Potential Measurements Research Articles

The combined leaching of copper, gold and uranium in chloride solutions. II. Concentrate leach tests

This study of the simultaneous leaching of copper, gold and uranium from a flotation concentrate is aimed at establishing the conditions that could be applied in a possible heap leach process that would recover all three metals (plus silver, if present) in a single step. The results obtained in this study confirm the results obtained in Part I (Nicol et al., 2024) that enhanced rates for leaching of chalcopyrite from flotation concentrates from two different sources can be obtained in acidic chloride solutions in the presence of chlorate ions. The measurements of the solution potentials during leaching with chlorate are similar to those obtained previously and confirm that chlorine generated by the chlorate-chloride reaction is the active oxidant.Uranium is dissolved even in the absence of chlorate by iron(III) as the oxidant. The latter is re-generated by reaction of iron(II) with chlorate. The dissolution of gold requires higher potentials, and it is only leached when the potential approaches 1.0 V in concentrated chloride solutions. At low chloride concentrations (1 M), gold is not dissolved because of apparent passivation.An electrochemical study of the behaviour of gold in chloride solutions in the presence of sulfide ions has shown that the passivation is probably the result of the formation of a layer of Au2S on the gold surface at low potentials before the addition of chlorate to the leach solutions i.e., before the generation of sufficient chlorine concentrations. At potentials above about 0.95 V Au2S is unstable being oxidised to AuCl2− and elemental sulfur thereby eliminating passivation.

High loading and sustained-release system of doxorubicin-carbon dots as nanocarriers for cancer therapeutics

Nanocarriers for drugs have been investigated for decades, yet it is still challenging to achieve sustained release from nanomaterials due to drug loading inefficiency and burst release. In this study, we developed novel functional carbon dots (CDs) and investigated the therapeutic efficacy by studying the loading efficiency and release behavior of the anticancer drug doxorubicin (DOX). CDs were successfully synthesized using a one-step pyrolysis method with varying concentrations of citric acid (CA) and thiourea (TU). Functional groups, morphology, particle size, and zeta potential of synthesized CT-CDs and DOX loaded CT-CDs were investigated by UV-visible, Fluorescence, dynamic light scattering, Zeta Potential measurements, FTIR, and transmission electron microscopy. The zeta potential data revealed DOX loading onto CT-CDs by charge difference, i.e. -24.6 ± 0.44 mV (CT-CDs) and 20.57 ± 0.55 mV (DOX-CT-CDs). DOX was loaded on CDs with a loading efficiency of 88.67 ± 0.36%.In vitrodrug release studies confirmed pH-dependent biphasic drug release, with an initial burst effect and sustained release of DOX was found to be 21.42 ± 0.28% (pH 5), 13.30 ± 0.03% (pH 7.4), and 13.95 ± 0.18% (pH 9) even after 144 h at 37 °C. The CT-CDs were non-toxic and biocompatible with L929 Fibroblasts cells. The cytotoxic effect of DOX-CT-CDs showed a concentration-dependent effect after 48 h with Glioblastoma U251 cells. Flow cytometry was used to examine the cellular uptake of CT-CDs and DOX-CT-CDs in L929 and U251 cells. It was observed that the maximum CT-CDs uptake was around 75% at the end of 24 h. This study showed that the synthesized fluorescent CT-CDs demonstrated a high drug loading capacity, pH-dependent sustained release of DOX, and high cellular uptake by mammalian cells. We believe this work provides practical and biocompatible CDs for chemotherapeutic drug delivery that can be applied to other drugs for certain therapeutic aims.

