Wet Ashing Research Articles

Application ICP-OES to Multielement Analysis on Plastic Waste and Blends with Vacuum Gas Oil: Developing a Sample Preparation Protocol

This paper introduces a new methodology for a routine metal analysis of plastic waste (PW) and PW blended with petroleum feedstock such as vacuum gas oil and VGO (PW/VGO). For such purposes, recycled polyethylene and polypropylene plastic were selected to mimic the potential feeds to be integrated at the Fluid Catalytic Cracking unit (FCC) to produce valuable products. Elements such as P, Ca, Al, Mg, Na, Zn, B, Fe, Ti, and Si were included in the method development. Different sample preparation methods were evaluated, such as microwave-assisted acid digestion (MWAD) and dry/wet ashing, followed by a fusion of the ash with lithium borate flux. Some PW homogenization pretreatments, such as cryogenic grinding and hot press molding, were also covered. The finding of this work suggests that MWAD with HNO3 and H2O2 is adequate for both types of samples and is the quickest sample preparation; however, the sample needed to be homogenized, and recoveries for Si and Ti may be biased for PW due to the limited solubilities of these elements in the nitric acid media. Carbon removal is required before fusion sample preparation and analysis due to the amount of carbon in PW samples. The sample needed to be homogenized for wet ash fusion but not for the pre-ash (dry) method. A benefit to the damp ash pretreatment is that the ash for the sample was created in the same crucible used for fusion digestion, avoiding material loss during sample management. Fusion from wet ash or carbon removal allowed for better acid solubility for Si and Ti in PW. The results of the PW samples evaluated matched well with those of both sample preparation methodologies. For most elements, precision was <10% regardless of the sample preparation; however, Fe and P had some variation using wet ash fusion, possibly due to contamination in an open digestion system or variation due to being close to the method limit of quantification (LOQ). The methodology reported here is robust enough to be implemented as routine analysis in any laboratory facility.

Mechanical processing of wet stored fly ash for use as a cement component in concrete

Wet storage effects on fly ash mean that processing may be necessary to achieve the physical properties required for use in concrete. This paper considers drying, de-agglomeration and milling of various wet stored fly ashes at laboratory and pilot/benchtop scales, towards meeting these. In the laboratory, different batch quantities and milling times with as-received/pre-screened materials were examined using a ball mill. Greater particle size reductions were obtained with increased milling time but at gradually reducing rates. Pre-screening and batch quantity had relatively minor effects on particle size reductions, with small differences also found between wet and dry stored fly ash. Extended milling time resulted in a darkening of colour; slight increases in loss-on-ignition, the main oxides content and crystalline components; reductions in water requirement (to a point); and greater reactivity. Similar effects were generally noted in concrete for the superplasticising admixture dose to achieve a target slump and compressive (cube) strength. At pilot/benchtop scale, a dryer-pulveriser and spiral jet mill were used, which gave general agreement with the behaviour noted in the laboratory, but with the effects tending to be less. Fineness levels in Standards were achievable, with subsequent performance in concrete, appearing to depend on the milling process used.

Distribution of 210Po activity and soil texture in agricultural soil.

The assessment of 210Po in agricultural soil matrices in different regions of Kerala and Karnataka was studied. The wet ash method was used to find the activity concentration of 210Po. The alpha activity was counted using a silver-activated zinc sulfide counter of 30% efficiency, and the activity was calculated. The average concentration of 210Po activity in soil samples ranged from 0.09 to 20.52Bqkg-1, with an average value of 4.47Bqkg-1. The soil texture was measured using the International Pipette method. Using the IBM Statistical Package of Social Science Software, the frequency distribution curve of 210Po is plotted and found to be lognormal. The data of 210Po are highly skewed, and the Kurtosis has a significant positive value. The 210Po activity concentrations are substantially within the World Health Organization's recommended limits.

