Second-order Model Research Articles

Lead (Pb) Sorption Kinetics by Clay Minerals: Bentonite and Zeolite

Background: Heavy metal pollution chiefly lead (Pb) causes various environmental disequilibrium and health hazards. Immobilization of lead (Pb) usingclay minerals is cost effective for metal remediation due to their higher surface area and negative charges. Methods: This study was taken up to assess the Pb removal potentials of bentonite and zeolite from contaminated water and to study the effect of sorbent dosage, initial Pb2+ concentrations and incubation time intervals on Pb adsorption and desorption was studied. Result: Zeolite was effective in immobilising Pb (78.0%) than bentonite (70.9%) which increased with increasing sorbent dosage and time intervals. The pseudo second-order kinetic model described the Pb adsorption precisely. Chemisorption was the dominant mechanism operating in aqueous solution system, hence, it could be concluded that zeolite can be utilized as an efficient sorbent for wastewater treatment.

Multidimensional Scale to Assess Digital Security in Adolescents

The study examined the psychometric properties of a Digital Security Scale (DSS-A) in a sample of 868 adolescents (460 female, 408 male), made up of 424 early adolescents (M age = 11.84 years, SD = 0.36) and 444 middle adolescents (M age = 13.44, SD = 0.49). The sample was randomly split into two for validation (n = 434) and cross-validation (n = 434) purposes. The results confirmed the fit of a one second-order factor model with four first-order factors (personal data protection, safe relationships, healthy internet use, and self-disclosure). As expected, digital security dimensions were positively associated with parental mediation. Measurement invariance was found in this model by gender and stage of adolescence. Latent mean comparisons showed differences by gender and stage of adolescence. Overall, findings indicate that the measurement model is helpful for measuring adolescents’ digital security behaviors.

Lithium-ion point-of-care ultrasound battery joint state of charge estimation

With recent advances in ultrasound technology, including accessibility and portability, point-of-care ultrasound systems (POCUS) are becoming ubiquitous in urban and rural health services. The efficient use of POCUS battery power is necessary due to the limited access to electricity in rural locations. Accurate estimation of the state-of-charge (SOC) of the onboard lithium-ion battery is crucial in ensuring the safe, efficient, and reliable operation of the battery management system (BMS). This research suggests a novel approach for striking a reasonable balance between the POCUS battery management systems computation time and SOC estimate accuracy. Given that the lithium-ion battery is a non-linear and time-varying system, it is modelled by a second-order RC equivalent circuit model (2-RC ECM). Real-time parametric identification is carried out using the method of recursive least squares with respect to an adaptive forgetting factor (AFFRLS). The joint SOC evaluation technique, ordering the results of real-time identification and the Extended Kalman Filter (EKF) recommended for estimating battery SOC at temperatures between 0 and 45 °C. Simulations were carried out using experimental data from the DST (Dynamic Stress Test), incremental current and, the Federal Urban Driving Program (FUDS) of the CALCE research group to evaluate the proposed approach. Based on the monitoring of dynamic changes in model parameters and the computational complexity of existing algorithms, the results reveal that the joint AFFRLS-EKF estimation proposed for the SOC strategy achieves good accuracy, high adaptability and rapid convergence of SOC estimation.

A risk-averse distributionally robust optimisation approach for drone-supported relief facility location problem

