Initial Purity Research Articles

Gold(I)-Catalyzed Rautenstrauch/Hetero-Diels-Alder/Retro-aza-Michael Cascade Reaction for the Synthesis of α-Hydrazineyl-2-cyclopentenones.

A one-pot synthesis of ring-fused, α-hydrazineyl-2-cyclopentenone derivatives is achieved by a gold(I)-catalyzed Rautenstrauch/hetero Diels-Alder/ring opening tandem reaction of suitable propargyl esters. By mixing the latter with a dialkylazodicarboxylate in the presence of a gold(I) catalyst, the 1,2-acyloxy migration/cyclization process (Rautenstrauch reaction) leads to cyclopentadienyl ester intermediates which are trapped by the heterodienophile present in situ. This provides strained intermediates which spontaneously undergo highly regioselective ring opening by a retro aza-Michael reaction promoted by the gold(I) catalyst, eventually yielding the target compounds. Six- and seven-membered ring-fused cyclopentenones bearing a pendant α-hydrazineyl moiety can be obtained in moderate to excellent yield (50-98%) by this approach, with a minimal erosion of the initial optical purity when using enantioenriched substrates.

Spontaneous Alignment of Boron Nitride Nanotubes into Polycrystalline Film Arrays for Enhanced Piezoelectric Nanogeneration

1D nanomaterials feature distinct physical properties owing to their characteristic anisotropy and size‐induced quantization; yet, creating an ordered ensemble of the nanomaterials is nontrivial, marking it as a grand challenge in materials science. Herein, the spontaneous alignment of a model 1D nanomaterial, boron nitride nanotube (BNNT), into a highly ordered multidomain film is presented. A conventional, benchtop gravity filtration is employed, during which thickening of the BNNT dispersion leads to a formation of the liquid crystal (LC) phase that is readily isolatable. The spontaneity of the phase separation excludes notoriously persisting synthetic impurities to a degree >99%, from ≈50% of the initial material purity. The LC‐based thin film features an aligned multidomain with an exceptionally low angular deviation of <2.5° and a domain size of >50 μm. A piezoelectric nanogenerator based on the thin film records a 1000‐fold increase in the piezocurrent compared to its random analog. This work demonstrates the first example of the spontaneous alignment of an unconventional nanotube system and the realization of the macroscopic properties therefrom, which can be readily expanded to 1D materials in general.

Development and morphological analysis of the zone refining process for high purity germanium

A highly efficient purification process has been developed to enhance the purity of germanium (Ge) up to 13 N from an initial 4N purity. Hall effect measurements demonstrated that part of the zone refined Ge (ZRGe) bars exhibited p-type conductivity and high purity with a net charge carrier concentration of around 4–9 × 1010 cm−3. Noteworthy observations include a rise in carrier concentration (1011 to 1012 cm−3) at a very low zone refining (ZR) velocity of 1 mm/min, which is attributed to the diffusion of impurities from the container into the Ge melt. The purification efficiency was enhanced by optimizing the ZR velocity to around 4–5 mm/min. Purification was carried out at different process steps using graphite and quartz containers. Subsequent microstructural examinations, conducted in conjunction with wet-chemical etching of the sample unveiled the presence of various grains, grain boundaries (GBs), and low & high-density of dislocation clusters: These observations were made in samples that had undergone zone refining under various gas atmospheres including argon, nitrogen and hydrogen. Electron back scattered diffraction (EBSD) analysis reveals the characteristics of multiple grains and grain boundaries (GBs) of Ge refined in argon and nitrogen atmosphere, including low-angle GBs, high-angle GBs with coincide site lattice (CSL) Σ3, Σ9, Σ27a, and random angle GBs. In contrast, the EBSD results of Ge refined in hydrogen atmosphere shows larger grains with only a few low-angle grain boundaries. The materials refined in argon and nitrogen show a lower carrier lifetime (10–30 μs) owing to the presence of various high angle grains boundaries as well as low purity. Conversely, zone refining in hydrogen resulted in the carrier lifetime of around 50 μs in polycrystalline Ge wafers with larger grains.

