Magnesium Nitrate Research Articles

Tamarind gum based magnesium ion conducting polymer membrane for energy storage applications

A solid bio polymer electrolyte (SPE) based on tamarind gum (TG) and magnesium nitrate was synthesized by a solution casting technique. The amorphous behavior is observed by X-ray diffraction (XRD) analysis, and the degree of crystallinity is calculated from the XRD deconvolution spectra. The interaction between the polymer and the salt was confirmed by Fourier transform infrared (FTIR) analysis. Using FTIR deconvolution spectra, the percentage of free ions can be calculated. The glass transition temperature (Tg) was determined via differential scanning calorimetry (DSC). A higher ionic conductivity (σ) of 1.97 × 10−4 S/cm is observed for the sample with 1 g of tamarind gum and 0.5 g of magnesium nitrate (4 TMN). The conduction mechanism shows that sample 4 TMN obeys the quantum mechanical tunneling model (QMT) at low frequency. The prepared SPEs follow the Arrhenius behavior, and the minimum activation energy (Ea) of 0.207 eV is observed for sample 4 TMN. The lowest relaxation time (τ) was 3.46 × 10−7 s for 4-TMN according to the tangent spectra. The transference number of ions (tion) is calculated by Wagner’s polarization method. The electrochemical stability window observed by linear sweep voltammetry (LSV) is 2.25 V. The primary battery is fabricated by using sample 4TMN, and an open circuit voltage (OCV) of 2.01 V is observed.

Analysis of potential genotoxicity of deicing material in the test for induction of dominant lethal mutations in germ cells of male Drosophila

Introduction. Long-term use of deicing materials (DM) is one of the significant factors causing the active distribution of various chemical compounds that are part of multicomponent deicing mixtures in the environment. In this regard, the expansion of methodological approaches to assessing their biological hazard remains important. Materials and methods. The DM used for research based on a mixture of urea with magnesium and ammonium nitrates. The DM was tested in the form of an aqueous solution and added to the soil to obtain an aqueous extract. The analysis includes test for induced dominant lethal mutations in Drosophila male germ cells. Results. All samples tested significantly reduced the fertility of Drosophila males. The frequencies of early dominant lethal mutations (EDLM) significantly exceeded the levels of the controls, and the effects of the soil extract appeared at the lowest concentration – 5 g/L and of the DM solution – 10 g/L. The trend in the rate of late dominant lethal mutations (LDLM) indicates to the death of sperm or a decrease in mating potency. Limitations. The method of inducing dominant lethal mutations in Drosophila melanogaster and the genotoxic effects assessment of DM in the germ cells of male flies within the study has no restrictions. Conclusion. The conducted test is so far the only one in the field of research into the genetic safety of multicomponent DMs using a method for induced dominant lethal mutations in Drosophila male germ cells. The results prove the high informative rate of the methodological approach which involves analyzing soil extracts to identify and assess a genotoxicity of DM component composition when it enters the soil which can become as a transit layer for migration of DM components and their products transformation into groundwater.

The Impact of Activated Carbon–MexOy (Me = Bi, Mo, Zn) Additives on the Thermal Decomposition Kinetics of the Ammonium Nitrate–Magnesium–Nitrocellulose Composite

This research investigates the impact of additives such as activated carbon (AC) combined with metal oxides (Bi2O3, MoO3, and ZnO) on the thermal decomposition kinetics of ammonium nitrate (AN), magnesium (Mg), and nitrocellulose (NC) as a basic AN–Mg–NC composite. To study the thermal properties of the AN–Mg–NC composite with and without the AC–MexOy (Me = Bi, Mo, Zn) additive, a differential scanning calorimetry (DSC) analysis was conducted. The DSC results show that the AC–MexOy (Me = Bi, Mo, Zn) additive catalytically affects the basic AN–Mg–NC composite, lowering the peak decomposition temperature (Tmax) from 534.58 K (AN–Mg–NC) to 490.15 K (with the addition of AC), 490.76 K (with AC–Bi2O3), 492.17 K (with AC–MoO3), and 492.38 K (with AC–ZnO) at a heating rate of β equal to 5 K/min. Based on the DSC data, the activation energies (Ea) for the AN–Mg–NC, AN–Mg–NC–AC, and AN–Mg–NC–AC–MexOy (Me = Bi, Mo, Zn) composites were determined using the Kissinger method. The results suggest that incorporating AC and AC–MexOy (Me = Bi, Mo, Zn) additives reduce the decomposition temperatures and activation energies of the basic AN–Mg–NC composite. Specifically, Ea decreased from 99.02 kJ/mol (for AN–Mg–NC) to 93.63 kJ/mol (with addition of AC), 91.45 kJ/mol (with AC–Bi2O3), 91.65 kJ/mol (with AC–MoO3), and 91.76 kJ/mol (with AC–ZnO). These findings underscore the potential of using AC–MexOy (Me = Bi, Mo, Zn) as a catalytic additive to enhance the performance of AN–Mg–NC-based energetic materials, increasing their efficiency and reliability for use in solid propellants.

