Positive Load Research Articles

In-Hospital Screening Campaign Against Hepatitis C Could Be Effective for Identifying More Patients Who Still Need Treatment.

Screening programmes for the detection of patients with hepatitis C virus (HCV) and positive viral load have been developed in many countries to achieve the World Health Organization's goal of HCV elimination by 2030. In Italy, a phased screening programme starting with individuals born between 1969 and 1989 has been implemented. To assess the prevalence of patients with positive viraemia identified through a universal screening campaign conducted among hospitalised patients at our centre during the calendar year 2022. All adult (aged ≥ 18 years) hospitalised patients, who participated in HCV screening from January to December 2022 were included, without any age restriction. Screening initially involved testing for anti-HCV antibodies and then patients who tested positive underwent further HCV-RNA testing. A total of 10,846 samples were collected. Five hundred and thirty cases (4.8%) tested positive for HCV antibodies, and 109 (1%) tested positive for both HCV antibodies and HCV-RNA. Among patients with a positive viral load, the median [IQR] age was 62 [53-77] years, with a significant age difference between males and females (59 [48-67] vs. 78 [62-88]; Mann-Whitney U-test, p = 0.001). Eighty-four (77%) patients with a positive viral load were outside the target age range specified in the current National Recommendations for free-of-charge screening. The non-negligible prevalence of patients with a positive viral load among an unselected group of hospitalised patients suggests that such settings could effectively enhance screening programmes aimed at HCV elimination. Additionally, this approach may help identify patients who are not currently included in the National Recommendations.

Clinical Features of Varicella-Zoster Virus-Associated Anterior Uveitis with or without Ophthalmic Herpes Zoster

ABSTRACT Purpose This study aimed to investigate the clinical characteristics, diagnostic markers, and treatment outcomes of varicella-zoster virus-associated anterior uveitis (VZV-AU) with and without ophthalmic herpes zoster (herpes zoster ophthalmicus (HZO) and zoster sine herpete (ZSH), respectively). Methods Clinical records of 47 VZV-AU patients (21 ZSH, 26 hZO) were retrospectively reviewed for clinical findings, medication use, and PCR using aqueous humor (AH) results. Results There was no significant difference in age, gender, visual acuity (VA), or intraocular pressure (IOP) between the two groups. At the initial visit, small-to-medium white keratic precipitates (KPs) were significantly more observed in ZSH group than in HZO group, although there was no significant difference in the frequencies of other ocular findings between the two groups. Early antiviral medication use was significantly higher in HZO group (96.2%) than in ZSH group (19.1%). PCR was performed in 85.7% of ZSH and 53.8% of HZO patients. VZV-DNA positivity and viral load were similar between groups. Multivariate analysis revealed a positive correlation between white KPs and VZV viral load in AH. Although the ultimate use of antiviral medication was still less in ZSH group (71.4%), there were no significant differences in VA and IOP at the last visit between the two groups. Conclusion Patients with ZSH had more white KPs and received less early antiviral medication than those with HZO. However, visual outcomes were similar between the two groups. Small-to-medium white KPs were significantly associated with the viral load of VZV in AH, suggesting that they could be an active marker.

The relationship between positive and painful emotions and cognitive load during an algebra learning task

The mechanism through which emotional states impact learning is not yet fully understood. Through the lens of cognitive load theory, this study examines the relationship between emotional valence and learning during an algebra-based mathematics task and explores cognitive load as a potential mechanism through which emotions impact learning. Using structural equation modelling and path analysis of Australian Year 7 and 8 Secondary School students completing an algebraic learning task, we test a hypothesised model whereby extraneous cognitive load mediates the relationship between positive emotions, painful emotions, and learning. This model was tested against an alternative model with emotions mediating the relationship between extraneous cognitive load and learning. Results demonstrate that extraneous cognitive load mediates the relationship between painful emotions and learning. Alternatively, positive emotions were related to learning but not mediated by extraneous cognitive load. Implications of these findings for teachers and educators are also discussed.