Optimisation of electron irradiation for creating spin ensembles in hexagonal boron nitride

Boron vacancy centre ( VB− ) ensembles in hexagonal boron nitride (hBN) have attracted recent interest for their potential as two-dimensional solid-state quantum sensors. Irradiation is necessary for VB− creation, however, to date only limited attention has been given to optimising the defect production process, especially in the case of bulk irradiation with high-energy particles, which offers scalability through the potential for creating ensembles in large volumes of material. Here we systematically investigate the effect of electron irradiation by varying the dose delivered to a range of hBN samples, which differ in their purity, and search for an optimum in measurement sensitivity. We find that moderate electron irradiation doses ( ≈5×1018 cm−2) appear to offer the best sensitivity, and also observe a dependence on the initial crystal purity. These results pave the way for the scalable and cost-effective production of hBN quantum sensors, and provide insight into the mechanisms limiting VB− spin properties.

Purification of Phycocyanin from Spirulina platensis Using Natural Deep Eutectic Solvents with Varied Hydrogen Bond Donor

Graphical Abstract Highlight Research Phycocyanin extract from Spirulina platensis was achieved. Highly pure phycocyanin was obtained through NaDES purification method. Strong antioxidant activity of phycocyanin was observed (IC50 <50 ppm). Successful removal of impurities confirmed by gel electrophoresis. Abstract Phycocyanin, a pharmacologically potent blue pigment extracted from Spirulina platensis, requires optimal purity for effective utilization. Traditional purification methods, although effective, are impeded by time and cost constraints. Addressing this challenge, aqueous two-phase systems (ATPs) incorporating natural deep eutectic solvents (NaDES) emerge as promising alternatives. These systems offer operational simplicity and cost-effectiveness, ensuring efficient purification with high purity and optimal recovery of phycocyanin. This study investigated the impact of various types of hydrogen bond donors (HBD) within choline chloride-based natural deep eutectic solvents (NaDES) on the purification of phycocyanin. Phycocyanin was extracted from Spirulina platensis biomass through ultrasonication and purified using an aqueous two-phase system with various HBD of NaDES, including urea, glycerol, and citric acid. The experimental design adhered to a completely randomized design. The initial purity index and yield of crude extract phycocyanin were 0.54±0.02 and 12.79±0.27%, respectively. The NaDES system with ChCl:citric acid exhibited superior performance, demonstrating a high purity index and recovery (2.3-fold, 71.83±2.36%) compared to ammonium sulfate (1.5-fold, 70.15±4.10%). The obtained phycocyanin was partially pure compared to commercial phycocyanin (purity index: 1.60), as indicated by SDS-PAGE. Moreover, the antioxidant activity of phycocyanin was enhanced post-purification, evident in the IC50 value of 40.54 ppm. In summary, organic acid-based NaDES has proven effective in increasing the purity and achieving a significant recovery percentage of phycocyanin compared to conventional ammonium sulfate methods. The antioxidant activity of phycocyanin was enhanced after purification. These results indicate the promising potential of NaDES-based ATP systems for producing functional protein-based ingredients, exemplified by phycocyanin.

Experimental Scale-Up and Technoeconomic Assessment of Low-Grade Glycerol Purification from Waste-Based Biorefinery.

The purification of waste-derived crude glycerol to the 2000 g scale is presented to provide a consolidated proof of concept. Starting from unprecedented low-quality glycerol from a second-generation biodiesel plant, currently disposed of at cost, a series of physiochemical steps are implemented to improve glycerol purity and recovery under relevant conditions. The study is carried out on two samples with initial purities of 38-57 wt % and ash contents of up to 16 wt %. Under the optimal process conditions, glycerol exhibits a remarkable increase to 85 wt % purity while preserving the overall glycerol recovery of the process of up to 71%. Among different purification steps, neutralization contributes to increasing the purity to 69 wt % while the remaining water and methanol evaporation have further increased the purity to >80 wt %. The adsorption step shows the smallest increase in glycerol purity despite it being required to decolorize and deodorize the final product. The developed process is further designed for industrial-scale application using Aspen Plus for a plant size of 1630 kg/h of purified glycerol which could achieve 82 wt % final purity and a maximum recovery of 77%. In addition, the process yields 315 kg/h of salable byproduct salts suitable as fertilizer and an overall CO2 emission of 0.70 ton per ton of purified glycerol mainly due to the unrecovered feedstock and solvent combustion. As a result, the proposed process implementation could generate positive revenues with a cost of the final products of €19.2 per ton.