Volcanic jets to commercial jets: synopsis and diagnosis

Aircraft encounters with volcanic ash have caused significant damage over the past 40 years, resulting in particular attention being given to the issue. We analyzed the volcanic ash-aircraft encounter database published by the USGS. We added new volcanic eruptions and parameters such as eruption types, and dry–wet. Then, we applied standard and advanced statistical methods.Over 130 encounters have been documented in the mentioned database, with volcanic ash causing severe abrasions to the windshield, airframe, wings, and engine components. In nine cases, aircraft engines failed. We applied the binary regression analysis and some laboratory melting experiments on volcanic ash. Besides phreatomagmatism, we use the term external water in this work to describe meteoric water that enters volcanic plumes through precipitation or melting ice on ice-capped volcanoes. We demonstrated that engine failure occurs when our regression analyses undergo dry-to-wet conditions. In other words, statistically, there is a positive correlation between wet ash encounters with aircraft and engine failure incidents. Moreover, experiments conducted at 900 °C and under 40 bar pressure showed increased sintering in the dry sample, while melting textures were more prevalent in hydrated samples. We concluded that despite the various eruptive dynamics of volcanic ash, the introduction of external water into the volcanic plumes, probably causing instantaneous hydration of volcanic ash, is a common factor in engine failure incidents. Thus, we have identified the reasons behind engine failures during encounters between aircraft and volcanic ash and the specific damage that can occur depending on the type of eruption involved.

Rapid and Complete Digestion of Refractory Geological Samples Using Ultrafine Powder for Accurate Analyses of Trace Elements.

Complete sample digestion is a prerequisite for acquiring high-quality analytical results for geological samples. Closed-vessel acid digestion (bomb) has typically been used for the total digestion of refractory geological samples. However, the long digestion time (4-5 days) and insoluble fluoride complexes still pose challenges for digesting refractory geological samples using this approach. In this study, an efficient and simplified digestion technique combining ultrafine powders from planetary ball milling with bomb digestion was developed for trace element analysis of refractory geological samples: peridotite and granitoid. The method shows two significant improvements compared with previous approaches. (1) By performing dry planetary ultrafine milling, the initial 200 mesh peridotite (<74 μm) could be reduced to 800 mesh (<20 μm) in 6 min at a ball-to-powder mass ratio of approximately 15 using 3 mm tungsten carbide milling balls. (2) Complete peridotite and granitoid dissolution were achieved in approximately 2 h, 60 times faster than what is achievable using previous methods (2 h vs 120 h). Moreover, ultrafine powders effectively suppressed insoluble fluoride formation during bomb digestion. A suite of peridotite and granitoid reference materials were measured to evaluate the stability of this method. This efficient, simple, and reliable sample digestion method could benefit geological, food, environmental, and other fields requiring solid sample decomposition via wet acid, fusion, combustion, or dry ashing.

Mechanical properties and hydration of fly ash-based geopolymers modified by copper slag

Copper slag (CS) is mostly used as concrete aggregate due to its low activity, which limits its application. Although CS can exhibit high activity in geopolymer systems, the mechanical properties of high-volume CS geopolymers are still poor, which limits the utilization of CS and the application of geopolymers. In this paper, CS and fly ash (dry grinding fly ash (DFA) and wet grinding fly ash (WFA)) were used to prepare geopolymers with high-volume CS, and the effects of CS on the mechanical properties, microstructure and hydration of fly ash-based geopolymers were investigated. The results showed that the addition of CS could effectively improve the compressive strength of fly ash-based geopolymers. Compared with geopolymer samples without CS, 40 % CS can increase the 7d and 28d compressive strength of dry grinding fly ash-based geopolymers by 37.8 % and 33.6 %, respectively; 50 % CS can increase the 7d and 28d compressive strength of wet grinding fly ash-based geopolymers by 59.2 % and 49.2 %, respectively. The addition of CS can promote the formation of N(C)-A-S-H and Fe-rich gels, and then improve the mechanical properties and microstructure of fly ash-based geopolymers.

