Samples For Testing Research Articles

Optimizing Sample Preparation for Destructive Testing in Resistance Spot Welding

Abstract The integrity and reliability of resistance spot welding, a crucial process in various manufacturing industries, are significantly influenced by the quality of sample preparation. This study focuses on advancing the methodologies and practices in the preparation of samples for resistance spot welding destructive tests, aiming to improve the precision and repeatability of the results. We discuss comprehensive approaches encompassing material selection, surface treatment, dimensional accuracy, and alignment procedures, emphasizing the importance of meticulous handling and preparation techniques, A significant focus is placed on the utilization of sophisticated alignment and measurement tools to enhance the consistency of the welding area subjected to destructive testing. our study demonstrates a significant improvement in the reliability and accuracy of welding machine calibration, ultimately contributing to the overall quality of the welding process. By integrating these refined processes, the study highlights a significant improvement in the reliability of welding tests, contributing to enhanced welding quality and performance in practical applications. Our findings underscore the critical role of detailed and standardized sample preparation in achieving accurate and reliable resistance spot welding destructive test outcomes, providing valuable insights for both industrial applications and further research in welding technology.

Donor-derived bartonellosis in solid organ transplant recipients from unhoused donors in Alberta

Bartonella quintana infection is rarely described to be transmitted through solid organ transplant (SOT). We report a cluster of using donor-derived B quintana infection and the attack rate from Bartonella seropositive donors. In this retrospective study of SOT recipients that received an organ from an unhoused deceased donor (UDD) in Alberta in 2022-2023, serology testing for Bartonella was performed indirect immunofluorescent assay on UDDs and recipients of UDDs with positive serology. Titers ≥1:64 were considered positive. During the study period, 31/32 UDDs were tested for immunoglobulin G to Bartonella (20 negative, 11 positive for B quintana and/or B henselae). Thirty-two organs were transplanted from the 11 seropositive donors. Six SOT recipients developed bartonellosis secondary to B quintana (4 SOT recipients received organs from 3 seropositive donors, and 2 SOT recipients from 1 UDD with no stored sample for testing). The attack rate for clinical disease from positive donors was 12.5% (4/32). The main presentation was skin nodules/papules (median 5.5 months) with bacillary angiomatosis in 4/6. Bartonella serology was positive in 5/6 SOT recipients (initially negative in 2) and blood B quintana quantitative polymerase chain reaction in 1. None had visceral involvement. All donors had history of substance use. This outbreak of bartonellosis reinforces the potential for unexpected donor-transmitted infections. Clinicians should be aware of high transmission of B quintana through transplant from infected UDDs.

A single-use electrochemical biosensor system for ultrasensitive detection of Aflatoxin B1 in rice, corn, milk, peanut, chili pepper samples

Aflatoxin B1, a common food contaminant in peanuts and corn and a genotoxic carcinogen in humans poses a significant risk for hepatocellular carcinoma, making its detection crucial; this study aims to develop a label-free electrochemical biosensor using a disposable indium tin oxide polyethylene terephthalate (ITO-PET) electrode modified with 3-Aminopropyltriethoxysilane for detecting Aflatoxin B1 in real food samples. Initially, optimization steps for the proposed biosensor were conducted using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. Characterization steps such as storage capacity, regeneration, and single frequency impedance (SFI) were completed for the proposed disposable biosensor after the optimization steps. The electrochemical biosensor, based on AFB1, exhibited excellent repeatability and reproducibility. It had a broad dynamic detection range from 0.1 fg/mL to 500 fg/mL, with low limits of detection (LOD) and quantitation (LOQ) at 0.19 fg/mL and 0.65 fg/mL, respectively. Finally, the proposed AFB1-based biosensor system was applied to real food samples (rice, chili pepper, milk, corn, and peanuts) for testing and validation.