Effect of pH on the microstructure and antibacterial properties of MgO nanoparticles by microwave-assisted solution combustion

The application of magnesium oxide (MgO) nanoparticles as a candidate material for antibacterial purposes has been limited by their relatively low antibacterial activity. In this study, antibacterial MgO nanoparticles were synthesised in one step using magnesium nitrate and citric acid as raw materials using an economical and environmentally friendly microwave-assisted solution combustion approach, while the effect of the pH of the reaction system (2, 4, and 7) on the structure and antimicrobial properties of the synthesised MgO nanoparticles was investigated. X-ray diffraction (XRD) analysis demonstrated the formation of cubic-phase MgO nanoparticles, and electron microscopy studies confirmed that MgO nanoparticles synthesised at a precursor solution pH of 4 had uniform size distribution with a small microcrystalline size (∼19 nm) and spherical granular morphology. In addition, the results of the plate colony counting method showed that the antibacterial rate of MgO-4 against Gram-negative Escherichia coli (106 CFU/mL) at a sample concentration of 100 μg/mL was as high as 99.86 %, which showed excellent antibacterial performance. These findings provide valuable insights into how to increase the degree of oxygen adsorption on the sample surface to participate in the reaction, as well as a potential method for constructing nanomaterials with high antimicrobial activity.

Hydrothermal synthesis of three-dimensional snowflake-like MgCO3@MnCO3@Mn3N2 composite materials and their application in aqueous zinc-ion battery cathodes

Aqueous zinc-ion batteries have attracted considerable interest in the energy storage sector due to their distinctive advantages. The use of water as an electrolyte enhances their environmental friendliness, and the abundant and low-cost nature of zinc resources confers a significant economic edge. Manganese-based materials, utilized as cathode materials in these batteries, offer favorable electrical conductivity, high theoretical capacity, and superior stability. The paper describes the hydrothermal synthesis of magnesium- and manganese-based composite material MgCO3@MnCO3@Mn3N2, through the optimization of the amounts of magnesium nitrate and urea, as well as the hydrothermal and calcination conditions. Under the optimal synthesis conditions, the composite material achieved a high capacity of 457.8 mAh/g at the current density of 50 mA/g, with capacity of 391.5 mAh/g at the current density of 100 mA/g. Notably, even at the current density of 200 mA/g, the capacity remained above 300 mAh/g. The SEM tests reveal that the MgCO3@MnCO3@Mn3N2 composite material exhibits three-dimensional snowflake-like morphology at the microscopic level. The EDS tests indicate a very uniform distribution of manganese and magnesium elements. Both infrared and Raman spectroscopy tests detected characteristic peaks of carbonate groups. The XPS tests show that the oxidation states of Mn and Mg elements are consistent with those of MgCO3 and MnCO3. In the XRD test, data fitting analysis indicates that the predominant components of the composite material are MgCO3 and MnCO3, with a ratio approximating 5:4. The presence of a small quantity of Mn3N2 is also identified within the composite material. The composite material synthesized under this composition exhibits superior electrochemical performance.

