Optimization and modelling of magnesium oxide (MgO) photocatalytic degradation of binary dyes using response surface methodology

Textile industry dye effluent contains a mixture of different kinds of dyes. Many times, photocatalysis is targeted as a solution for the treatment of dye effluent from the textile industry. Many researches have been published related to the photocatalysis of single textile dyes but in the real-world scenario, effluent is a mixture of dyes. Magnesium oxide (MgO) is used as a photocatalyst to treat a mixture (binary solution) of Methylene blue (MB) and Methylene violet (MV) along with individual MB and MV dyes in this article. MgO shows remarkable photocatalytic activity at about 93 and 88% for MB and MV dye in binary solution within 135 min. Furthermore, to study the influence of process parameters, experiments are designed with the help of the central composite design (CCD), and Response surface methodology (RSM) is used to study the interactions between parameters. For this study, five parameters are selected i.e., Photocatalyst dosage, initial concentration of both dyes, time of exposure to the light source, and pH of the binary solution. The photocatalytic process is also optimized and finally optimization of process parameters is validated with an experiment. The result of the validation experiment is very close to the predicted photocatalytic activity.

Multifunctional carbon nanotubes coated stainless steel mesh for electrowetting, hydrophobic, and dye absorption behavior

Electrowetting behaviour for carbon nanotubes (CNT) grown on stainless steel mesh was investigated. The effect of temperature, time, and applied bias voltage on the contact angle of water droplets was studied. The impact of temperature variation on contact angle was also performed for the temperature ranging from 25 to 70 °C. A decrement of contact angle by 68% was observed for the mentioned range indicating a transition from a hydrophobic to hydrophilic nature. A similar trend was observed on the application of electric potential to the CNT-modified stainless-steel mesh ranging from 0 to 8 V with a transition of contact angle from 146 to 30 deg respectively. A comparative analysis for the contact angle variation with time for CNT-coated mesh and uncoated mesh was performed for 180 min. It is observed that uncoated mesh shows a reduction in contact angle to 0 deg with time while the CNT coated mesh shows surplus hydrophobicity with a 2 deg decrement in the extent of time. CNT-modified mesh successfully absorbs 95% of rhodamine B (RB) dye and detergent from water in 10 cycles.

Electrospun membrane of bismuth vanadate-polyvinylidene fluoride nanofibers for efficient piezo-photocatalysis applications

The fabrication of a Poly (vinylidene fluoride) membrane (PVDF) and ceramic-assisted bismuth vanadate-polyvinylidene fluoride (BiVO4-PVDF) composite membrane was achieved through the utilization of the electrospinning technique. The composition and structure of the fabricated membranes were characterized by X-ray powder diffraction, Raman analysis, scanning electron microscopy, Thermo gravimetric analyzer, Fourier transform infrared spectroscopy, and UV-Vis spectroscopy techniques. The prepared polymeric membranes were then utilized for catalytic investigation and to explore, how structure affects catalytic activity using 5 mg/L, 10 mL methylene blue (MB) dye solution. Ultrasonication, visible light irradiation, and the combination were used to study piezocatalysis, photocatalysis, and piezo-photocatalysis, moreover, degradation intermediates were also explored using scavengers. Electrospun BiVO4-PVDF (BV-PVDF) composite has been found to have better piezocatalytic and photocatalytic properties than PVDF. The experimental findings reveal that the composite of BiVO4-PVDF demonstrates the highest efficiency in dye degradation, achieving a maximum degradation rate of 61% within a processing time of 180 min. The rate of degradation was calculated to be 0.0047 min-1, indicating a promising potential for the composite in the field of dye degradation.

Review on Multicatalytic Behavior of Ba0.85Ca0.15Ti0.9Zr0.1O3 Ceramic

Ferroelectric materials are known to possess multicatalytic abilities that are nowadays utilized for removing organic pollutants from water via piezocatalysis, photocatalysis, piezo-photocatalysis, and pyrocatalysis processes. The Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZTO) ceramic is one such ferroelectric composition that has been extensively studied for electrical and electronic applications. Furthermore, the BCZTO ceramic has also shown remarkable multicatalytic performance in water-cleaning applications. The present review explores the potentiality of BCZTO for water-cleaning and bacterial-killing applications. It also highlights the fundamentals of ferroelectric ceramics, the importance of electric poling, and the principles underlying piezocatalysis, photocatalysis, and pyrocatalysis processes in addition to the multicatalytic capability of ferroelectric BCZTO ceramic.

