Gravimetric Method Research Articles

Reconciled estimation of Antarctic ice sheet mass balance and contribution to global sea level change from 1996 to 2021

AbstractThe Antarctic Ice Sheet (AIS) has been losing ice mass and contributing to global sea level rise (GSLR). Given its mass that is enough to cause ∼58 m of GSLR, accurate estimation of mass balance trend is critical for AIS mass loss monitoring and sea level rise forecasting. Here, we present an improved approach to reconciled solutions of mass balance in AIS and its regions from multiple contributing solutions using the input-out, altimetric, and gravimetric methods. In comparison to previous methods, such as IMBIE 2018, this approach utilizes an adaptive data aggregation window to handle the heterogeneity of the contributing solutions, including the number of solutions, temporal distributions, uncertainties, and estimation techniques. We improved the regression-based method by using a two-step procedure that establishes ensembled solutions within each method (input-output, altimetry, or gravimetry) and then estimates the method-independent reconciled solutions. For the first time, 16 contributing solutions from 8 Chinese institutions are used to estimate the reconciled mass balance of AIS and its regions from 1996 to 2021. Our results show that AIS has lost a total ice mass of ∼3213±253 Gt during the period, an equivalent of ∼8.9±0.7 mm of GSLR. There is a sustained mass loss acceleration since 2006, from 88.1±3.6 Gt yr−1 during 1996–2005 to 130.7±8.4 Gt yr−1 during 2006–2013 and further to 157.0±9.0 Gt yr−1 during 2014–2021. The mass loss signal in the West Antarctica and Antarctic Peninsula is dominant and clearly presented in the reconciled estimation and contributing solutions, regardless of estimation methods used and fluctuation of surface mass balance. Uncertainty and challenges remain in mass balance estimation in East Antarctica. This reconciled estimation approach can be extended and applied for improved mass balance estimation in the Greenland Ice Sheet and mountain glacier regions.

Aspects of thermal utilization of organic poultry waste

Relevance. Currently, poultry farming, as part of the agro-industrial complex, is showing strong growth, which leads to an increase in the generation of organic waste. Chicken manure is a problematic organic waste from poultry farming in terms of its quantity, environmental hazard and moisture content. On the other hand, chicken manure is a potential renewable source of phosphorus. The use of chicken manure as a technogenic deposit of phosphorus will improve the level of environmental and food security. Aim. Research of influence of parameters of plasma and pyrolysis treatment of chicken manure on waste weight loss and phosphorus content in biochar. Methods. Experimental studies of the treatment of chicken manure with microwave plasma and induction pyrolysis; determination of the mass fraction of moisture during drying and loss of waste mass during disposal by the gravimetric method; determination of phosphorus in biochar using the Denizhe colorimetric method modified by A. Malyugin and S. Khrenova. Results and conclusions. The author has carried out the experimental studies on the treatment of chicken manure with microwave plasma and induction pyrolysis. It was shown that effective ways to reduce the mass of chicken manure and prevent environmental pollution are the treatment of manure with microwave plasma and its induction pyrolysis. It was established that when chicken manure is processed in microwave plasma in an inert environment at temperatures up to 1560°C, the mass of waste is reduced by 92.76% with an exposure duration of 7 minutes. At the same time, the content of P2O5 in biochar is up to 52.2 g/100 g of biochar. Further exposure to plasma leads to vitrification of the waste. As the time of treatment of chicken manure with microwave plasma increases, the loss of waste mass grows exponentially. Induction pyrolysis of chicken manure in an inert environment at a temperature of 1000°C makes it possible to reduce the mass of waste by 92.30%. P2O5 content in biochar grows with increasing pyrolysis temperature and amounts to 12.64 g/100 g of biochar. Biochar obtained by treating chicken manure with microwave plasma and induction pyrolysis can be considered as a source of phosphorus. The results obtained indicate the possibility of utilizing chicken manure using microwave plasma and induction pyrolysis.