Enhancing thermal conductivity of novel ternary nitrate salt mixtures for thermal energy storage (TES) fluid

Efficient thermal energy storage (TES) is crucial for concentrated solar power (CSP) plants, necessitating the exploration of advanced heat transfer fluids with enhanced thermal conductivity. Conventional binary nitrate salt mixtures have limitations in thermal performance, prompting research into ternary mixtures and nanoparticle additives. This study investigates novel ternary nitrate salt mixtures comprising potassium nitrate (KNO₃), lithium nitrate (LiNO₃), and magnesium nitrate hexahydrate (Mg(NO₃)₂·6 H₂O) as high-performance TES fluids during the during the heat absorption phase. Seven different salt compositions were synthesized and characterized using the laser flash technique to evaluate their thermal conductivity over 100–400°C. Results revealed a significant influence of composition on thermal conductivity, with maximum values during melting ranging from 0.0777 W/m·K to 0.7373 W/m·K. Melting points varied from 335 K to 340.39 K, demonstrating tailorability through compositional adjustments. Furthermore, incorporation of 0.5 wt% aluminum oxide (Al₂O₃) nanoparticles resulted in substantial thermal conductivity enhancements, with the most significant increase observed in TSF10 (from 0.0777 W/m·K to 0.491 W/m·K). These improvements are attributed to enhanced phonon transport, increased surface area, and Brownian motion facilitated by Al₂O₃ nanoparticles. The study provides a comprehensive cost analysis, including raw material costs, and discusses the potential efficiency gains for CSP applications. The findings contribute to the development of high-performance and cost-effective TES fluids, advancing the efficiency and viability of sustainable energy generation.

Partitioning of the high-level radioactive waste from the purex process by 40% TBF in isoparaffin using magnesium nitrate as a salting-out agent

Centrifugal contactor rig trials of the partitioning flowsheet were carried out using simulated and real high level waste solutions obtained by reprocessing of WWER-100 spent nuclear fuel with burn-up of 47 MW day/t. 40% TBP in Isopar M was used as a solvent with magnesium nitrate as a salting-out agent. Complete removal of Cs, Sr, Zr and Mo to raffinate was achieved. Rare earth elements, Am and Cm were totally concentrated in TPE and REE product. Comparison of the results of this work with previous trials with iron (III) nitrate as a salting-out agent [1] demonstrated that using magnesium nitrate as a salting-out agent resulted in higher decontamination factors of TPE and REE fraction from Cs (~10000) than using iron (III) nitrate (7500).

Correlation of Dielectric Properties and Vibrational Spectra of Composite PVDF/Salt Fibers.

Nitride salts were added to polyvinylidene fluoride fibers and then the fiber mats were prepared by electrospinning. An experimental investigation of the structure was provided by Raman, FTIR, SEM, and XRD. The phase ratio of the polymer was studied both theoretically and experimentally in connection with the addition of the hydrates Mg(NO3)2, Ca(NO3)2, and Zn(NO3)2 salts. The comparison of simulated and experimental data for vibrational spectroscopies is discussed. We provide a comparison of triboelectric, dielectric, and compositional characterization of PVDF fibers doped with three types of nitride hydrates. Doping of PVDF fibers with magnesium nitrate hexahydrate leads to significant improvement of the triboelectric performance.

Enhancing solar cell productivity with MgAl2O4–ZnAl2O4 blended anti-reflection coatings

The enhancement of productivity in solar cells primarily relies on the application of anti-reflection coatings. The current research employs coating materials such as MgAl2O4, ZnAl2O4 and blended MgAl2O4–ZnAl2O4 as an anti-reflective layer on the monocrystalline Si solar cells by employing RF sputter coating method. Magnesium nitrate hexahydrate and aluminium nitrate nonahydrate were utilized for the synthesis of MgAl2O4 by the sol-gel technique. ZnAl2O4 was synthesized using zinc nitrate hexahydrate and aluminum nitrate nonahydrate by sol–gel procedure. The performance of coated photovoltaic cells was evaluated through different characterization techniques. From the optical study, the blended MgAl2O4-ZnAl2O4 coating shows the maximum absorbance of around 93 % and lowest reflectance of 9 %. The MgAl2O4–ZnAl2O4 blend achieves a maximum power conversion efficiency (PCE) of 22.12 % in a controlled light source and 19.21 % in direct sunlight. Compared to other solar cells, blended MgAl2O4–ZnAl2O4 demonstrates low resistivity (4.23 × 10−3 Ω-cm), high carrier concentration (35.81 × 1020 cm−3) and maximum hall mobility (12.96 cm2/Vs). From the surface temperature measurement, it is evident that the MgAl2O4–ZnAl2O4 blend coated solar cell exhibits lowest temperature of 38.2 °C under simulated light. The experimental results indicate that the blended MgAl2O4–ZnAl2O4 coated photovoltaic cells exhibits superior productivity than the various coated and uncoated solar cells. Therefore, it can be stated that MgAl2O4–ZnAl2O4 blends are the excellent antireflective materials for achieving desired PCE in solar photovoltaic cells.