Reduce energy consumption in your laboratory – switch ultra-low temperature freezers from – 80 °C to –70 °C. A pilot study on short term storage of plasma samples for coagulation testing

It is common practice in laboratories to store biological samples in ultra-low temperature (ULT) freezers. There is growing interest in raising the temperature of ULT freezers in order to save energy and reduce expenses, as energy conservation becomes increasingly important and sustainable laboratory practices gain popularity. In our laboratory, plasma samples are stored for three months for diagnostic purposes. We therefore took the opportunity to investigate the effect of two different storage temperatures (−70 °C vs −80 °C), on activated partial thromboplastin time (APTT), factor VIII (FVIII), international normalized ratio (INR) and factor VII (FVII) measurements on paired plasma samples collected from 26 individuals after three months of storage. Automated coagulation analysers CS-5100 and ACL TOP were used to perform the tests. We found no consistent difference between the two storage temperatures for any of the four coagulation parameters (all p-values > 0.05). We conclude that the temperature of ULT freezers used to store plasma samples for APTT, FVIII, INR, and FVII measurements can be safely increased from −80 to −70 °C without affecting the stability of the samples.

Feasibility and Safety of Transesophageal Mediastinal Cryobiopsy in the Diagnosis of Mediastinal Pathologies

Introduction: Endobronchial ultrasound-guided transbronchial needle aspiration remains the gold standard for the diagnosis of mediastinal pathologies. Its greatest limitation has been the low diagnostic yield in lymphoproliferative disorders as well as insufficient samples for molecular testing. Transesophageal examinations using an EBUS scope have helped increase the diagnostic yield by allowing for additional biopsies of paraesophageal and intra-abdominal lesions. Similarly, the novel approach of transbronchial mediastinal cryobiopsy has further increased the yield by providing larger and better-preserved biopsies. Both complimentary techniques have shown great individual feasibility and safety. However, the feasibility of transesophageal cryobiopsies in the evaluation of mediastinal pathologies remains a subject of debate. Aim: The aim of the study was to investigate the safety and feasibility of transesophageal EBUS-guided mediastinal cryobiopsies performed at our center. Methods: We conducted a retrospective review of 30 patients who underwent mediastinal cryobiopsy through the esophagus at our institution between October 2023 and March 2024. Data on patient demographics, diagnostic yield, and complications were collected and analyzed. Results: The mean patient age was 43 years, with a gender distribution of 60% male and 40% female. The primary indications included suspicion of lymphoproliferative disorders, suspected sarcoidosis, and malignancies with paraesophageal lesions. The overall diagnostic yield was 93%. No major complications were noted in any of the patients. Conclusion: Transesophageal mediastinal cryobiopsy appears to be a promising complimentary technique for mediastinal evaluation with a relatively high diagnostic yield and favorable safety profile. However, further studies with larger cohorts are warranted to validate the findings at our institution.

Uniaxial compressive strength prediction based on measurement while drilling data: A laboratory study

The uniaxial compressive strength is one of the most important basic parameters of rock, which is essential for surrounding rock stability analysis and support scheme design of underground engineering. At present, it is time consuming and costly to take a large amount of core samples for laboratory testing, and the mechanical properties of the cores may be affected by mining disturbance, which can easily lead to inaccurate result. The measurement while drilling (MWD) technology provides a new approach to solve the above challenge. The key to implementing this technology is to establish a correlation model between drilling parameters and rock mechanics parameters. Based on the characteristics of polycrystalline diamond compact (PDC) bits in drilling and rock breakage, this paper analyzes the mechanical state of the bit in breaking rock. A theoretical correlation model between the torque, feed force of the bit and the uniaxial compressive strength of the rock has been developed. To verify the accuracy of the theoretical model, the uniaxial compressive strength of five different types of rocks (red sandstone, green sandstone, limestone, marble and shale) was obtained through laboratory mechanical tests. The torque Mb, feed force Fb and other parameters in the drilling process of these five rocks were tested through the newly developed MWD test system. The correlation between the drilling parameters and the uniaxial compressive strength of rock was established. The results showed that the feed force Fb and torque Mb measured at five different types of rocks indicate a linear increasing trend with an increase in depth of cut h. Meanwhile, a strong linear relationship between the feed force Fb and torque Mb is evident. This paper proposes an MWD-based method to rapidly conduct the in-situ measurement of the uniaxial compressive strength of various rocks.

A meta-analysis of livestock brucellosis prevalence in Indonesia.

