Nickel Sulfate Research Articles

Allergens Causing Allergic Contact Dermatitis in Cosmetic Products: A Systematic Review

Background: The increasing use of cosmetics worldwide has led to a rise in allergic reactions, particularly due to inadequate risk assessment. Identifying common allergens in cosmetic products causing dermatitis is crucial for effective prevention and management strategies. Objectives: This systematic review aims to determine the list of allergens that most commonly cause allergic contact dermatitis in cosmetic products and to find the patch test positivity rate for cosmetic products. Methods: This systematic review, following the PRISMA guidelines, investigated patch test results on cosmetic-induced contact dermatitis from January 2013 to September 2023 on PubMed, Cochrane, and Medline databases. Inclusion criteria comprised retrospective cohort and clinical trial studies reporting patch test positivity rates and positive allergens in cosmetics, with eligibility determined through independent screening, full-text evaluation, and data extraction. Exclusion criteria comprised abstract-only publications, non-English or Indonesian languages, review articles, and studies with incomplete text. Result: 13 studies were included out of 2,162 initially screened articles, involving 111,097 participants. The selected studies encompassed ten retrospective studies and three clinical trials conducted in various locations, including India, Brazil, North America, Korea, Sweden, and the Czech Republic. The patch test positivity rate ranged from 13% to 100%. The predominant allergens identified in cosmetics were nickel sulfate, fragrance mix I, cobalt chloride, para-phenylenediamine base, potassium dichromate, and balsam of Peru. Conclusion: This systematic review highlights the diversity in patch test positivity rates and identifies key allergens responsible for allergic contact dermatitis in cosmetic products, emphasizing the need for comprehensive evaluation and awareness of cosmetic safety.

Role of the ROS/NLRP3/caspase-1 pathway in NiSO4-induced cellular pyroptosis and apoptosis in H9c2 cells

According to comprehensive research, the cardiovascular system is damaged by nickel exposure. The present study selected rat cardiomyocytes (H9c2 cells) and subjected them to varying doses of sodium nickel sulfate (NiSO4) for 24hours to better understand the mechanism of cardiovascular damage caused by NiSO4 exposure. The relevant indicators were detected employing biochemical analysis, real-time quantitative polymerase chain reaction (RT-qPCR), and western blot, and flow cytometry was used to detect the cell apoptosis rate. The study revealed that the survival rate of H9c2 cells fell significantly when the concentration of NiSO4 exposure rose. Moreover, it caused oxidative stress in H9c2 cells by raising the expression of reactive oxygen species and the concentration of LDH in the cell supernatants. After NiSO4 exposure, the levels of ASC, NLRP3, gasdermin D, and caspase-1 in H9c2 cells increased, suggesting that H9c2 cells underwent pyroptosis induced by NiSO4. In addition, NiSO4 exposure also led to inflammation, with increased levels of interleukin [IL]-18, IL-1β. After adding the antioxidant N-Acetyl-L-cysteine (NAC), the level of ROS indicated that the oxidative stress level in H9c2 cells was reduced, western blot inhibited inflammation, the level of pyroptosis was reduced, and the activity of the NLRP3/caspase1 signaling pathway was reduced. To examine the connection between pyroptosis and apoptosis, the cells were treated with the caspase1 inhibitor Z-YVAD-Fluoromethyl Ketone (Z-YVAD-FMK, YVAD), which resulted in a significant decrease in the rate of cell apoptosis as well as a reduction in the activity of the related protein in the signaling pathway, which in turn decreased the level of pyroptosis. NiSO4 could induce pyroptosis in H9c2 cells through the ROS/NLRP3/caspase-1 axis. Furthermore, NiSO4-induced apoptosis and pyroptosis were found to be reduced by the addition of the caspase-1 inhibitor.