Drone-supported last-mile humanitarian logistics applications play a crucial role in the rapid and efficient delivery of essential relief items, such as medicine, blood, and vaccines, during disaster and emergency situations. This paper explores a novel drone-supported relief facility location problem (DSRFLP) aimed at establishing an effective drone-supported last-mile humanitarian logistics system. The problem involves making joint decisions for both pre-disaster and post-disaster phases while considering the characteristics of drone-based delivery operations and uncertain demands. In the pre-disaster phase, we make the decisions regarding the locations of drone-supported relief facilities, inventory prepositioning of relief items, assignment of drones to the opened facilities, and allocation of drones to disaster demand sites. In the post-disaster phase, we make decisions related to delivery quantities. To tackle the challenge of incomplete demand distribution information in chaotic disaster environments, we establish a distributionally robust optimisation (DRO) model to handle the uncertainty of demands. This model adopts worst-case mean Conditional Value-at-Risk as the risk measurement, reflecting the risk-averse attitude of humanitarian organisers. In this paper, three ambiguity sets (box, ellipsoidal, and polyhedral) are considered to describe the ambiguity distributions of demands. To overcome the computational challenge, we reformulate the DRO model under three ambiguity sets into two mixed-integer linear programming models and one second-order cone programming model, which can be efficiently solved by off-the-shelf solvers. Furthermore, we validate our proposed DRO model through a small-scale example and a large-scale case study based on the Lushan earthquake in China. The computational outcomes underscore the superior performance of the proposed DRO model to mitigate the impact arising from incomplete probability distributions. We propose managerial implications and insights to support the decision-making of humanitarian organisations based on the experimental results. Finally, we propose two extended models to incorporate multiple relief items and equity constraints in priority settings and conduct numerical experiments to adapt to various real-world disaster scenarios.

Intention to engage in ecotourism development: validation and extension of the Resident Empowerment through Tourism Scale (Version 2.1)

ABSTRACT This work, based on the conceptual work by Scheyvens and van der Watt (2021), amends the original Resident Empowerment through Tourism Scale (RETS) by including three new dimensions: economic empowerment, cultural empowerment, and environmental empowerment. In so doing, the modified scale is applied in a region of Ecuador not known for its ecotourism opportunities, to determine how residents’ (n = 500) perceived empowerment factors into their intent to engage in ecotourism endeavours through a modified theory of planned behaviour model. Psychometric properties of the 13-item modified RETS were strong. Six of the nine proposed hypotheses were supported via structural equation modelling using IBM Amos 28.0. The first-order model (of perceived empowerment) accounted for 33% of the variance in attitudes about engaging in ecotourism and 82% of the variance in behavioural intentions to engage in ecotourism. A second-order model increased variance explained in attitudes to 70% and in behavioural intentions to 89%.

Heavy metal application of response surface optimized-lipopeptide biosurfactant produced by Pseudomonas aeruginosa strain CGA-02 in low-cost substrate

Cost-effective methods of biosurfactant production with minimal environmental impact are needed as global demand continues to increase. This study evaluated lipopeptide biosurfactant production in a Pseudomonas aeruginosa strain CGA-02 using a low-cost carbon substrate. The structural properties of the biosurfactant and applicability of the biosurfactant in heavy metal removal were evaluated. Response surface methodology (RSM) involving central composite design (CCD) was used to optimize process parameters to maximize biosurfactant production. The study identified sugar cane molasses and sodium nitrate as carbon and nitrogen sources of choice for bacterial growth and biosurfactant production, with a relatively 2.64-fold increase in biosurfactant yield under optimized conditions. Analysis of the biosurfactant measured a surface tension reduction of water from 72.2 ± 0.26 to 30.5 ± 0.2 mN/m at 40 mg/L critical micelle concentration. GC–MS and FTIR analysis revealed structural properties of the lipopeptide biosurfactant, with fatty acid components predominantly 9-octadecenoic acid (oleic acid), n-hexadecanoic acid, cyclotetrasiloxane and trimyristin, and infrared peaks belonging to amine, carboxyl, nitrile, alkanol, ether and carbonyl groups. Capture of heavy metals using the biosurfactant was evaluated in soil microcosms. Removal rates of 80.47, 100, 77.57, 100, and 97.57% were recorded for As, Pb, Hg, Cd and Cr respectively after 12 weeks of incubation. There was no significant difference (p < 0.05) in the removal efficiency of the biosurfactant and an analogous chemical surfactant, sodium dodecyl sulphate. First and second-order kinetic models described heavy metal removal rates by the biosurfactant. We demonstrate the production of a useful biosurfactant using low-cost waste carbon.

