Test Methods Research Articles

View Quality Assessments: A Pilot Study of Field Methods

ABSTRACT This paper describes findings from a workshop during which participants evaluated a series of window views. An explorative approach was applied to identify issues and testing methods useful in daylight research. The participants visited nine rooms with views of varied content, complexity, and viewing distance under the overcast sky. Participants used surveys with quantitative and qualitative questions, hand drawings, illuminance measurements, and photography to appraise the view quality. Subsequently, daylight simulations and neurocognitive tests have been carried out in two rooms with “bad” and “good” views. Multi-directional views were valued more than narrow or single-directional views. The cognitive testing showed numerical differences in several measures and a significant correlation between the difference scores for sadness and the difference scores for Trail Making Test-B across two rooms. The study identified that buildings of historical value, a presence of greenery, colored building facades, or a presence of people (content) contribute to a positive assessment of the view but are not included in the assessment criteria.

Designing a macroprudential capital buffer for climate-related risks: an application to transition risk

ABSTRACT This paper investigates macroprudential capital buffers to mitigate systemic transition risks and increase the resilience of the banking sector. Leveraging granular data and state-of-the-art stress testing methods, it quantifies potential bank losses attributed to transition risks. Focusing on short-term transition scenarios, the paper documents a significant variance among banks in their risk exposure, with the most exposed institutions being those characterized by lower excess capital. We introduce a methodological framework for tailoring bank-specific buffer requirements to cover these losses, offering macroprudential authorities a practical method for calibrating climate-related macroprudential capital buffers, complementing microprudential policies. While the focus of this application is on transition risks, the framework can be extended to capture all climate risks in general. The study demonstrates the potential of macroprudential capital buffers to mitigate potential climate-related losses and contributes to the understanding of the appropriate prudential policy response to these challenges.

Combining theory and usability testing to inform optimization and implementation of an online primary care depression management tool

BackgroundThe ‘Ottawa Depression Algorithm’ is an evidence-based online tool developed to support primary care professionals care for adults with depression. Uptake of such tools require provider behaviour change. Identifying issues which may impact use of an innovation in routine practice (i.e. barriers to and enablers of behaviour change) informs the selection of implementation strategies that can be deployed with the tool to support use. However, established theory-informed barriers/enablers assessment methods may be less well suited to identifying issues with tool usability. User testing methods can help to determine whether the tool itself is optimally designed. We aimed to integrate these two methodological approaches to i) identify issues impacting the usability of algorithm; and ii) identify barriers to and enablers of algorithm use in routine practice.MethodsWe conducted semi-structured interviews with primary care professionals in Ottawa, Canada. To evaluate usability, participants used a written patient scenario to work through the algorithm while verbalizing their thoughts (‘Think Aloud’). Participants were then asked about factors influencing algorithm use in routine practice (informed by the Theoretical Domains Framework). We used the codebook approach to thematic analysis to assign statements to pre-specified codes and develop themes pertaining to usability and routine use.ResultsWe interviewed 20 professionals from seven practices. Usability issues were summarised within five themes: Optimizing content and flow to align with issues faced in practice, Enhancing the most useful algorithm components, Interactivity of the algorithm and embedded tools, Clarity of presence, purpose, or function of components, and Navigational challenges and functionality of links. Barriers to and enablers of routine use were summarised within five themes: Getting to know the algorithm, Alignment with roles and pathways of influence, Integration with current ways of working, Contexts for use, and Anticipated benefits and concerns about patient communication.ConclusionsWhilst the Ottawa Depression Algorithm was viewed as a useful tool, specific usability issues and barriers to use were identified. Supplementing a theory-based barriers/enablers assessment with usability testing provided enhanced insights to inform optimization and implementation of this clinical tool. We have provided a methods guide for others who may wish to apply this approach.

Cefiderocol AST in a real-life Klebsiella pneumoniae collection: challenges in the ATU range.