Glycine-magnesium nitrate tetrahydrate: A unique energetic complex for direct combustion synthesis of nanosized MgO

While numerous combustion methods have been explored for the synthesis of magnesium oxide (MgO), this study presents a unique approach that intentionally overcomes the inherent diffusion limitations associated with traditional combustion synthesis. This was achieved by forming a fuel and oxidizer complex from a 1:1 mol ratio of magnesium nitrate:glycine using the solvent evaporation method. Single crystal x-ray diffraction (SC-XRD) confirmed complex formation. DSC-TGA indicated that the complex reactivity is altered from a physical mixture and exothermically decomposes after partial dehydration. The resulting complex was then combusted to form MgO. The product morphology, as revealed by SEM, showed agglomerated foam-like structures with nanoscale particles on the order of 10 nm. This work demonstrates the potential for a host of metal nitrate-glycine complexes and opens possibilities for tailored applications from fertilizer delivery to catalyst formation.

Efficient Removal of Methylene Blue Dye from Aqueous Media Using Facilely Synthesized Magnesium Borate/Magnesium Oxide Nanostructures.

Methylene blue dye in water sources can pose health risks to humans, potentially causing methemoglobinemia, a condition that impairs the blood's ability to carry oxygen. Hence, the current study investigates the synthesis of novel magnesium borate/magnesium oxide (Mg3B2O6/MgO) nanostructures and their efficiency in removing methylene blue dye from aqueous media. The nanostructures were synthesized using the Pechini sol-gel method, which involves a reaction between magnesium nitrate hexahydrate and boric acid, with citric acid acting as a chelating agent and ethylene glycol as a crosslinker. This method helps in achieving a homogeneous mixture, which, upon calcination at 600 and 800 °C, yields Mg3B2O6/MgO novel nanostructures referred to as MB600 and MB800, respectively. The characterization of these nanostructures involved techniques like X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, N2 gas analyzer, and field-emission scanning electron microscope (FE-SEM). These analyses confirmed the formation of orthorhombic Mg3B2O6 and cubic MgO phases with distinct features, influenced by the calcination temperature. The mean crystal size of the MB600 and MB800 samples was 64.57 and 79.20 nm, respectively. In addition, the BET surface area of the MB600 and MB800 samples was 74.63 and 64.82 m2/g, respectively. The results indicated that the MB600 sample, with its higher surface area, generally demonstrated better methylene blue dye removal performance (505.05 mg/g) than the MB800 sample (483.09 mg/g). The adsorption process followed the pseudo-second-order model, indicating dependency on available adsorption sites. Also, the adsorption process matched well with the Langmuir isotherm, confirming a homogeneous adsorbent surface. The thermodynamic parameters revealed that the adsorption process was physical, exothermic, and spontaneous. The MB600 and MB800 nanostructures could be effectively regenerated using 6 M HCl and reused across multiple cycles. These findings underscore the potential of these nanostructures as cost-effective and sustainable adsorbents for methylene blue dye removal.