Indonesia has a long history of livestock brucellosis, but the overall pooled prevalence remains unclear. This study aims to determine the pooled estimated prevalence of livestock brucellosis in Indonesia using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Five databases were searched and screened using predefined inclusion and exclusion criteria. Data from included studies were extracted and analyzed using a random effects model in R 4.3.0 for pooled estimated prevalence, subgroup meta-analysis, and meta-regression. Publication bias and sensitivity tests were conducted using Egger's test, funnel plot, trim and fill plot, and leave-one-out. The screening process identified 46 included studies, representing 47,057 samples for brucellosis testing. The pooled estimated prevalence for livestock brucellosis was 3.25% (95% CI, 1.81%-5.78%) with high heterogeneity (Q = 2130.91, p = 0, I2=98%). Subgroup meta-analysis indicated no significant difference in the prevalence of livestock brucellosis across the main islands in Indonesia (p = 0.44) and across provinces in Sulawesi Island (p = 0.83), but significant differences were found among provinces in Java (p < 0.01). The subgroup meta-analysis based on animal type showed no significant difference between cattle, small ruminants, and pig brucellosis estimated prevalence (p = 0.26). Between serological tests, no significant difference was found (p = 0.77). Meta-regression showed no significant difference in brucellosis prevalence from 1988-2023. Egger's test and funnel plot showed publication bias. Trim and fill test indicated 21 studies should be added. As most studies were conducted in Java and Sulawesi Islands, caution should be exercised in interpreting the results, emphasizing the necessity of increasing the study of brucellosis in other regions.

Improving adherence to severe malaria treatment guidelines in children at a Ugandan regional hospital: assessment of a quality improvement initiative

BackgroundMalaria is the leading cause of hospitalizations and death in Uganda, particularly in children under the age of five. Studies have shown that adherence to the World Health Organization (WHO) guidelines for the management of severe malaria reduces mortality in hospitalized children. This study aimed to determine the impact of targeted interventions on adherence to the WHO severe malaria treatment guidelines in children at a Ugandan hospital as part of a quality improvement initiative.MethodsInterventions included workflow changes, such as obtaining patient blood samples for diagnostic testing by the admitting healthcare provider as well as utilizing patient caregivers to assist nursing staff in timing medications. An additional intervention was the use of an admission checklist sticker. The post-intervention sample was compared to the baseline assessment. The primary outcome was the proportion of patients receiving care consistent with all aspects of the WHO guidelines. Secondary outcomes included the proportion of patients receiving malaria diagnostic testing, those receiving at least 3 doses of artesunate, the timely administration of artesunate, and adherence to other guideline components. Statistical analyses were conducted using GraphPad PRISM 9.0. Comparisons between groups were analysed using Chi-square or Fisher’s exact test for categorical variables and Mann–Whitney test for continuous variables.ResultsThe post-intervention group included 230 patients with a median age of 5 years [4–8], and 58% of patients were male. Adherence to all aspects of the WHO guidelines was achieved in 10% of patients in the post-intervention group compared to 3% of patients in the baseline (P = 0.007). Appropriate malaria diagnostic testing was performed in 85% of patients post-intervention compared to 66% of patients in the baseline (P < 0.0001). Patients in the post-intervention group were more likely to receive the minimum 3 doses of artesunate (86%) than in the baseline (74%) (P = 0.008). Patients in the post-intervention group were more likely to receive artesunate doses on time than in the baseline (dose 2 P = 0.02, dose 3 P = 0.003).ConclusionsTargeted, low-cost interventions led to improvement in adherence to severe malaria treatment guidelines. The most notable changes were in malaria diagnostic testing and antimalarial administration.

Nationwide registry-based trial of risk-stratified cervical screening.