Investigation of the Storage and Stability as Well as the Dissolution Rate of Novel Ilaprazole/Xylitol Cocrystal.

Reflux esophagitis, a treatment for gastric ulcers known as Ilaprazole (Ila), is not stable during storage and handling at room temperature, requiring storage at 5 degrees Celsius. In this study, to address these issues with Ila, coformers rich in oxygen (O) and hydroxyl (OH) groups capable of forming hydrogen bonds with were selected. These coformers included Xylitol (Xyl), Meglumine (Meg), Nicotinic acid (Nic), L-Aspartic acid (Asp), and L-Glutamic acid (Glu). A 1:1 physical mixture of Ila and each coformer was prepared, and the potential for cocrystal formation was predicted using differential scanning calorimetry (DSC) screening. The results indicated the potential for cocrystal formation in the Ila/Xyl physical mixture. Subsequently, Ila and Xyl were mixed in ethyl acetate (EA) in a 1:1 ratio, and after 28 h of slurry, the formation of Ila/Xyl cocrystal was confirmed through solid-state CP/MAS 13C NMR spectrum analysis, showing intermolecular hydrogen bonding and conformational changes. Furthermore, the 1:1 ratio of Ila/Xyl cocrystal was confirmed through solution-state NMR (1H, 13C, and 2D) molecular structure analysis. To assess the stability of Ila/Xyl cocrystal at room temperature, it was stored and compared with Ila at 25 ± 2 °C and relative humidity (RH) of 65 ± 5% over three months. The results showed that the purity of Ila/Xyl cocrystal remained at 99.8% from the initial purity of 99.75% over the three months, while Ila was predicted to decrease from an initial 99.8% purity to 90% after three months. Additionally, at 25 ± 2 °C and RH 65 ± 5%, a specific impurity B in Ila/Xyl cocrystal was observed to be 0.03% over three months, whereas Ila was predicted to increase from an initial 0.032% to 2.28% after three months. To evaluate the dissolution rate of Ila/Xyl cocrystal, a formulation was prepared and compared with Ila at pH 10, with a dosage equivalent to 10 mg of Ila. The results showed that Ila/Xyl cocrystal reached 55% within 15 min and 100% within 45 min, while Ila was predicted to reach 32% at 15 min and 100% only after 60 min. However, overall, the Ila/Xyl cocrystal showed results equivalent to or exceeding the dissolution rate of Ila. Therefore, it is predicted that the Ila/Xyl cocrystal will maximize its effectiveness as a more convenient crystal structure for formulation development, allowing storage and preservation at room temperature without the need for the problematic 5 °C refrigeration during ambient conditions and storage, addressing the issues associated with Ila.

Study on the Purification Effect and Equilibrium Distribution Coefficient of Impurities during Zone Refining of Fluorene

High-purity fluorene is widely used in optoelectronic materials, biology, medicine, and other fields. It is a kind of industrial chemical with high added value. In this paper, zone melting purification technology was used to study the purification effect of fluorene on the zone travel rate, the zone length, the zone passing number, and the zone temperature difference. The concentration distribution of fluorene and the impurities 2-methylbiphenyl, 4-methylbiphenyl, 4-methyldibenzofuran, and dibenzofunan along the moving direction of the melting zone was obtained. A one-pass zone refining model of fluorene was established; the effective distribution coefficients of the four impurities above were obtained via mathematical software fitting; and the equilibrium distribution coefficients were further calculated, which were 0.2441, 0.5850, 0.2377, and 0.3497, respectively. The k0 of all impurities was less than 1. The purification effect of fluorene can be improved by using a larger zone length in the initial zone melting purification process, a smaller zone travel rate in the whole zone melting purification process, multiple zone melting purification processes, and a larger zone temperature difference. After four zone melting purification processes, the purity of fluorene increased from 97.62% to 99.08%, which was nearly 1.5% higher than the initial purity of fluorene. Zone melting purification technology provides a new idea for the preparation of high-purity fluorene.