What did it used to look like? A case study from tall, wet mainland Mountain Ash forests prior to British invasion

AbstractThere has been extensive commentary about historical First Nations' land management in Australia, including in tall, wet forests, and therefore their condition at the time of the British invasion in 1788. Popular texts have interpreted records kept by early British invaders to argue that extensive areas of tall, wet forest were kept open through frequent burning by the First Peoples. However, these interpretations conflict with historical and ecological evidence, which is rarely acknowledged in public discourse. Here, we present evidence about what Victorian Mountain Ash (Eucalyptus regnans) forests were like at the time of the British invasion. We show that at the time of the British invasion, most areas of mainland Mountain Ash forests were likely to have been naturally dense and wet, with: (1) overstorey trees spaced relatively widely; and (2) an understorey consisting of a cool temperate rainforest mesic layer. Ecological and physiological evidence suggests that Mountain Ash forests evolved under conditions where high‐severity wildfire was comparatively rare, leading to patterns of landscape‐level cover dominated by relatively mature forests. This is broadly consistent with reports from the First Peoples, early historical accounts, paintings, and photographs. These forests were not open or park‐like, as may have been the case in some other Australian vegetation types. However, these forests were not wilderness, but places of significance to the First Peoples. Understanding forest structure at the time of the British invasion is critically important in establishing historical reference conditions for guiding appropriate restoration programmes, especially the reinstatement of traditional ecological knowledge, after long periods of post‐British invasion disturbance and degradation. Notably, the dense, wet understorey that characterizes Mountain Ash forests should be recognized as an inherent and entirely natural part of the ecological dynamics of this ecosystem, with approaches to thin, burn, or remove it highly likely to be counterproductive and have a range of detrimental environmental effects.

Physical-chemical composition of bean accesses Phaseolus vulgaris L. produced in the brazilian Semiarid

Beans are one of the most consumed and produced foods in Brazil, however, uncertified seeds and grains, that is, “creole” accessions, are neglected in the development of research that allows knowledge of their proximate composition and nutritional potential. The objective of this work was to evaluate and statistically compare the proximate composition of seeds when raw in three accessions of creole beans (black, white and big blue), produced in the Mesoregion of Borborema, state of Paraíba, Brazil, a region known as having great plant agrobiodiversity. The raw seeds were crushed, then evaluated for water content on a wet basis (w.b.), ash, protein, lipid and carbohydrate content. The results were subjected to analysis of variance, and the means were compared using the Tukey test (p&lt;0.05). The accessions showed statistically significant differences between them in terms of proximate composition, however, the averages evaluated were compatible with those found for bean seeds in other trials.

Carbon dioxide removal via weathering of sugarcane mill ash under different soil conditions

Sugarcane mill ash has been suggested as having high potential for carbon dioxide removal (CDR) via enhanced weathering (EW), but this had not been quantitatively assessed. The aims of this study were to 1) assess the CDR potential of various sugarcane mill ashes via EW, and 2) investigate the impact of soil conditions and mill ash properties on the CDR. This was done by characterising physical and chemical properties of five mill ashes from Australia and simulating weathering using a one-dimensional reactive transport model. The model was parameterised to simulate weathering of 100 t/ha of wet ash (47–65% water) or crushed basalt for 15 years under various combinations of soil pH and carbon dioxide partial pressure (pCO2). A sensitivity analysis was undertaken in a two-level factorial design to test the effect of pH, pH buffering, material surface area, infiltration rate, plant uptake of nutrients, organic matter cation exchange surfaces, and pCO2 on modelled CDR. The simulated CDR of the mill ashes was significantly less than the basalt (p < 0.001) but mostly did not differ significantly between ashes (p > 0.05). Weathering of mill ash removed 0.0–4.0 t CO2/ha (0.00–0.040 t CO2/t wet ash) cumulatively, similar to some basalts and olivine modelled in the literature. The theoretical maximum CDR of the mill ashes (based on amount of weatherable material applied) was achieved in around 5 years. The estimate of CDR varied by orders of magnitude depending on conditions. It was least when initial soil solution pH was lowest (4.5, unbuffered), pH was at 6.5 or less with constant buffering, and pCO2 was low (600 ppm). CDR was also significantly lower when calculated directly from accumulation of carbon in dissolved and solid phases rather than stoichiometrically from cation release. The effects of pH and pH buffering quantified here may explain low measured CDR from EW in field trials on acidic soils and highlight the need for more realistic modelling of pH buffering capacity. Overall, mill ash shows high potential for CDR via EW, especially if lifecycle benefits are considered, although this must be validated in the field.