Sorbents based on foamed phosphate glass for collecting petroleum oil products from contaminated soils and water surfaces

Relevance. The need to clean from pollution soils and water areas contaminated with oil and chemical industry wastes. Physico-chemical methods are one of the effective ways of cleaning, provided that sorbents are applied in time to collect contaminants from the surface of water areas and landscapes. Sorption is the most efficient and cost-effective method for relatively small scale pollution. Despite the variety of existing sorbents, in most cases when cleaning up accidental spills, first of all, economic benefits and oil capacity value of the sorbent are guided. However, such essential criteria as: 1) main purpose (type of polluted surface and nature of pollution); 2) physical and chemical properties, including structural characteristics and acid-base adsorption centers; 3) peculiarities of oil or other pollutants adsorption. Taking into account these factors, it is possible to develop and improve the formulation of sorbents based on phosphate foams. Introduction of various modifying additives into material composition is likely to expand their field of application. Aim. Development of formulation and technological features of obtaining new phosphate sorbents in relation to their intended purpose: for collecting oil and petroleum product spills from soil or water surfaces. Methods. Gravimetric, microscopic spectroscopic, statistical and comparative methods. Results and conclusions. The authors have compared sorbents no. 1 and 2 in terms of physical and chemical properties, morphology and cleaning efficiency. Based on our laboratory studies, we concluded that sorbent no. 1 is better suited for sorption from aqueous surfaces and sorbent no. 2 is better suited for soil cleaning. Both sorbents have the potential to improve their technological properties. This allows refining the formulation of these materials with further testing in laboratory and field conditions, for example, at oil spill sites. For this purpose, it is possible to change the material composition using a different foaming agent, applying modifying additives and varying the temperature mode of firing. Development of new compositions and methods of sorbent foaming will make it possible to select optimal characteristics for each type of contamination. The author proposed as well to create phosphate biosorbent obtained by immobilization of fungi and bacteria on the surface of highly porous carrier. In this case, after sorption of pollution, adsorbed substances will undergo biodegradation with the formation of safe products, and the sorbent will perform the role of fertilizer.

Experimental Study for the Sorption and Diffusion of Supercritical Carbon Dioxide into Polyetherimide.

Supercritical carbon dioxide (SCCO2) is a non-toxic and environmentally friendly fluid and has been used in polymerization reactions, processing, foaming, and plasticizing of polymers. Exploring the behavior and data of SCCO2 sorption and dissolution in polymers provides essential information for polymer applications. This study investigated the sorption and diffusion of SCCO2 into polyetherimide (PEI). The sorption and desorption processes of SCCO2 in PEI samples were measured in the temperature range from 40 to 60 °C, the pressure range from 20 to 40 MPa, and the sorption time from 0.25 to 52 h. This study used the ex situ gravimetric method under different operating conditions and applied the Fickian diffusion model to determine the mass diffusivity of SCCO2 during sorption and desorption processes into and out of PEI. The equilibrium mass gain fraction of SCCO2 into PEI was reported from 9.0 wt% (at 60 °C and 20 MPa) to 12.8 wt% (at 40 °C and 40 MPa). The sorption amount increased with the increasing SCCO2 pressure and decreased with the increasing SCCO2 temperature. This study showed the crossover phenomenon of equilibrium mass gain fraction isotherms with respect to SCCO2 density. Changes in the sorption mechanism in PEI were observed when the SCCO2 density was at approximately 840 kg/m3. This study qualitatively performed FTIR analysis during the SCCO2 desorption process. A CO2 antisymmetric stretching mode was observed near a wavenumber of 2340 cm-1. A comparison of loss modulus measurements of pure and SCCO2-treated PEI specimens showed the shifting of loss maxima. This result showed that the plasticization of PEI was achieved through the sorption process of SCCO2.