FDC susceptibility testing is challenging as none of the commercial tests have been proven to accurately determine the susceptibility in the area of technical uncertainty (ATU). Here, we evaluated the performance of different FDC testing methods on Klebsiella pneumoniae isolates around this range. A challenging collection of 104 K. pneumoniae isolates with different FDC susceptibility was designed, including high representation (70%) of the 2024-ATU (21-23 mm) ± 1 mm. MICs were determined by broth-microdilution (BMD) reference method, commercial BMD (ComASP®, EUMDROXF®), MIC-gradient strips (Liofilchem) and disk-diffusion (DD) (Liofilchem, ThermoFisher). MIC devices evaluation was performed following ISO 20776-2:2021, calculating essential agreement (EA) and bias. DD results were evaluated following 2023 and 2024-EUCAST-guidelines, calculating major errors (ME) and very major errors. Categorical agreement (CA) was determined for all the methods. Overall, EUMDROXF® and ComASP® showed 81.7% (95% CI = 72.9-88.6) and 88.5% (95% CI = 80.8-93.9) EA, +2.6% and +27.9% bias and 99.0% (95% CI = 94.7-99.9) and 98.1% (95% CI = 93.3-99.8) CA, respectively. Liofilchem MIC-gradient strips exhibited 47.1% (95% CI = 37.2-57.1) EA, +2.9% bias and 93.3% (95% CI = 86.7-97.3) CA. In DD, variability between manufacturers was elevated. CA lowered and ME increased more than 10% with 2024-EUCAST-breakpoints modification. DD performance was insufficient to assess FDC resistance in K. pneumoniae and modification of EUCAST-breakpoints did not solve the problem. ComASP® panel fulfilled ISO criteria and could be used as MIC-confirmatory method, at least in K. pneumoniae. However, EUMDROXF®, even close, did not fulfil the EA criterion. MIC-gradient strips exhibited major limitations.

The Anthelmintic Activity of Nepeta racemosa Lam. Against Gastrointestinal Nematodes of Sheep: Rosmarinic Acid Quantification and In Silico Tubulin-Binding Studies

Gastrointestinal nematodes (GINs) inflict significant economic losses on sheep and goat farming globally due to reduced productivity and the development of anthelmintic resistance. Sustainable control strategies are urgently needed including the exploration of medicinal plants as safer alternatives to chemical anthelmintics. This genus of plants is used for anti-inflammatory, antioxidant, and antimicrobial activities. In this study, we aimed to evaluate the anthelmintic activities of Nepeta racemosa Lam. MeOH extract, n-hexane, dichloromethane (DCM), ethyl acetate (EtOAc), n-buthanol (n-BuOH) and aqueous (H2O) subextracts, and quantify rosmarinic acid in the active extract by the HPLC method, and perform in silico molecular docking studies of rosmarinic acid to examine its binding interactions with tubulin. The anthelmintic activity of the plant extracts on gastrointestinal nematode eggs and larvae (L3) of the sheep was assessed using in vitro test methods such as the egg hatch assay and larval motility assay, conducted over a 24 h period (1, 2, 3, 4, 6, 8, 24). All extracts exhibited 100% effectiveness in the egg hatch inhibition assay, regardless of concentration (50–1.5625 mg/mL). The EtOAc subextract shows the highest effectiveness at 79.66%, followed by the MeOH extract at 74.00%, water at 64.00%, n-hexane at 67.00%, and DCM at 61.00%, and the lowest effectiveness is observed with n-BuOH at 51.66% in the larval motility assay. The major compound of EtOAc extract, the most active extract of N. racemosa, was determined as rosmarinic acid and its amount in the extract was determined as 14.50 mg/100 mg dry extract. The amount of rosmarinic acid in the MeOH extract was found to be 0.21 mg/100 mg dry extract. n-Hexane, DCM, n-BuOH, and H2O extracts’ rosmarinic acid content was lower than the LOQ value. As tubulin plays an important role in the mechanism of anthelmintics, the major compound of the most active extract (NR-EtOAc) rosmarinic acid was docked onto the colchicine-binding site of the tubulin (5OV7) protein. Rosmarinic acid showed a similar activity spectrum to the anthelmintic drug albendazole. The discovery of low-cost and low-toxicity anthelmintic compounds is very important.