Differential Diagnosis of Irritant Versus Allergic Contact Dermatitis Based on Noninvasive Methods

Introduction: Irritant contact dermatitis (ICD) is characterized by direct injury to the epidermal cells, activating the innate immune response. Allergic contact dermatitis (ACD), in contrast, is delineated by a delayed hypersensitivity reaction of type IV. Despite the distinct etiopathogenic mechanisms underpinning each condition, the differentiation between them presents a significant diagnostic challenge. Objective: This study aims to determine whether a combination of clinical evaluation and noninvasive measurements—encompassing oxidative stress, erythema, hydration, melanin content, transepidermal water loss (TEWL), hemoglobin concentration, and skin texture and volume—can distinguish ICD from ACD. Methods: Two cohorts, each comprising 21 patients, were evaluated: one diagnosed with ICD and the other with ACD. All participants underwent biophysical and clinical assessments, along with Antera® 3D evaluations. Tape strips were utilized for skin sampling, and oxidative stress levels were measured via fluorescence assessments. Results: ICD prompts an almost immediate inflammatory reaction (peaking at 24 hours), whereas ACD incites a delayed response (72 hours). Noninvasive evaluated parameters as hemoglobin concentration, skin texture and volume, melanin content, erythema, and TEWL showed significant differences between the ICD and ACD cohorts (p < 0.05). The allergens amcinonide, nickel sulphate, cobalt chloride, budesonide, PPD, and thiuram mix were found to induce elevated levels of oxidative stress. Conclusions: The evaluation of patients with noninvasive parameters, including transepidermal water loss (TEWL), hemoglobin concentration, and skin texture and volume, could markedly aid in distinguishing irritant contact dermatitis from allergic contact dermatitis (ACD). Nevertheless, the study is constrained by a limited sample size.

The Clinical Phenotype of Patients with Contact Polysensitization, a Retrospective Cohort.

Background: Polysensitization, defined as contact sensitization to three or more allergens, is an allergic phenotype with a common genetic background. Our study aims to characterize the clinical features of patients with polysensitization. Methods: We analyzed patch test results of 5,082 patients from a designated contact dermatitis clinic in Tel Aviv between 2012 and 2022 and compared the polysensitized group with nonsensitized and oligosensitized patients, hence patients reacting to 1 or 2 allergens. Results: About 8.5% of patients were polysensitized. In the nonsensitized group, there were significantly fewer female patients and more children (P < 0.05) than in the polysensitized group. Asthma prevalence was linearly associated with the number of positive reactions in patch test. Polysensitized patients were more commonly suffering from hand eczema and an occupational etiology (P < 0.05). Textile dye mix, lyral, fragrance mix II, formaldehyde, colophonium, and p-phenylendiamine were more common sensitizers among the polysensitized group, whereas nickel sulfate, 2-hydroxyethyl methacrylate, fragrance mix 1, p-tert-butylphenol formaldehyde resin, and sodium metabisulfite were more common among the oligosensitized group. Conclusions: The association between polysensitization, asthma prevalence, and sensitization to volatile allergens raises an intriguing clinical phenotype. Further mechanistic studies are needed in this regard.

Synthesis of NiO: BaO nano structure by chemical method with Antibacterial activity to Escherichia coli, Klebsiella spp., Staphylococcus aureus, Staphylococcus epedermidis andcandida spp