Ocular loaiasis in France: the first case report from Brittany

We report the case of a 21-year-old Cameroonian woman residing in France for one year, who presented to our department with left eye discomfort and itching. Examination revealed a mobile translucent cord beneath the nasal-inferior conjunctiva, prompting suspicion of loaiasis. Anesthesia was administered for extraction, revealing a 31 mm male Loa loa. A positive microfilarial load, albeit low, confirmed the diagnosis and the diagnostic workup excluded other locations. Treatment with diethylcarbamazine was well-tolerated. This case highlights the importance of considering loaiasis in non-endemic regions and underscores the need for interdisciplinary collaboration in its diagnosis and management.

Research on the Connection Technology of Assembled Monolithic Residential Wallboard

In this paper, a novel technique for connecting residential shear walls to floor slabs is investigated. Shear wall structures with two different connection methods were established and numerically analyzed using ABAQUS (2024) finite element software. The two structures were connected by sleeve grouted connections (hereinafter referred to as the original structure) and profile + bolted connections (hereinafter referred to as the new structure). Numerical analyses yielded a positive maximum load for the new structure 1.41 times that of the original structure and a negative maximum load 1.12 times that of the original structure. The ratio of the ultimate tensile strength (load value corresponding to the peak point) to the yield strength (load value corresponding to the yield point) of the two structures (strength-to-yield ratio) was in the range of 1.15–1.27. The original structure was 2.62 times more ductile in the negative direction and 2.24 times more ductile in the positive direction than the new structure. The stiffness degradation of the new structure was greater in the later stages of loading, and that of the original structure was greater in the early stages of loading. The original structure had 1.08 times the energy-consuming capacity of the new structure. The cost of labor and materials for the original structure was approximately 1.50 times the cost of the new structure. The results of the data analysis showed that, compared to the original structure, the new structure had comparable performance in terms of strength-to-flexure ratio, ductility, stiffness degradation, and energy dissipation capacity. However, the new structure was more advantageous in terms of load-bearing capacity and required lower construction costs than the original structure. Therefore, the connection nodes designed in this paper are of great significance for engineering practice.

Power Generation Characteristics of Disk-Shaped Magnetohydrodynamic Generator Driven by Rotating Detonation

The power generation characteristics of a disk-shaped magnetohydrodynamic generator driven by rotating detonation with potassium-seeded hydrogen–air mixture are examined via quasi-two-dimensional numerical simulations. For unburned gas injection in the outward and inward directions, the rotating direction of the detonation wave is set so that the azimuthal velocity enhances the radial electromotive force. The simulation results show that the power output in the outward flow configuration exceeds that of the inward flow configuration. In the outward flow configuration, the radial gas velocity around the contact surface is the main contributor to the power generation, while in the inward flow configuration, the low gas velocity in almost the entire region and the vortices around the contact surface lead to poor power output. The characteristics in not only the power output mode but also the power input mode in which the voltage is applied externally between the electrodes are investigated. Under the positive load voltage, high enough for providing negative current, the Lorentz force occurs in the same direction as the propagation of the detonation wave; otherwise, the Lorentz force is induced in the opposite direction of the detonation wave.

Personal characteristics and transmission dynamics associated with SARS-CoV-2 semi-quantitative PCR test results: an observational study from Belgium, 2021-2022.