Individual and Joint Effect of Oleic Acid Imidazoline and CeCl3 on Carbon Steel Corrosion in CO2-Saturated Brine Solution

In production and transportation systems of the oil industry, brine solutions contain high concentrations of chloride and dissolved CO2, which is a very corrosive medium to which carbon steel is exposed. Therefore, finding new effective and environmentally friendly corrosion inhibitors is of great importance. The effect of CeCl3 (in concentrations from 5 mg dm−3 to 20 mg dm−3) and oleic acid imidazoline (IOA) (in concentrations from 5 mg dm−3 to 20 mg dm−3) separately and their mixtures (in concentrations from 5 mg dm−3 to 15 mg dm−3 of CeCl3 and from 5 mg dm−3 to 20 mg dm−3 of IOA) as corrosion inhibitors of AISI 1018 carbon steel corrosion in simulated brine solution saturated with CO2 at 60 °C were examined by means of weight-loss testing, electrochemical measurements (polarization resistance, linear polarization with Tafel extrapolation, electrochemical impedance spectroscopy) and surface analyses (scanning electron microscopy with energy-dispersive X-ray spectroscopy analyses, Raman spectroscopy and X-ray diffraction). All test methods showed a higher efficiency of compounds′ mixtures (from 62.77% to 97.94%) and a higher degree of corrosion protection compared to the action of individual compounds (efficiency from 3.43% to 94.61% for IOA and from 57.58% to 96.27% for CeCl3). Imidazoline, a common corrosion inhibitor in CO2-saturated systems, most likely forms a surface film with voids via its adsorption on steel surface, while cerium carbonate tends to fill these voids by creating a more compact film. In this way, a denser and thicker surface film is formed.

Eye injuries and defective vision in school and club sports - Arguments for DIN-approved glasses suitable for school sports

Visual deficits/ametropia are particularly significant obstacles in sports because the visual system controls/corrects all of an athlete's movements. However, athletes are at increased risk for eye injuries caused by high-velocity objects e.g. balls or physical contact with opponents. This article presents the current (German) figures on eye injuries in club and school sports and evaluates the risk of eye injuries in various sports.2392 eye injuries, selected from the 221273 club sports injuries recorded in the Ruhr University Bochum and ARAG Sports Insurance database for the period 1987-2017 were evaluated. The school sports eye injuries recorded by the German Social Accident Insurance for 2019 were also analyzed.Of all the club sports injuries recorded, 1.08% were eye injuries; of these, 19.7% had to be treated in hospital, 13.9% required surgery, and 56.9% prevented the injured athletes from working. Blunt trauma was the most common cause of injury, comprising more than 50% of cases. Eye injuries were strongly overrepresented in club sports injuries sustained during water polo, squash, badminton, and tennis (injury proportion ratio [IPR] = 5.1-8.8). In school sports, eye injuries comprised 1.83% of the reported cases.Eye injuries in sports are relatively rare, but often serious. Based on the increased IPR found for some sports, further studies must analyze the risk of eye injury in more detail. Eye protection in the form of sport-appropriate glasses should be used.In addition, the article addresses the problem of "defective vision in sport" and its adequate correction and shows the requirements for spectacles suitable for (school) sport using the example of DIN 58184 "Spectacles suitable for school sports - Requirements and test methods".

Tracing Eponymous Word Combinations in Education and Pedagogy

Currently, there is a significant focus on the exploration and classification of eponymous terminology across a range of fields of study. Scholars are particularly interested in the term’s foundation, theoretical underpinnings, and the lexicographic aspects of its application across various domains. Notably, eponymous terms are most prominent in medical, economic, political, historical, and technical fields. However, there is a need to broaden research efforts in pedagogy and education terminology, which includes several eponymous terms. The study was conducted following dictionary criticism principles and tackled the analysis of quantitative and qualitative data on eponymous phrases found in three English-language special dictionaries. The ultimate objective was determining the feasibility of including eponym terms in a dictionary. The research objectives were outlined to achieve this goal. The authors carefully selected and analysed the terminology, identifying corresponding semantic fields and conducting a structural and grammatical analysis of 93 eponymous phrases. They identified various semantic fields, such as “Diseases and Mental Disorders,” “Psychology and Psychological Expertise,” “Pedagogical Schools, Principles, and Educational Institutions,” “Educational Reforms,” and “Reports on Education,” among others, and provided commentary on the practicality of including eponymous terms in a dictionary of education. Research on eponyms has revealed that they share similar grammatical and nominative structures as non-eponymic terms, functioning as individual words and word groups. Typically, eponyms consist of two elements: a noun and an adjective or a noun and another noun. Anthroponyms –names derived from people – are often used in eponyms to describe the founders of pedagogical schools and trends, developers of psychological theories and testing methods, and scientists who have identified diseases and mental disorders requiring unique learning approaches. Additionally, eponyms may incorporate place names and names of literary or mythical characters, creating phrases like Pickwick Syndrome, Munchausen Syndrome, Summerhill School, and the Bologna Declaration. Furthermore, the primary eponymous trends within the semantic fields have been identified through a rigorous analysis of both quantitative and qualitative data. The findings align with the global trend observed at the study’s outset, where medical eponymy prevails. Therefore, terminologists and lexicographers must focus on the study of this eponymous terminology.