Nanostructured materials have garnered significant attention due to their remarkable chemical and physical characteristics. Because of their exceptional qualities and potential uses in technology. Nanostructured transition metal oxides are one of the many nanomaterials that need particular attention. The goal of this study was to synthesize nickel oxide and barium oxide nanostructures by the reaction of Nano powders: nickel sulphate NiSO4, barium chloride BaCl3, and molten sodium hydroxide, potassium hydroxide (NaOH: KOH) and examine their physical and biological properties. According to the results of UV–Vis, the gap band of the nanostructure was calculated with a range of 3.6–3.27 eV. Scanning Electron Microscopy (SEM) pictures appear to create aggregated nanoparticles with particle size of 29 nm according to Transmission electron microscopy (TEM) with a spherical shape. This results proved that NiO: Ba nanostructure an efficient and stable. It was observed that the diameter of the inhibition zone bacteria include E. coli and Klebsiella spp. (21,18) mm while inhibition zone of bacteria S. aureus,S. epidermidisgram positive bacteria and yeast candida spp.(19,19 and 21)mm. As can be shown, the antibacterial activity of the (NiO: BaO), nanostructure increases with decreasing concentration and is more effective against E. coli gram-negative than it is against S. aureus and S. epedermidis gram-positive. This finding might be explained by the fact that, due to differences in their cell wall composition, gram-negative bacteria are more vulnerable to antibacterial medications than gram-positive ones. The synthesized NiO: Ba nanostructures had the potential for higher inhibition and killing of gram-negative than gram-positive bacteria.

Enhancing energy storage with binder-free nickel oxide cathodes in flexible hybrid asymmetric solid-state supercapacitors

The need for flexible electrode materials for the development of flexible supercapacitors has drawn scientific interest recently. We present the successful synthesis of nickel oxide thin films using the successive ionic layer adsorption and reaction (SILAR) method, with the use of three different cationic precursors. This paper provides comprehensive details on the synthesized nickel oxide structure, morphology, and elemental analysis in addition to its electrochemical characteristics, which include specific capacitance (SCs), charge transfer resistance, etc. The produced nickel oxide electrodes achieved specific capacity as 120 C g−1, 517 C g−1, and 1147 C g−1 with different nickel precursors such as nickel chloride, nickel nitrate, and nickel sulfate respectively, at a 1 mA cm−2 current density. A flexible hybrid asymmetric solid-state supercapacitor (FHASS) (S:NiO//PVA-KOH//CuS) device delivered SCs of 165 Fg−1 at a 0.5 mA cm−2 current density, with a maximum SE of 58.87 Wh kg−1 at SP 347 W kg−1. FHASS device exhibits capacitive retention and coulombic efficiency of between 79 % and 96 % after 5000 successful GCD cycles. Also, the device retained an outstanding 97 % of its capacitance at a 175º bending angle. Furthermore, to illustrate its real-world applicability, the constructed device underwent 30 s of charging to a lightning LED table lamp for 90 s. The fabricated device is bringing a new era of broad integration of device-grade applications.

Comparison of patch testing Brazilian (Green) propolis and Chinese (poplar-type) propolis: Clinical epidemiological study using data from the Information Network of Departments of Dermatology (IVDK).

Propolis types differ regarding their chemical composition. To compare patch test results based on Brazilian (Green) propolis with data based on Chinese (poplar-type) propolis, and to evaluate the specifications of raw materials used for the PT preparations. In the Information Network of Departments of Dermatology (IVDK), 1290 consecutive patients were patch tested with Brazilian (Green) propolis (NH400, SmartPractice Europe). Patch test reactivity was compared with results obtained with Chinese (poplar-type) propolis (NA71, SmartPractice Europe) by calculating frequencies and corresponding 95% confidence intervals. Data on the specifications of raw materials used for NH400 and NA71 were obtained from the manufacturer. Positive reactions to NH400 were found in 303 (23.5%) patients with unclear clinical relevance in most cases. Patients reacting to NH400 were less often sensitised to fragrances and colophony, but more often to nickel sulphate and cobalt chloride than patients reacting to NA71. The NH400 batch used contained high levels of aerobic bacteria, and was not purified by ethanolic extraction. Pattern of concomitant reactivity along with raw material properties suggests that the high frequency of positive reactions to NH400 may primarily result from bacterial contamination or impurities in the PT preparation rather than from propolis constituents.