Highly pure hydrogen production via the thermocatalytic decomposition of methane over Ni/SiO2.MgO catalysts: Impact of the catalyst's chemical composition

The goal of current research is to focus on exploring the effects of various MgO/SiO2 ratios, emphasizing their impact on the structure properties and advancing the catalytic activity and the chemical life span of Ni-catalysts by an exciting mixture of SiO2 and MgO to generate COx-bare hydrogen and nanocarbon simultaneously from methane decomposition reactions. SiO2/MgO mixed oxides with different ratios (0.5, 1, and 2) were ready via a facile co-precipitation method from magnesium nitrate and sodium metasilicate and used as supports for various nickel contents (30, 40, 50, and 60 wt%) followed by an impregnation technique. Different analytical techniques, such as XRD, BET, SEM, EDS, H2-TPR, and TPO, were used to characterize the catalysts before and after the catalytic runs. The prepared catalysts with various SiO2/MgO molar ratios depicted the BET surface area limiting from 37.9 to 143.4 m2 g−1, indicating remarkable surface improvements. The vast CH4 conversion of 64 % earned on the 50 wt% Ni/SiO2·MgO at 575 °C. Moreover, lower deactivation was detected regarding this catalyst at 600 min on stream.

Effect of Annealing Temperature on Thermal Behaviour and Crystallinity of Zinc Oxide Supported Magnesium Aluminate (ZnO/MgAl2O4) Via Green Synthesis One Pot Fusion

Zinc oxide-supported magnesium aluminate (ZnO/MgAl2O4) was synthesized by the one-pot fusion method, consuming magnesium nitrate, aluminum nitrate, and citric acid as starting precursors. The samples prepared were annealed at temperatures ranging from 700 to 900°C to study the influence of annealing temperature on thermal behaviour and crystalline properties. The thermal behaviour of ZnO/MgAl2O4 was characterized by thermogravimetric analysis (TGA), while the structural properties and crystalline phase of ZnO/MgAl2O4 were analysed by X-ray diffraction (XRD). The TGA results show that there were three stages of decomposition in the sample. The first stage indicates the removal of water content from the sample; the second stage indicates the decomposition of citric acid; and the third stage represents the crystallization phase formation at a temperature range of 800- 950°C. The percentage of citric acid decomposition increases with increasing annealing temperatures up to 800°C. However, the decomposition rate gradually reduces at annealing temperatures between 850 and 900°C. XRD analysis results suggest that microstructured ZnO/MgAl2O4 with high crystallinity can be obtained at the highest annealing temperature. It can be concluded that the result of thermal behaviour represented by the decomposition stage is corroborated with structural and crystalline properties at increasing annealing temperatures.

Elucidating the role of magnesium in alkali-silica reaction: Performance and mechanisms

Alkali-silica reaction (ASR) is a major concrete deterioration causing volume expansion, cracking, and hence degradations in the strength and permeability of concrete structures. Despite a variety of ASR mitigation approaches having been investigated, the successful use of chemical admixture is limited to lithium salts, which have negative impacts on cement hydration and shrinkage behavior of concrete. To explore alternative substances for effective and economic ASR mitigation, the role of magnesium nitrate in mortars containing reactive aggregate is investigated at varying Mg/alkali ratios from 0 to 3.0 in terms of volume expansion, cracking behavior, silica dissolution, and modifications of ASR products. The results indicate that, at a Mg/alkali ratio of 0.74, the expansion and surface cracking density of the ASR-impacted mortar were decreased by 21.1 % and 39.1 %, respectively, which is superior to the efficacy of lithium nitrate. The 51.3 % less silica dissolution from aggregate, suppressed ASR gel formation, fewer Q3 polymerization sites in the silicate chains, less packed structure, and reduced alkali/Si ratio of the reaction products elucidate the underlying mechanisms across multiple length scales.

Thermal Characterization of [C2Im][NO3] and Multivalent Nitrate Salts Mixtures

Due to their intrinsic properties, the current applicability of ionic liquids is enormous. In particular, their use in electrochemistry is beyond question. Numerous studies on these compounds and their mixtures, especially with lithium salts, focus on their use as electrolytes for batteries and other energy storage devices. This includes thermal energy storage devices, where 4th generation ionic liquids and their derivatives show a huge potential. Nevertheless, considering the uneven availability of the raw materials, such as lithium, research has extended to mixtures of these compounds with other salts of different metals that are more abundant and widely distributed, such as magnesium or aluminum. This work presents a comprehensive thermal characterization, using differential scanning calorimetry and thermogravimetry, of the protic ionic liquid ethylimidazolium nitrate and its mixture with magnesium and aluminum nitrate salts at different concentrations. Additionally, a comparison between these results and previous studies of mixtures of this ionic liquid with lithium nitrate, as well as mixtures of the protic ionic liquid EAN with the same metal salts, was also performed. The results indicated that the salt addition tends to broaden and reduce crystallization and melting peaks, while the glass transition becomes more visible and shifts to higher temperatures with increasing salt concentration. This is due to the disorder generated by the rearrangement of ions in the polar domains, which erodes the hydrogen bond network of the protic ionic liquid. Nevertheless, the thermal stability of the blended samples does not change significantly compared to the bulk ionic liquid.