In well-screened populations, most cervical cancers arise from small groups of women with inadequate screening. The present study aims to assess whether registry-based cancer risk assessment could be used to increase screening intensity among high-risk women. The National Cervical Screening Registry identified the 28,689 women residents in Sweden who had either no previous cervical screening or a screening history indicating high risk. We invited these women by SMS and/or physical letter to order a free human papillomavirus (HPV) self-sampling kit. The Swedish national HPV reference laboratory performed extended HPV genotyping and referred high-risk HPV-positive women to their regional gynecologist. A total of 3691/28,689 (12.9%) women ordered a self-sampling kit and 10.0% (2853/28,689) returned a sample for testing. Participation among women who had never attended screening was low, albeit improved. Up to 22.5% of women in other high-risk groups attended. High-risk HPV types were detected in 8.3% of samples. High-risk HPV-positive women (238/2853) were referred without further triaging and severe cervical precancer or cancer (HSIL+) in histopathology were detected in 36/158 (23%) of biopsied women. Repeat invitations gave modest additional participation. Nationwide contacting of women with high risk for cervical cancer with personal invitations to order HPV self-sampling kits resulted in high yield of detected CIN2+. Further efforts to improve risk-stratified screening strategies should be directed to improving (i) the precision of the risk-stratification algorithm, (ii) the convenience for the women to participate and, (iii) ensuring that screen-positive women are followed-up.

Cross-sectional evaluation of online direct-to-public calprotectin testing

Objective Why about a quarter of patients with inflammatory bowel disease (IBD) suffer symptoms for more than a year before their diagnosis made is unclear. Low public awareness, embarrassment and...

Open-source cold and hot scientific sheet press for investigating polymer-based material properties

To produce samples for both material testing and molded sheets/parts, this article details an open-source scientific cold and hot press design. It consists of two independent and modular upper and lower plate (929 cm2) assemblies each containing four 125 W insulated steel strip heaters. The steel housing for these heaters is entirely modular and designed for ease of manufacture, assembly, and customization. This system allows a researcher with access to a hydraulic press to repurpose existing equipment into a multipurpose hot and cold press, or if an independent machine is warranted, an additional welded support frame and commercially available bottle jack offer standalone operation. By utilizing this small-scale hot press either in conjunction with a hydraulic press or on its own, samples can be produced to determine the critical material properties of any polymer, composite, or polymer blend. A series of modular molds allow for the rapid production of flat sheet stock and solid testing samples adhering to the ASTM D695 standard for rigid plastics tested in compression and ASTM D638 standard for testing plastics in tension. The sheet mold offers the user the ability to produce stock sheets that can be cut and assembled into 2.5-D applications with post processing.

A mechanical characteristic capture method considering printing configurations for buildability modeling in concrete 3D printing

The structure failure modeling of 3D printing concrete (3DPC) during production is crucial for structure design, manufacturing process control and optimization. Serving as model inputs, the accuracy of 3DPC fresh material properties measurement highly affects the model prediction performance. The measured mechanical properties of freshly printed concrete strongly depend on the geometry, deformation and hardening process of used samples in testing. Herein, we propose an all-in-one method (AIOM) that synchronously considers these key factors (layer geometry, deformation, and hardening process) to more accurately capture the early-age mechanical performance distribution in printed structures. Different parametric-mechanical buckling models and two printable cementitious materials with distinct hardening characteristics (printable cement and printable geopolymer) were used to validate the performance of AIOM, with the traditional testing method, uniaxial unconfined compression test (UUCT), as the reference. Compared with UUCT, AIOM can improve the buildability prediction accuracy by 11.9 % to 50.8 % for different validation scenarios. This novel testing method for 3DPC fresh material properties contributes to improving the accuracy of 3DPC structure failure models, thereby facilitating a better production phase control for 3DPC.

A Mixed Methods Approach to Understanding the Public Health Impact of a School-Based Citizen Science Program to Reduce Arsenic in Private Well Water.