Comparison of Hardness by Electrolytic and Electroless Deposition of Nickel on Aluminium

Abstract The work deals with the hardness characteristic of substrates coated with nickel through two primary methods: electrolytic deposition and electroless Ni-P deposition. The optimised process parameters for both the process was determined by varying a particular parameter keeping the rest constant in order to obtain minimum crystallite size of Ni. The size of the crystallite were determined using Scherrer’s equation. The optimized combination of process parameter for electrolytic deposition is: 270gm/lt of Nickel Sulfate, 60gm/lt Nickel Chloride, 35gm/lt Boric Acid, current density of 90mA/cm2 bath temperature of 55°C. The optimized combination of process parameter for electroless Ni-P deposition: 34gm/lt Nickel Sulfate, 23 gm/lt Sodium Hypophosphite, 46 gm/lt of Lactic acid, 42 gm/lt of Sodium Citrate, pH 5.0 and bath temperature 85°C. The optimised deposition rate 22μm/hr. Micro-hardness (Vickers) tests were conducted on the coated samples with a 50 gf load. The cause for difference in hardness was due to buildup of residual stress during deposition of Nickel on the substrate(aluminium). The orientation and surface texture of the materials are determined.

Comparative study of Ni nanoparticles synthetized using electroless Ni plating waste and an analytical Ni reagent. Characterization and possible application in magnetic fluids

Wastewater from the electroless industry represents a potential danger to the environment and health, mainly due to its heavy metal content. In this study, nickel nanoparticles were synthesized through chemical reduction precipitation by using an electroless nickel plating waste and hydrazine sulfate as reducing agent. The aim of the present work is twofold. First we want to extract the metal from the aqueous medium, minimizing its content to levels allowed by environmental regulations. Second, we aim to valorize the residue by recovering the precipitated nickel to be applied as a solid phase in a magnetic fluid (MF). It is found that the present synthesis method using N2H4 as reducing agent, allowed us to minimize the Ni concentration in the aqueous waste in 97.49 %. The properties of the recovered Ni precipitate is compared with the Ni nanoparticles (NPs) obtained from a solution prepared with analytical grade nickel sulfate. The synthesized materials from both the waste (Ni-R) and analytical reagent (Ni-A) were characterized by comparing their chemical, physical, and morphological properties. In both cases, the Ni-R and Ni-A precipitates, spherical Ni NPs of 8–10 nm crystallite sizes are obtained, agglomerated in a bimodal size distribution centered at 174.6 and 383.4 nm, and a monomodal size distribution centered at 63.6 nm, respectively. Both Ni precipitated samples are ferromagnetic, but the Ni-R sample has a higher magnetic saturation of 40 emu/g compared to 8 emu/g of the Ni-A sample. The difference in the rheological behavior of both precipitates could be attributed to the presence of surface oxidation having a relatively less contribution in the case of the Ni-R particles due to the higher average size of the particles. The Fe content, probably coming from the nickel-plated parts in spent baths, is slightly higher in the Ni-R sample. Thus, the present work shows that it is possible to valorize an industrial Ni-based residue, by obtaining Ni precipitates that in magnetic fluids give even better results than those expected under more rigorous experimental conditions, i.e., in cases where the quality of the chemical precursors is usually a determining factor.

Allergens causing contact dermatitis of the feet: Investigation and analysis of allergic reaction causes.

Allergic contact dermatitis of the feet is a significant problem that affects the quality of life and requires attention from the medical community due to the number of studied and still unidentified allergens. The purpose of this review article is to summarize the available scientific data regarding the most common allergens that cause ACD of the feet. Nickel sulphate, neomycin sulphate, thiuram mix and colophony occupy a significant place in the prevalence of allergies. The prevalence of sensitization to rubber and leather products can vary depending on the ethno-demographic characteristics of the country, as well as the specifics of a person's professional activity, such as the use of protective waterproof shoes, increased humidity of the microclimate, and atopy in anamnesis. Patch testing has been shown to be an important method for identifying allergens, however, not all footwear components are tested during patch testing with standard allergen series, requiring the use of patches made from patient shoe samples. Expanding the scope of patch testing to include other possible allergens is important for the accurate diagnosis of ACD of the feet and a more detailed study of those allergens that were previously considered rare.