Porous Hierarchical Ni/Mg/Al Layered Double Hydroxide for Adsorption of Methyl Orange from Aqueous Solution

A basic urea technique was successfully used to synthesize Mg/Al-Layered double hydroxides (Mg/Al LDHs), which were then calcined at 400 °C to form Mg/Al-Layered double oxides (Mg/Al LDOs). To reconstruct LDHs, Mg/Al LDOs were fabricated with different feeding ratios of Ni by the co-precipitation method. After synthesis, the Ni/Mg/Al-layered double hydroxides (NMA-LDHs) with 20% and 30% Ni (S1 and S2) were roasted at 400 °C and transformed into corresponding Ni/Mg/Al-layered double oxides (NMA-LDOs) (S1a and S2b, respectively). The physiochemical properties of synthesized samples were also evaluated by various characterization techniques, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR), and Brunauer, Emmett, and Teller (BET). The adsorption behavior of methyl orange (MO) onto the synthesized samples was evaluated in batch adsorption mode under varying conditions of contact time, adsorbent quantity, and solution pH. As the dosage amount increased from 0.01-0.04 g, the removal percentage of MO dye also increased from 83% to 90% for S1, 84% to 92% for S1a, 77% to 87% for S2, and 93% to 98% for S2b, respectively. For all of the samples, the adsorption kinetics were well described by the pseudo-second-order kinetic model. The equilibrium adsorption data were well fitted to both Langmuir and Freundlich models for methyl orange (MO). Finally, three adsorption-desorption cycles show that NMA-LDHs and NMA-LDOs have greater adsorption and reusability performance for MO dye, signifying that the design and fabrication strategy can facilitate the application of the natural hydrotalcite material in water remediation.

Ball-milling synthesized Bi2VO5.5 for piezo-photocatalytic assessment

The mechanochemical ball milling followed by heating at 650 °C for 5 h successfully produced the single-phase Bi₂VO_5.5 powder. Catalytic activity for methylene blue dye degradation was investigated. Raman spectroscopy and X-ray diffraction were used to confirm the phase formation. The sample's charge carrier transportation behavior was ascertained using time-dependent photocurrent analysis. The piezo-photocatalysis experiment yielded a 63% degradation efficiency for the ball-milled Bi₂VO_5.5 sample. The pseudo-first-order kinetics of the piezo-photocatalytic dye degradation are discerned, and the significant k value of 0.00529 min^-1 is achieved. The scavenger test declares the h⁺ radical is the predominant active species during the piezo-photocatalysis experiment. Vigna radiata seeds were used in a phytotoxicity test to evaluate the germination index. The mechanochemical activation method facilitates reactions by lowering reaction temperature and time. The effect of improved piezo-photocatalytic efficiency on the ball-milled Bi₂VO_5.5 powder is an unexplored area, and we have attempted to investigate it. Here, ball-milled Bi₂VO_5.5 powder achieved improved dye degradation performance.

Cotton functionalized with polyethylene glycol and graphene oxide for dual thermoregulating and UV-protection applications

A thermoregulating smart textile based on phase change material (PCM) polyethylene glycol (PEG) was prepared by chemically grafting carboxyl-terminated PEG onto cotton. Further deposits of graphene oxide (GO) nanosheets were made on the PEG grafted cotton (PEG-g-Cotton) to improve the thermal conductivity of the fabric and to block harmful UV radiation. The GO-PEG-g-Cotton was characterized by Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and field emission-scanning electron microscopy (FE-SEM). With an enthalpy of 37 and 36 J/g, respectively, the DSC data revealed that the functionalized cotton's melting and crystallization maxima occurred at 58 °C and 40 °C, respectively. The thermogravimetric analysis (TGA) presented that GO-PEG-g-Cotton was thermally more stable in comparison to pure cotton. The thermal conductivity of PEG-g-Cotton increased to 0.52 W/m K after GO deposition, while pure cotton conductivity was measured as 0.045 W/m K. The improvement in the UV protection factor (UPF) of GO-PEG-g-Cotton was observed indicating excellent UV blocking. This temperature-regulating smart cotton offers a high thermal energy storage capability, better thermal conductivity, thermal stability, and excellent UV protection.