Study on Preparation of Calcium-Based Modified Coal Gangue and Its Adsorption Dye Characteristics

Efficient and thorough treatment of dye wastewater is essential to achieve ecological harmony. In this study, a new type of calcium-based modified coal gangue (Ca-CG) was prepared by using solid waste coal gangue as raw material and a CaCl2 modifier, which was used for the removal of malachite green, methylene blue, crystal violet, methyl violet and other dyes in water. When the dosage of Ca-CG was 1–5 g/L, the dosage of Ca-CG was the main factor affecting the dye adsorption effect. The adsorption effects of Ca-CG on four dyes were as follows: malachite green &gt; crystal violet &gt; methylene blue &gt; methyl violet. Kinetics, isotherms and thermodynamic analysis showed that the adsorption of malachite green, methyl blue, crystal violet and methyl violet by Ca-CG fitted the second-order kinetic model, and adsorption with chemical reaction is the main process. The adsorption of four dyes by Ca-CG conformed to the Freundlich model, which is dominated by multi-molecular layer adsorption, and the adsorption was easy to carry out. The adsorption process of Ca-CG on the four dyes was spontaneous. The results of FTIR, XRD and SEM showed that the calcium-based materials such as lipscombite and dolomite were the key to the adsorption of malachite green by Ca-CG, and the main mechanisms for the adsorption of malachite green by Ca-CG are surface precipitation, electrostatic action, and chelation reaction. Ca-CG adsorption has great potential for the removal of dye wastewater.

Development of a Scale to Assess University Faculty’s Knowledge, Attitudes, and Practices in Special Education

With the increasing number of university students with disabilities, university professors play a significant role in teaching and assessment. The purpose of this study was to develop and validate a scale to assess university faculty’s knowledge, attitudes, and practices in relation to providing special education services. A total of 210 faculty members recruited from 15 universities in Taiwan participated in this study. The sample included lecturers (n = 51), assistant professors (n = 75), associate professors (n = 66), and professors (n = 18). The proposed Faculty Perspectives on Special Education Scale (FPSES), a 32-item scale, includes three subscales: Special Education Knowledge (SEK), Attitudes Towards Students (ATS), and Provision of Services (POS). Data collected were analyzed using descriptive statistics, item analysis, correlation analysis, t tests, exploratory factor analysis (EFA), and confirmatory factor analysis (CFA). Results showed that FPSES has satisfactory internal consistency reliability, with Cronbach’s ? ranging from .93 to .96 and test-retest reliabilities, with coefficient ranging from .88 to .96. The FPSES also exhibited favorable content validity. Furthermore, the CFA confirmed a good fit between the proposed second-order model and the sample data, thereby ensuring the construct validity. In summary, FPSES is a favorable assessment tool with good psychometric properties, which provides insights into faculty perspectives, attitudes, and practices in the provision of special education services for university students with disabilities. Recommendations are provided for future research and the Office of Disability Services at the university. Received: 29 March 2024 / Accepted: 30 April 2024 / Published: 5 May 2024

Validation of the translated Negative Physical Self Scale in a sample of Asian women living in Canada.

Body dissatisfaction is often linked to the internalization of Western beauty standards. Existing measures of body dissatisfaction, developed in Western societies, may fail to capture complex variations across ethnicities and cultures. The Negative Physical Self Scale (NPSS) assesses cognitive, affective, perceptual, and behavioural facets of body dissatisfaction. While unique in its consideration of Chinese ideals of body image, the NPSS has recently been translated and validated in a North American sample. The English-translated version of the NPSS has the potential to be an appropriate body dissatisfaction assessment tool for Asian women living in North America. The current study aims to validate the NPSS in an Asian female population living in Canada. A sample of 899 undergraduate women residing in Canada with self-identified Asian ethnicity completed an online survey consisting of the NPSS and other measures of body dissatisfaction. An initial confirmatory factor analysis indicated that the four-factor structure of the NPSS, previously suggested in a primarily non-Asian North American sample, was a poor fit for the data. A second-order multidimensional model, based on a model proposed during the original development of the NPSS in a Chinese sample, indicated good fit once items were removed due to loadings < .60. High internal consistency between subscales and strong convergent validity with other measures were demonstrated. Notably, the NPSS Body Concern subscale demonstrated high convergence with other popular measures of body dissatisfaction and has the potential for use as a brief measure of body dissatisfaction among North American Asian females in clinical and research settings. The NPSS provides a valid assessment of body dissatisfaction among a sample of Asian women living in Canada, a specific subpopulation that has not been previously investigated. The findings highlight the importance of developing culturally sensitive measures of body dissatisfaction for differing ethnic and cultural groups.