Purification of the Al2Cu intermetallic compound via zone melting crystallization technique

The widespread interest in intermetallic compounds has driven the development of their structures and properties, as well as their applications as alternative structural and potentially functional materials. As more and more intermetallic compounds with complex compositions enter the application market, their performance improvement and sustainable recycling face many challenges, where the influence of impurities plays a crucial role. Here, we proposed the direct purification of intermetallic compounds by fractional crystallization and verified for the first time the feasibility and effectiveness of zone melting for the purification of intermetallic Al2Cu. After ten passes of zone melting, results showed no separation of Al and Cu, the major components of Al2Cu. Further analyses demonstrated the homogeneity and remelting stability of Al2Cu before and after zone melting. In addition, the total impurity concentrations at the front and the end of cast Al2Cu bars decreased with increasing number of passes, respectively. After ten passes of zone melting, Al2Cu bar with an initial purity of 3N exhibited higher refining efficiency than those with an initial purity of 4N. Among all impurities, the distribution coefficients of Fe, Si, Zn, and Ti were obviously less than unity (k < 1). Whereas the impurities Ca, Mg and Mn showed behaviors of distribution coefficients less than and/or close to unity.

Prospective BASECAMP-1 experience in patients with gastrointestinal (GI) cancer: Identifying patients with human leukocyte antigen (HLA) loss of heterozygosity (LOH) for a future therapeutic trial exploiting LOH as a tumor vulnerability.

209 Background: Metastatic colorectal (CRC), pancreatic (PANC), and gastroesophageal cancers are the leading causes of GI cancer–related mortality (5-y survival: 15%, 3%, and 5%-6%, respectively) (ACS 2022). HLA LOH is a recurrent mechanism of immune escape observed in 15%-20% of GI cancers (Hecht R., ASCO GI 2022). The Tmod platform is a logic-gated chimeric antigen receptor (CAR) T-cell modular system, comprising a carcinoembryonic antigen (CEA)- or mesothelin (MSLN)-targeting CAR activator and a separate HLA-A*02-targeting blocker receptor. Both in vitro/in vivo, Tmod CAR T therapy kills cells with HLA-A*02 LOH (tumor) without harming cells with retained HLA-A*02 expression (normal). However, HLA-A*02 LOH can only be therapeutically exploited if patients are identifiable through a feasible and timely clinical workflow. Methods: We established a biobanking protocol (BASECAMP-1, NCT04981119) to determine whether HLA-A*02 LOH patients can be prospectively identified. Patients with CRC, PANC, or non-small cell lung cancer (NSCLC), and a high risk for incurable relapse, were screened first using a standard HLA assay. Heterozygous HLA-A*02 positive tumor samples were then assessed for LOH using a bioinformatic algorithm applied via the Tempus xT platform. Results: As of Sep 1, 2022, 83 patients were consented at 4 institutions. HLA status was obtained from 70 patients and 28 were identified as HLA-A*02:01 heterozygous (40%; expected frequency based on USA NMDP data, 27.6%). LOH results were available for 16 patients; 4 LOH-positive patients were identified (25%, 2 PANC, 2 NSCLC). The LOH assay sensitivity declines below a tumor purity of 40% (Hecht R., ASCO GI 2022). Six patients had a tumor purity of 20% (all with PANC, a tumor known for high stromal content), limiting possible LOH detection. The impact of tumor purity on LOH sensitivity was highlighted in a patient with a low initial sample tumor purity (30%) that resulted in a 41% probability of HLA-A*02:01 LOH (below positive threshold). A second sample with a higher tumor purity (70%), obtained from formalin-fixed, paraffin-embedded sections, resulted in a 92% probability of HLA-A*02:01 LOH (positive). Conclusions: BASECAMP-1 prospective identification of HLA-A*02 LOH is feasible in the real-world setting. The frequencies of the HLA-A*02 allele and of HLA-A*02 LOH in this cohort mirrored expected population frequencies. LOH results can be obtained within a clinically feasible workflow and timeframe, although samples with a &lt; 40% tumor purity have a reduced sensitivity for LOH detection, an issue recurrently observed in patients with PANC. The BASECAMP-1 strategy enables prospective identification of appropriate patients for future therapeutic clinical trials using Tmod CEA and MSLN logic-gated CAR T cells. Clinical trial information: NCT04981119 .

Quantum Correlation Dynamics of Three Qubits in Non-Markovian Environments

We investigate the quantum correlation dynamics of three independent qubits each locally interacting with a zero temperature non-Markovian reservoir by using the Geometric measure of quantum discord (GQD). The dependence of quantum correlation dynamicson amount of non-Markovian, the degree of initial quantum correlation and purity of the initial states are studied in detail. It is found that the quantum correlation of such three qubits system revives after instantaneous disappearance period when a proper amount of non-Markovian is present. A comparison to the pairwise quantum discord and entanglement dynamics in three qubits system is also made.