Examining the Impact of Cultivated Land Distance from Riparian Areas on the Growth and Quality of Red Kratom Alkaloids

The Kratom plant, a valuable forest species with medicinal potential, thrives in the Riparian area of Empangau Village, Kapuas Hulu District. This study explores the correlation between Kratom cultivation land distance from the river and alkaloid content. Employing a survey method, the research focuses on two locations: one situated 20-50 meters from the river (location 1) and another 580-650 meters away (location 2). Utilizing a quantitative approach and gravimetric methods, the study analyzes alkaloid content in Kratom extracts. The study reveals significant influences on pH, organic carbon, total nitrogen, phosphorus (P2O5), calcium, magnesium, potassium, sodium, cation exchange capacity (CEC), base saturation, and alkaloid compounds, contingent on the distance from the riparian area. Location 2 exhibits superior attributes, boasting a plant height of 6.02 m, stem diameter of 8,532 m2, 30 primary branches, leaf area of 262,576, and a total alkaloid content of 15,491%, surpassing location 1 with an average plant height of 5.66 m, stem diameter of 8,286 m2, 26.6 primary branches, and leaf area of 257,586. Variations in environmental conditions, vegetation, temperature, humidity, and nutrient availability contribute to these differences in alkaloid growth and quality, highlighting the potential for optimized Kratom cultivation in specific Riparian areas

Sodium salt of dodecyl benzene sulphonic acid as an effective corrosion inhibition for different heat-treated steel in sulphuric acid medium

Abstract The purpose of this work is to use electrochemical and gravimetric techniques to investigate the inhibition of DBSS on the corrosion of heat-treated dual-phase AISI 1040 steel in a 0.5 M sulphuric acid solution at 35 °C. The corrosion studies are performed by potentiodynamic polarization study (PDP), electrochemical impedance study (EIS), and gravimetric method. To confirm the inhibition surface characterization like x-ray diffraction technique (XRD) analysis, scanning electron microscopy (SEM), and EDS analysis are performed. Depending on the phase change of metals due to heat treatment, the corrosion inhibition of the heat-treated metal increased when it was exposed to 0.5 M H2SO4 at 35 °C in the presence of dodecyl benzene sulphonic acid sodium salt (DBSS) inhibitor. The highest inhibition efficiency of 63%, 82%, 87%, 43%, and 63% was obtained for AISI 1040 steel at heat treatment conditions of Normalized, Quenched at 700 °C, Quenched at 750 °C, Quenched at 790 °C and Quenched at 900 °C respectively. In the gravimetric and electrochemical study, the IE increases with the increase with the concentration of DBSS unto 75% from gravimetric analysis and 87% from PDP analysis for Quenched at 750 °C and 790 °C respectively. The metal protection is achieved by heat treatment process as well as by using DBSS as inhibitor. Corrosion inhibition on the metal’s surface was confirmed by SEM and XRD. In addition, the adsorption of DBSS on the anodic and cathodic sites of the metal surface was well explained.

Comparison of Gravimetric Determination of Methane Sorption Capacities of Coals for Using Their Results in Assessing Outbursts in Mines

The gravimetric method for determining coal gas sorption has many advantages and limitations. The article presents the influence of various factors on the results of methane sorption on coal. In mining practice, in addition to sorption properties of coal, knowledge of methane sorption capacity and effective diffusion coefficient determined when assuming a unipore sorption/desorption model are crucial for predicting sudden releases of methane from coal seams to a mine ventilation environment. In Poland, determining sorption capacities of coals for methane is mandatory when starting mining operations in new parts of coal deposits threatened by outbursts. Traditionally, gravimetric microbalances, such as intelligent gravimetric analysis (IGA), are used to determine adsorption capacity and desorption rate. Recently, newer microbalances XEMIS have been introduced to the market. Two gas laboratories, AGH in Krakow and CLP-B in Jastrzebie-Zdroj, respectively, compared experimental adsorption isotherms using XEMIS microbalances with mutually exchanged coal samples. Both sorption capacity at the pressure of 1 bar (a1bar) and effective diffusion coefficient (De) were independently determined for the coal samples tested. The results obtained are comparable despite the use of different microbalance XEMIS models. The conducted studies and comparative evaluation of the results allowed for assessing procedures for determining sorption properties using XEMIS microbalances. The exchange of laboratory experiences also allowed for the identification of methodology factors crucial for the development of a uniform procedure for conducting similar studies with XEMIS microbalance. The proposed factors for testing the sorption behavior of methane in coal structures may be helpful in mining practice.