Cradle to gate life-cycle assessment of battery grade nickel sulphate production through high-pressure acid leaching

The rising global demand for high-purity nickel (Ni) sulphate, primarily used in lithium-ion batteries, is largely met by processing Indonesian laterite ores via hydrometallurgy. However, this supply chain is associated with significant environmental challenges and lack of transparent industrial data. This study uses a cradle-to-gate life cycle assessment (LCA) approach to quantify the greenhouse gas (GHG) emissions and energy use associated with the production of mixed hydroxide precipitate (MHP) from low-grade Indonesian laterites via high-pressure acid leaching (HPAL), which is then refined in China for the production of battery-grade nickel sulphate hexahydrate (NiSO4·6H2O, NSH). Fifteen impact categories are analyzed using established impact assessment and allocation (mass and economic) methods. The analysis reveals that feed preparation/HPAL and purification are the stages that contribute most to environmental impacts and in particular to global warming potential (GWP). Mass allocation results in higher environmental impacts, with 36.8 kg CO2-eq per 1 kg of Ni in NSH for GWP, compared to 33.8 kg CO2-eq per 1 kg of Ni in NSH when economic allocation is used. Sensitivity analysis shows a potential reduction (up to 13 %) in key impact categories if production of NSH is fully integrated in Indonesia or a greener electricity mix is used. Overall, our results indicate that the production of MHP in Indonesia and its refinement to NSH in China has a GWP about two times higher than the global average. Given the limited number of LCA studies for the production of battery-grade nickel, this study highlights major environmental concerns for the NSH production process from Indonesian laterites and identifies opportunities for improvement, towards a more sustainable global battery supply chain.

Nitrogen Requirement and Nitrogen Form Preference by Radermachera hainanensis and R. sinica Plug Seedlings

Abstract Radermachera hainanensis Merr. and R. sinica Hemsl. are popular foliage plants raised from seeds. Nitrogen fertilizer can significantly influence medium pH and EC, plug seedling growth, and photosynthesis. Plug seedlings of both species, each with one pair of leaves, were subjected weekly to nutrient solutions with nitrogen (N) concentrations ranging from 0 to 32 mM. Nitrogen-deficient plants exhibited the lowest leaf area, SPAD-502 value, and shoot dry weight but the highest root-to-shoot ratio. Leaf area, SPAD-502 value, and root and shoot dry weights increased with increasing N concentration up to 12-16 mM, and gradually decreased thereafter. Well-grown plants with 12-16 mM N exhibited peak maximal fluorescence (Fm), photochemical quenching (qP) and the lowest minimal fluorescence (Fo) and non-photochemical quenching (qN). Seedlings received nutrient solutions with varying proportions of NH4-N: NO3-N (0:100, 25:75, 50:50, 75:25, and 100:0, in percentages) at 16 mM N. Both species exhibited reduced leaf area, SPAD-502 value, and plant dry weights when supplied with only NO3-N or NH4-N. Maximum growth was achieved at a 50% NH4-N: 50% NO3-N ratio. Species used in this study: Golden jasmine tree, Radermachera hainanensis Merr.; China Doll, Radermachera sinica Hemsl. Chemicals used in this study: ammonium nitrate; sodium dihydrogen phosphate; potassium sulphate; potassium nitrate; magnesium sulfate heptahydrate; calcium sulfate dihydrate; calcium nitrate tetrahydrate; ammonium sulfate; boric acid anhydrous; potassium chloride; ferrous sulfate heptahydrate; disodium ethylenediaminetetraacetic acid dihydrate; copper sulfate pentahydrate; zinc sulfate heptahydrate; molybdic acid; manganese sulfate monohydrate; nickel sulfate hexahydrate; sodium hydroxide.