Laboratory tests to understand tephra sliding behaviour on roofs

Following explosive eruptions, loading from tephra fall deposits can lead to roof collapse. However, the load may be reduced significantly by tephra sliding on pitched roofs. We present small-scale laboratory tests to investigate tephra sliding behaviour on metal, fibre cement sheet and tile roofing. We tested 10–30 cm thicknesses for dry and wet deposits of pumice, scoria and basaltic ash. We found that tephra did not slide on roof pitches ≤ 15° for coarse-grained deposits and ≤ 12° for dry ash. Thin deposits of wet ash were stable at pitches ≤ 30°. In addition, tephra was mainly shed on pitches ≥ 32° for metal roofs and ≥ 35° for fibre cement and tiles. Using these results, we have produced an initial set of sliding coefficients for tephra for simply pitched roofs that can be used to help prioritise roofs for clearing during an eruption and assist in designing roofs to withstand tephra fall.

The Effect of Wood Ash and Soil Applications on the Behavior and Survival of Spodoptera frugiperda (Lepidoptera: Noctuidae) Larvae on Maize.

Cryptic feeding inside maize whorls makes it difficult to control fall armyworm (FAW). Smallholder farmers use alternative methods of control, of which the efficacy is uncertain. We determined the efficacy of wood ash and soil for the control of FAW and recorded its effect on larval preference and ballooning. Maize plants were artificially infested with larvae of different instars and treatments were either soil, wet ash, or dry ash, applied as single preventative or curative applications. Larvae exhibited non-preference for treated leaves in choice tests. The efficacy of treatments varied largely between experiments. Under laboratory conditions, ash treatments resulted in significant mortality of 1st and 5th instars. Dry and wet ash as curative applications for 1st instars resulted in 67 and 66% mortality, respectively, compared to mortality recorded in the control (22%). Under field conditions, survival of 3rd instars on treated plants was low (21-34%), compared to 70% on untreated plants. Due to the high variability in efficacy, the use of these alternative methods does not guarantee effective control. They do, however, have a place in IPM systems if applied as soon as infestations are observed and when larvae as still small. Recommendations on the use of ash and soil as spot treatments against FAW are provided.

Toward effective utilization of fly ash and multi-binder system with fly ash in concrete

This paper describes first the situation of fly ash in various ASEAN countries. Then the development of fly ash utilization in Thailand is discussed, which includes fly ash specification, standards on durability and service life design for fly ash concrete, and in the final, study results of application potential of various off-spec fly ashes are elaborated. Characteristics of fly ash in different ASEAN countries are different and have different problems. Thailand has 2 major sources of fly ash which have significantly different properties, especially CaO content (high and low CaO). Therefore, the standard specification of the Thai fly ashes classifies the fly ashes based on both quality classes (Classes 1, 2, and 3, with class 1 having the highest quality) and CaO content (high and low CaO). The effects of the fly ash were considered in the durability and service life design standard, for example in estimating the diffusion coefficient of chloride, critical chloride content, carbonation coefficient, and sulfate resistance. Lastly, examples of comparative study results on some off-spec fly ashes (high free lime, dumped wet, and high LOI fly ashes) are demonstrated.

Effects of Physicochemical Properties on the South-South Estuaries’ Microbial Community Structure