Enhanced emulsification properties of microalgae protein through gellan gum conjugation: Mechanistic insights and applications in curcumin encapsulation and delivery

The emulsification properties of microalgae protein (MP) are poor, especially under acidic and neutral conditions, which may limit the broad applications of MP in food processing. This study aims to explore the effects of gellan gum (GG) on the emulsification properties of MP. Firstly, MP-GG complexes were prepared and their structures characterized. Subsequently, MP-GG complexes stabilized emulsions were prepared and their stability evaluated. Finally, these emulsions were employed for the encapsulation and delivery of curcumin to evaluate their potential as an efficient nutrient delivery medium. Results indicated that MP-GG complexes were formed under various pH conditions, with pH 6 identified as optimal for complexes stability (zeta-potential value was −31 mV). UV–vis and fluorescence spectroscopy demonstrated that GG did not significantly alter the MP's structure but induced slight conformational changes, leading to the burial of some amino acid residues. Zeta potential measurements confirmed that MP-GG complexes were stabilized by strong electrostatic repulsions. The increase of GG content was conducive to providing more negative charge and promoting the dissolution and dispersion of the MP-GG complexes (MP: GG = 1: 1). Emulsions stabilized by MP-GG complexes exhibited smaller droplet sizes and improved stability compared to those stabilized by MP alone, especially at oil phase volume fractions of 60 % and 70 %. Rheological analysis indicated that GG enhanced emulsion stability by increasing viscosity, and higher oil phase volume fractions facilitated better MP-GG complexes adsorption on oil droplets, strengthening network structures of emulsions. During in vitro simulated gastrointestinal digestion, emulsions with a 70 % oil phase exhibited higher curcumin retention rate (31.09 %) and lower curcumin bioaccessibility (13.23 %) compared to those with a 60 % oil phase. This suggests that emulsions with higher oil phase volume fractions may be more suitable for colon-targeted curcumin delivery, with potential applications in promoting colon health. These findings confirm that the complexation of MP and GG was an effective way to improve the emulsification properties of MP. Emulsions stabilized by MP-GG complexes can serve as stable nutritional delivery systems for fat-soluble bioactive compounds.

OTHR-08 ANALYSIS OF INCIDENCE AND TRENDS IN NEUROLOGICAL MALIGNANCIES IN BULAWAYO FROM 2012 TO 2021

Abstract OBJECTIVES We aim to quantify the incidence of neurological malignancies in Bulawayo from 2012 to 2021, to Identify any significant changes in the incidence rates over the decade, to explore the demographic, geographic, and socioeconomic factors that may influence the incidence of these malignancies and to compare the incidence trends with national and international data to understand the regional context.,as well as to identify any potential risk factors or preventive measures that could be targeted to reduce the incidence of neurological malignancies in Bulawayo. METHODS A retrospective observational study with analysis of primary data for 139 patients with neurological malignancies, collected from Cancer Registry for Zimbabwe’s southern region(Bulawayo being the center) over a decade will be done using SPSS and trends in terms of type of malignancy, distribution between sex and among different age groups as well as incidence for each year will be identified. RESULTS The results will quantify the incidence,as well as show the changes in incidence rates over the decade.it will also show the epidemiology of different neurological malignancies in the sample population and trends according to age and sex. CONCLUSION The key findings include trends of incidence for the given 10 years as well as variation in pattern of different malignancies across sex and age. The findings of the study will contribute to the understanding of neurological malignancies in Bulawayo as well as the Zimbabwe at large, however more evidence should be assessed in larger trials or by using national data.

Phenolic and Anti-Nutrients Compositions of Selected Underutilized Seeds: African Oil Bean Seed (Pentaclethra macrophylla), Cashew Nut Seed (Anacardium occidentale), Cucumeropsis Seed (Cucurbita maxima), Groundnut Seed (Arachis hypogeal) and Soya Bean Seed (Glycine max)