An efficient and economical way to obtain porcine muscle stem cells for cultured meat production

Cultured meat technology is an emerging and promising strategy for animal protein production. Muscle stem cells are regarded as important seed cells for generating muscle fiber in vitro because of their proliferative and myogenic differentiation potential. However, current approaches for the isolation and purification of muscle stem cells are low-yield and high-cost, limiting the industrial production of cultured meat. Here, we reported an efficient and economical protease combination consisting of pronase and dispase II for the isolation of primary muscle stem cells, achieving 5.06 ± 0.12 × 106 nucleated cells and 3.19 ± 0.19 × 106 Pax7+ cells from 1 g of porcine muscle tissue. Furthermore, by investigating the effect of initial purity on the proliferation and differentiation potential of muscle stem cells, we found that higher purity of initial muscle stem cells promoted the maintenance of myogenic properties of cells after expansion but reduced the total number of obtained cells. Based on nucleated cells isolated from 1 g of porcine muscle, muscle stem cells purified by 0.5 h of pre-plating yielded 2.19 ± 0.16 × 108 cells with myogenic differentiation capacity after 20 days of expansion, which was 5-fold higher than those purified by fluorescence-activated cell sorting (FACS). Therefore, a modified approach was developed to obtain porcine muscle stem cells for cultured meat production, involving tissue digestion with the pronase and dispase II combination and purification through pre-plating for 0.5 h. This approach was simple, efficient, and economic, which would facilitate the industrial production of cultured meat.

A facile and universal method to purify silica from natural sand

Abstract The major constituents of sand are silica and silicates. The facile and low-cost purification technology of silica from natural sand is of magnificent importance to the industrial applications of silicon-based materials. Herein, we report a green, low-cost, and universal method to purify silica from natural sand. Sand from deserts, rivers, and seas is selected as the representative of natural sand. The initial purity of silica is 52.1 wt% for desert sand, 39.3 wt% for river sand, and 35.8 wt% for sea sand. High-purity silica has been successfully separated and purified from natural sand via ball milling, reacting with 30 bar CO2 and hydrochloric acid. The purity of silica derived from natural sand reaches &gt;96 wt%. In this work, the mechanism for the purification of silica from natural sand is discussed. This study provides a new method to separate high-purity silica from natural sand without the generation of toxic and harmful substances.

Does Heparin Affect 99mTc-MAA In Vitro Stability?

Pulmonary embolism (PE) can be diagnosed by perfusion lung scintigraphy using human albumin macroaggregates labelled 99mTc (99mTc-MAA). When PE is suspected, subcutaneous Low Molecular Weight Heparin (LMWH) should be administered even before the results of the PE diagnostic flowchart. In our study, we aimed to evaluate a possible interaction (in vitro interference) between 99mTc-MAA and LMWH. The reconstitution of MAA kit was performed according to the manufacturer's instruction. After labelling, we carried out the following preparations: a standard dose of 99mTc-MAA alone, as control; 99mTc-MAA and enoxaparin at different ratios. According to the manufacturer's instruction, the radiochemical purity was performed and evaluated immediately (T0), after 15 and 30 minutes after incubation (T15 and T30). We compared the radiochemical purity of 99mTc-MAA with: (i) radiochemical purity of 99mTc-MAA and enoxaparin (11 ratio), (ii) radiochemical purity of 99mTc-MAA and enoxaparin (0.5 ratio), and (iii) radiochemical purity of 99mTc-MAA and enoxaparin (ratio 2). No significant differences were found between all the measured parameters at each time point for each ratio. We also tested the stability of 99mTc-MAA in physiological conditions (at 37°C in PBS): the initial radiochemical purity of 99mTc-MAA was 99.78%. The values of 99mTc-MAA radiochemical purity were high in all conditions of possible interaction with LMWH, with values ranging from 98.00% at T0 to 95% at T30. We found no statistically significant change in the in vitro stability of 99mTc-MAA in the presence of enoxaparin, excluding a possible direct interference. Future studies will be needed to check the 99mTc-MAA stability under physiological conditions.