Automated infrared ashing with palladium nitrate as an ashing aid for the determination of selenium in plant foods by inductively coupled plasma mass spectrometry.

Based on the automatic light wave ashing instrument, palladium nitrate was used as an ashing aid for the first time to collect selenium in the process of food ashing pre-treatment, and a method for the determination of selenium in food by ashing method was established with inductively coupled plasma mass spectrometry. At the same time, the effects of magnesium nitrate, rhodium nitrate, and nickel nitrate as ashing aids on selenium collection were investigated using certified plant standard materials. The capture of selenium by magnesium nitrate, rhodium nitrate, and nickel nitrate as ashing aids did not exceed 50%. Using palladium nitrate as an ashing aid, six food standard materials were measured, with selenium recovery rates ranging from 97 to 106%. A complete analysis cycle can be completed within an hour. The method detection limit of selenium was 0.021μgg-1, and the relative standard deviation of five measurements was less than 7%. The experimental results show that palladium nitrate is an excellent ashing aid for capturing selenium, and it is far superior to the other three aids. In addition, the mechanism of palladium nitrate as an ashing aid for capturing selenium was discussed.

Understanding the Roles of Excipients in Moisture Management in Solid Dosage Forms.

Excipients are ubiquitous in pharmaceutical products, and often, they can also play a critical role in maintaining product quality. For a product containing a moisture-sensitive drug, moisture can be deleterious to the product stability during storage. Therefore, using excipients that interact with moisture in situ can potentially alleviate product stability issues. In this study, the interactive behavior of starch with moisture was augmented by coprocessing maize starch with sodium chloride (NaCl) or magnesium nitrate hexahydrate [Mg(NO3)2·6H2O] at different concentrations (5 and 10%, w/w). The effect of the formulation on drug stability was assessed through the degradation of acetylsalicylic acid, which was used as the model drug. The results showed that coprocessing of the starch with either NaCl or Mg(NO3)2·6H2O impacted the number of water molecule binding sites on the starch and how the sorbed moisture was distributed. The coprocessed excipients also resulted in lower drug degradation and lesser changes in tablet tensile strength during post-compaction storage. However, corresponding tablet formulations containing physical mixtures of starch and salts did not yield promising outcomes. This study demonstrated the advantageous concomitant use of common excipients by coprocessing to synergistically mitigate the adverse effects of moisture and promote product stability when formulating a moisture-sensitive drug. In addition, the findings could help to improve the understanding of moisture-excipient interactions and allow for the judicious choice of excipients when designing formulations containing moisture-sensitive drugs.

Exploration of Whitlockite Nanostructures for Hemostatic Applications.

Background Calcium magnesium phosphate (CMP)-based whitlockite is a promising biomaterial for hemostasis and regenerative applications. Regenerative approaches aimto advance tissue repair and recovery in different clinical scenarios. Whitlockite is a biocompatible and biodegradable mineral that has garnered impressive consideration for its interesting properties, making it an appealing candidate for therapeutic applications. Aim This study aimed to evaluate the hemostatic behavior of synthesized whitlockite nanoparticles. Materials and methods Coprecipitation and hydrothermal methods were used to synthesize whitlockite nanoparticles. Calcium nitrate, magnesium nitrate, and diammonium hydrogen phosphate were used as precursors to prepare this material. Results Crystalline phases of whitlockite(Ca3Mg)3(PO4)and calcium magnesium phosphateCa7Mg2P6O2were observed through X-ray diffraction (XRD) patterns, along with relevant properties of the phosphate functional group detected through Raman spectra. This study explores the hemostatic adequacy of CMP-based whitlockite using different methodologies. The capacity of the materials to actuate platelet conglomeration and encourage clot arrangement is assessed usingin vitro experiments. Moreover, this study investigates the regenerative potential of CMP-based whitlockite in tissue-building applications. Conclusion The structural and morphological parameters provide crucial insights into the proper formation of the material, and the hemoclot assessment aids in understanding its coagulation behavior. Future investigations and clinical trials will be instrumental in fully harnessing the potential of CMP-based whitlockite for advancing hemostasis and regenerative medicine.