THE RELATIONSHIP BETWEEN OCCUPATIONAL SAFETY AND HEALTH BEHAVIOR AND WORKPLACE ACCIDENTS IN MICRO, SMALL AND MEDIUM RATTAN BUSINESSES IN GRESIK DISTRICT

Work accidents are caused by events in the work environment which are certain to harm various parties and even lead to disability and even the most fatal event, namely death. Work accidents in Gresik Regency Rattan MSME's that appear to dominate are due to a lack of knowledge, attitudes, compliance and Personal Protective Equipment. The aim is to find out how the relationship between Occupational Safety and Health behavior and the incidence of work accidents in Rattan Micro, Small, and Medium Enterprises in Gresik Regency. The study was conducted cross-sectionally and classified as quantitative. The total population involved is 278 workers who worked in 16 semi-finished rattan MSME's. The selected participants were randomized (simple random sampling) and Slovin's formula, resulting in a total of 165 workers as respondents. Data collection was conducted through three main methods, namely direct observation, interviews, and questionnaires. The variables used are OHS behavior which includes OHS knowledge, OHS attitude, OHS compliance and the use of personal protective equipment (independent), while the incidence of work accidents (dependent). Data analysis used 2 statistical test methods, both Chi-square and Fisher's exact test. The results of the study concluded several statements, there is a relationship between knowledge and work accidents (p = 0.008), there is a relationship between attitude, compliance with work accidents (p = 0.000), there is a relationship between Personal Protective Equipment and work accidents (p = 0.004). The dominant factor influencing work accidents is the factor of compliance with work instructions (OR 13.993). Suggestions for improvement are that it is hoped that Gresik Regency Rattan MSME 's will impose regular training on work safety procedures to workers in order to increase workers awareness as well as to ensure that PPE is available and used.

The Current Applications of Metabolomics in Understanding Endometriosis: A Systematic Review

Endometriosis is a common gynecological disease that affects approximately 10–15% of reproductive-aged women worldwide. This debilitating disease has a negative impact on the quality of life of those affected. Despite this condition being very common, the pathogenesis is not well understood. Metabolomics is the study of the array of low-weight metabolites in a given sample. This emerging field of omics-based science has proved to be effective at furthering the understanding of endometriosis. In this systematic review, we seek to provide an overview of the application of metabolomics in endometriosis. We highlight the use of metabolomics in locating biomarkers for identification, understanding treatment mechanisms and symptoms, and relating external factors to endometriosis. The literature search took place in the Web of Science, Pubmed, and Google Scholar based on the keywords “metabolomics” AND “endometriosis” or “metabolome” AND “endometriosis”. We found 58 articles from 2012 to 2024 that met our search criteria. Significant alterations of lipids, amino acids, as well as other compounds were present in human and animal models. Discrepancies among studies of significantly altered metabolites make it difficult to make general conclusions on the metabolic signature of endometriosis. However, several individual metabolites were elevated in multiple studies of women with endometriosis; these include 3-hydroxybutyrate, lactate, phosphatidic acids, succinate, pyruvate, tetradecenoylcarnitine, hypoxanthine, and xanthine. Accordingly, L-isoleucine and citrate were reduced in multiple studies of women with endometriosis. Including larger cohorts, standardizing testing methods, and studying the individual phenotypes of endometriosis may lead to more separable results.

Trends in Immunotherapy (IO) Use and Survival Among Patients With High-Incidence Stage IV Cancers Across the United States.