Exposure to arsenic (As) in well water is a well-documented public health issue for Maine and New Hampshire, as well as for other states in the United States and abroad. Arsenic contamination of well water in these locations is primarily attributed to metasedimentary bedrock that leaches As into groundwater. However, As can also enter groundwater reserves from soils contaminated by the historical use of arsenical pesticides. Approximately half of the households in Maine and New Hampshire rely on private wells, many of which have elevated As. Arsenic exposure has been associated with an increased risk of cancer, cardiovascular disease, reduced infection resistance, and lower intelligence quotient in children. Despite these known health impacts, well water testing and treatment are not universal. We have approached the problem of low well water testing rates in Maine and New Hampshire communities by developing the All About Arsenic (AAA) project, which engages secondary school teachers and students as citizen scientists in collecting well water samples for analysis of As and other toxic metals and supports their outreach efforts to their communities. We assessed this project's public health impact by analyzing student data relative to existing well water quality datasets in both states. In addition, we surveyed private well owners who contributed well water samples to the project to determine the actions taken to mitigate As in well water. Students collected 3,070 drinking water samples for metals testing, and 752 exceeded New Hampshire's As standard of . The AAA data has more than doubled the amount of information available to public health agencies about well water quality in multiple municipalities across both states. Students also collected information about well types and treatment systems. Their data reveal that some homeowners did not know what type of wells they had or whether they had filtration systems. Those with filtration systems were often unaware of the type of system, what the system was filtering for, or whether the system was designed to remove As. Through interviews with pilot survey participants, we learned that some had begun mitigating their exposure to As and other toxic metals in response to test results from the AAA project. A school-based approach to collecting and analyzing private well water samples can successfully reach communities with low testing rates for toxic elements, such as As and other metals. Importantly, information generated through the program can impact household decision-making, and students can influence local and state policymaking by sharing information in their communities. https://doi.org/10.1289/EHP13421.

Effects of Er2O3 contribution on microstructure and mechanical properties of high entropy and dual phase alloys

The study aimed to look at the differences between a high entropy alloy and a dual phase high entropy alloy with high iron and Mn content. It also wanted to find out what happened when a small amount of the rare earth element erbium oxide (Er2O3) was added to these alloys, especially on the mechanical and microstructure of the alloy. The first step in this study was to get 99 % pure metal powders, which were then made by dividing the powders into 30 g of equal weight. The powders were mixed evenly and then pressed into 10-g blocks under 6 tons of pressure. They were then set up to be melted in an arc. Four of the eight samples that were melted in an arc under vacuum were treated with heat. The four different compositions were then turned into small metallographic samples for SEM, EDX, Mapping, XRD, and microhardness tests. The study's imaging and analysis processes were also carried out. After that, SEM images were taken at various magnifications (100X, 500X, 1000X, 2500X, and 5000X), and EDS and XRD analyses were done on different structures found in these images. These analyses were based on literature research about the clarity of the metallographic images in the alloy, which showed the study's metallographic differences. The samples were put through microhardness and wear tests to see which one was stronger and less worn. The dual phase high entropy alloy (A2) was stronger and less worn than the high entropy alloy (A1). Er2O3 had little effect on the alloys' mechanical properties or microstructure. The heat treatment that was done to the samples helped the metallographic structure. In terms of physics, it didn't change the hardness much, but it did make the material wear less quickly.

Evaluation of female university students’ knowledge, attitudes, and practices toward human papillomavirus infection and vaccination. Multicenter cross-sectional study