The conceivably chemical gold of the marine environment is affected by a myriad of natural and artificial challenges. The physical and chemical challenges faced by microbes in the ocean are one among the many myriads of activities that affect marine microbial life. As the depth of the ocean increases, temperature declines, salinity increases, and the availability of nutrients dwindle, pollution from a variety of sources such as recreation, fish culture, and the assimilation and transport of pollution effluents through river can greatly affect the physiochemical and biodiversity of the ocean life. The total community DNA was extracted using the ZR soil microbe DNA Miniprep kit. The amplicon Library was prepared using the reversible terminator sequencing on Miseq, illumina’s integrated next-generation sequencer by Inqaba Biotechnological as per 16S metagenomic sequencing Library preparation. For the determination of pH, the pH meter was used; the conductivity meter was used for conductivity; the salinometer was used for salinity, the heating method was used for total dissolved solids (TDS); Nephelometer was used for turbidity; the filter method was used for total suspended solids (TSS); palintest Nitratest method was used for Nitrate determination; Total alkalinity was determined by the standard titrimetric method; for Total hardness, the EDTA titrimetric method was used; the wet ashing method was used for metals; Hydrogen carbonate was determined by titrimetric method; sulfate and Chloride were determined by turbidimetric and argentometric method respectively. The total read counts from the kingdom across the three zones are 4981 (82.70%), 991 (94.11%), and 45835 (46.64%) for Okrika, Ibaka, and Brass, respectively. The total read counts from the phyla across the three zones are 1222 (21.73%) for Proteobacteria, 221 (21.33%) for Firmicutes, and 14712 (14.97%) for Firmicutes, respectively. The salinity and sodium values were 2.96 and 3.23 and 567.31 and 422.91 for the top and bottom, respectively, in Ibaka. The salinity and sodium values were 13.55 and 12.94 and 1877.68 and 1874.02 for top and bottom, respectively, for Okrika. The salinity and sodium values were 11.65 and 8.51 and 1238.69 and 1338.82 for the top and bottom, respectively, for Brass. The number of bacteria phyla obtained from the sediment was found to depend on the physicochemical parameters (sodium, salinity, pH, etc.).

Comparison of three digestion methods for determination of lead and cadmium in milk and dairy products

Background: Toxic metals enter the human food chain through water, soil, and plants. High consumption of dairy products makes it necessary to measure their concentrations in milk and its products. Methods: In this study, four samples of dairy products, including milk, dough, yogurt, and cream were selected. They were spiked with concentrations of 0, 20, 40, and 60 μg/kg of lead (Pb) and cadmium (Cd) separately. In all samples, the concentration of these metals was determined using graphite furnace atomic absorption spectroscopy (GFAAS) after microwave, wet, and dry ashing digestion methods. To select the best digestion method, recovery percentage, linearity of increasing concentrations, relative standard deviation (RSD), and the limit of detection were used. Results: According to the results, the RSD of all measurements was less than 5%. The instrument detection limit for Pb and Cd were 0.188 and 0.157 μg/L, respectively. The recovery efficiency of all digested samples by three methods was between 75.7% and 120%. According to the linearity index and R2 , the microwave digestion method with 90 to 110% efficiency was the best for Pb-spiked samples, and the dry digestion method was the best for Cd-spiked samples. Conclusion: Considering all indexes, microwave digestion was the best method for Pb and Cd samples.

Providing buckwheat plants with macronutrients for different fertilization systems in the conditions of the Northern Forest-Steppe of Ukraine

Aim. The method of research, which is highlighted in the article, is the detection of changes in the ontogeny of buckwheat, associated with the provision of plant nutrients for different fertilization systems and the presence of physiological functional relationships between several macroelements with justification, in plants and their influence on the formation of productivity. Methods. The scheme of the experiment included a mineral fertilizer system – N45Р45К60, N25Р25К30 and N15Р25К30 + N15 (fertilizing plants at the IX stage of organogenesis). These variants were superimposed on variants without treatment (control) and with seed treatment with BTU. Reasonable determinations include humus content - according to Tyurin’s method, easily hydrolyzed nitrogen - according to Kornfield’s method, mobile phosphorus and potassium - according to Chirikov’s method. Plant samples were subjected to wet ashing according to the Ginzburg method. Results. The introduction of mineral fertilizers helped to increase the content of macroelements in the soil. At the time of crop emergence, the reserves of alkaline hydrolyzed nitrogen in the 0-20 cm soil horizon ranged from 74.6 mg/kg to 80,5 mg/kg. It was the least in the control variant. The content of mobile phosphates reached 126,6 mg/kg in the control variants and increased to 144.3 and 165.6 mg/kg of soil when mineral fertilizers were applied. This trend remained in the phase of mass flowering. The amount of Р2О5 in the soil also changed under the influence of applied fertilizers. The difference between the tested variants and the control was 56.7 mg/kg of soil in the seedling phase and 32.5 mg/kg of soil in the mass flowering phase. The content of macroelements in the soil had a positive effect on the supply of nutrients to the plant. On average, over the years of research, in the variants with the introduction of NRK and seed treatment with BTU, buckwheat plants were provided with nitrogen and phosphorus, the potassium content in the plants was insufficient. Conclusions. A close relationship was obtained between the supply of plants with nitrogen, phosphorus, potassium and crop productivity, which was – r = 0.81; 0.74; 0.91 respectively.

