Chemistry Laboratory Research Articles

Underground Roots for Ancestral Futures: Exploring Lithium Through an Experimental Alliance between Chemistry and Anthropology

Amid the push for decarbonization and the rise of lithium-ion batteries, global demand for lithium urges an examination of its materiality. Drawing on Barry's chemical geography, which gathers various concerns related to the study of chemicals in the field, and Bachelard's meta-chemical proposal, which challenges a substantialist understanding of chemicals, we propose an experimental alliance between a chemist and an anthropologist concerned with different ways of problematizing lithium's materiality. Guided by a commitment to Latin American territories and embracing a slow science ethos, we seek to foster a sense of responsibility rooted in the material genealogy of chemical substances. Through ethnographic analysis of lithium extraction practices in the Salar de Atacama, Chile, and examination of lithium behaviors in materials chemistry laboratories in Argentina and Europe, we establish a partial connection between lithium chemical labs and underground ancestral lithium brines. Ultimately, we envision futures that acknowledge the ancestral origins of Latin American undergrounds, resisting the univocity of a future-oriented, battery-ion age. In so doing, we endeavor to cultivate a mode of attention concerned with place and deep-time materiality, challenging lineal illusions of progress while embracing the complexities of our planetary present and past.

MULA, an affordable framework for multifunctional liquid automation in natural- and life sciences with a focus on hardware design, setup, modularity and validation

The implementation of automation has already had a considerable impact on chemical and pharmaceutical industrial laboratories. However, academic laboratories have often been more reluctant to adopt such technology due to the high cost of commercial liquid handling systems, although, in many instances, there would be a huge potential to automate repetitive tasks, resulting in elevated productivity. We present here a detailed description of the setup, validation, and utilization of a multifunctional liquid automation (MULA) system that can be used to automate various chemical and biological tasks. Considering that such a setup must be highly customizable, we also designed MULA with respect to modularity, providing detailed insight as far as possible. Including all 3D-printed parts and the used Hamilton gastight micro syringe, the total construction cost is approximately 700 €. This allows us to achieve a highly reliable and accurate system that exceeds the precision of a classical air displacement pipette while still retaining the ability to use closed vial (septa) setups. To encourage other groups to adopt this setup, detailed instructions and tips for every step of the process are provided, along with the complete CAD design of MULA and control code, which are freely available for download under the CC BY NC 3.0 license.

Analysis of Comprehension Difficulties in Chemistry and Their Impact on Student Interest in Learning

Chemistry is often considered a difficult subject for learners due to its abstract concepts and complex terminology. This can lead to difficulties in understanding the material and a decrease in students' interest in studying chemistry. The aim of this research is to describe and explain the factors of difficulty understanding in solving chemistry material experienced by students. The research method used is descriptive qualitative. The results show that 62.3% of students experience slight difficulty and 37.7% experience moderate difficulty in understanding chemistry material. The interest in learning chemistry of class XII MIA students is categorized as sufficient with a percentage of 46.68%. Factors causing difficulties in understanding chemistry material include a lack of understanding of mathematical concepts, the predominance of lecture methods, limited learning media, and the suboptimal use of chemistry laboratories. The conclusion of this research provides an overview that the factors causing difficulties in understanding chemistry material affect students' interest in learning. Therefore, these findings can be used as evaluation material to improve the quality of chemistry education in schools.

Characterization of tuberculosis diagnostics by GeneXpert MTB/Rif in Villa Clara, Cuba

GeneXpert MTB/RIF is a real-time polymerase chain reaction molecular test recommended since 2010 that is able to simultaneously detect the presence of Mycobacterium tuberculosis and Rifampicin resistance within two hours. The aim of the research was to characterize the diagnosis of tuberculosis by GeneXpert MTB/RIF in the Provincial Laboratory of Microbiology and Sanitary Chemistry of the Provincial Centre of Hygiene Epidemiology and Microbiology of Villa Clara, Cuba in the period January 2018-December 2020. A descriptive cross-sectional study was conducted. The study population consisted of 710 samples from patients suspected of tuberculosis. Of the total number of samples studied, 131 (18.5%) were positive; Ciego de Avila and Camagüey were the provinces with the highest percentage of positive results, with 53.8% and 32.0%, respectively. Sputum was the predominant sample type with the highest percentage of positivity (20.7%). The group of those previously treated had the highest percentage of positivity (40.0%). It is concluded that the provinces of Ciego de Avila and Camagüey were the provinces with the highest percentages of positivity, and sputum proved to be the most useful sample for GeneXpert MTB/RIF.