IO has transformed cancer management, but its adoption in advanced cancer patients varies by tumor type. With more Stage IV patients undergoing surgery, understanding site-specific outcomes in these challenging patients is essential. We aimed to evaluate IO use and survival trends for Stage IV cancer patients across high-incidence cancers in the US. Patients diagnosed with Stage IV prostate, breast, melanoma, colorectal, renal, bladder, lung, or pancreas cancer were identified from the National Cancer Database (2004-2020). Cochrane-Armitage test and Kaplan-Meier methods assessed IO and overall survival across three periods: 2004-2010, 2011-2015, and 2016-2020. Among 1 425 731 Stage IV cancer patients, most had lung (50.0%), pancreas (12.5%), and breast cancer (9.3%), while the least had melanoma (2.2%). From periods 1 to 3, IO use increased from 1.0% to 24.6%, notably in melanoma (9.5% to 58.5%, p < 0.001). Melanoma exhibited the greatest survival gains (median survival: 7.1 to 14.9 months). Absolute increases in 3-year overall survival rates ranged from 3.4% in pancreas (1.7% to 5.1%) to 21.4% in melanoma (15.7% to 37.1%). Utilization of IO is tumor-site specific and associated with improved survival rates for Stage IV cancer, with varied success across types. Variations in receipt highlight ongoing challenges to ensure equitable adoption.

Research on the Reliability of SiC MOSFET Devices

This paper investigates the short-circuit, avalanche, crosstalk, and switching oscillation problems associated with the application of SiC MOSFETs. It examines the generation mechanisms, working mechanisms, and testing methods for these four issues. The study proposes methods to enhance the device's anti-short-circuit capability by assessing the degree of short-circuit in advance, improve the device's anti-avalanche capability through protective measures, suppress switching oscillations by controlling dead time and output distortion compensation, adjusting parasitic parameters through control algorithms, and mitigate bridge-arm crosstalk using various suppression techniques.

Damage constitutive model and mechanical properties of a concrete limestone composite after acid corrosion

Damage constitutive model and mechanical properties of a concrete limestone composite after acid corrosion

Defining Running Intensity Domains from Critical Speed Derived from a 3-Minute All-Out Running Test

Background/Objectives: This study examines the utility of the 3-min all-out test (3MT) in determining exercise intensity domains through critical speed (CS), offering a practical alternative to traditional VO2max-based methods. Methods: Eighteen trained runners completed both the 3MT and a graded treadmill test. CS, VO2max, and HRmax were measured and compared to markers such as ventilation threshold (VT), gas exchange threshold (GET), lactate threshold (LT), onset of blood lactate accumulation (OBLA), CS, and VO2max, which are threshold markers for defining six exercise intensity domains. Results: Results demonstrate that CS reliably distinguishes among six exercise intensity domains with greater precision and less variability than heart rate (HR) or VO2-derived metrics. Notably, HR was unable to differentiate between high-intensity domains, highlighting its limitations for performance prescription. Compared to VO2max testing, the 3MT offers a simpler, non-invasive, and time-efficient approach to identifying training zones and monitoring performance. CS effectively delineated moderate-to-heavy, heavy-to-severe, and severe-to-extreme intensity domains, with strong correlations to performance thresholds. The findings emphasize the accessibility and reliability of the 3MT, particularly in overcoming the logistical challenges of traditional testing methods. Conclusions: This research underscores the potential of the running 3MT as a valuable tool for individualized training prescription and performance monitoring in both research and applied sports contexts, paving the way for a broader adoption in athletic training methodologies.

Correcting Ski Resort Trajectories Extracted from Video

Accidents at ski resorts present a significant safety concern, underscoring the urgency of addressing these issues. This study aims to enhance safety protocols by providing resort operators with more effective data analysis methodologies. We present and test methods for analyzing video footage from downhill ski areas where detailed information needed to correct errors, due to perspective, lens distortion, etc., is not available. This can be the case, e.g., for webcam footage and accidental videos (e.g., on YouTube). As much of this kind of video is available and could be used for statistical analysis, methods are needed that allow for at least for an approximate consideration of such aspects. Using video footage obtained from various ski resorts, we developed and tested several methods for analyzing and correcting the trajectories of skiers captured in the videos. Our analysis revealed that using five reference lines, along with the most appropriate x and y coordinate corrections, is an effective approach for achieving precise calibration of the video data. The corrected trajectory data, adjusted for perspective distortions and scaling inaccuracies, provide a detailed basis for analyzing skier behavior and identifying high-risk zones prone to collisions.