Following harmonization efforts by the Belgian National Reference Center for SARS-CoV-2, semi-quantitative PCR test (SQ-PCR) results, used as a proxy for viral load, were routinely collected after performing RT-qPCR tests. We investigated both the personal characteristics associated with SQ-PCR results and the transmission dynamics involving these results. We used person-level laboratory test data and contact tracing data collected in Belgium from March 2021 to February 2022. Personal characteristics (age, sex, vaccination, and laboratory-confirmed prior infection) and disease stage by date of symptom onset were analyzed in relation to SQ-PCR results using logistic regression. Vaccine effectiveness (VE) against a high viral load (≥107 copies/mL) was estimated from the adjusted probabilities. Contact tracing involves the mandatory testing of high-risk exposure contacts (HREC) after contact with an index case. Odds ratios for test positivity and high viral load in HREC were calculated based on the SQ-PCR result of the index case using logistic regression models adjusted for age, sex, immunity status (vaccination, laboratory-confirmed prior infection), variant (Alpha, Delta, Omicron), calendar time, and contact tracing covariates. We included 909,157 SQ-PCR results of COVID-19 cases, 379,640 PCR results from index cases, and 72,052 SQ-PCR results of HREC. High viral load was observed more frequently among recent cases, symptomatic cases, cases over 25 years of age, and those not recently vaccinated (>90 days). The vaccine effectiveness (VE) of the primary schedule in the first 30 days after vaccination was estimated at 47.3% (95%CI 40.8-53.2) during the Delta variant period. A high viral load in index cases was associated with an increased test positivity in HREC (OR 2.7, 95%CI 2.62-2.79) and, among those testing positive, an increased likelihood of a high viral load (OR 2.84, 95%CI 2.53-3.19).

Inflammatory signature in amyotrophic lateral sclerosis predicting disease progression

Experimental studies identified a role of neuroinflammation in the pathogenesis of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). However, the role of inflammatory molecules as diagnostic and prognostic biomarkers in patients with ALS is unclear. In this cross-sectional study, the cerebrospinal fluid (CSF) levels of a set of inflammatory cytokines and chemokines were analyzed in 56 newly diagnosed ALS patients and in 47 age- and sex-matched control patients without inflammatory or degenerative neurological disorders. The molecules analyzed included: interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-17, granulocyte colony stimulating factor (GCSF), macrophage inflammatory protein (MIP)-1a, MIP-1b, tumor necrosis factors (TNF), eotaxin. Principal component analysis (PCA) was used to explore possible associations between CSF molecules and ALS diagnosis. In addition, we analyzed the association between CSF cytokine profiles and clinical characteristics, including the disease progression rate score, and peripheral inflammation assessed using the Neutrophil-to-lymphocyte ratio (NLR). PCA identified six principal components (PCs) explaining 70.67% of the total variance in the CSF cytokine set. The principal component (PC1) explained 26.8% of variance and showed a positive load with CSF levels of IL-9, IL-4, GCSF, IL-7, IL-17, IL-13, IL-6, IL-1β, TNF, and IL-2. Logistic regression showed a significant association between PC1 and ALS diagnosis. In addition, in ALS patients, the same component was significantly associated with higher disease progression rate score and positively correlated with NLR. CSF inflammatory activation in present in ALS at the time of diagnosis and may characterize patients at higher risk for disease progression.

Impact of 3D learning resources on learning resilience: mediating roles of positive emotion and cognitive load

Three-dimensional (3D) learning resources are increasingly being integrated into classrooms and becoming important teaching tools. Learning resilience is a crucial factor affecting learning outcomes. However, the impact of 3D learning resources on learning resilience has not been received sufficient academic attention. This study constructs a structural equation model based on the broaden-and-build theory and cognitive load theory to examine the impact of 3D learning resources on learning resilience. To examine the mechanism of this impact, including the mediating roles of positive emotion and cognitive load, we collected 963 valid questionnaires from college students in Shandong Province, China. The results indicate that 3D learning resources are significantly positively correlated with positive emotion and learning resilience and negatively correlated with cognitive load. Moreover, cognitive load is negatively correlated with learning resilience. Positive emotion and cognitive load serve as mediators in the relationship between 3D learning resources and learning resilience. Therefore, developing high-quality 3D learning resources, cultivating positive emotions among students and reducing cognitive load can enhance college students’ learning resilience and mitigate academic risks.