Conversion of Isopropanol to Diisopropyl Ether over Cobalt Phosphate Modified Natural Zeolite Catalyst

This study aims to produce diisopropyl ether (DIPE) via isopropanol dehydration using cobalt-phosphate-supported natural zeolite catalysts. The catalytic activities of the zeolite/CoO and zeolite/Co(H2PO4)2 were compared. The as-prepared catalysts were assessed using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, and N2 adsorption-desorption. Surface acidity was determined using the gravimetric method with pyridine as the probe. The results of this study showed that natural zeolite was favorably impregnated by CoO and Co(H2PO4)2 species. The impregnation process affected the textural and acidic features of the catalysts. The zeolite/Co(H2PO4)2 catalyst with a loading of 8 mEq.g-1 exhibited the highest surface acidity of 1.827 mmol.g-1. This catalyst also promoted the highest catalytic activity towards isopropanol dehydration, with an isopropanol conversion of 66.19%, DIPE selectivity, and yield of 46.72% and 34.99%, respectively. The cobalt phosphate species promoted higher catalytic activity for isopropanol dehydration than the CoO species. This study demonstrated the potential of cobalt phosphate-supported natural zeolite catalysts for DIPE production with adequate performance. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Alkaline range pH sensor based on chitosan hydrogel: A novel approach to pH sensing

Monitoring of pH under extreme alkaline range is still a challenge due to the lack of accuracy and validity. This research developed a novel pH sensor (hydrogel/BTB) based on the transition of bromothymol blue from the hydrogel matrix into the pH-examining sample solution. The hydrogel/BTB sensor was synthesized through the solvent casting of chitosan, citric acid as the crosslinker, and bromothymol blue as a pH-sensitive dye. The structure of hydrogel/BTB was characterized using Fourier-transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDS), Field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) analysis, and thermogravimetric analysis (TGA). The effect of various parameters on pH determination was investigated. The developed pH sensor demonstrated a linear detection range validated from pH 10 to 14 using the gravimetric method, and from pH 11 to 14 using the colorimetric method. The sensor successfully detected pH in alkaline tap water, carbonate buffer, and ethanol amine buffer. The transition of bromothymol blue is described by the Peppas-Korsmeyer kinetic model. The activation and Gibbs free energy were obtained as 357.1 J/mol and 260 J/mol, respectively. This work furnished a new mechanism for pH detection, and it has excellent potential for developing novel sensors in this field.

Physicochemical and sensory properties of cookies with cricket powder as an alternative snack to prevents iron deficiency anemia and chronic energy deficiency

Cricket contains high protein content, making them a valuable resource for enhancing nutritional properties of cookies for prevents Iron Deficiency Anemia (IDA) and Chronic Energy Deficiency (CED) in female adolescents. This study evaluates the physicochemical properties and acceptability of cookies enriched with cricket powder. An experimental study with five treatments was conducted: F0 (0 %), F1 (5 %), F2 (10 %), F3 (15 %), and F4 (20 %). Texture was determined using a texture analyzer and color was assessed using a chromameter. Chemical attributes, including macronutrients, were determined using thermogravimetric, drying ash, Kjeldahl, Soxhlet, by difference, and gravimetric methods. Micronutrients (Fe, Ca, Zn) were measured using ICP-OES, amino acid profiles were analyzed using the HPLC, and in vitro protein digestibility was assessed using the enzymatic method. One-way ANOVA with Tukey's post hoc test, Kruskal-Wallis, and Mann-Whitney were used for statistical analysis. Adding cricket powder to cookies increased their nutritional content. While it reduced the lightness of the cookies' color, the texture quality remained comparable to commercial products. The F3 formulation was the most liked by panelists, and the best formulation was obtained in F4. In conclusion, adding cricket powder affects the physicochemical properties and consumer acceptance of the cookies, enhancing their nutrient content and protein digestibility.