The study aimed to assess the levels of anti- nutrients and phenolic compounds in under-utilized seeds such as African oil bean seed (Pentaclethra macrophylla), cashew nut seed (Anacardium occidentale), cucumeropsis seed (Cucurbita maxima), groundnut seed (Arachis hypogeal), and soya bean seed (Glycine max). The goal was to understand the impact of these compounds on the nutritional value of the seeds and to identify potential preventive measures. Neglected and under-utilized crops are plant species that have historically been used for food, fiber, fodder, oil, or medicinal purposes but have diminished in importance over time due to specific supply and utilization constraints. These constraints may include poor shelf life, unrecognized nutritional value, low consumer awareness, and reputational issues (such as being considered famine food or "poor people’s food," often due to changes in agricultural practices). Anti- nutrients are substances commonly present in food that can be harmful to humans and can limit the availability of nutrients to the body. Sun-dried soya bean and groundnut seeds were ground, while African oil bean, cucumeropsis, and cashew nut seeds were mechanically dehulled and ground without heat. Oxalate and phytate levels were determined through titration, and carotenoid levels were determined spectrophotometrically. Various methods were used to determine the presence of tannins, trypsin inhibitors, cyanogenic glycosides, hemagglutinins, saponins, alkaloids, phenols, steroids, and flavonoids. It was found that African oil bean seed had higher concentrations of the analyzed anti-nutrients and phenolic compounds compared to the other seeds studied.

Physical activity, screening cancer, and savings rate as indicators of health responsibility

Introduction: The health of individuals can change gradually over time as a result of the choices they make. Aim: The study aimed to examine indicators such as physical activity levels, screening participation, and household savings in the context of their role as potential measures of individual health responsibility. The second aim was to identify cognitive barriers and motivations influencing physical activity, breast and cervical cancer screening participation, and money-saving habits. Material and methods: The analysis used available data on physical activity, the screening level (for breast and cervical cancer), and household savings rates. Then, the data for Poland were presented against the background of available averages for the European Union. The data came from Eurostat, Eurobarometer - the official survey instrument used by the European Parliament. Results: According to Eurobarometer data, 65% of respondents in Poland have never been physically active in 2022 (vs in the European Union 45%). In 2022, the percentage of women who were screened for cervical cancer in Poland was 34% of women. And the cervical cancer program (cytology) was used by 10.9% of people. In 2022, the household saving rate was 12.7 % in the EU, and in Poland -2.89%, where the lowest rate occurred in Greece and the highest in Germany (Eurostat data). Conclusion: The low level of physical activity and participation in screening tests in Poland, compared to EU countries, highlights the need to intensify public health promotion activities. Additionally, promoting saving as an important element of health responsibility can not only improve the financial well-being of citizens but also have a positive impact on their mental health.

Plasma potential and ion energy characteristics in BP-HiPIMS discharge with double layer

Abstract As an emerging ion acceleration plasma source, the bipolar-pulse high power impulse magnetron sputtering (BP-HiPIMS) discharge has been widely studied by academia and industry due to its ability to adjust the ion kinetic energy. Formation of the double layer (DL) potential structure during the BP-HiPIMS positive pulse is vital for accelerating ions, but its structural characteristics are still unclear. In this work, to understand the DL characteristics affected by various discharge parameters, the evolution of plasma potential V p and ion energy in BP-HiPIMS discharge with copper target has been investigated systematically using an emissive probe and mass spectrometer together. Spatial plasma potential measurements show that the DL is established in front of the target during the positive pulse, whose boundary potential drop U DL to accelerate ions can be increased to ∼60 V at a lower operating gas pressure (p= 0.6 Pa) and a higher applied positive pulse voltage (U + = 200 V). The ignition onset time of DL after applying the positive pulse can be shortened to ∼25 μs by decreasing the gas pressure and increasing the positive pulse voltage or negative pulse duration. After DL ignition, a group of high-energy copper ions with energy higher than the surrounding plasma potential can be recognized in the ion energy distribution function curves in the downstream plasma. This result illustrates that the copper ions can be ionized in the high-potential plasma region and be accelerated by the DL boundary potential drop. In addition, a global current balance model of the DL in BP-HiPIMS is developed, which suggests that the U DL can be well adjusted by increasing the positive pulse voltage U + especially for U + > 200 V as verified by the experimental potential measurements. All results suggest that the copper particles play an important role in the formation of DL and the DL plays an important role in accelerating copper ions.