Prevalence and detection of SARS-CoV-2 by RT-PCR: an analytical study

Background: The COVID-19 pandemic has significantly affected the healthcare system. RT-PCR has played a major role in the confirmation of SARS-CoV-2 thus helping in an early diagnosis, clinical interventions and patient isolation. This study was conducted to ascertain the importance of RT-PCR testing among symptomatic and asymptomatic cases in different age groups with association to infection. Methods: This retrospective cohort study was conducted from August 2020 to August 2021, in the Department of Microbiology, Autonomous State Medical College and Sarojini Naidu Memorial Hospital, Firozabad, Uttar Pradesh, India. Samples were collected from a total of 342, 281 cases which comprised of symptomatic patients (ILI, SARI), asymptomatic contacts, those seeking hospitalization, travelers and were subjected to testing by RT-PCR. The cases were divided into group A of patients presenting with symptoms ≤7 days, group B of patients with signs and symptoms >7 days and group C comprised of asymptomatic cases. The symptoms of patients were associated with the Ct values of the E/N screening gene and the RdRp/ORF1ab confirmatory genes. The Chi-square test was done to test the statistical significance of association of symptomatic patients with the outcome of the test. Results: The number of positive samples were 4,342 showing a prevalence of 1.3%. The maximum prevalence of infection was found in the age group of 20-29 years followed by the age group 30-39 years (p-value <0.05). The maximum positivity and high viral load were seen in the patients who presented with symptoms ≤7 days with Ct values ≤25. Conclusion: The maximum infection was found in the young age group. The screening and confirmatory genes could be detected in the samples of asymptomatic cases also which was helpful in isolating them and breaking the chain of further spread of the virus.

Effectiveness and toxicity of multidisciplinary treatment of head and neck cancer among people with HIV: Real-world evidence from a tertiary cancer center in Brazil.

e24139 Background: The incidence of head and neck squamous cell carcinoma (HNSCC) is rising among people with HIV (PWH). Previous studies have shown an increase in treatment-related toxicities in this population. This study aims to determine the demographics and treatment outcomes in this patient group at a tertiary cancer center in Brazil. Methods: HNSCC patients (pts) with HIV diagnosis treated at our institution between 2009 and 2022 were included. Medical charts were analyzed to extract clinical data. Log rank was used to compare survival estimates and stratified Cox regression model was used for univariate and multivariate analyses. Results: Our search identified 75 pts with HIV among 5956 pts with HNSCC. Median age at cancer diagnosis was 53 years (IQR 49-59.5), 80% were male and 82.7% had a smoking history. Most pts had an oropharynx primary tumor (38.7%) and locally advanced disease (80%), with T3 and T4 tumors in 55 pts (73.3%) and N+ in 48 pts (64.1%). A feeding tube (FT) was placed in 32% of pts before treatment. HIV viral load was detectable in 23 (30.7%) pts and 19 (25.3%) had a CD4 count of fewer than 200 cells/mm³, while 97.3% of the pts were on combination antiretroviral therapy at the time of HNSCC diagnosis. 26 pts were operated with curative intent and 20 pts received adjuvant therapy. In the total population, concurrent cisplatin-based chemoradiation (CCRT) was prescribed to 26 pts (34.7%) and 34 (45.3%) received radiotherapy (RT) alone. 65.4% of the pts in the CCRT group and 20.6% in the RT group were unable to complete treatment as prescribed, mostly due to toxicity. No pts with positive viral load or CD4 < 200 cells/mm³ were able to complete CCRT. Treatment toxicity led to hospitalization in 24% of pts and 7 pts needed FT placement. There were 8 deaths during treatment, 5 in pts with CD4 < 200 cells/mm³. Positive viral load was associated with CCRT interruption (p = 0.03) and a CD4 count of less than 200 cells/mm³ increased the risk of death during treatment (p = 0.02). Median overall survival (OS) was 31.7 months (IQR 14.6-53.7). Multivariate analysis did not show a statistically significant decrease in OS in pts with positive viral load or CD4 < 200 cells/mm³. Factors associated with worse OS on multivariate analysis were FT usage (HR = 2.91; 95% CI: 1.45-5.83) and Eastern Cooperative Oncology Group Performance Status (ECOG-PS) greater than 1 (HR = 3.26; 95% CI: 1.46-7.24). Conclusions: HNSCC treatment in PWH is associated with a high discontinuation rate, even in pts with antiviral therapy. High toxicity rates and deaths during treatment were observed. Positive viral load and low CD4 count were considered contributing factors. ECOG-PS and enteral feeding tube usage were independently associated with worse survival. The development of more tailored strategies in this population is needed to improve outcomes in patients with HNSCC and HIV.