Comparative Study of the Effective Properties of 0-3 and Gyroid Triply Periodic Minimal Surface Cement-Piezocomposites

In the present numerical simulation work, effective elastic and piezoelectric properties are calculated and a comparative study is conducted on a cement matrix-based piezocomposite with 0-3 and gyroid triply periodic minimal surface (TPMS) inclusions. The present study compares the effective properties of different piezoelectric materials having two different types of connectivity of the inclusions namely, 0-3 inclusions where the inclusions are physically separated from each other and are embedded within the matrix and the second one is TPMS inclusions having interpenetrating phase type connectivity. Effective properties are calculated for four different materials at five different volume fractions namely, 10%, 15%, 20%, 25%, and 30% volume fractions of inclusion by volume. In terms of effective properties and direct piezoelectric effect, TPMS piezocomposite is found to perform better compared to 0-3 piezocomposite. Lead-free piezoelectric material 0.5Ba(Ca_0.8Zr_0.2)O₃ - 0.5(Ba_0.7Ca_0.3)TiO₃ demonstrates better performance compared to all other material inclusions studied. The present study attempts to highlight improved piezoelectric effective properties of lead-free material-based piezocomposites with TPMS inclusions.

Effect of Poling on Photocatalysis, Piezocatalysis, and Photo-Piezo Catalysis Performance of BaBi4Ti4O15 Ceramics

This study focuses on analyzing the poling effect of BaBi₄Ti₄O₁₅ (BBT) on the basis of photo and piezo-catalysis performance. BBT powder is prepared via a solid state reaction followed by calcination at 950 °C for 4 h. BBT is characterized by an X-ray diffractometer, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The optical bandgap of BBT is evaluated with the help of Tauc's plot and found to be 3.29 eV, which comes in the photon energy range of ultra-violet radiation. BBT powder is poled by using Corona poling in the presence of 2 kV mm^-1 of electric field. An aqueous solution of methyl blue (MB) dye in the presence of UV radiation is used to evaluate the photo/piezocatalysis performance. Photocatalysis, piezocatalysis, and photo-piezo catalysis degradation efficiencies of poled and unpoled BBT powder are tested for 120 min of UV light irradiation. Photo-piezocatalysis shows degradation efficiencies of 62% and 40% for poled and unpoled BBT powder, respectively. Poling of BBT powder shows significant enhancement in degradation performance of MB dye in aqueous solution. Scavenger tests are also performed to identify reactive species.

Coding Metamaterial Analysis Based on 1-Bit Conventional and Cuboid Design Structures for Microwave Applications

This study aimed to investigate the compact 1-bit coding metamaterial design with various conventional and cuboid shapes by analysing the bistatic scattering patterns as well as the monostatic radar cross-section for microwave applications. The construction of this metamaterial design depends on binary elements. For example, 1-bit coding metamaterial comprises two kinds of unit cell to mimic both coding particles such as '0' and '1' with 0° and 180° phase responses. This study adopted a 1 mm × 1 mm of epoxy resin fibre (FR-4) substrate material, which possesses a dielectric constant of 4.3 and tangent loss of 0.025, to construct both elements for the 1-bit coding metamaterial. All simulations were performed using the well-known Computer Simulation Technology (CST) software. The elements were selected via a trial-and-error method based on the phase response properties of the designs. On the other hand, the phase response properties from CST software were validated through the comparison of the phase response properties of both elements with the analytical data from HFSS software. Clear closure was obtained from these findings, and it was concluded that the proposed conventional coding metamaterial manifested the lowest RCS values with an increasing number of lattices. However, the cuboid-shaped design with 20 lattices demonstrated an optimised bistatic scattering pattern of -8.49 dBm². Additionally, the monostatic RCS values were successfully reduced within the 12 to 18 GHz frequency range with -30 to -10 dBm² values. In short, the introduced designs were suitable for the proposed application field, and this unique phenomenon is described as the novelty of this study.

Sonophotocatalytic Dye Degradation Using rGO-BiVO4 Composites

Reduced graphene oxide (rGO)/bismuth vanadate BiVO₄ composites are fabricated with varied rGO amounts (0, 1, 2, and 3 wt%) through the synergetic effects of ultrasonication, photoinduced reduction, and hydrothermal methods, and the materials are tested as tools for sonophotocatalytic methylene blue (MB) dye degradation. The effect of rGO content on the sonophotocatalytic dye degradation capabilities of the composites are explored. Characterization of the proposed materials is done through transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy as well as scanning electron microscopy. The coexistence of BiVO₄ and rGO is confirmed using Raman spectroscopy and XRD. TEM confirms the existence of interfaces between rGO and BiVO₄ and XPS affirms the existence of varied elemental oxidation states. In order to investigate the charge carriers transportation, time-dependent photocurrent responses of BiVO₄ and 2 wt%- rGO/BiVO₄ are done under visible light irradiation. The sonophotocatalytic MB dye degradation in an aqueous medium displays promising enhancement with rGO doping in rGO/BiVO₄ composite. The 2 wt%- rGO/BiVO₄ sample exhibits ≈52% MB dye degradation efficiency as compared to pure BiVO4 (≈25%) in 180 min of the sonophotocatalysis experiment. Phytotoxicity analysis through germination index is done using vigna radiata seeds.

