unconformities, carbonate breccias, and similar age bauxites spreading across Dinarides s.l., Serbia, Bosnia and Herzegovina, Montenegro, Croatia (Inner and External Dinarides, Western and East Vardar Zone), including Hellenides in Greece, has provided valuable paleogeographic and geodynamic insights. The findings of this study, combined with the available mineralogical and geochemical data, deformation, including the resulting provenances of intra-Mesozoic bauxite deposits, have led to a complex and intriguing discussion on the tectonic origin of similar age unconformities across Dinaride-Hellenide and Vardar Zone Neotethyan regions. These Dinaride-Hellenide intra-Mesozoic unconformities, carbonate breccias, and widespread bauxites are a fascinating puzzle as no study deals with the complex and controversial processes of repeated regional-scale uplifts, erosion, and bauxite formation. The ambiguity revolves around the geodynamic origin of the Jurassic ophiolites in the first place and its connection with mid-Mesozoic Cimmerian orogenic events (Neocimmerian stage). Thus, the Triassic – Jurassic(Lower Cretaceous) Inner Dinaride Ophiolite belt is particularly interesting accounting for the absence of the latest Jurassic – earliest Cretacous stratigraphic interval. Many of the bauxite ores are produced on Middle Triassic to Jurassic parental limestones, whereby the hiatus can last until the beginning of the Upper Cretaceous. The Triassic rifting and opening of “Dinaric Tethys”, which likely caused the pre-Neocimmerian Late Triassic shoulder uplift of early passive margins, continued into the Jurassic mid-oceanic spreading. The Triassic and Jurassic-aged zircon grains in bauxites, including new data extracted from the bauxite geochemical database, corroborate a volcanic parental affinity originating from exposed Jurassic volcanic rocks. The new geochemical analysis allowed the separation of ultramafic from mafic bauxite sources, whereby acidic sources are absent or well hidden within Inner Dinarides. Bauxite deposits at the southern edge of the Inner Dinaride area show an abundance of incompatible Mn, demonstrating a significant transgressional Oxfordian eustatic high-stand episode (precipitation of Mn on top of submerged paleokarst/bauxites). This, a Red Sea-type small ocean basin with a NE-vergent suprasubduction (“Dinaric Tethys”), lasted until the end of the Jurassic (also dated by metamorphic imprints). The tectonic exhumation processes of Inner Dinaride ophiolites involving the Neocimmerian compressive event caused the widespread uplift episode in the latest Jurassic – earliest Cretaceous, occasionally lasting until the Albian (Austrian unconformity). As a result, mid-Mesozoic long-lasting hiatuses allowed intense weathering of numerous uplifted parental limestone sites, frequently producing at least two cycles of laterites and bauxite ores. The Neocimmerian episode includes the limited length (shorter cross-lithospheric across-strike width) of the latest Jurassic ophiolite obduction on top of abutting continental crust, inclusive of the onset of Lower Cretaceous Vranduk turbidites (another marker of the closing “Dinaric Tethys”)

Middle Miocene syn-rift sequence on the central Gulf of Suez, Egypt: Depositional environment, diagenesis, and their roles in reservoir quality

The middle Miocene sediments, a key oil reservoir within the syn-rift structures of the Gulf of Suez, have received limited research attention despite their geological importance. To bridge this gap, we analyzed well cores and petrophysical data from the middle Miocene sandstone-shale sequence (Sidri Member) in the Belayim field, one of Egypt’s major oil fields, to assess the depositional and diagenetic characteristics and evaluate reservoir quality. It is subdivided into three sandstone units separated by calcareous shale interbeds. The units show distinct lateral and vertical distribution, reflecting an upward change in depositional environment, transitioning from shoreface, deltaic condition, to embayment settings, interrupted by shale deposition during transgression episodes. The sediments originated from uplifted and tilted rift margins along NW-SE trending faults. During the syn- to post-rift burial to depths exceeding 2.5 km, diagenetic processes, including compaction, dissolution, and cementation, altered the sandstones’ primary properties, resulting in significant petrophysical variations. Porosity reaches up to 30% in well-sorted, medium-grained sandstones with dissolution, corresponding to bulk density as low as 2.1 g/cm3 and permeability up to 1000 mD, while cementation reduced porosity in certain intervals, creating heterogeneity in grain density and permeability. Reservoir quality of the sandstones ranges from poor to excellent with variable oil saturation. Notably, the lower sandstone unit, located within an anticline structure, displays good to excellent quality and up to 70% oil saturation. These findings highlight the influences of syn-rift dynamics in shaping the middle Miocene sequence and the potential for optimizing hydrocarbon exploration and production strategies across the region

Synthesis and Characterization of Cross-linked Poly(N-(2-hydroxyethyl)acrylamide)