Hand eczema in Italian patients referred for patch testing: A retrospective SIDAPA study (2016-2023).

Hand eczema (HE) is a common skin disease with a negative impact on patients' quality of life in occupational and non-occupational settings. Up-to-date, data on HE in Italian patients referred for patch testing are lacking. To characterise the profile in terms of demographics, aetiology and patch test results of Italian patients affected by HE referred for patch testing. A retrospective descriptive study on consecutive patients affected by HE who underwent patch testing from 2016 to 2023 in eight dermatology clinics was performed. HE patients were divided into two groups according to the exclusive (HE-only group) and not-exclusive (HE+ group) hand involvement, and compared to patients with eczema localised in body areas other than hands (NHE group). One thousand five hundred and ninety-seven patients were affected by HE (35.3% males; mean age 42.7 years), 60.2% belonging to the HE-only group and 39.8% to the HE+ group. Occupational dermatitis was diagnosed in 33.2% of HE-only patients, 25.0% of HE+ patients and 5.2% of NHE patients (p < 0.001). HE-only patients presented: Allergic Contact Dermatitis (ACD), Irritant Contact Dermatitis (ICD), atopic HE in 48.1%, 47.5% and 7.1%, respectively; hyperkeratotic palmar, acute recurrent vesicular and nummular clinical subtypes in 52.2%, 43.9% and 11.9%, respectively; relevant positive patch test reactions in 48.1% (nickel sulphate 18.9%, methylchloroisothiazolinone/methylisothiazolinone 10.6%, methylisothiazolinone 8.6%, p-phenylenediamine 6.0% and potassium dichromate 4.7%). HE patients, and particularly those with exclusive hand involvement, show a particular profile in terms of demographic and clinical characteristics, etiologies and relevant positive patch test reactions.

Allergic contact dermatitis in adults with and without atopic dermatitis: Evaluation of the Spanish Contact Dermatitis Registry (REIDAC).

Atopic dermatitis (AD) and allergic contact dermatitis (ACD) are inflammatory skin conditions whose association is not clearly defined. To identify differences in ACD profile between patients with and without AD among those referred for patch testing. Additionally, to determine the prevalence of sensitisation to standard Spanish contact allergens in both groups. We analysed two groups (AD and non-AD) within the Spanish Registry of Research in Contact Dermatitis and Cutaneous Allergy (REIDAC). Contact allergy, clinical relevance and epidemiological data were compared between them. A total of 5055 patients were included. Among them, 23% (1168) had a history or final diagnosis of AD. At least one positive reaction was seen in 468 (40%) of AD patients and 1864 (48%) of non-AD patients. In both groups, the most common positive reactions were to nickel sulphate, methylchloroisothiazolinone/methylisothiazolinone and cobalt chloride. Age-adjusted OR for sensitisation to nickel sulphate was 0.72 (95% CI: 0.61-0.86), indicating a decreased likelihood of sensitisation in AD patients compared to non-AD individuals. We did not find an increased presence of ACD in patients with AD referred for patch testing, exhibiting similar profiles to non-AD population, except for a negative relationship between AD and sensitisation to nickel sulphate.

Trachyspermum ammi Mediated Green Synthesis of NiO Nanoparticles: Dual Role in Photocatalytic Degradation and Anti-bacterial Efficacy