POS0834 COMPARISON OF NOVEL INFLAMMATORY MARKERS IN IDIOPATHIC AND SECONDARY LEUKOCYTOCLASTIC VASCULITIS

Background

Positive diagnosis of Leukocytoclastic vasculitis (LV) is easy to establish via cutaneous biopsy, while etiologic diagnosis can be quiet challenging which leads to a still concerning high rate of idiopathic LV (ILV). Novel inflammatory Ratios such as platelet to lymphocyte ratio (PLR), neutrophil to lymphocyte ratio (NLR), C-reactive protein (CRP) to albumin ratio (CAR) and Fibrinogen to albumin ratio (FAR) have been recently described in multiple inflammatory pathologies, but their description and role in distinguishing idiopathic and secondary LV (SLV) is yet to be explored.

Objectives

We conducted a study aiming to compare new inflammatory markers and their potential role in distinguishing both LV subtypes.

Methods

Cross sectional study in which LV diagnosis was retained on cutaneous biopsy examination from January 2001 to November 2020. Patient’s clinical assessment and laboratory data measured for each patient included age and sex, aspect and extent of the LV cutaneous lesions, neutrophil (N) count, lymphocyte (L) count, platelet (PLT) count, CRP, albumin (ALB), gammaglobulin (GG). PLR, NLR, CAR and FAR were calculated according to the results of individual items. We have also defined the number of positive aetiological examination (NPE) as the sum in a unique patient of the positive para clinical examinations involved in the etiological assessment of LV.

Categorical variables were compared with the χ2 -test. Comparisons of the differences of continuous variables were performed by the Mann–Whitney U test or Student’s t-test. Pearson correlation ratio was used for linear correlation analysis.

Results

A total of 77 patients were included in this study with 52 patients in the SLV group and 25 patients in the ILV group, demographic and clinical characteristics of both groups were distributed respectively as followed: mean age at diagnosis was 44+/-18 vs 49+/-21, gender ratio was at 29/23 vs 11/14, petechial aspect (89% vs 92%), ecchymotic aspect (64% vs 52%), necrotic aspect (46% vs 28%), extent to the trunk (31% vs 46%) and extend to upper limbs (50% vs 55%), none of these differences were statistically significant (p>0.05).

Aetiologies of SLV were distributed as followed: IGA vasculitis 16 cases, Sjogren’s syndrome 6 cases, Systemic lupus erythematous and cryoglobulinemia 5 cases each, Viral hepatitis and infectious endocarditis 3 cases each, rheumatoid arthritis, granulomotosis with polyangeitis, post streptococcal and chlamydia infection 2 cases each, Castleman’s disease, tuberculosis, lymphoma, primary APS, periarteritis nodosa and parvovirus B19 infection 1 case each.

Comparison of PLR, NLR, CAR and FAR showed statistically significant difference in means between SLV and ILV groups with 199 (177-309) vs 127 (79-193) (p=0.01) for PLR, 3.6 (1.9-5.1) vs 2.3 (1.7-3.4) (p=0.048) for NLR, 1.9mg.g-1 (0.4-3.6) vs 0.6mg.g-1 (0.2-1.9) (p=0.043) for CAR, 156mg.g-1 (91-192) vs 108mg.g-1 (82-148) (p=0.034) for FAR.

PLR, CAR and FAR were significantly positively correlated to NPE (r=0.463, P<0.001; r=0.434, P<0.001 and r=0.411, P<0.001 respectively), there was no significant correlation between NLR and NPE (r=0.165, P=0.151).

Conclusion

In conclusion, this is the first study to explore the role of PLR, NLR, CAR and FAR in LV, it demonstrates that elevation of these ratios is a good predictor of SLV and that PLR, CAR and FAR were correlated with NPE in LV, which leads us to suggest to exhaustively explore patients with elevated ratios in order to make sure not to miss any underlying aetiology and provide more specific management for LV patients.

Disclosure of Interests

None declared

AB1362 LOCATION AND NUMBER OF SARCOIDOSIS GRANULOMA, A POSSIBLE DIAGNOSTIC ARGUMENT?