Sustainable and Beneficial: Pollutant Absorption and Relative Humidity Control in Display Cases by Saturated Salt Solutions

ABSTRACT In the light of sustainability, the nearly forgotten control of relative humidity (RH) in display cases with saturated salt solutions is re-evaluated. Spilling and creeping of salts can be avoided. By choosing magnesium nitrate or potassium carbonate, the temperature dependence of the RH and the emission of harmful gases are negligible. Measurements with metal oxide semiconductor (MOS) gas sensors showed such solutions to be excellent absorbers for corrosive pollutants such as acids and aldehydes, especially the alkaline potassium carbonate (hitherto not used in museums). The practical application of such solutions in display cases is currently being tested in a community science project in a number of museums. This will result in improved guidelines for conservators and it is hoped, in a revival of this passive, failsafe, low-carbon footprint technique.

تقييم جودة المياه في سد سماقولي للشرب والري و تربية الاسماك

لقد أجريت هذه الدراسة لمعرقة نوعية المياه وملائمته لمختلف الاغراض كالشرب والري وتربية السمك في سد سماقولي وذلك بالاعتماد على مقياس نوعية وجودة المياه (WQI) بدلالة رقم مقياسى لاى استخدام مطلوب ، جمعت عينات المياه من ثمانية مواقع خلال فتره امتدت من شهر ايلول 2021 لغاية تموز 2022، حيث تم تحديد معيار جودة او نوعية المياه (WQI) لأغراض الشرب ، وذلك بالاعتماد على أهم خمسە عشر معيارًا فيزيائيًا وكيميائيًا بما في ذلك: الأس الهيدروجين(PH)،التوصيل الكهربائي EC))، التعكرTurbidity)) ، الأكسجين المذاب DO))، الأكسجين الكيميائي الحيوي المطلوب ، القاعدية الكلية TA))، العسرة الكلية TH))، أيونات الكالسيوم والمغنيسيوم Ca & Mg ions))، الصوديومNa) )، البوتاسيوم K))، الكلوريد Cl))، النتريتNO2) )، النترات NO3)) والكبريتاتSO4) ). كما إعطيت الوزن النسبي لكل متغيراو معيار تراوحت من 1 إلى 5 بناءً على أهم متغيراو معيار ضروري واساسى للحياة المائية والاستخدام اليومى و المنزلي. أشارت النتائج الدراسة إلى أن مياه سد سماقولي بمدخله ومخرجه صالحة للشرب بعد اجراء المعالجة التقليدية، اذ تراوحت نتائج (DWQI) لجميع المواقع بين ( 68.11إلى 83.93)، اما بالنسبة لمؤشر جودة او نوعية مياه الري (IWQI)، تم تحليل العينات المدروسة لمحتويات EC ونسبة امتصاص الصوديوم (SAR) والصوديوم (Na + 1) والكلوريد (Cl-1) وبيكربونات(HCO3).كما تراوحت نتائج (IWQI) من (68.84 إلى 70.20)، وهذا يدل الى أن عينات المياه تقع ضمن فئة الحصر المنخفض (LR) والمتوسط (MR) لأغراض الري. واخيرا سبع معايير استعملت شملت: الأس الهيدروجيني(PH)، التعكر (Turbidity) ، المواد الصلبة الذائبة (TDS)، الأكسجين المذاب (DO) ، القاعدية الكليةTH) ) والنتراتNO3) ). لتقييم نوعية وملائمة مياه سد سماقولى لتربية الاسماك بالاعتماد على محدودية المعيارى لكل وحدة من تلك المعاييرز أشارت النتائج لتلك المعايير فى جميع المواقع إلى أن المياه ملائمة ضمن محدودية المعايير لتربية الاسماك باستثناء معيارالعسرة الكلية TH..