Concordance of Whole-Slide Imaging and Conventional Light Microscopy for Assessment of Pathologic Response Following Neoadjuvant Therapy for Lung Cancer

Pathologic response is an end point in many ongoing clinical trials for neoadjuvant regimens, including immune checkpoint blockade and chemotherapy. Whole-slide scanning of glass slides generates high-resolution digital images and allows for remote review and potential measurement with image analysis tools, but concordance of pathologic response assessment on digital scans compared with that on glass slides has yet to be evaluated. Such a validation goes beyond previous concordance studies, which focused on establishing surgical pathology diagnoses, as it requires quantitative assessment of tumor, necrosis, and regression. Further, as pathologic response assessment is being used as an end point, such concordance studies have regulatory implications. The purpose of this study was 2-fold, which was as follows: first, to determine the concordance between pathologic response assessed on glass slides and that assessed on digital scans, and second, to determine if pathologists benefited from using measurement tools when determining pathologic response. To that end, hematoxylin and eosin–stained glass slides from 64 non–small cell lung carcinoma specimens were visually assessed for percent residual viable tumor (%RVT). The sensitivity and specificity for digital vs glass reads of pathologic complete response (0% RVT) and major pathologic response (≤10% RVT) were all >95%. When %RVT was considered as a continuous variable, the intraclass correlation coefficient of digital vs glass reads was 0.94. The visual assessments of pathologic response were supported by pathologist annotations of residual tumor and tumor bed areas. In a separate subset of hematoxylin and eosin–stained glass slides, several measurement approaches to quantifying %RVT were performed. Pathologist estimates strongly reflected measured %RVT. This study demonstrates the high level of concordance between glass slides evaluated using light microscopy and digital whole-slide images for pathologic response assessments. Pathologists did not require measurement tools to generate robust %RVT values from slide annotations. These findings have broad implications for improving clinical workflows and multisite clinical trials.

Virtual Sensing of Nitrite: A Novel Control for Safe Denitrification in Recirculating Aquaculture Systems (RASs)

Recirculating aquaculture system (RAS) technology is seen worldwide as a solution for sustainable fish production. However, there are still deficiencies in the process technology imperiling consistent operation and thus economic results. Drawbacks are linked to essential processes of the water treatment systems such as denitrification. Nitrogenous waste needs to be removed from RAS process water to maintain an adequate production environment for fish and to mitigate the environmental impact of discharged process water. At present, denitrification lacks reliable process control, especially regarding the organic carbon feed to heterotrophic denitrification processes. An investigation into heterotrophic denitrification in an experimental RAS resulted in the discovery of a virtual sensor based on measurements of the oxidation reduction potential (ORP). The virtual sensor responds to an insufficient carbon feed to denitrification. It is based on the oxidation of nitrite in an ozone-enhanced foam flotation installed downstream of the denitrification. The sensor essentially delivers a binary signal denoting either a complete or an incomplete denitrification process. The virtual sensor can be used for reliably controlling heterotrophic denitrification. It requires an upgraded process chain employing ozone-enhanced foam flotation (protein skimmer) downstream of the denitrification. However, the virtual sensor does not require any additional instrumentation.

Method—Best Practices and Common Pitfalls in Experimental Investigation of Electrochemical CO2 Reduction at Gas Diffusion Electrodes

Gas diffusion electrodes (GDEs) play a crucial role in the development of electrochemical CO2 reduction (eCO2R) toward an economically viable process. While membrane electrode assemblies (MEAs) are currently the most efficient approach due to their low cell voltage, electrolyte supported GDEs still present a valuable tool for the characterization of catalysts under industrially relevant current densities, allowing for direct measurement of the electrode potential against reference electrodes. In this study, common experimental methods of iR correction and pressure control in eCO2R literature studies on GDEs are analyzed and compared regarding their potential impact on the reported results. It is revealed that failure to account for dynamic changes in iR-drop can lead to significant inaccuracies in reported electrode potentials. Additionally, common methods for the application of differential pressure across GDEs are shown to impact the performance, leading to additional errors in experimental results. Based on these findings, an experimental protocol for the application of single high frequency response as a method for iR correction is developed, providing a tool for reproducible electrochemical characterization of GDEs in eCO2R.