A 3-month-old neonatal rhesus macaque HFMD model caused by coxsackievirus B1 infection and viral tissue tropism.

Coxsackievirus B1 (CVB1), an enterovirus with multiple clinical presentations, has been associated with potential long-term consequences, including hand, foot, and mouth disease (HFMD), in some patients. However, the related animal models, transmission dynamics, and long-term tissue tropism of CVB1 have not been systematically characterized. In this study, we established a model of CVB1 respiratory infection in rhesus macaques and evaluated the clinical symptoms, viral load, and immune levels during the acute phase (0-14 days) and long-term recovery phase (15-30 days). We also investigated the distribution, viral clearance, and pathology during the long-term recovery period using 35 postmortem rhesus macaque tissue samples collected at 30 days postinfection (d.p.i.). The results showed that the infected rhesus macaques were susceptible to CVB1 and exhibited HFMD symptoms, viral clearance, altered cytokine levels, and the presence of neutralizing antibodies. Autopsy revealed positive viral loads in the heart, spleen, pancreas, soft palate, and olfactory bulb tissues. HE staining demonstrated pathological damage to the liver, spleen, lung, soft palate, and tracheal epithelium. At 30 d.p.i., viral antigens were detected in visceral, immune, respiratory, and muscle tissues but not in intestinal or neural tissues. Brain tissue examination revealed viral meningitis-like changes, and CVB1 antigen expression was detected in occipital, pontine, cerebellar, and spinal cord tissues at 30 d.p.i. This study provides the first insights into CVB1 pathogenesis in a nonhuman primate model of HFMD and confirms that CVB1 exhibits tissue tropism following long-term infection.

Investigation of RBM10 mutation and its associations with clinical and molecular characteristics in EGFR-mutant and EGFR-wildtype lung adenocarcinoma