IntroductionHaving good knowledge and a favorable attitude toward human papillomavirus (HPV) and HPV vaccinations is the cornerstone for increasing the use of HPV vaccinations and preventing cervical cancer. The objective of this study was to evaluate the level of knowledge, attitudes, and practices regarding HPV and HPV vaccinations, as well as to identify associated factors among female undergraduate health science students at both the University of Gondar (UoG) and Bahir Dar University (BDU), Amhara, Ethiopia.MethodsInstitutional-based multicenter descriptive cross-sectional study was conducted from June 1, 2023, to July 30, 2023. A multistage sampling technique was used to select 633 female undergraduate health science students, and data were collected using a structured, self-administered questionnaire. The data were coded, entered in Epi-data, and exported to SPSS for analysis. Variables with a P-value < 0.25 in the bivariate analysis were inserted in a multivariate logistic regression model, and those with a P-value of < 0.05 in the multivariate binary logistic regression were considered statistically significant factors for knowledge, attitude, and practice regarding HPV and vaccine against it.ResultsThe study included 600 participants with a mean age of 20.8 ± 0.75 years. Using Bloom’s cutoff points for the KAP study, among the participants, 436 (72.7%) had good knowledge about HPV, whereas 315 (52.5%) had good knowledge about HPV vaccinations. More than half of the participants, 359 (59.8%) heard about HPV vaccinations in Ethiopia. More than half of the participants, 342 (57%) had favorable attitudes toward HPV vaccinations. Only 261 (43.5%) participants believed the HPV vaccine was safe and effective. All participants had never been tested for HPV, and 471 (78.5%) refused to have their samples for regular HPV testing. The factors like ages between 21 and 23 years (AOR, 2.12, 95% CI: 1.22–3.09) and favorable attitudes toward HPV vaccinations (AOR: 1.88; 95%, CI: 1.15–3.41) were associated with the participant’s knowledge about HPV vaccinations. Having good knowledge about the virus (AOR: 1.92; 95%, CI: 1.11–5.88) and its vaccine (AOR:1.60; 95%CI: 1.07–2.47) were factors associated with the attitude of the participants about HPV vaccinations. Additionally, HPV vaccination practice was significantly associated with the attitude of the participants toward HPV vaccinations (AOR: 1.85; 95%CI: 1.15–3.45), knowledge about HPV (AOR: 1.18; 95%CI: 0.55–5.50), and HPV vaccinations (AOR: 1.85; 95%CI: 1.08–2.44).ConclusionThis study revealed that half of the students had good knowledge and a favorable attitude toward HPV vaccinations, but there was poor HPV vaccination practice. There is still a need for continued health education, training, and counseling services for students to strengthen HPV vaccination practices, improve students’ attitudes and knowledge about the benefits of vaccination, and improve counseling abilities against HPV-induced cancer.

Diagnostic yield and safety of repeat bronchoscopy in pulmonary disease: A five-year retrospective analysis

AimIn this study, we aim to analyze the frequency and indications of repeat bronchoscopic procedures performed at our hospital over a five-year period. MethodsThis retrospective study was conducted at the Department of Pulmonary Diseases, Akdeniz University, and included patients who underwent bronchoscopy between January 1, 2018, and May 31, 2024. Patients who required a repeat bronchoscopy were identified. Inclusion criteria for the repeat bronchoscopy group were non-diagnostic initial bronchoscopy or the need for additional samples for molecular testing in lung cancer patients. Exclusion criteria included patients with incomplete medical records or those who did not provide informed consent for the repeat procedure. FindingsA total of 3877 patients underwent bronchoscopy in this time periods. Among these, 69 patients (1.8 %) required a repeat bronchoscopy. The mean age of these patients was 61.3 ± 11.7 years, with 54 (78 %) being male. The most common reason for the repeat procedure was the non-diagnostic outcome of the initial bronchoscopy (n = 53, 77 %), followed by cases where the initial bronchoscopy was diagnostic for lung cancer but insufficient for molecular testing (n = 16, 23 %). Among the 16 patients who underwent molecular testing, sufficient samples for molecular tests were obtained in 12 patients (75 %) following the second bronchoscopy. Molecular tests were negative for driver mutations in 6 patients, while 6 patients tested positive (PD-L1, n = 5; EGFR, n = 1). In 4 patients (25 %), the sample was reported as insufficient for molecular testing. Patients who underwent repeat bronchoscopy had the second procedure an average of 38.5 ± 59.7 days after the initial procedure. No complications developed in patients undergoing repeat bronchoscopy, except for bleeding not requiring intervention related to the bronchoscopy procedure. ConclusionIn conclusion, regardless of the reason, repeated bronchoscopy in suitable patients is safe and has a high diagnostic yield.