ABSTRACT Nowadays, there is a lot of discussion in science about green chemistry of nanomaterials, from synthesis to various environmental applications. Herein, we describe a simple, environmentally friendly, economically feasible, free of additives, phytosynthetic methodology for the synthesis of cubic phased NiO nanoparticles using the seed extract of Trachyspermum ammi (also known as Ajwain), which acts as a capping and reducing agent that helps in reducing nickel sulphate (NiSO4.6 H2O) to NiO via co-precipitation method. Various spectroscopic techniques were involved in investigating the phase, morphology, functional groups, crystallinity, size, elemental confirmation, optical property with band gap of the green synthesised NiO Nanoparticles. Moreover, green NiO nanoparticles displayed excellent degradation efficiency for the reduction of industrial pollutant, Allura red and possible mechanism were also suggested. Nearly 91.73% of the Allura red was degraded using the synthesised NiO nanoparticles within 90 min when exposed to UV-light. Moreover, the used nanoparticles were renewed and again their photocatalytic performance was assessed for three consecutive cycles. In addition to photocatalytic activity, the green NiO nanoparticles revealed the considerable anti-bacterial activity against Staphylococcus aureus and Escherichia coli and the dead percentage was calculated as 92.56% and 94.33% respectively. In this work, green NiO nanoparticles was involved as a dual functioning agent for effective photocatalytic and anti-bacterial studies.

Separation of nickel and iron from ferronickel via sulfuric acid leaching and hydrothermal precipitation

ABSTRACT Here, a hydrometallurgical process was proposed to separate nickel (Ni) and iron (Fe) from ferronickel. The effects of different factors, namely hydrothermal temperature, initial Fe2+ concentration, and Ni2+ concentration, on the hematite precipitation process, were detail investigated. Ferronickel powders were leached using a 120 g/L H2SO4 solution at 85 °C for 8 h. The final pH of the leaching solution was controlled at 3.0−4.5, and the Fe2+ concentration was maintained at 50−60 g/L. Copper from the ferronickel powder was first leached in the early stage of the leaching process, and then it was reduced by an excess of ferronickel powder, leading to its enrichment in the leaching residue. Approximately 50 g/L of Fe ions was successfully removed and precipitated as hematite containing 60% Fe, 0.3% Ni, and 1.5% S during hydrothermal precipitation at 200 °C for 3 h. Through evaporation crystallization at 90 °C for 8 h, large particles of nickel sulfate hexahydrate (NiSO4·6H2O) containing 19.4% Ni, 0.074% Fe, and 10.69% S were obtained. Moreover, through freezing crystallization at −8 °C for 1 h, smaller particles of NiSO4·6H2O product containing 20.3% Ni, 0.014% Fe, and 11.13% S were synthesised.

Selective double-layer on black Ni-P enhances solar absorption and reduces corrosion

This work investigates a double-layer configuration for the black Ni-P layers used in solar adsorption technology, aiming to increase the absorption of a broader range of solar wavelengths. This multilayer configuration has a surface with increased roughness and absorption area. The valleys were porous materials, which were connected to an underlying metallic sub-layer that is susceptible to corrosion. In turn, this corrosion induced changes to the top layer. The Ni-P layer was deposited by the electroless technique using an acid nickel sulfate bath as a source of metal ions and a reducing agent of sodium hypophosphite. Etching initiated an oxidation process on the surface, forming a layer of amorphous black nickel oxide for absorption. The surface features of the black Ni-P double layer consist of an uneven surface that aids sunlight adsorption. Carbon steel (AISI 1018) with different surface finishes was used for depositing Ni-P and black Ni-P, aiming to establish correlations with solar adsorption. The sample with an increased surface roughness obtained a higher absorption percentage than a single layer. The corrosion rate was calculated as 7 mmpy for the black Ni-P layer by applying polarization curves. A 6 µm-thick Ni-P double layer was obtained, achieving 96% absorption within the 300–2,000 nm range.