BackgroundRBM10 is commonly mutated in lung adenocarcinoma (LUAD). However, its role in the pathogenesis of LUAD remains undefined. EGFR-mutant LUAD represents a distinct subset of non-small cell lung cancer (NSCLC). The function of RBM10 in tumor pathogenesis is supposed to differ between EGFR-mutant and EGFR-wt LUAD. This study aimed to interrogate the prevalence of RBM10 mutation in a large cohort of Chinese patients with LUAD and investigate the association of RBM10 mutation with clinical and molecular characteristics of EGFR-mutant and EGFR-wt LUAD. MethodsTumor sequencing data from 2848 Chinese patients with LUAD were retrospectively reviewed and analyzed. The prevalence of RBM10 was also compared with other three cohorts: OrigMed (n = 1222), MSKCC (n = 1267), and TCGA (n = 566). The associations of RBM10 mutation with clinical and molecular characteristics were assessed. An external cohort of 182 patients with LUAD who received PD-1 inhibitor were used to investigate the association of RBM10 mutation with clinical outcomes upon immunotherapy. ResultsOur cohort showed a higher prevalence of RBM10 in EGFR-mutant LUAD than in EGFR-wt LUAD (14.8 % vs. 6.5 %, p < 0.001). The enrichment of RBM10 mutations in EGFR-mutant LUAD was also seen in another Chinese cohort (OrigMed: 14.9 % vs. 7.8 %, p < 0.001), but not in the two western cohorts (MSKCC: 7.4 % vs. 9.5 %, p = 0.272; TCGA: 8.1 % vs. 6.7 %, p = 0.624). RBM10 mutations co-occurred more frequently with EGFR L858R mutations (23.7 %) than with other types of EGFR mutations (19 del: 7.7 %; other: 7.1 % in others, p < 0.001). In EGFR-mutant LUAD, RBM10 mutations were more commonly found in stage I (18.2 %) and II (21.8 %) vs. stage III (9.4 %) and IV (11.3 %) tumors (p < 0.001). The proportion of PD-L1 positive expression in EGFR-mutant LUAD with concomitant RBM10 mutation was not different from that those without RBM10 mutations (41.8 % vs. 47.9 %, p = 0.566). In contrast, RBM10 mutation occurred more frequently in EGFR-wt LUAD at stage II-IV (stage II: 12.0 %, stage III: 8.7 %, stage IV: 6.6 %) than at stage I (2.8 %). EGFR-wt LUAD with concomitant RBM10 mutations had higher proportions of PD-L1 expression positivity (78.9 % vs. 61.9 %, p = 0.014) and higher tumor mutational load (8.97 vs. 2.99 muts/Mb, p < 0.001) than those without. Patients with EGFR-wt LUAD who also harbored RBM10 loss of function (LOF) mutations had a longer median PFS upon immunotherapy than those with RBM10 non-LOF mutations (7.15 m vs. 2.60 m, HR = 4.83 [1.30–17.94], p = 0.010). ConclusionWe comprehensively investigated RBM10 mutations in a Chinese cohort with LUAD. Compared to western cohorts, a significant enrichment of RBM10 mutations in EGFR-mutant LUAD compared to EGFR-wildtype LUAD in the Chinese population. RBM10 mutation shows different associations with clinical and molecular characteristics between EGFR-mutant and EGFR-wt LUAD, suggesting a divergent mechanism between these two subsets via which RBM10 deficiency contribute to tumor pathogenesis. The findings contribute to our understanding of the molecular landscape of LUAD and highlight the importance of considering population-specific factors in cancer genomics research.

We /r/ Tongan, not American: Variation and the social meaning of rhoticity in Tongan English

AbstractThe current paper argues that speakers of Tongan English, an emergent variety spoken in the Kingdom of Tonga, may use rhoticity to construct a cosmopolitan and globally oriented local social identity. A variationist analysis of non‐prevocalic /r/ in a corpus of 56 speakers reveals a change in progress towards rhoticity led by young females, whereas an affiliation with Liahona High School, a Mormon secondary school, predicts advanced adoption of the feature. I argue that rhoticity carries a positive ideological load for younger speakers as an index of globalness, modernity and Western cultural values, whereas for Liahona‐affiliated speakers, an additional indexicality of rhoticity is Mormonism. Linguistic constraints on variation mirror patterns found in previous studies on L1/L2 varieties and are thus more universal, whereas social constraints on variation are best examined through a local lens.

Thoughts of the February 20, 2023 Defne aftershock

On February 6 2023, two large earthquakes with magnitudes of Mw 7.8 (Pazarcık) and Mw 7.6 (Elbistan) occurred consecutively along the East Anatolian Fault Zone in eastern Turkey, causing enormous casualties and heavy damage. This devastating sequence of earthquakes was followed by the Defne aftershock on February 20 near Antakya province, which increased the damage and loss of life. Here, the teleseismic broadband P velocity waveforms are inverted to obtain the coseismic finite-fault slip distribution of the February 20, 2023 Defne aftershock. It was found that the rupture was controlled by the failure of a single asperity with the largest displacement of approximately 0.75 m, which occurred between 6 and 20 km depth. The source mechanism indicated a dominant left-lateral faulting with a significant normal component and released a total seismic moment of 5.85x1018 Nt.m. Coseismic Coulomb stress changes modelling showed that the Defne aftershock rupture was triggered by the earthquake sequence and that the February 6 Pazarcık earthquake had a dominant effect. In the stress modelling carried out on the Dead Sea Fault, the northern segment of the fault remained in the region of significant positive stress loading. Considering the positive stress load over 1 bar created by the earthquake sequence and the Defne aftershock ruptures, as well as the fact that no major earthquake has occurred for more than 600 years, it is clear that the probability of rupture in the northern part has increased significantly and the seismic hazard is high.