Performance and regression analysis of air-cooled thermoelectric cooling system using response surface methodology and numerical simulation

In this study, the response surface methodology (RSM) combined with numerical simulation (NS) techniques is used to perform regression model of an air-cooled thermoelectric cooler (TEC) system. To obtain the interaction models between the thermal resistance (Rh) of the external hot-side heat sink and the internal structure parameters of the TEC (leg height, h; leg width, w; numbers of P/N leg pairs, N), regarding the key performance of the TEC. According to the NS and RMS results Imax, Qcmax, and Qh decline with the rise of Rh under different N, h, and w. The decline rate is rise with the elevation of N, the increase of the w, and the decrease of the h. COP and Tcmin decrease with an increase in h, while increase with an increase in w, N, and Rh. The key factors Rh, w, h and N in the air-cooled TEC system are studied using RSM. The second-order response models for the response variables (COP, Tcmin, Qcmax,Imax and dTmax) with respect to the influencing factors (Rh, w, h and N) are established using the Box-Behnkn Design (BBD) method in RSM.

Development and validation of the mindful eating scale (Mind-Eat Scale) in a general population

BackgroundMindful eating is a concept that is increasingly being used to promote healthy eating. Observational studies have suggested associations with healthier eating behaviors, lower weight status, and favorable cardiovascular biomarkers. However, existing scales assessing mindful eating have some limitations. Our study aimed to develop and validate a scale assessing the level of mindful eating in a general population. MethodsThe Mind-Eat Scale was developed in four main steps: 1. Generating an initial item pool covering all aspects of mindful eating; 2. Reviewing items with experts and naive individuals; 3. Administering the scale to a large and representative sample from the NutriNet-Santé cohort (N=3,102); 4. Conducting psychometric analyses. Construct validity was assessed using exploratory (EFA) (N1=1,302) and confirmatory (CFA) (N2=1,302, N3=498) factor analyses. Content, discriminant, convergent, and divergent validity, internal consistency, and test-retest reliability were examined. ResultsThe initial pool of 95 items was refined to 24 items using EFA. The EFA highlighted six dimensions: Awareness, Non-reactivity, Openness, Gratitude, Non-judgement, and Hunger/Satiety, consisting of four items per dimension. CFAs showed a good fit for first and second-order models. Adequate content validity was confirmed. Discriminant, convergent, and divergent validity were supported by significant differences between subgroups of individuals, and correlations with eating behaviors and psychological well-being scales. The Mind-Eat Scale showed good reliability for all six dimensions, with high McDonald's ω and adequate intraclass correlation coefficients (ICC). ConclusionsThis study validated the first tool assessing a total mindful eating score and its sub-dimensions in a general population. This scale can be an asset for clinical and epidemiological research on dietary behavior and related chronic diseases.

Modeling Mn(II) autocatalytic sorption on MnOx-coated filtration media

This study reports a newly developed kinetic model for predicting manganese (Mn) removal in Mn-coated filtration media. Manganese oxides (MnOx) adsorb and catalyze the oxidation of Mn in the liquid phase to regenerate sorption sites. The most common kinetic models (pseudo-first- and second-order models) do not consider the regeneration of reactive sites, thereby inadequately describing the long-term uptake of Mn(II) by MnOx. We propose a new kinetic model that considers both the rapid initial sorption of Mn(II) onto MnOx and its subsequent slow oxidation to Mn(Ox). This model was generalized to account for different pH, temperatures, and initial Mn concentrations. The enhanced model demonstrated a prediction error of +/−1 % on the Mn(II) concentration measured in the column effluent of two different MnOx media recovered from industrial filters. Although the contribution of oxidation was found to be 10 times smaller than that of adsorption, it is important to consider if for the prediction of Mn(II) uptake over a 4-h column experiment.