Fostering scientific reasoning competencies: investigating impacts of cross- and within-content area experimentation using the competency triad

ABSTRACT Educational standards and science education research suggest that experiments can be used to foster scientific reasoning competencies. So far, little is known about whether to sequence experiments from one or multiple content areas for this purpose. Therefore, we compared two sequences in an experimental study to investigate the influence of content areas of experiments on competencies’ development: Based on the same underlying structure, the first, homogeneous sequence includes four kinetics experiments. The second, heterogeneous sequence involves experiments from kinetics, thermodynamics, and redox chemistry. A total of 97 students participating in undergraduate chemistry lab courses were randomly assigned to one of the sequences. The changes in competencies within the sequences were compared based on the ‘competency triad’ differentiating between underlying knowledge (dispositions), the use of this knowledge (processes), and the quality of the resulting investigations (products). The results show that both sequences are comparably suitable to foster scientific reasoning competencies. However, in the post-experiments, we found a tendency of increased inadequate or irrelevant content-related reasoning by bringing in and conflating concepts from previous experiments such as activation energy or the chemical equilibrium (in particular Le Chatelier's principle). We discuss these findings concerning the consequences of sequencing experiments for fostering scientific reasoning.

A Multiweek Experimental Project Bringing Real-World Lithium Batteries into a Third-Year Undergraduate Analytical Chemistry Laboratory

A Multiweek Experimental Project Bringing Real-World Lithium Batteries into a Third-Year Undergraduate Analytical Chemistry Laboratory

Orthogonal Linking of Gemcitabine by Acyclovir and Bortezomib: A Rational Chemistry Laboratory Introduction of Both Noncovalent and Covalent Dynamics

Orthogonal Linking of Gemcitabine by Acyclovir and Bortezomib: A Rational Chemistry Laboratory Introduction of Both Noncovalent and Covalent Dynamics

Coding with AI in the Physical Chemistry Laboratory

Coding with AI in the Physical Chemistry Laboratory

Pengaruh Imbangan Terigu, Tepung Garut (Maranta arundinacea L.) dan Tepung Wortel (Daucus carota L.) terhadap Karakteristik Kulit Pangsit Kukus

The purpose of this study was to obtain the best results of the ratio of flour, arrowroot flour, and carrot flour to the characteristics of steamed dumpling skins. This research was conducted at the Chemistry Laboratory of the Faculty of Agriculture, Ma'soem University, Chemistry Laboratory at the Bakti Asih Bandung School of Analysis, Bandung Sibaweh Chemistry Laboratory from June to August 2023. This study used a randomized block design (RBD) with a total of 5 treatments, namely treatment A (70:30:0), treatment B (70:25:5), treatment C (70:20:10), treatment D (70:15 :15), and treatment E (70:10:20). The characteristic parameters observed were chemical parameters consisting of water content, carbohydrate content, and beta-carotene content, and sensory parameters were carried out by 25 panelists for the level of preference for color, aroma, taste, and elasticity. The results showed that the best treatment resulted from treatment D with a balance of 70 Wheat : 15 Garut Flour : 15 Carrot Flour which was produced from the effectiveness test. Steamed dumpling skin treatment D balance 70 Wheat : 15 Arrowroot Flour : 15 Carrot Flour with organoleptic values ??for color, aroma, firmness and taste respectively 3.36 (neutral), 3.08 (neutral), 3.48 ( neutral), 3.08 (neutral) and chemical content in the form of water content of 22.88%, carbohydrate content of 28.01% and beta carotene content after steaming of 0.15 mg.