Evaluation of the collapse susceptibility of loess using machine learning

Evaluating collapse susceptibility of loess is essential for the construction of transportation lines in loess regions as it provides guidance for ground treatment. For the existing methods, a large number of boreholes need to be drilled along transportation lines to collect intact samples for laboratory tests, which make them very time and cost-consuming. In this study, loess’s collapse susceptibility is evaluated using Multi Expression Programming (MEP) and Back-Propagation Neural Network (BPNN). According to analysis of wetting-induced loess collapse, the gravimetric water content at the initial state (w0), net vertical stress (σ-ua), void ratio at the initial state (e0), void ratio at the liquid limit state (eL), and plastic index (Ip) are chosen as input variables. A comprehensive database incorporating 200 oedometrically soaking tests is established to train and test the two algorithms. The collapse potentials of loess are well predicted using MEP and BPNN, as demonstrated by high values of coefficient of determination (R2>0.88) and small values of mean absolute error (MAE<0.008) and root mean squared error (RMSE<0.012). Following ASTM D5333-03 [5], the degree of loess collapse is classified with accuracies of 98 % and 90 % for MEP and BNPP respectively. Furthermore, sensitivity analysis shows the contribution of each variable to the prediction of collapse potential follows the order of e0>eL>Ip>σ-ua>w0. The machine learning is expected to assist the code of practice ASTM D5333-03 [5] in achieving an efficient site-investigation of collapsible loess for the construction of transportation lines.

Increasing the Strength and Impact Toughness of Carbon Steel Using a Nanosized Eutectoid Resulting from Time-Controlled Quenching.

High-carbon steels are normally used as tool materials. The use of such steels for construction is limited due to their increased brittleness and poor weldability. However, it appears that high-carbon steels possess certain hidden reserves for enhanced plasticity and strength if properly heat-treated. An unconventional heat treatment was applied to carbon eutectoid steel (0.8 wt.% C) in order to increase its strength and impact toughness simultaneously. Samples for tensile and impact testing were held at 800 °C for different time ranges from 3 min to 9 min with subsequent cooling in oil. It was established that for each type of sample, an optimal holding time exists that is responsible for increased strength and high impact toughness. The hardness and microhardness levels of the surface and under-surface regions of the samples reached 390 HV after optimal heat treatment. An X-ray revealed a shift of the (211)α-peak to the lower 2-theta angles after heat treatment with the optimal holding time; this indicates an increase in carbon content in alpha solid solutions of approximately 0.12 wt.%. Thus, a nanostructured mixture of low-carbon martensite and thin cementite plates is formed in the under-surface region of carbon eutectoid steel after heat treatment, with a controlled holding time at the austenitizing temperature.

The Influence of the Activeness of Following Instagram @Ngajilagi.id on Interest in Reading the Qur'an in Indonesia

This study aimed to assess the extent of interest in reading the Quran among @ngajilagi.id followers, the level of engagement of Instagram users with the @ngajilagi.id account, and whether there's a correlation between interest in Quranic reading and Instagram activity among followers in Indonesia. This research adopted a quantitative ex-post facto approach, employing targeted sampling and simple linear regression analysis for hypothesis testing. The findings indicate a substantial level of interest in Quranic reading in Indonesia. The study revealed that 4% fell within the deficient category, 21% in the low category, 29% in the medium category, 36% in the high category, and 10% in the very high category. Regarding Instagram activity on @ngajilagi.id in Indonesia, it was moderate. The analysis indicated that 8% fell within the deficient category, 21% in the low category, 38% in the mild category, 23% in the high category, and 10% in the very high category. Based on the analysis and data processing conducted by the researchers, it was found that the significance value is 0.000 &lt; 0.05. This indicates that the null hypothesis (H0) is rejected, and the alternative hypothesis (H1) is accepted. Therefore, it can be concluded that the activity of followers of the Instagram account @ngajilagi.id influences the interest in reading the Qur'an in Indonesia, with an influence of 24.7%.

Melanoma Detection and Classification using Deep Learning

Melanoma is a type of carcinoma with a notably high mortality rate. Accurate diagnosis of this aggressive cancer is crucial due to its severe implications. Key diagnostic indicators include asymmetrical shape, heterogeneous color, diameter greater than 6 mm, and irregular borders, which dermatologists typically identify through visual examination. The conventional method for carcinoma detection is biopsy, involving the removal or scraping of skin samples for extensive laboratory testing. This process is both painful and time- consuming. To improve patient experience and enhance diagnostic efficiency, computer-based detection using image processing techniques and deep learning algorithms, specifically Convolutional Neural Networks (CNNs), has been developed to accurately identify melanoma. Keywords: Deep learning, CNN, Computer- based detection