Comparison of Homoclinic Bifurcations Between Grid-Following and Grid-Forming Converters

A second-order model is developed to describe the essential behavior of the grid-following converter (GFLC) and the grid-forming converter (GFMC) for studying the synchronization characteristics of grid-connected converter systems. In this paper, a general set of criteria in terms of the manifolds and saddle quantity is derived for studying the homoclinic bifurcation behavior of GFLCs and GFMCs. It is shown that three unstable periodic orbits and two homoclinic bifurcations may exist for the GFLC, while only one stable periodic orbit and one homoclinic bifurcation may exist for the GFMC. It is also found that after the onset of the first homoclinic bifurcation, the stable equilibrium point (SEP) is surrounded by the stable manifolds of the unstable equilibrium point (UEP), which forms the SEP's basin of attraction, for both GFLCs and GFMCs. In this case, the converters may lose their synchronization if the trajectory crosses over the UEP. Therefore, system parameters should be designed to avoid the onset of the aforementioned bifurcation so that the SEP's basin of attraction can be significantly enlarged to contain the UEP. As a result, the GFLC or GFMC can eventually resynchronize with the grid even when its trajectory passes the UEP. Finally, experimental results are provided to verify these theoretical findings.

Influence of Error-Augmentation on the Dynamics of Visuomotor Skill Acquisition: Insights from Proxy-Process Models.

Our study addresses the critical question of how learners acquire skills without the constant crutch of feedback, utilizing a specialized training approach with intermittent feedback. Despite recognized benefits in skill retention, the underlying mechanisms of intermittent feedback in motor control neuroscience remain elusive. Leveraging a previously published dataset from visuomotor learning experiments with intermittent feedback, we tested a wide range of proxy-process models that posit the presence of an inferred error signal even when an explicit sensory performance is not present. Furthermore, these proxy-process models investigated the impact of error-augmentation (EA) training on visuomotor learning dynamics. Rigorous cross-validation consistently identified a second-order proxy-process model structure accurately predicting motor learning across subjects and learning tasks. Model parameters elucidated the varying influences of EA settings on the rates of change in error, inter-trial variability, and steady-state performance. We then introduced a dynamic-Proxy support Multi-Rate Motor Learning (dPxMRML) model, which shed light on EA's effects on the fast and slow learning dynamics. The dPxMRML model accurately predicted subjects' performance during and beyond training phases, highlighting EA settings conducive to long-term retention. This research yields crucial insights for personalized training program design, applicable in neuro-rehabilitation, sports, and performance training.

Evaluating hydrothermal liquefaction hydrochar from sewage sludge as a phosphorus resource through struvite production

Hydrothermal liquefaction (HTL) has attracted considerable attention for valorizing sewage sludge to biofuels while the solid residue, hydrochar, has received little attention for its final application. In the current work hydrochar recovered from hot separation in a pilot-scale HTL plant is evaluated for its nutrient value, in particular as a sustainable Phosphorus (P) resource. Following thorough characterization of the hydrochar, P recovery as struvite (NH4MgPO4.6H2O) is investigated to produce a fertilizer with a lower heavy metal content that could be used in current agricultural practices. P extraction using inorganic (hydrochloric and sulphuric) and organic (citric) acids is evaluated by applying 0.1- 1mol/L of acids for 1- 12h with a liquid/solid ratio of 10mL/g. A second-order polynomial model was established by response surface methodology (RSM) to predict the P extraction with different acids. The optimum operating conditions for maximum P extraction (94%) are suggested as 0.7M of acid strength (H2SO4) and 6.5h of extraction time. Addition of citric acid (CA) during the struvite precipitation from acid-leached P solution was found to improve the struvite purity from 36.6% to 54% with a reduction in heavy metal content. Furthermore, morphological analysis validated the formation of struvite. Upon comparison with the regulations, hydrochar was found to exceed some of the heavy metal limits but was low in polyaromatic hydrocarbons (PAHs), per- and polyfluorinated substances (PFAS) and showed low toxicity to Aliivibrio fischeri. P extraction and struvite precipitation are shown to reduce heavy metal contents below regulatory limits with P recoveries from 40-67%. Thus, as an alternative to direct land application of hydrochar, harvested struvite from hydrochar could be applied as a fertilizer with no apparent environmental risk.