Characterizing Two‐Qubit Non‐Classical Correlations and Non‐Locality in Mixed Local Dephasing Noisy Channels

AbstractThe dephasing effects of two independent local mixed static‐Ornstein Uhlenbeck (STC‐OUK) noisy channels on the dynamics of two‐qubit non‐classical correlations, non‐locality, and entanglement are addressed. Here, i) local quantum Fisher information; ii) local quantum uncertainty; iii) uncertainty‐induced non‐locality; iv) Bell non‐locality; and v) negativity to quantify two‐qubit non‐classical correlations, non‐locality and entanglement, respectively, and their loss under the influence of mixed noise are used. The findings show that measure (i) compared to measure (ii) remains more effective in demonstrating non‐classical correlations. For the two‐qubit state with maximum purity, measure (iii) remains less fragile to the mixed STC‐OUK noise than measure (iv) but gets more vulnerable as the initial purity of the two‐qubit state falls. It is intriguing that measures (i), (ii), and (v) completely freeze after a particular interval, yet measures (iii) and (iv) remains partially preserved indefinitely. When compared to other two‐qubit correlation quantifiers, measure (v) exhibits non‐Markovian behavior and the phenomenon of sudden death and birth. Markovian and non‐Markovian dynamical maps, and extended two‐qubit correlations, can be induced by optimizing the current configuration. Finally, under the influence of mixed dephasing effects, robust and strengthened quantum correlations beyond entanglement in the two‐qubit Werner state is shown.

A comparative study of the effects of aqueous mixed amines on biogas upgrading based on 13C nuclear magnetic resonance (NMR) analysis

As a key technology for biogas upgrading, mixed amines scrubbing can meet the world's demand for renewable energy by ensuring high methane (CH4) purity while achieving low energy regeneration. In this paper, several monoamines with excellent performance in biogas upgrading process were selected to study the effectiveness of their blends for biogas upgrading and compared with 30 wt% monoethanolamine (MEA). The biogas upgrading effect, carbon dioxide (CO2) loading, regeneration effect and CO2 desorption heat of mixed amines were determined by batch experiments. 13C NMR was used to mechanistically interpret and quantify the carbocation trend of the amine solution before and after the reaction and regeneration. The results showed that the biogas upgrading and regeneration effect of the mixed amines combined with methyl monoethanolamine (MMEA) and N-methyldiethanolamine (MDEA) was the best, and its initial methane purity, saturated CO2 loading, regeneration rate and CO2 desorption heat after upgrading were 100%, 0.617 mol CO2/mol amine, 54.3% and 64.91 kJ/mol CO2, respectively. Except for the saturated loading which was second only to MMEA/dimethyl monoethanolamine (DMMEA) with 0.624 mol CO2/mol amine, all the performances are optimal and the CO2 desorption heat is 19.01% lower than that of 30 wt% MEA, which can effectively reduce the regeneration energy consumption of the reaction. The results of 13C NMR showed that the increase of bicarbonate content could effectively reduce the regeneration energy consumption and enhance the initial regeneration rate, and the increase of carbamate could accelerate the initial uptake rate and methane purity, which could provide theoretical support for the subsequent screening of mixed amines to achieve different reaction purposes.

Extracellular Secretion and Simple Purification of Bacterial Collagen from Escherichia coli

Because of structural similarities with type-I animal collagen, recombinant bacterial collagen-like proteins have been progressively used as a source of collagen for biomaterial applications. However, the intracellular expression combined with current costly and time-consuming chromatography methods for purification makes the large-scale production of recombinant bacterial collagen challenging. Here, we report the use of an adapted secretion pathway, used natively byEscherichia colito secrete curli fibers, for extracellular secretion of the bacterial collagen. We confirmed that a considerable fraction of expressed collagen (∼70%) is being secreted freely into the extracellular medium, with an initial purity of ∼50% in the crude culture supernatant. To simplify the purification of extracellular collagen, we avoided cell lysis and used cross-flow filtration or acid precipitation to concentrate the voluminous supernatant and separate the collagen from impurities. We confirmed that the secreted collagen forms triple helical structures, using Sirius Red staining and circular dichroism. We also detected collagen biomarkers via Raman spectroscopy, further supporting that the recombinant collagen forms a stable triple helical conformation. We further studied the effect of the isolation methods on the morphology and secondary structure, concluding that the final collagen structure is process-dependent. Overall, we show that the curli secretion system can be adapted for extracellular secretion of the bacterial collagen, eliminating the need for cell lysis, which simplifies the collagen isolation process and enables a simple cost-effective method with potential for scale-up.