Antihyperuricemia Potential of Ethyl Acetate Fraction from Ethanolic Stem Extract of Arcangelisia flava

Arcangelisia flava, with its secondary metabolites in flavonoids, has shown promising potential as an alternative treatment for hyperuricemia. The study aimed to determine the effectiveness of the ethyl acetate fraction from the ethanolic stem extract of Arcangelisia flava in inhibiting xanthine oxidase. This research, conducted at the Medical Basic Chemistry Laboratory Universitas Sriwijaya in September–December 2022, used in vitro study methods. The stem of Arcangelisia flava was extracted by maceration using ethanol. The ethanolic stem extract of Arcangelisia flava was then fractionated using n-hexane and ethyl acetate. The ethyl acetate fraction and ethanolic extract of Arcangelisia flava were measured to inhibit the xanthine oxidase using UV-vis spectrophotometry with allopurinol as a comparison. The IC50 was calculated by linear regression. The ethanol extract and ethyl acetate fraction have flavonoids, alkaloids, terpenoids, and quinones. The IC50 value of the ethanol extract was 30.04 ppm, the ethyl acetate fraction was 23.99 ppm, and the allopurinol was 17.16 ppm. The ethyl acetate fraction inhibited xanthine oxidase better than the ethanol extract. The study's significant finding is that the ethyl acetate fraction of the ethanolic stem extract of Arcangelisia flava strongly inhibits xanthine oxidase, offering a potential new avenue for treating hyperuricemia.

Design and Implementation of a Mentorship Course That Utilizes Senior Undergraduate Chemistry Students As Learning Assistants in the Introductory Chemistry Laboratory to Foster Transferable Skill Development

Design and Implementation of a Mentorship Course That Utilizes Senior Undergraduate Chemistry Students As Learning Assistants in the Introductory Chemistry Laboratory to Foster Transferable Skill Development

Effectiveness of the pH Master Application on Acid-Base Concepts as a Digital Alternative to Conventional Laboratory Practices for Enhancing Student Learning Outcomes"

Traditional Chemistry Laboratories, such as acid-base reactions, are hard to demonstrate for present-day students in their lab classes when they need to have the knowledge exchange we had, graduating (and teaching) with mortar boards lined up and ready for weddings. The Evaluation Of The Digital Platform “pH Master” For Enhancing Chemistry Student Performance Through A Virtual Imitation of Traditional Lab Practices The study used Akker's research and development model, including initial studies, product design, testing products, and trials. Validation was done using the Aiken formula by two expert validators and three practitioners for all items with a V value greater than 0.87. Surveys for needs analysis involved 45 students, and the learning effects were assessed with 90 students across three schools. Results Students responded favourably to the pH Master app and perceived ineffable pedagogical value. Most students agreed on the necessity of doing practical activities about what was being learned, and almost all also had trouble understanding study materials specifically related to acids and bases. The results showed a statistically higher mean n-gain value in the experimental group than in control one (0.6622 versus 0.5691) by independent t-test across three schools at p < 0,001 significance level between the two groups. This then confirms that the media created did support student learning. This study highlights the potential of the pH Master app to enhance student learning experience and active involvement in chemical education, which suggests a promising approach towards digitalising conventional practical work.

Hazardous Chemical Laboratory Fire Risk Assessment Based on ANP and 3D Risk Matrix

Hazardous Chemical Laboratory Fire Risk Assessment Based on ANP and 3D Risk Matrix

Student Perceptions of Undergraduate Chemistry Laboratory Shaped by the COVID-19 Pandemic

Student Perceptions of Undergraduate Chemistry Laboratory Shaped by the COVID-19 Pandemic

Research on the Reform of Chemistry Laboratory Teaching under the Construction of Green Ecological Environment

Research on the Reform of Chemistry Laboratory Teaching under the Construction of Green Ecological Environment

Decoding educational augmented reality research trends: a topic modeling analysis