Evapotranspiration-linked silica deposition in a basal tracheophyte plant (Lycopodiaceae: Lycopodiella alopecuroides): implications for the evolutionary origins of phytoliths.

Phytoliths, microscopic deposits of hydrated silica within plants, play a myriad of functional roles in extant tracheophytes - yet their evolutionary origins and the original selective pressures leading to their deposition remain poorly understood. To gain new insights into the ancestral condition of tracheophyte phytolith production and function, phytolith content was intensively assayed in a basal, morphologically conserved tracheophyte: the foxtail clubmoss Lycopodiella alopecuroides. Wet ashing was employed to perform phytolith extractions from every major anatomical region of L.alopecuroides. Phytolith occurrence was recorded, alongside abundance, morphometric information, and morphological descriptions. Phytoliths were recovered exclusively from the microphylls, which were apicodistally silicified into multiphytolith aggregates. Phytolith aggregates were larger and more numerous in anatomical regions engaging in greater evapotranspirational activity. The tissue distribution of L.alopecuroides phytoliths is inconsistent with the expectations of proposed adaptive hypotheses of phytolith evolutionary origin. Instead, it is hypothesized that phytoliths may have arisen incidentally in the L.alopecuroides-like ancestral plant, polymerizing from intraplant silicon accumulations arising via bulk flow and 'leaky' cellular micronutrient channels. This basal, nonadaptive phytolith formation model would provide the evolutionary 'raw material' for later modification into the useful, adaptative, phytolith deposits seen in later-diverging plant clades.

Kinetics of mixed binder strength gain

Introduction. The storage of pond ash at ash dumps has a negative impact on the environmental situation in the nearby settlements, dumps constantly dust and pollute water sources. To solve this problem, it is proposed to use ash from pond ash as a component of mixed binder. Since the specific surface area of pond ash is different throughout the dump, it is necessary to study its influence on the strength set of mixed binder under different curing conditions.Materials and methods. The equipment on which the experiment was carried out is listed. To determine the specific surface ПСХ-12 device was used, ash drying was carried out in a desiccator. The samples were stored in a normal solidification chamber. The chemical composition of pond ash from TPP-5 of Omsk was presented.Results. Experimental data on the strength of samples of mixed binder at the age of 1,3,7,14,21,28,90 days of normal hardening and data on the strength of samples after heat and humidity treatment are presented. Durability of mixed binder composition with specific surface of hydraulic ash of 460-490 m2/kg under normal hardening conditions amounts to 42.57 MPa which corresponds to natural strength. The composition with the use of pond ash 460-490 m2/kg after water removal increased strength by 12% in comparison with the control composition. Compositions with specific surface of wet pond ash 220-250, 340-370, 650-700 m2/kg show durability results lower than the control ashless composition irrespective of hardening conditions.Discussion and conclusions. It is proved that the use of pond ash with a specific surface of 460-490 m2/kg is rational. Its strength under normal conditions of hardening is 42,57 MPa, which corresponds to the strength of the concrete. The composition with the use of wet pond ash 460-490 m2/kg after heat and moisture treatment has an increase in strength by 12% compared to the control composition. Increased strength of mixed binder compositions is associated with acceleration of pozzolanic reaction in them, the products of which have a positive effect on the strength of the products.

Analyses of Chemical and Physical Egg Quality Parameters of Laying Hens Housed in Different Conditions in Turkey