Effect of spinach (Spinacia oleracea) leaf extract on the aluminum (Al) as a green corrosion inhibitor in HCl medium

Green corrosion inhibitors have recently attracted much attention due to their non-toxic properties, especially plant extracts. This study used spinach leaf extract (Spinacia oleracea) as a corrosion inhibitor on aluminum in an HCl medium. Spinach leaf extract (Spinacia oleracea) was obtained by maceration method, using ethanol as the solvent, which was then distilled to purify the extract. The corrosion inhibition properties were studied by the gravimetric method. The results showed that spinach leaf extract (Spinacia oleracea) can efficiently decrease the corrosion rate of aluminum in an HCl medium, achieving a maximum efficiency of 96.7742 %. Spinach leaf extract (Spinacia oleracea) formed a protective layer on the aluminum surface via adsorption and chemisorption, thus increasing surface coverage and blocking mass transfers. As the inhibitor concentration increases, the corrosion rate decreases, and the corrosion inhibition efficiency increases. This study shows that spinach leaf extract (Spinacia oleracea) is a viable organic corrosion inhibitor option with high efficiency.

An advancement of the gravimetric isotope mixture method rendering the knowledge of the spike purity superfluous

The gravimetric isotope mixture method is the primary method to determine absolute isotope ratios. This method, however, depends on the existence of suitable spike materials and knowledge of their purities. Determining the purity of the spikes can be tedious and labour-intensive. In this publication, an advancement of the gravimetric isotope mixture method, rendering the determination of the purity of the spike materials unnecessary, is presented. The advancement combines mass spectrometry and ion chromatography leading to an approach being independent of the purity of the spike materials. In the manuscript the mathematical background and the basic idea of the novel approach are described using a two-isotope system like copper or lithium.Graphical abstract

Comparison of Olea pollen sampling between gravimetric and volumetric traps (NW of Morocco)

Olea pollen is considered one of the most critical causes of respiratory allergic disease in the Mediterranean region, contributing to different symptoms in allergic sufferers. Due to the high increase in the prevalence of olive pollen caused by the expansion of cultivated areas especially in the Mediterranean region, the aim of this study was to examine the Olea pollen sampling efficiency between gravimetric and volumetric pollen traps over the period 2018–2022. Our data demonstrated that Olea pollen season start-date was generally recorded earlier with volumetric trap than shown with gravimetric method. Moreover, the peak dates occurred mainly in May for the years studied. Across the entire period, the greatest pollen concentrations were reached in the week 11th and >60 % of the total Olea pollen were already reached after the ninth week of sampling in 2020. In general, the evolution of pollen sampling for both methods demonstrates similar temporal development. Variations in the seasonal pollen integral could be attributed to the elevation above ground level at which the traps were placed, exposure to regional winds, the influence of long-range transported pollen and the mode of pollen transport. The findings indicate that the gravimetric method was equally practical as the volumetric method in estimating airborne pollen.