Effect of Various Diamines on the Mechanical, Thermal, and High‐Frequency Dielectric Properties of Polyimide and Their Composites With Functionalized Hollow Silica Fiber

ABSTRACTIn this study, three different series of polyimides (PIs) and their composites fabricated using various chemical structure of diamines and functionalized hollow silica fiber (FHSF) were synthesized. The experimental results of three PIs indicate that the addition of fluorine atoms into the pending groups of PI can decrease the glass transition temperature (Tg) with increase in the chain flexibility and this can lower the dielectric constant of PI. The high‐frequency dielectric constants of the composite materials decrease with increase in the loadings of FHSF. These phenomena are possibly accredited to the steric hindrance effect caused by the presence of trifluoromethyl groups of PI polymer chain and FHSF, which can interrupt the PI chain packing and increase their free volumes, resulting in the decrease of Tg and the dielectric properties of PIs. The high‐frequency circuit transmission loss properties of fabricated composite materials measured using the Test Methods Manual IPC‐TM 650 2.5.5.14 are lower than those of pure polymer matrix, recommending that the prepared materials could be selected as interlayer dielectrics for nano‐level electronic.

Nationwide cervical precancer screening in Ghana: concurrent HPV DNA testing and visual inspection under an expanded hub-and-spoke model

Cervical cancer continues to disproportionately burden women in sub-Saharan Africa, and is the commonest gynecological cancer in Ghana. The Cervical Cancer Prevention and Training Centre (CCPTC), Battor, Ghana spearheaded the Ghana arm of the mPharma 10,000 Women Initiative (mTTWI) between September 2021 and October 2022. The aim of this study was to examine the outcomes of nationwide concurrent screening using high-risk human papillomavirus (hr-HPV) DNA testing and visual inspection methods, as well as factors associated with the screening outcomes. We conducted a descriptive retrospective cross-sectional study to estimate the prevalence of hr-HPV infection (nationally and regionally) and cervical lesions among women screened by graduates of our training center in their own settings (spokes) with remote supervision and mentoring by CCPTC trainers (hub). We modeled factors associated with hr-HPV infection using nominal logistic regression. Among 5217 women screened (mean age, 40.1 years), the overall prevalence of hr-HPV infection and cervical lesions were 29.1% (95% confidence interval [CI] 27.9–30.3) and 3.7% (95% CI 3.2–4.2), respectively. The prevalence distribution varied widely among regions, with the highest recorded in the Oti Region (32.8%) and the lowest recorded in the Upper West (20.7%) and North-East (20.7%) regions. The most frequently detected HPV genotype was other hr-HPV type(s) only (non-HPV16, non-HPV18) (23.5%; 95% CI 22.3–24.7), followed by HPV16 only (1.5%; 95% CI 1.2–1.8), and mixed infection with HPV18 + other hr-HPV type(s) (1.2%; 95% CI 0.9–1.5). Factors found to be significantly associated with hr-HPV infection among women screened included age < 35 years, having a relationship status apart from married/cohabitation, nulliparity, and HIV positivity. Drawing from our implementation of this model within the mTTWI, we posit that while Ghana prepares for organized screening, coordinating opportunistic screening could enable a phased expansion of cervical precancer screening with the help of international and local partners. This approach, combined with concurrent testing (hr-HPV DNA testing and visual inspection), holds promise for mitigating loss to follow-up among women requiring additional evaluation and lesion management.