BIO PROTECTIVE TREATMENT OF WOOD

The article covers issues related to biological protection of wood. It is shown that wood, especially chopped (dead) wood is exposed to both external natural factors and the action of various microorganisms. Natural factors, especially ultraviolet rays of solar radiation, change the chemical composition of wood and destroy lignin as the least stable part of wood. Wood is more intensively destroyed by various microorganisms ‒ bacteria and fungi. Wood contains many nutrients - starch, sugar, fats, compounds of nitrogen, phosphoric acid, sulfur, potassium, calcium and magnesium. All of them are an excellent environment for the settlement and reproduction of various microorganisms. It is noted that among hardwoods, beech wood is most negatively affected by microorganisms, especially in the warm period of the year. This wood is a valuable breed from which furniture, planed veneer and various parts and products in the construction industry are made. Therefore, it is very important to keep it intact and attractive for a long time by treating it with bioprotective agents. The purpose of the research is to determine the biostability of beech wood after its treatment with bioprotective agents. An analysis of the biological destruction of wood and the use of protective materials was conducted and it was established that the paucity of data to explain and describe the bioprotection process, the neglect of environmentally safe means leads to the biodestruction of wooden structures under the action of microorganisms. A bioprotective agent based on copper oxychloride, nickel sulfate and soda ash was used in a certain ratio of components. Control and treated samples of beech wood were placed in the prepared soil and after 60 days the weight loss of the samples was determined. Studies have shown that the biostability of beech wood treated with a bioprotective agent is 4.3 times higher than that of untreated samples. The idea of the reproduction of microorganisms in the material and their death has been revealed, which, accordingly, shows changes in the metabolic processes of the vital activity of microorganisms. It has been established that the use of treated surfaces oil-wax and azure reduces the biodegradation process by more than 8 times for untreated samples. Keywords: beech wood, bioprotective treatment, bioprotective agents, biostability determination method, mass loss, treatment efficiency.

Preparation and Characterization of Nickel Ferrite (NiFe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;) Nanoparticles by Surfactant-Free Electrochemical Method

Nickel ferrite (NiFe2O4) Nanoparticles have been synthesized by a simple surfactant-free electrochemical method at room temperature using iron plates as the cathode and anode electrode. nickel sulfate hexahydrate solution used as the electrolyte has a concentration of 0.04 M and pH 10. The voltage applied varied from 6, 9, and 12 V. We found that voltage and hydroxyl ions (OH-) presence have an important role in the formation of nickel ferrite nanoparticles. Particle size can be controlled by voltage. Nickel ferrite nanoparticles were produced in the form of gray powder and exhibited ferromagnetic properties. Material produced exhibits spinel oxide characteristics that confirms nickel ferrite presence. Nickel ferrite produced are nearly spherical with narrow size distribution having the size that can be classified as nanomaterial. Good electrochemical performance is legitimately observed for NiFe2O4 prepared in this work. This simple method is promising as a facile synthesis method for nickel ferrite nanoparticles.

Comprehensive Exploration of Optics and Magnetism in a Hydrothermally Synthesized Nickel(II) Complex.

The hydrothermal reaction of 2-MeIm (2-MeIm: 2-methylimidazole) with nickel sulfate hexahydrate in methanol afforded a mononuclear complex formulated as [Ni(SO4)(2-MeIm)2(H2O)3]·CH3OH (1). The title compound was described by X-ray single-crystal diffraction, thermal assessment, IR, and UV-vis spectroscopy. The crystal structure of 1 is composed of segregated [Ni(SO4)(2-MeIm)2(H2O)3] neutral entities and a solvent methanol molecule. Two (2-MeIm) ligands, a sulfate group, and a water molecule reside in the equatorial positions of the vertices in this 6-fold coordination. Two aqua ligands lay in the apical positions, resulting in a subtly distorted octahedral framework, as was supported by spectroscopic analysis. The complex's self-assembly is firmly governed by robust O-H···O/N-H···O interactions. Further details on these bonds have been furnished via Hirshfeld surface scrutiny and 2D fingerprint plots. As proven by TGA/DSC analysis, raising the temperature of 1 above 60 °C instigates progressive decomposition stages, which culminates in the production of metal oxide as the ultimate product at 700 °C. The optical analysis suggests the dielectric nature of the material with large direct and indirect gap energies of 5.25 and 4.96 eV, respectively. The results of magnetic studies suggest that 1 undergoes a transition to a magnetically ordered state below 6 K.