Unlocking the power of Dryopteris filix mas extract: A green solution for corrosion inhibition in A210Gr carbon steel in acidified 3% wt. NaCl environment

This study investigates the corrosion inhibition effectiveness of Dryopteris filix-mas L. (DFM) extract for A210Gr carbon steel in a 3 % NaCl solution. The DFM ethanolic extract was successfully prepared and comprehensively characterized using a combination of spectroscopic and physicochemical techniques, including HPLC, FTIR, and NMR (1H and 13C). These analyses confirmed the presence of key phenolic compounds, with Quercetin-3-O-diglucoside (Q3ODG) being the major component, comprising 82.14 % peak area as identified by HPLC. The extract, obtained via an economical ethanol extraction method, exhibited a maximum inhibition efficiency up to 88 % at a concentration of 400 ppm, as determined through electrochemical impedance spectroscopy (EIS), open circuit potential (OCP), potentiodynamic polarization (PDP), and weight loss measurements. Temperature studies revealed a drop in efficiency to 70.14 % at 323 K, indicating a temperature-sensitive inhibition mechanism. Extended immersion times led to a slight decrease in efficiency due to partial desorption, though significant protection remained after 72 h. The primary corrosion inhibition mechanism was determined to be physisorption, following the Langmuir isotherm model, with a ΔGads0 value of − 24.02 kJ/mol, indicating a spontaneous adsorption process. Thermodynamic analysis revealed an increase in Ea from 22.11 kJ/mol (blank) to 56.61 kJ/mol (400 ppm), confirming the formation of a strong protective barrier. Surface characterization techniques, including FTIR, XRD, SEM, and AFM, further confirmed the presence of a protective film rich in polar organic compounds. Complementary Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) studies provided detailed insights into the molecular interactions, highlighting the key role of hydrogen bonding and van der Waals forces in the adsorption of Q3ODG onto the steel surface. These findings underscore the potential of DFM extract as an effective and sustainable corrosion inhibitor, advancing the application of biocompounds in corrosion control and encouraging further exploration of their industrial applications and environmental benefits.

The impact of climate change on variations in rutting resilience of asphalt pavement across the climate zones in China

This study aims to investigate resilience differences of asphalt pavements across China's climate zones in response to climate change. The impacts of climate change on rutting depth (RD), influence degree on rutting resilience, and Greenhouse Gas emissions in various climate zones were evaluated, and adaptation measures were proposed. The findings indicate that the warmer climate zones will be significantly affected. Freeways in these zones, serving for 10 years under projected climate conditions 40 years ahead, are expected to have RD increments exceeding 2 mm. Carbon dioxide equivalent emissions could increase by 23.1 million tons (a 39.4% increase) compared to current conditions. The degree of influence of climate change on rutting resilience will significantly differentiate among the climate zones. Four potential adaptation measures have been proposed to urgently enhance rutting resilience in response to climate change.