Inhibitory Effect of Fennel Fruit Essential Oil and Its Main Component Anethole of Corrosion on Steel Plates in 1 M HCL

Corrosion worldwide causes large losses of metal, which is why various ways are being sought to slow it down. The aim of this study was to investigate the inhibitory effect of fennel fruit essential oil (Foeniculum vulgare Mill.) and its main component anethole. The inhibitory effect of three different concentrations of the fennel essential oil and anethole (1.0 mL/L, 1.5 mL/L, and 2.5 mL/L) in a solution of 1 M HCl at 298 K for 6 h on a sheet of low-carbon steel was investigated. The inhibitory effect was established using gravimetric methods evaluating weight loss, corrosion rate, and inhibition efficiency, as well as electrochemical methods. In gravimetric studies, the inhibition effect of the inhibitors fennel essential oil and isolate anethole at a concentration of 2.0 mL/L was 70.85% and 45.86%, respectively. The anodic polarization curve data at 298 K demonstrate that the anethole and fennel essential oil adsorption on the metal surface creates a barrier that hinders hydrogen ions’ access and prevents them from being reduced on the steel surface’s cathode sites. Fennel essential oil acting as a mixed type-inhibitor can replace synthetic organic substances and could become an alternative to be used as environmental corrosion inhibitors.

LNG density measurement by gravimetric method

Density is a critical parameter in the liquefied natural gas (LNG) industry, which necessitates the study of measurement methods. Standard methods for calculating LNG density are employed in downstream LNG custody transfer, but it still faces challenges in density measurement in the upstream, such as in LNG plants and LNG refueling station. In this paper, a gravimetric density measurement method was established for LNG plants, which is SI-traceable as it relies on volume and mass. A home-made sampling device was developed and employed to obtain the LNG volume and mass. The principle involves trapping LNG in a known-volume quantitative tube within the sampling device. The LNG is then transferred to a vacuum sampling cylinder and weighed using a mass compactor. This approach not only provides representative samples but also enables compositional analysis while performing density calculations according to ISO 6578. Feasibility and practicality tests of this novel method were conducted in an LNG plant. The test results indicate that the reproducibility is 0.6 %(RSD), and the relative expanded uncertainty is 2.0 % (k = 2). Compared to the revised Klosek and McKinley method (RKM), it shows a relative difference of −0.3 % to 1.5 %, demonstrating the applicability to LNG plants.

The Reproductive Biology of Auchenoglanis biscutatus and Protopterus annectens from Lower River Benue Wadata, Makurdi-Nigeria

Data on the reproductive biology of Auchenoglanis biscutatus and Protopterus annectens were collected between april 2019 to march 2020. Reproductive parameters including sex ratio was determined as number of males by number of females, gonadosomatic index as total gonad weight by body weight and expressed in percentage while fecundity was obtained via volumetric and gravimetric methods. There was a slight dominance of males over females of both species (1.1:1) with more immature individuals caught within the study period. Higher GSI, gonad length and gonad weight (0.87±0.06, 15.94±0.89 and 3.01±0.19) were recorded in Auchenoglanis biscutatus during dry season while GSI and gonad weight (4.06±0.62, 5.63±0.45) of Protopterus annectens and number of mature fishes (0.35) were higher during rainy season. The relative fecundity for Auchenoglanis biscutatus investigated had no significant difference in both seasons (7.99±0.94, 8.22±0.78) while the relative fecundity for Protopterus annectentens differed significantly among the wet and dry seasons (3.43±0.94, 0.48±0.22). The relative fecundity of Protopterus annectens (11.59±2.04) was higher than that of Auchenoglanis biscutatus (8.04±0.75).it was concluded that the study of the sex ratio indicates that males were higher than females.

Absorptive Capacity of Gingival Retraction Cords in Hemostatic Solutions: An In Vitro Study.