Background

Sarcoidosis is a non-necrotizing granulomatous disease which diagnosis is often challenging and requires elimination of other causes of granulomatous lesions. Location and number of granulomatous lesions in patients are not yet established as arguments in diagnosing this disease.

Objectives

We therefor conducted a study aiming to compare locations and number of granulomas between patients with sarcoidosis and patients with other granulomatous diseases (OGD).

Methods

Cross sectional study in which were included patients in whom non-necrotizing granulomatous lesions have been identified via biopsy over a period of 11 years (2010 to 2021) then were stratified into two groups: sarcoidosis group and OGD group. Categorical variables were compared with the χ2 –test or Fisher’s test. Comparisons of the differences of continuous variables were performed by the Mann–Whitney U test or Student’s t-test. Pearson correlation ratio was used for linear correlation analysis.

Results

30 patients were included in the sarcoidosis group and 32 in the OGD group.

Aetiologies in the OGD group were: 10 tuberculosis cases, 5 lymphoma cases, 4 Primary biliary cholangitis cases, 1 Castleman’s disease and 12 idiopathic granulomas.

Mean age was respectively in both groups 51+/-13 versus 57+/-17 years old (p=0.128), sex ratio (F/M) was 29/1 versus 27/5 (p=0.197).

Associated signs were distributed in both groups as followed: 11(37%) versus 5(16%) general signs (p=0.085), 15(50%) versus 20(63%) lymphadenopathy (p=0.442), 4(13%) versus 6(19%) inflammatory arthralgias (p=0.733), 13(43%) versus 2(6%) cutaneous lesions (p=0.001), 4 versus no ocular manifestations (p=0.049), 20 (66%) versus 3(9%) pulmonary manifestations (p<0.001), 5 (17%) versus 10 (31%) abdominal manifestations (p=0.239).

Cutaneous, salivary gland and ENT granulomas were significantly more frequent in patients with sarcoidosis with respectively 11(37%) versus 1 (3%) (12.3 risk ratio 95%CI 10.4 to 14.4)(p=0.001), 8 (27%) versus 0% (p=0.002), 8(27%) versus 2(6%) (4.5 risk ratio 95% CI 3.1 to 5.9)(p=0.025).

Lymph node, hepatic and pulmonary granulomas prevalence was not significantly higher in sarcoidosis patients, 17 (57%) versus 24 (75%) (p=0.180), 2 (7%) versus 5 (16%)(p=0.427), 3(10%) versus 0%(p=0.308).

Mean number of granulomas found in one patient was significantly higher in sarcoidosis patients with 1.7 (95% CI 1.5 to 2) versus 1.1 (95%CI 1 to 1.2) (p=0.001).

There was also a significant correlation between the number of granulomas in one patient and the angiotensin converting enzyme titres (r=0.566, 95% CI 0.360 to 0.771); (p=004).

Conclusion

This study shows that sarcoidosis patients have more often granulomas in the skin, salivary gland and ENT regions, and that the number of granulomas is on average superior in sarcoidosis than in OGD, these findings could be considered when establishing future diagnostic algorithms, as taking into account these elements could ease this diagnostic challenge in clinical practice.

Disclosure of Interests

None declared

Effect of TiO2/V2O5 substitution on the optical and radiation shielding properties of alkali borate glasses: A Monte Carlo investigation

In this paper, we used Geant4 Monte Carlo simulations to investigate the effect of TiO₂/V₂O₅ substitution on the radiation shielding properties of alkali borate glasses in the chemical form of 30Li₂O+55B₂O₃+5ZnO + xTiO₂+(10 - x)V₂O₅, where x = 0, 2.5, 5, 7.5, and 10 mol%. Also, the optical properties were examined by evaluating several factors such as molar refraction (R_m), metallization criterion (M), molar polarizability (α_m), dielectric coefficients (static and optical), optical transmission (T), and reflection loss (R_L). The radiation shielding properties of the tested glasses were estimated by determining the mass attenuation coefficient, and other related factors such as the tenth value layer (TVL), the mean free path (MFP), the electron total stopping powers (Ψ_e) and the electron continuous slowing down approximation range (CSDA) (Φ_e) for different energy values. The results of Geant4 Monte Carlo were compared with the theoretical values calculated by XCOM platform. The results revealed that the TiO₂/V₂O₅ substitution had a remarkable influence on the gamma shielding properties for the tested glasses. On the other hand, the optical properties slightly changed by the TiO₂/V₂O₅ substitution. The gamma shielding properties of the tested glasses were compared with many samples in terms of MFP. The present glasses showed superior features to apply for optical and radiation shielding applications.