Effect of surface charge on laser-produced silver nanoparticles for dye reduction and surface-enhanced Raman spectroscopy

Silver nanoparticles (Ag NPs) are widely used in biological, chemical, and physical fields due to their distinct properties. However, the effect of surfactants with different polarities on the catalytic and surface-enhanced Raman spectroscopy (SERS) performance of Ag NPs has not been thoroughly studied. Here, we tailor the surface charge of laser-synthesized Ag NP without changing their morphology and investigate their catalytic and SERS capabilities. The surfactant-free silver nanoparticles (NPBare), synthesized via pulsed laser ablation in liquid (PLAL), are subsequently coated with ionic surfactants sodium dodecyl sulfate (NPSDS) and cetyltrimethylammonium bromide (NPCTAB). The synthesis and morphology of Ag NPs are confirmed using UV-Vis absorption spectroscopy and scanning electron microscopy. The surface charge of fabricated NPs is determined using zeta potential (ZP) measurements. The ZP values of NPBare, NPSDS, and NPCTAB are determined to be -17 mV, 28.7 mV, and 5.58 mV, respectively. The catalytic activity of bare and coated Ag NPs was tested against the cationic and anionic dyes, Methylene blue (MB) and Methyl orange (MO) respectively. The reduction rate of both dyes was highest when using NPBare. However, in the case of coated nanoparticles, the rate of MB and MO reduction depends on the difference between the ZP of the dye and nanoparticles: the rate of reduction increases with the difference between the zeta potentials of the dye and coated nanoparticles increases. The SERS capability of bare and coated NPs was evaluated for anionic (MO) and cationic (MB, Rhodamine B, and Crystal Violet) dyes. The SERS intensity of dyes strongly enhanced with the increase in ZP difference between the dye molecules and NPs. Surface charge modified NPs shown excellent SERS sensitivity with detection limit up to nanomolar for dye molecules as well as the homogeneity of NPs demonstrated in Raman mapping results with relative standard deviation of 17%. The results suggest that the electrostatic interaction between the nanoparticles and dye molecules plays a dominant role in SERS enhancement. These findings highlight the significance of surface charge in improving the catalytic and sensing properties of noble metal nanoparticles.

Nanocasting synthesis of mesoporous CeO2 particle abrasives from mesoporous SiO2 hard templates for enhanced chemical mechanical polishing performance

Mesoporous abrasive particles exhibit superior chemical mechanical polishing/planarization (CMP) performance, as compared with the corresponding bulk materials. Nevertheless, the lack of control over the shape and particle size or distribution extremely restricts the development of mesoporous abrasives and their potential applications. To overwhelm these drawbacks, pure and ytterbium-doped mesoporous ceria (mCeO2 and mCeYbO2) spheres with well-defined morphology and good uniformity were synthesized via a straightforward nanocasting strategy using high-quality mesoporous silica spheres as hard templates and metal nitrates as precursors. The resulting samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, UV–vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, Zeta potential, and N2 adsorption-desorption measurements. The as-prepared mCeO2 and mCeYbO2 products exhibited enriched surface defects (trivalent Ce, vacancy oxygen, hydroxyls) and polycrystalline porous frameworks with a surface area of up to 160 m2/g and pore size of 4–7 nm. Benefiting from these synergistic attributes, the flexible and defective particle abrasives enabled significant improvements in both surface quality and removal efficiency during oxide-CMP, as compared to commercial CeO2. A possible CMP mechanism was proposed on the basis of the physical contact state, adsorption and adhesion behavior, as well as tribochemical interaction occurred at CeO2–SiO2 interfaces. This work demonstrates highly promising abrasive materials advancement combining architecture and defect engineering towards high-performance oxide-CMP.

Exploration and Practice of Treatment Technology for Casing Damage in Gas Wells

Abstract In order to solve the adverse effects of casing damage on potential exploration measures such as layer inspection and hole repair, repeated fracturing, and bridge plug fishing in gas wells, to prevent the problem of annular pressure, and to effectively ensure the safety production of gas wells, exploratory research on the treatment technology for casing damage in gas wells has been carried out. First, the principle of casing damage and the technical difficulties of treatment are systematically analyzed. Then, combined with auxiliary technologies such as casing cutting and milling, various technological processes were introduced, including cement squeeze sealing, chemical squeeze sealing, permanent annular sealing, casing patching, small casing wellbore reconstruction, and casing milling and squeeze sealing. Successfully tested on-site in over ten wells, a series of treatment technologies for gas well casing damage has been developed, providing a technical reference for the treatment of other gas wells with casing damage. Furthermore, in response to the challenges faced by the technology of gas well casing damage, new technical ideas and development directions have been proposed to promote continuous improvement in the low-cost and high-reliability aspects of gas well casing damage treatment technology.