Ultralocal Model-Free Adaptive Supertwisting Nonsingular Terminal Sliding Mode Control for Magnetic Levitation System

The magnetic levitation technology has attracted blooming attention from all walks of life thanks to its superiorities such as non-contact and active control. While the intrinsic features of open-loop instability and strong nonlinearity, along with the uncertain external disturbance make the levitation control particularly significant and difficult. For speeding up the convergence and obtaining a better stability and disturbance robustness, this paper proposes an ultra-local model-free adaptive super-twisting nonsingular terminal sliding mode control (ULMF-ASTNTSMC) strategy for the magnetic levitation system. Different from the conventional model-based control, ultra-local model-free control breaks the constraint of a precise system model. Therefore, an improved second-order ultra-local model is established for the magnetic levitation system. For the benefit of finite time convergence and non-singularity, the nonsingular terminal sliding mode surface is chosen. As a second-order algorithm, super-twisting (ST) algorithm can fundamentally suppress the chattering effect of the sliding mode control (SMC). An adaptive super-twisting algorithm is designed for the further improvement of the system dynamic response. The stability of the proposed scheme is strictly verified based on the Lyapunov stability theory. Simulation and experimental comparisons with the existing control methods validate the exceeding performance of the proposed strategy under various operating conditions.

Characterization and application of synthesized calcium alginate-graphene oxide for the removal of Cr3+, Cu2+ and Cd2+ ions from tannery effluents

Environmental sustainability has gained acceptance to achieving the goal of a secure ecosystem with a reliable management system. Heavy metal remediation of aqueous streams is of special concern due to the intractability and persistence in the environment. Adsorption is a potential alternative to the existing inefficient conventional technologies for the removal and recovery of metal ions from aqueous solutions and becomes vital to align with the Sustainable Development Goals (SDGs) and mitigate the adverse environmental and social impacts. Calcium Alginate-Graphene oxide (CA-GO) composite has been synthesized for the adsorption of heavy metals including Cr3+, Cu2+, and Cd2+ ions from tannery effluents. Graphene oxide is prepared from commercial graphite powder and reacted with sodium alginate and calcium chloride to form the beads of CA-GO composite. The developed composite was characterized by FTIR, elemental analysis, SEM, XRD analysis, and Raman spectroscopy. Moreover, the effect of pH, adsorbent dosage, contact time, and initial concentration of metal ions on the adsorption capacity were investigated through batch experiments. At a pH>3.0 (pHzpc), the carboxyl group of CA-GO was deprotonated to make the surface negatively charged and facilitate metal adsorption. The optimum pH and maximum adsorption capacity of CA-GO for removal of Cr(III), Cu(II), and Cd(II) were 4.5, 6.0, and 7.0, and 90.58, 108.57, and 134.77mgg-1, respectively. The kinetics, adsorption isotherms, and thermodynamics were studied to determine the adsorption mechanism. The kinetic of adsorption adopted the second-order model. Thermodynamic parameter were calculated and the adsorption process was determined to be exothermic and spontaneous at room temperature. The developed composite has been efficaciously applied for the removal of metal ions and pollution from real tannery effluents.

Finding and implementing the numerical solution of an optimal control problem for oscillations in a coupled objects system