Rancang Bangun Sistem Pembelajaran SMP Nurul Islam Tanahbaya dengan Metode Agile Scrum

This study aims to design and develop a learning management system (LMS) at SMP Nurul Islam Tanahbaya using the Agile Scrum methodology. The developed system aims to enhance the effectiveness of the learning process by facilitating digital interaction between students and teachers and by providing an integrated platform for learning management. This study involves several stages, starting with problem identification, data collection, verification of needs and issues, Scrum process and development, testing, and conclusion drawing. The results of the study indicate that the application of the Agile Scrum method in the development of the LMS at SMP Nurul Islam Tanahbaya can improve development completion time and produce a system that meets the needs. This LMS features functionalities such as chats, material management, assignments, announcements, discussion forums, assessments, surveys, and recommendations. The Learning Management System (LMS) developed for SMP Nurul Islam Tanahbaya has been tested using blackbox testing methods. The results of the blackbox testing show that the system is valid and capable of performing all expected tasks effectively. Therefore, the developed LMS is expected to significantly contribute to improving the quality of learning at SMP Nurul Islam Tanahbaya and support a more effective and efficient educational process.

Sublethal and lethal toxicity assessment of lanthanum and gadolinium to Daphnia magna in a 7-day test method.

The use of rare earth elements has increased in recent years, leading to a rise in environmental concentrations. Despite the growth in number of studies regarding toxicity, knowledge gaps remain. For Daphnia magna, standardized test methods involve exposure periods of either 48 h or 21 days to assess toxicological effects. In this study, the exposure period was adjusted to 7 days to evaluate sublethal endpoints not measurable in 48-h tests. Additionally, this approach enabled us to obtain results within a shorter time frame than that required for 21-day tests. This study focused on the individual toxicity of lanthanum (La) and gadolinium (Gd) to Daphnia magna. We assessed mortality, feeding rate, somatic growth, and maturity under static conditions, modifying the media by adding MOPS buffer to maintain an initial pH of 6.8 and providing Raphidocelis subcapitata as a daily food source. Results showed that the solubility of La decreased considerably, with the highest recovery rate dropping from 133.33% at the start to 32.73% by the end of the 7-day exposure period. In contrast, Gd solubility remained stable, with a recovery rate of 86.88% at the start and 81.30% at the end of the test. Daily lethal concentrations (LCx) were calculated, revealing LC10 values on the first day, LC20 on the second day, and LC50 by the third day for La and the second day for Gd. By the test's end, the LC10, LC20, and LC50 values were 30.40, 78.96, and 403.67 µg L-1 for La, and 10.67, 33.73, and 241.28 µg L-1 for Gd. For the sublethal endpoints, maturity was the most sensitive endpoint with the EC20 and EC10 corresponding to 0.79 and 0.26 µg L-1 for La and 0.39 and 0.14 µg L-1 for Gd. Gd had a higher toxicity in all endpoints assessed. While a thorough comparison to existing literature remains challenging due to variations in endpoints assessed, the methodology employed in this study yielded a range of informative results. This approach provides a useful range-finding test for Daphnia magna toxicity assessments, particularly for preliminary screening, and may complement standardized methodologies.

The Effect of Oxidation on Coal’s Molecular Structure and the Structure Model Construction of Oxidized Coal Molecular

Three kinds of 1/3 coking coals with different degrees of oxidation were used for this study in Inner Mongolia, China. Using analytical testing methods such as X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance carbon spectroscopy (13C-NMR) and Fourier transform infrared spectroscopy (FT-IR), combined with computer-aided software such as Chemdraw, Materials Studio (2017), and MestRenova, three coal samples were characterized and analyzed. On this basis, the molecular formulas of three coal samples with different degrees of oxidation were constructed by optimizing the model energies: we used C228H165N3O21S4 for Suhaitu9# coal, C244H171N3O31S2 for Guoyu coal, and C225H177N3O33S2 for Lu9# coal. The results showed that, at the same coal rank, the oxidation degrees of S9, GY, and L9 coal samples were 21.10%, 48.30%, and 53.12%, respectively. As the oxidation degree increased, the proportion of oxygen-containing functional groups and nitrogen oxides in the coal macromolecular structure gradually increased. The bridge circumference ratios were 0.3786, 0.3351, and 0.2228, respectively, showing a gradual decrease. The average methylene chain lengths were 4.9569, 2.6843, and 1.9055, respectively, showing a gradual decrease. This indicates that the condensation degree of the compounds decreases with the increase in the degree of oxidation. These findings reflect the effect of oxidation on the modeling of coal’s macromolecular structure and lay a theoretical foundation for the further study of impact of the degree of oxidation on the physicochemical properties of coal.