Assessing the climatic niche changes and global invasion risk of Solanum elaeagnifolium in relation to human activities

As an invasive plant, Solanum elaeagnifolium has posed a serious threat to agriculture and natural ecosystems worldwide. In order to better manage and limit its spread, we established niche models by combining distribution information and climate data from the native and invasive ranges of S. elaeagnifolium to analyze its niche changes during its colonization. Additionally, we evaluated its global invasion risk. Our results showed that the distribution of S. elaeagnifolium is affected by temperature, precipitation, altitude, and human activities. Solanum elaeagnifolium exhibits different degrees of niche conservatism and niche shift in different invasion ranges.During the global invasion of S. elaeagnifolium, both the niche shift and conservatism were observed, however, niche shift was particularly significant due to the presence of unoccupied niches (niche unfilling). Solanum elaeagnifolium generally occupied a relatively stable niche. However, a notable expansion was observed primarily in Europe and China. In Australia and Africa, its niche largely remains a subset of its native niche. Compared to the niche observed in its native range, its realized niche in China and Europe has shifted toward lower temperature and higher precipitation levels. Conversely, in Africa, the niche has shifted toward lower precipitation levels, while in Australia, it has shifted toward higher temperature. Our model predicted that S. elaeagnifolium has high invasion potential in many countries and regions. The populations of S. elaeagnifolium in China and Africa have reached the adapted stage, while the populations in Australia and Europe are currently in the stabilization stage. In addition, our research suggests that the potential distribution of S. elaeagnifolium will expand further in the future as the climate warms. All in all, our study suggests that S. elaeagnifolium has high potential to invade globally. Due to its high invasive potential, global surveillance and preventive measures are necessary to address its spread.

Automation in the Maritime Transport System – A Framework for Planning Resilient Operations

Abstract Maritime transport systems (MTS) are becoming increasingly automated, integrated and complex. New technology, automation and autonomous systems will contribute to safer, greener, and more efficient transport systems. However, the advancements pose new challenges, and it is a need to understand and manage the potential brittleness and risks. Uncertainties and the unknown should be prepared for when planning the implementation of new technology. Hence, this paper presents a framework to support the planning for resilient operations when introducing autonomy in a MTS. The framework is based on a resilient approach and is the first draft of a framework being developed within the research project Maritime Resilience Management of an Integrated Transport system (MARMAN). The approach is intended to facilitate a process where MTS actors work systematically to identify challenges, clarify potential future measures, and prepares for integrating automation and autonomy in a system. The method emphasizes the needs for cooperation, coordination and integrated planning across different transport modalities, organizational boundaries and stakeholders. But also between humans and technology, focusing on the different levels of planning (i.e. strategic, tactical and operational), where the main objectives will be to increase resilience by coping with potential critical events. In addition, continuous learning and commitment between actors and how to use the new technology are crucial for enhancing resilience.