In the modern world, where efficiency, stability, and precision play a crucial role, the development and application of optimal control strategies in oscillatory systems hold significant importance. The issues related to the numerical solution of control problems associated with damping oscillatory systems consisting of two objects are considered. To numerically solve the discussed problem, the gradient projection method, based on the formula for the first variation of the functional, and the method of successive approximations, associated with the linearity of boundary problems describing oscillatory processes, are applied. The oscillations of one object are described by a wave equation with first-order boundary conditions, while a second-order ordinary differential equation models the oscillations of the other object. Furthermore, the original and the adjoint boundary value problems are solved using direct methods at each iteration step. An algorithm for the numerical solution of the problem is proposed, and based on this algorithm, a software code for implementation is developed. The numerical results obtained in the study demonstrate that there is convergence in terms of functionality, and the approximately optimal controls found in this process are minimizing sequences in the control space. The mechanism of controlling and regulating the operation of the system according to its input constraints is provided by observed feedback, allowing systems with limited excitation to maintain stability and optimal functioning in conditions of changing external or internal circumstances. The obtained results can also be used to forecast the system's behavior in the future, resource planning, prevention of emergencies, or optimization of production processes

UPTAKE OF Co(II), Pb(II) AND Ni(II) IONS BY Annona senegalensis STEM BARK BIOCHAR FROM AQUEOUS SOLUTION: OPTIMIZATION, KINETIC AND THERMODYNAMIC STUDIES

The concern for heavy metal pollution in the environment is especially so since they are non-biodegradable. The use of agro materials in the removal of these heavy metal pollutants has been recognized as a low-cost alternative to the costly conventional remediation techniques. The equilibrium sorption of the chemically activated Anonna senegalensis stem bark was investigated. Using standard techniques, the physicochemical properties of activated carbon (MAASC) were ascertained. By using a simultaneous batch adsorption approach, the adsorption of Co2+, Pb2+, and Ni2+ onto MAASC was examined as a function of pH, solution temperature, initial metal ion concentration, agitation time, adsorbent dose, particle size, and carbonization temperature. The equilibrium sorption data generated were fitted into Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models as well as pseudo first-order, pseudo-second-order and intraparticle diffusion kinetic models. From the obtained results, it was discovered that the Langmuir isotherm provided the best match conformation of all the models, except for Pb2+, which was best for Freundlich with an R2 of 0.95. Physisorption was shown to be the mechanism by Dubinin-Radushkevich. For Co2+, Pb2+, and Ni2+, respectively, the pseudo second-order kinetic model had R2 values of 0.997, 0.999, and 0.999 that best matched the data. Both intraparticle diffusion and the boundary layer effect also contributed to regulating the rates of the adsorption process. The study's thermodynamic results showed that Ho for Co2+, Pb2+, and Ni2+ were 27.51, 19.70, and 13.37 KJ/mol, respectively. These values are all positive and suggest an endothermic reaction, supporting the physisorption mechanism.

Assessing complex PTSD and PTSD: validation of the German version of the International Trauma Interview (ITI)

ABSTRACT Background: With the introduction of the ICD-11 into clinical practice, the reliable distinction between Posttraumatic Stress Disorder (PTSD) and Complex Posttraumatic Stress Disorder (CPTSD) becomes paramount. The semi-structured clinician-administered International Trauma Interview (ITI) aims to close this gap in clinical and research settings. Objective: This study investigated the psychometric properties of the German version of the ITI among trauma-exposed clinical samples from Switzerland and Germany. Method: Participants were 143 civilian and 100 military participants, aged M = 40.3 years, of whom 53.5% were male. Indicators of reliability and validity (latent structure, internal reliability, inter-rater agreement, convergent and discriminant validity) were evaluated. Confirmatory factor analysis (CFA) and partial correlation analysis were conducted separately for civilian and military participants. Results: Prevalence of PTSD was 30% (civilian) and 33% (military) and prevalence of CPTSD was 53% (civilians) and 21% (military). Satisfactory internal consistency and inter-rater agreement were found. In the military sample, a parsimonious first-order six-factor model was preferred over a second-order two-factor CFA model of ITI PTSD and Disturbances in Self-Organization (DSO). Model fit was excellent among military participants but no solution was supported among civilian participants. Overall, convergent validity was supported by positive correlations of ITI PTSD and DSO with DSM-5 PTSD. Discriminant validity for PTSD symptoms was confirmed among civilians but low in the military sample. Conclusions: The German ITI has shown potential as a clinician-administered diagnostic tool for assessing ICD-11 PTSD and CPTSD in primary care. However, further exploration of its latent structure and discriminant validity are indicated.