Background and Objectives: Gingival retraction is a critical pre-impression procedure in fixed prosthodontics, crucial for exposing tooth margins and ensuring accurate impressions for restorations like crowns and bridges. This study aimed to evaluate the absorptive capacity of different gingival retraction cords. Materials and Methods: Ninety samples each of Ultrapak (Ultradent, South Jordan, UT, USA) #00, braided cord, coreless thread, and monofilament thread (totaling 270 samples) were immersed in 0.9% NaCl, 10% aluminum chloride, and 12.7% ferrous sulfate solutions for 120, 300, and 1200 s. The liquid absorption capacity was measured using a gravimetric method, and the data were analyzed using an F-test, setting the significance threshold at p < 0.05. Results: The results revealed statistically significant differences in absorption, particularly for aluminum chloride and ferric sulfate (p < 0.001). Ultrapak demonstrated the highest absorption, followed by the coreless cotton thread, while the monofilament thread absorbed the least, especially at 1200 s. Conclusions: These findings indicate that Ultrapak's superior absorption could enhance moisture control during procedures, highlighting the importance of selecting an appropriate retraction cord for optimal clinical outcomes. Further research is needed to confirm these findings in a clinical setting.

Effect of Ni Addtion on Electroless Cu for High Density Interconnect PCB Substrate

Introduction Nowadays, high-density interconnect (HDI) printed circuit board (PCB) substrates have been widely applied to high-end electronics to meet the increasing input and output (I/O) density and small footprint area. Micro-via, a tiny structure buried among build-up layers that provide electrical interconnection is a key component in the HDI substrate. However, the preparation of micro-via is facing new challenges. It is not only required that the size of the micro-via scales down to meet the increased interconnect density, but also that the micro-via should withstand severe operating conditions in different scenarios. Therefore, it is of great importance to improve the quality of micro-vias during processing and manufacturing. The micro-via structure is a sandwich structure that is processed by electroless Cu plating and Cu electrolyte plating sequentially, and thus the quality of the electroless Cu layer can significantly affect the reliability of micro-via. In this work, we mainly focused on the electroless Cu plating process and investigated the effect of the electroless Cu deposition speed on the quality of the micro-via structure. SIM and HR-TEM characterizations were employed to investigate the micro-structure inside the electroless Cu layer. Materials and Method In this study, we used the common alkaline ion catalyst method to prepare the electroless Cu layer. The electroless Cu plating and electrolyte Cu plating was conducted on a PCB Resin Coated Copper (RCC) substrate that was cleaned by soft etching in an acid condition. The surface is then pre-dipped in an anionic solution, and palladium ions were adsorbed using an alkaline ion catalyst. The electroless Cu processes adopted in a reaction bath that consists of Cu resource (CuSO4·5H2O), complexing agent (KNaC4H4O6·4H2O) and reductant (HCHO). The whole reaction was conducted in the alkaline condition with a PH of 12.5, and the thickness of the electroless Cu deposition was controlled at around 0.20 µm. NiSO4 is selected as the Ni precursor to alter the Ni concentration in the reation bath. The contents of Ni addition were selected as 50 %, 100 %, 200 % and 300% of a conventional process at a bath temperature of 27 ºC. The thickness of the plated Cu layer was measured by a gravimetric method. Results and discussion TEM observation was used to identify the structure at the interface. Fig. 1 shows the TEM observation of the sample with 50 % and 200 % Ni concentrate. There are some nanovoids found at the interface between the Cu substrate and electroless Cu, which is arguably due to hydrogen generated during electroless Cu plating. The sample with a higher reaction speed has more nanovoids. It can be due to that the higher reaction speed can generate more hydrogen bubbles in the bath that can attach to the electroless Cu layer, leading to nanovoids as shown in Fig. 1. The samples prepared at different bath temperatures are under investigation to illustrate that the reaction speed can significantly affect the Cu electroless layer quality. Conclusions In this work, we investigated the Ni effect in electroless Cu on the RCC substrate. It is found that the higher Ni incorporation can lead to massive nanovoids generation and fine Cu grains in the electroless layer, which is a potential risk for the reliability of the HDI substrate. By reducing the Ni incorporation content, the number of nanovoids can be effectively reduced. Figure 1

The Effect of Cation Contamination on the Water Transport for PEM Water Electrolysis