Application of lentinan in suppression of Marek's disease virus infection

Marek's disease virus (MDV) is an extremely widespread avian immunosuppressive virus. In recent years, many reports have shown that there are still cases of MDV infection and immunosuppression after immunization with the vaccine. Consequently, there is a need to develop alternative complementary approaches for strengthening the efficacy of MDV prevention and control measures. Lentinan (LNT) is a macromolecular compound with immune-enhancing activity extracted from shiitake mushrooms. To explore the value and effectiveness of administering LNT through drinking water in the prevention and control of MDV, this study first observed the effects of high and low doses of LNT on weight gain, organ development, viral replication, and antibody titer of an avian influenza virus subtype H9 (AIV-H9) inactivated vaccine in specific pathogen-free (SPF) chicks infected with the wild strain of MDV. The results showed that both high and low doses of LNT significantly alleviated the weight gain retardation and liver and spleen enlargement caused by MDV infection, and significantly inhibited the replication of MDV in SPF chicks (P < 0.05), compared with the MDV-positive control group, both high and low doses of LNT significantly increased the antibody titer of AIV-H9 after immunization with inactivated AIV-H9 vaccine (P < 0.0001). On this basis, we also observed the effects of a chicken Marek's disease meq gene deletion live vaccine (SC9-1 strain), administered alone or in combination with LNT, on MDV infections of varying virulence in Hy-Line Brown chicks. The results showed that combined administration of LNT and the SC9-1 vaccine resulted in a significant alleviation of weight gain retardation and liver and spleen enlargement due to MDV infection (P < 0.05), as well as a significant inhibition of MDV replication and release in Hy-Line Brown chicks compared to the vaccine alone (P < 0.0001). These findings suggest that LNT not only alleviates the adverse effects of MDV infection in chickens but also enhances the efficacy of MDV vaccination, offering a potential auxiliary measure for controlling MDV infection.

Phase behavior and interaction of strong polyelectrolyte dextran sulfate and whey protein isolation: Effects of pH, protein/polysaccharide ratio, and salt addition

The strong polyelectrolyte dextran sulfate (DS) is an anionic polysaccharide with a high negative charge, characterized by high stability and pH independence. DS and whey protein isolate (WPI) were selected to study the specific effects of highly negatively charged polysaccharides on the phase behavior and interaction of WPI/DS complexes (1 % w/v) under varying external conditions (pH, WPI:DS ratio, and salt addition). The phase diagrams, zeta potential, and laser confocal scanning microscopy measurements indicated that the WPI/DS complexes did not dissociate even at pH 1 due to the pH independence of DS. The exclusion volume effect of DS promoted WPI self-aggregation at high salt concentrations, which inhibited acidification-induced dissociation. Isothermal titration calorimetry indicated that the WPI/DS interaction is a spontaneous exothermic reaction driven by both enthalpy and entropy changes due to electrostatic interactions. This study provides valuable information on the interactions between highly negatively charged polysaccharides and proteins.

Corrosion of Copper, Cupronickel, Nickel Aluminium Bronze and Super-Duplex Stainless Steel Rotating Cylinder Electrodes in Seawater under Turbulent Flow Conditions

The corrosion of uncoated metals in a marine environment restricts the choice of suitable engineering metals and alloys. Anodic dissolution of metal and cathodic reduction of oxygen are important processes and formation of a surface oxide film can affect both electrode reactions. Charge transfer and mass transfer data can provide information on corrosion rate and mechanism. Several metals and alloys having a history of use in marine engineering are considered, including copper, two copper alloys (cupronickel and nickel aluminium bronze) plus a more recent addition to strong, corrosion resistant alloys (a super duplex stainless steel). The rotating cylinder electrode offers the benefits of a controlled, turbulent flow of electrolyte, facilitating controlled mass transfer in a compact cell geometry which is well-suited to bench-top operation. These features are illustrated using a variety of electrochemical techniques, including open-circuit potential vs time monitoring, linear sweep voltammetry, rotation speed step- or potential step current transients and linear polarisation resistance measurements. Seawater taken from Langstone Harbour, Hampshire, UK, was filtered, air-saturated, pH 8.0 and maintained at 25 °C. Dimensionless group correlations and graphical plots (using an analogous approach to the Koutecky-Levich equation for an RDE) enabled contributions of charge transfer-, mixed- and mass transfer- controlled data to be appreciated, allowing the Tafel slopes of electrode reactions, the diffusion coefficient of dissolved oxygen, the mass transfer coefficient for oxygen reduction and the mean corrosion rate to be estimated.