Research on deflection correction performance of movable crossbeam during pressurization of ultra-large hydraulic press

In this paper, the deflection of the movable crossbeam during the pressurization process of the ultra-large hydraulic press is studied. The electromechanical and hydraulic systems of the ultra-large hydraulic press are analyzed, and a joint AMESim-ADAMS simulation model of the mechanical system, the oil system, and the correction control system are established. The simulation analyzes the deflection control of the working cylinder in the 1600 MN pressurized state, the movable crossbeam in the positive load without deflection correction, positive load with deflection correction, eccentric load with 300 mm of deflection in X-positive direction, and eccentric load with 300 mm of deflection in XZ-positive direction. The results show that the correction control system needs to be turned on synchronously at the beginning of the pressurization; under the pressure of 1600 MN and the maximum eccentricity of 300 mm, the velocity error of the movable crossbeam can be controlled within 7 %, and the parallel control precision can reach 0.14 mm/m.

Cylindrical Steel Tanks Subjected to Long-Duration and High-Pressure Triangular Blast Load: Current Practice and a Numerical Case Study

This paper presents an investigation into the design of ammonia tanks for long-duration and high-pressure blast loads. The focus is on cylindrical steel tanks that apply as outer pressure-tight containers for double-walled tanks storing refrigerated liquefied gases. Based on limited empirical data, it is known in the tank industry that these tanks can withstand an explosion pressure up to a peak overpressure of approximately 10 kPa and 100 ms positive load duration. However, there is a growing need to design tanks for higher peak overpressures in order to establish a higher safety standard and accommodate unforeseen future requirements. This paper explores the concept of adapting established steel tank designs to handle high-pressure and long-duration overpressure due to blast events. Numerical analysis is conducted on a representative steel tank geometry subjected to a triangular blast load of 30 kPa with a 300 ms positive load duration. Various load application and calculation options are analyzed numerically. Considering the challenging nature of analyzing tank structures under blast load, the paper addresses controversial aspects discussed in the literature and presents a suitable analysis concept for a deflagration blast scenario for cylindrical tanks. The results provide insights into the expected structural behavior of the tank under high-pressure and long-duration overpressure. The main finding is that the calculation method developed in this study demonstrates the feasibility of utilizing steel tanks in scenarios involving long-duration and high-pressure blast loads. Furthermore, the paper provides recommendations to guide future studies in this area. The findings have implications for the design and construction of tanks in critical infrastructure and offer valuable insights for engineers and researchers in this field, improving safety standards and ensuring adaptability to future utilization concepts.

Allelopathic Effects of Lantana camara L. Leaf Aqueous Extracts on Germination and Seedling Growth of Capsicum annuum L. and Daucus carota L.