THE INFLUENCE OF DIFFERENT PURITY OF NATURAL ALFALFA SEEDS ON THE PROCESSING EFFICIENCY

This paper presents the results of the seed processing of ten lots of natural alfalfa seed with different purity (from 68.0% to 86.5%). The test was carried out at the seed processing center of the Institute for forage crops Kruševac-Serbia. Seed losses, processing output, seed yield and quality of the processed seed were investigated. It is important that the difference between the amounts of pure seed from laboratory assessment and the actual amount after processing, are low. The purity of natural alfalfa seed depends on the crop condition and the harvest process. In the seed processing of small-grained leguminous plants, the processing output of seed is directly dependent on the percentage of weed species and other species in the natural seed. Seeds of quarantine weeds of dodder and curly dock are a particularly big problem in alfalfa seeds. In the case of high-purity seeds with low quarantine weeds share, processing output are high. By the legal procedure on the seed quality, the content of pure seed, inert materials, weeds and other species in the processed seeds is defined. The efficiency of the alfalfa seed processing depends on the initial purity of the seed, as well as the applied technical and technological process of seed processing. Based on the obtained results, it is possible to optimally adjust and select the appropriate equipment for the processing of alfalfa seed, depending on the quantity and type of weeds and other ingredients in the natural alfalfa seeds.

Recycling of rare earths from fluorescent lamp waste by the integration of solid-state chlorination, leaching and solvent extraction processes

Rare earths (RE) are currently considered some of the most critical elements, being crucial in future sustainable applications. Their high demand, price fluctuations, supply risk and geopolitical factors increase the interest in recovering RE from secondary sources such as pre-consumer scrap, industrial residues and end-of-life products. RE recovery from fluorescent lamp wastes and their subsequent selective separation was successful along a three-step process: (i) solid-state chlorination (SSC), (ii) leaching at pH 3 and (iii) solvent extraction. SSC is the key-step to separate RE from residual material. Optimal SSC parameters were set by using an experimental statistical design which allows for evaluating the cross effects between temperature, residence time and NH4Cl:waste ratio. The digestion step was optimized as well reaching a liquid:solid ratio (L:S) of 40 which accounted for a reduction of 20% in the use of water. Yttrium and Europium have been recovered separately from the pregnant solution by a four-stage cross-flow solvent extraction process combining Cyanex 923 and Cyanex 572 reaching initial purities ≥ 94%. This approach is an integrated process for RE recycling from fluorescent lamp wastes, which contributes to reducing chemicals consumption at better process economy.

Evaluation of devolatilization behaviour of different carbonaceous materials under rapid heating for the novel HIsarna ironmaking process

A drop-tube furnace coupled with quadrupole mass spectrometer (DTF-QMS) was employed to simulate rapid heating conditions that carbonaceous materials experience during HIsarna injection with the measurement of gas composition change as a result. A devolatilization study for thermal coal (TC) and charcoal (CC) samples was carried out at three temperatures of 1000, 1250 and 1500 °C under an initial high purity Ar gas environment. The volatiles released were measured online by QMS, while the char yield was determined directly by the weight of particles collected and the deficit was calculated by subtracting the gas yielded from the total weight loss. The study reveals that working temperature has a strong impact on the devolatilization rate, the maximum weight loss and the variation in gas species produced. Due to intensification in the carbon oxidation and secondary reactions at higher temperatures, there was an increase in the weight loss, which led to a greater yield of H2 and CO but less yield of hydrocarbons, CO2 and H2O. Despite lower volatile matter content in charcoal, the weight loss for charcoal (29%) was higher than that for thermal coal (23%) at 1500 °C. Although the amount of H2 produced for both materials is similar, the amount of CO produced by charcoal is twice of that by thermal coal, and accounts for 79% of the total gas weight formed by charcoal. This suggests that a higher rate of carbon oxidation takes place through O2 containing groups within the charcoal, which results in lower char efficiency. It was found that thermal coal produces a significant amount of tar, while a large number of particles in the form of soot/dust escaped from the bulk material during charcoal injection but no tar formation was observed.