The aim of the present study is to determine the content of chemical and physical quality parameters of hen eggs (liquid whole egg (LWE), liquid egg yolk (LEY), and liquid egg white (LEW)) produced for different housing and feeding conditions in Turkey. Chemical quality parameters (protein, lipid, and moisture) and physical quality parameters (total soluble solid (°Brix), pH, conductivity, and yolk:white ratio) were analyzed using different egg samples. Kjeldahl, wet ashing, and oven-drying official methods were used for the protein, total lipid, and moisture analyses of egg samples. The highest protein content in the LEY and LEW samples were found to be 19.0% and 15.13%, respectively for the tenth sample having fortified feeding (selenium+DHA) parameters. For LWE samples, it was also obtained 15.65% with the second sample having a not fortified feeding parameter. The highest total lipid content for LWE samples was determined as 10.43% for the seventh sample which housed under cage free conditions and fed with organic (omega3+EPA+DHA) fortifiers, while it was found with a value 25.7% for the second and third LEY samples possessing a not fortified feeding parameters. The highest moisture content was determined as 78.37%, 54.64%, and 89.11 for thirty-first LWE sample (with not fortified feeding), third LEY sample (with not fortified feeding) and sixth LEW sample (having cage free and organic parameters), respectively. As a result, the minimum, average, and maximum contents of the chemical and physical quality parameters were determined for laying hen eggs raised in several housing and feeding conditions in Turkey.

Mass spectrometric investigations into 3D printed parts to assess radiopurity as ultralow background materials for rare event physics detectors

New data are reported for polyvinylidene fluoride (PVDF), polyphenylene sulfide (PPS), and two forms of polyetherimide (PEI, branded ULTEM 1010 and 9085). Data for starting filaments and both simple and complex printed parts are reported. PVDF filaments and simple printed beads, were found to have values of approximately 30 and 50 ppt for Th-232 and U-238, respectively, while a more complex spring clip part had slightly elevated Th-232 levels of 65 ppt, with U-238 remaining at 50 ppt. PPS filament was found to have concentrations of 270 and 710 ppt for Th-232 and U-238, respectively, and were not chosen to be printed as those levels were already higher than other material options. ULTEM 1010 filaments and printed complex spring clip parts were found to have concentrations of around 5 and 7 ppt for Th-232 and U-238, respectively, illustrating no significant contamination from the printing process. ULTEM 9085 filaments were found to have concentrations of around 9 and 5 ppt for Th-232 and U-238, respectively, while the printed complex spring clip part was found to have slightly elevated concentrations of 25 and 7 ppt for Th-232 and U-238, respectively. These results were all obtained using a novel dry ashing method in crucibles constructed of ultralow background electroformed copper or, when applicable, microwave-assisted wet ashing digestion. Samples and process blanks were spiked with Th-229 and U-233 as internal standards prior to dry/wet ashing and determinations were made by inductively coupled plasma mass spectrometry (ICP-MS). In order to maintain high radiopurity levels, pre-cleaning the filaments before printing and post-cleaning the parts is recommended, although the printing process itself has shown to contribute very minute amounts of radiocontaminants.

Preparation of Cementitious Material with Wet Fly Ash by Hydrothermal Reaction and Calcination

A large amount of wet-discharged fly ash has caused serious harm to the ecological environment, so the utilization of fly ash has received attention. This paper analyzes the formation of products of fly ash–lime system under the autoclave process by X-ray diffraction (XRD) analysis and thermogravimetric–differential thermal (TG-DSC) analysis. The hydrothermal reaction product generation was quantitatively analyzed using the hydrochloric acid selective dissolution method to quantify the degree of reaction of fly ash in the pressure evaporation specimens in combination with the reaction degree of lime in the autoclave specimens. The hydrothermal reaction products were calcined and hydrated, and the mineral composition of the calcined products and the mechanical and microstructure of the hydrated products were analyzed. The results show that hydrothermal reactions occur in the fly ash–lime pressure evaporation system to produce C2SH, C3AH6, C3ASH4, and other products. The optimum ratio of lime is 22%, and the appropriate autoclave parameter is 140 °C for 8 h. Under this condition, the reaction degree of fly ash is 15.39%, the reaction degree of CaO is 78.63%, and its f-CaO value is 4.93%. The formation of C2SH in the hydrothermal reaction ranged from 14.33% to 18.53%, and the formation of C3ASH4 ranged from 14.06% to 15.26%. The hydrothermal reaction products were calcined at 850 °C for 1.5 h to produce new gelling materials with gelling phases, such as C12A7, α’L-C2S, β-C2S, and C2AS. The compressive and flexural strengths of the new gelling materials reached 34.4 MPa and 6.4 MPa, respectively, at the age of 180 days.