The monomer N-(2-hydroxyethyl)acrylamide is used in many investigations for the synthesis of various copolymers, e.g. block- or graft- copolymers. Polymers based on this monomer have been widely investigated, e.g. as capillary adsorbed coatings, for stimuli-sensitive polymer synthesis, in bioengineering research, for adhesive hydrogels. They have good biocompatibility, stability and durability. This study describes the process of the synthesis of homopolymer hydrogels based on monomer N-(2-hydroxyethyl) acrylamide by the free radical polymerisation method with thermal initiation using 1,2-ethanediol dimethacrylate as a crosslinker. The polymerization process was initiated by 2,2‘-azobis(2-methylpropionamidine) dihydrochloride. The cross-linked homopolymer poly(N-(2-hydroxyethyl)acrylamide) hydrogels were structurally characterized after the purification of unreacted reactants. Structure characterization of the obtained homopolymer was performed using the Fourier transform infrared spectroscopy (FTIR). Analysis of the obtained FTIR spectra confirmed that the polymerization process was successfully completed, by breaking the double bonds from the N-(2-hydroxyethyl) acrylamide and the 1,2-ethanediol dimethacrylate, which resulted in the formation of a new crosslinked homopolymer products. Hydration capacity of synthesised homopolymer hydrogels was examined in the function of pH values and temperatures. Based on the obtained results, these homopolymer hydrogels show great potential for further research opportunitiesand new applications

Pregled cinka u zemljištu i zrnu pšenice u Srbiji – postoji li rizik od nedostatka cinka u ishrani baziranoj na pšenici?

Zinc (Zn) soil deficiency negatively affects crop yields and the quality of staple food globally. Soil Zn availability is declining due to soil conditions and is further impacted by factors such as agricultural practices, especially the use of phosphorus fertilizers, which can reduce Zn uptake in wheat. As a result, wheat grain often contains low Zn levels, and its bioavailability is limited, contributing to insufficient Zn intake through wheat-based foods. This review focuses on plant-available Zn status in soils, Zn in wheat grains, and the human population in Serbia, emphasizing the connections between these issues. Data on soils with low available Zn, rather low Zn in wheat grain and general lack of results on Zn concentration in crop plant tissues and application of Zn fertilizers suggest that further research is needed to evaluate nutritional status of wheat plants for Zn. Existing data suggest that Zn deficiency in humans could be a concern in Serbia, especially with dietary shifts toward more plant-based diets. Given the high consumption of wheat in the country, biofortification presents a promising and solution to improve Zn levels in wheat grain in a sustainable way. Agronomic biofortification, through application of soil and foliar Zn fertilizers can enhance Zn concentration in wheat grain and improve human nutrition, thus reducing the risk of deficiency in the population.Nedostatak cinka u zemljištu negativno utiče na prinos i kvalitet osnovnih prehrambenih namirnica širom sveta. Dostupnost cinka biljkama u zemljištu opada pod uticajem različitih faktora, najpre osobina zemljišta, a može biti dodatno smanjena faktorima poput agrotehničkih mera, naročito primenom fosfornih đubriva, što može da dovede do toga da usevi kao što je pšenica slabije usvajaju cink. Zbog toga je koncentracija cinka u zrnu pšenice često niska, a njegovu biološku raspoloživost u organizmu dodatno ograničavaju različiti faktori, što doprinosi nedovoljnom unosu cinka ishranom. U fokusu ovog preglednog rada su koncentracija dostupnog Zn u poljoprivrednom zemljištu, nivo cinka u zrnu pšenice i njegov značaj za zdravlje ljudi u Srbiji, sa posebnim osvrtom na vezu između ovih aspekata. Podaci o zemljištima sa niskim sadržajem dostupnog Zn, relativno niskim nivoima Zn u zrnu pšenice, kao i opšti nedostatak rezultata o koncentraciji Zn u tkivima gajenih biljaka i o primeni cinkovih đubriva, ukazuju na potrebu za daljim istraživanjima kako bi se procenio nutritivni status pšenice u pogledu Zn. Budući da je potrošnja pšenice u Srbiji velika, postojeći podaci sugerišu da deficit cinka kod ljudi može biti značajan problem, naročito zbog trenda prelaska na ishranu sa više biljnih namirnica. Agronomska biofortifikacija, proces tokom kog se đubriva unose u zemljište ili se primenjuju folijarno, predstavlja efikasno rešenje za povećanje nivoa cinka u zrnu pšenice i može doprineti boljoj ishrani ljudi, smanjujući rizik od njegovog nedostatka u populaciji

Bioactivity of the Tree of Heaven Leaf Extracts Incorporated into Biopolymer Matrix Against Spongy Moth Larvae

The bioactivity of the Ailanthus altissima crude leaf extract (CLE) and a leaf extract incorporated into a biopolymer matrix (BPM) was tested against Lymantria dispar larvae. The crude leaf extracts and those incorporated into a chitosan–gelatin polymer matrix were examined in choice and non-choice assays at 0.01, 0.05, 0.5, and 1% concentrations for feeding deterrent activity, contact, and digestive toxicity. The CLE exhibited moderate deterrent activity at all concentrations, whereas the BPM showed a very strong deterrent effect at 0.5% and 1% and a strong effect at 0.1% and 0.01%. No significant differences in digestive or contact toxicity were observed between the CLE and BPM groups and the control groups. The BPM also influenced larval behavior after digestion, decreasing consumption and growth and increasing development time. The higher bioactivity of the CLE compared to the control group is attributed to its high content of total phenols, flavonoids, and tannins, whereas the enhanced bioactivity of the BPM is due to its incorporation into the biopolymer matrix. Given its very strong deterrent activity, and absence of contact and digestive toxicity, the BPM can be recommended as a potential environmentally friendly bioproduct for forest pest control after field evaluation