Allelopathy is the chemical interactions between plants that might lead to either stimulation or inhibition of growth, community structure, and plant invasions. Lantana camara L. is a noxious invasive weed that negatively affects seed germination, seedling growth, and increases the mortality of the crop plant. The objective of this work was to assess allelopathic effect of L. camara leaf aqueous extract on germination and seedling growth of Capsicum annuum (pepper) and Daucus carota (carrot). The aqueous extract of Lantana leaf samples was used as a source of allelopathic effects. Data were collected for germination and seedling growth parameters. The result indicated that the highest concentration of the allelopathic extract (20 mg/L) has demonstrated significantly the highest germination inhibition rate GIR (60.00%), germination speed V (2.54 U/day) for D. carota as GIR (70.00%), mean germination time MGT (0.36 days), and GI (0.67%) for C. annuum seeds. The highest concentration of the allelopathic extract (20 mg/L) has recorded the highest plumule inhibition rate PIR (59.63%) and radical inhibition rate RIR (48.95%) for D. carota seeds, as well as PIR (27.47%) and RLR (79.49%) for C. annuum. The largest negative allelopathic index (-60.00% or allelopathic intensity of 60.00%) was recorded for D. carota seeds, whilst (-63.43% or allelopathic intensity of 63.43%) was recorded for C. annuum seed germination. For D. carota seed germination, the first principal component (PC1) has got high positive loads from GI (0.36), RLR (0.31), GR (0.34), allelopathic index AI (0.34), relative length of plumule RLP (0.24), and V (0.30). By contrast, PC1 for D. carota seed germination has got the highest negative component loads recorded by GIR (-0.34), PIR (-0.24), MGT (-0.35), and RIR (-0.31). In allelopathic effect on C. annum seed germination, the first principal component (PC1) has got high positive scores from relative length of radical RLR (0.31), RLP (0.33), germination rate GR (0.33), V (0.33), and AI (0.33). Likewise, the high negative component loads were recorded by GIR (-0.33), PIR (-0.33), RIR (-0.31), and MGT (-0.32). The result of the present study demonstrated that GIR, PIR, and RIR were directly related to negative allelopathic activity.

Dual‐input step‐up switched‐capacitor multilevel inverter with reduced voltage stress on devices

SummaryThis paper proposes a single‐phase dual‐input step‐up switched‐capacitor multilevel inverter that employs three capacitors, 15 switches, and two diodes to provide 13 voltage levels and triple‐voltage boosting factor in its symmetric form and 37 levels with voltage boosting factor of 3.6 in its asymmetric version. This high boosting factor is accomplished without utilizing any transformer. For each output voltage level, there exists flow paths for both the positive and negative load current directions, which makes the proposed inverter capable of supplying any load type with variety of power factors (zero to unity). The voltage balancing of the capacitors takes place naturally, which tackles the need to auxiliary charge‐balancing circuits or control mechanisms. The proposed inverter can generate negative levels without the end‐side H‐bridge. Moreover, the voltage stress on the semiconductor devices is less than the peak output voltage. The increased number of levels and sinusoidal‐like waveform of the output voltage waveform enhances the quality and lowers the harmonic content of the load voltage and current waveforms, even for resistive loads. As the result, the load‐side filter can be downsized or removed. This paper employs the fundamental frequency method (FFM) as the switching technique, which is simple to implement and also operates the switches at low frequencies, leading to lower switching losses. The ascendancy of proposed inverter over similar counterparts has been investigated through comprehensive comparative analysis. Moreover, the correct performance of the proposed inverter at different modulation indices, and load types as well as during dynamic load changes has been verified by simulation and experimental analysis.

Generalized model of an ideal diode

To simplify the calculation of nonlinear circuits, a piecewise linear approximation of the current-voltage characteristic of nonlinear elements is used. The nonlinear elements are replaced by equivalent circuits containing ideal diodes in this case. There may be nonlinear elements, the equivalent circuits of which may contain both ideal diodes and positive and negative resistances in real electrical circuits. Therefore, it is very important to correctly calculate such circuits, especially if the presence of negative resistance can lead to uncertainty in determining the state of an ideal diode. This can expand the class of correct problems. The article examines all possible states of an ideal diode with both positive and negative load resistance. The reason for the uncertainty in determining the state of an ideal diode is considered. The possibility of eliminating this uncertainty by extending the "classical" model of an ideal diode with two states is considered. The possibility of the existence of a third state of an ideal diode is considered. An equivalent circuit for an ideal diode for this state is obtained taking into account Kirchhoff's laws and the law of conservation of energy. A generalized equivalent circuit for an ideal diode has been obtained, using which you can correctly calculate any currents and voltages in any circuit. The resulting generalized model of an ideal diode with three states expands the class of correct problems, which was limited to circuits in which it was impossible to unambiguously determine the state of an ideal diode using a “classical” ideal diode with two states.