Large-scale hydrogen production by PEM water electrolysis (PEMWE) in the energy sector requires a deep understanding of the system behaviour in failure cases and possible recovery procedures. This includes the purification of the anolyte feed water because the contamination with ions can cause the PEMWE stack to breakdown.[1] For instance, the presence of iron trace cations or other metal cations in the feed water leads to a performance loss due to higher ohmic resistance of the cell and higher iR-free voltages.[2] [3] Moreover, cation contamination might influence the water transport in a PEMWE cell. In principle, the transfer of the water molecules to the cathode is proportional to the proton flux from the cathode to the anode. The proportionality factor is defined as water transport coefficient and is also temperature dependent.[4] In case of the mono- and multivalent cations as trace elements in the feed water, the water loading of the membrane, which is expressed by water molecules per sulfonic acid group of the membrane, λ, decreases over time and leads to successive increase in the ohmic resistance. [5] However, the influence of cation contamination on the water transport in PEMWE is poorly understood to date.In this work, we investigated the effect of cation contamination in the anode feed water on the water crossover for PEMWE. Cation contamination experiments were carried out at a constant current density by adding different concentrations such as K2SO4, Na2SO4, etc. to the anode feed water. All electrochemical measurements were carried out in an in-house test bench equipped with a single cell of 5 cm2 geometric electrode area and potentiostat with booster. A commercially available catalyst coated perfluorosulfonic acid membranes (loading of 0.3 mg cm-2 geo Pt/C and 1 mgcm-2 geo IrOx) was used. The anode and cathode compartments were kept at atmospheric pressure and cell temperature of 80°C. To determine the water crossover from anode to cathode at different current densities, the cathode exhaust was cooled in a heat exchanger and measured by a gravimetric method. [4] Firstly, a conditioning procedure was performed with purified feed water until steady cell performance was achieved. The cell performance was evaluated using polarization curves, electrochemical impedance spectroscopy (EIS) and water crossover measurements. The last two are of particular interest, because they provide information about membrane humidification. The Tafel slope and mass transport overvoltage were established from the polarization curves and high frequency resistance (HFR). We observed a significant rise of the cell voltage by adding cations to the anode water feed within few hours. The analysis of Tafel slope and EIS data also reveal an increase of ohmic and mass transport resistances. In these experiments, we were able to correlate the HFR results with the water crossover as a function of the nature of the cation and its concentrations. Our data shows that the specific water crossover per current density decreases as a consequence of cation contamination. The switch back to purified feed water allows us to monitor the dynamics of the performance recovery process obtained from EIS and water crossover measurements. Additional measurements of the polarization curves and HFR were used to distinguish between reversible and irreversible degradation processes due to the cation contamination.Altogether, we present the effect of cation contamination on the water transport processes and provide deeper insights into the mass transport and performance losses for PEMWE.

Laboratory Evaluation of Soil Moisture Sensors for Precision Irrigation in Agriculture

Water is essential for agricultural production and food security, making efficient water use critical. Accurate measurement of soil moisture is vital for scheduling irrigation, ensuring that crops receive the right amount of water at the right time. This prevents both under- and over-irrigation, conserving water and maximizing crop production. Currently, digital soil moisture sensors are used for their accuracy and instant measurement capabilities. The soil moisture sensor's functionality was evaluated through observations of four Capacitive soil moisture sensors 1.2 (SMS A, B, C, D) at various moisture levels, with gravimetric method verification. The calibrated linear equations demonstrated a strong linear relationship for each sensor. The coefficient of determination (R2) were also found to be 0.92, 0.93, 0.91 and 0.93 respectively. These R² values indicate a strong linear relationship for each sensor. An automated drip irrigation module was developed by integrating these soil moisture sensors with the Arduino platform. The system activates the irrigation motor when soil moisture content falls below the field capacity or a desired set value, and turns it off once the required moisture level is reached. This sensor-based automated drip irrigation module enables farmers to irrigate their fields precisely and efficiently, delivering the right quantity of water at the right time. The system is also suitable for deficit irrigation practices, improving crop yield and water use efficiency.