AbstractThis study aims to examine the temporal evolution and changes of research interests and trends in the educational augmented reality (AR) literature. To this end, 3718 articles published in the 2003–2022 period and indexed in the Scopus database were analyzed through machine learning-based semantic topic modeling and descriptive analysis. The findings indicate a notable upswing in studies on educational AR, particularly since 2015. The articles were categorized into eleven primary themes through topic modeling analysis. The three most prevalent topics in terms of volume are “Augmented Reality in Education and Cultural Heritage”, “Medical Education and Patient Care”, and “Enhancing Safety and Information in Food Consumption”. Observations across different times reveal that “Augmented Reality in Electrical and Electronic Systems” and “Gesture-Based Instruction and Maintenance” were studied in the initial periods. Since 2015, there has been a notable increase in applications falling under the “Serious Games” category. The least voluminous and slowest-evolving topics are identified as “Serious Games for Children with Autism Spectrum Disorder”, “Augmented Reality in Chemistry and Biology Laboratories”, and “Augmented Reality for Safe and Efficient Driving”. Considering the recent momentum gained by these topics, it is anticipated that they will become popular topics for future studies. This study represents a significant milestone as the first and most comprehensive research using machine learning in its field, not only explaining the current state of the field but also providing valuable information for future research efforts.

Large-scale assessment of characteristic plant species on Eurasian saline and alkaline soda ecosystems

From an ecological standpoint, saline and alkaline habitats are considered as extreme environments for vascular plants because salinity and alkalinity serve as primary structuring factors that significantly influence the species richness of vegetation cover. The non-alkaline salinity stress on plants primarily results from interactions of NaCl, Na2SO4, and other neutral salts, whereas alkalinity stress is caused by NaHCO3 and Na2CO3, accompanied by an increase in pH. Some halophytes and salt-tolerant plants are well-adapted to such permanent abiotic stress. Surprisingly, they are able to survive and reproduce under environmental conditions of more than 200 mM NaCl concentration and are also able to live permanently in extreme conditions. The aim of this study was to identify characteristic and indicator plant species for permanently alkaline soda and non-alkaline saline wetland habitats, and to analyze the relationship between the chemical composition of water and the plant’s saturation index. Based on the obtained results we can conclude that plant species identified to live in high saline conditions may also grow under high alkaline conditions. Two groups were distinguished based on the salinity and alkalinity: “Saline group” includes all types of halophytes and halotolerant species, while “Soda group” includes obligate alkalophytes and alkalotolerant species. However, the diversity of plants in alkaline environment is bigger than in saline environment, and most of the halotolerant species grow in both alkaline soda and saline habitats. It is possible to identify three indicator species requiring alkaline soda habitats to live in (Aster tripolium, Puccinellia limosa, Suaeda pannonica) and three indicator species that dominantly grow in non-alkaline saline habitats (Juncus maritimus, Salicornia prostrata, Suaeda salsa). Different independent variables have been identified and analyzed to understand their influence on the species saturation index by calculating percentage of characteristic plant species of the entire region. It was identified that the plant saturation index has a significant positive relationship with the Mean Temperature of the Warmest Quarter, Topsoil Sand, and Clay fraction variables, and there is a significant negative relationship with the Solid Earth surface heat flow, as the heating can increase the extremity of the environment. Identification of indicator species of salinity and alkalization makes it possible to determine the type of soil, water bodies and habitats as a rapid biomonitoring method as a visual observation, without the use of expensive equipment and chemical laboratory tests.

The Deposition by Raffaello Sanzio: New analytical insights on old cross sections for the characterisation of pictorial palette

In 2020, 500th anniversary of Raffaello Sanzio death, his Deposition (1507), -the altarpiece known also as the Pala Baglioni, today located at the Borghese Gallery in Rome-has been subjected to conservative revision and preventive conservation project. This included in-depth diagnostic campaigns through most modern non-invasive techniques, together with the analysis of old cross sections from the same Pala. These latters, prepared between 1966 and 1972, preserved in ICR laboratory of chemistry and testing materials archive, have been used to deepen the knowledge of Raffaello painting techniques. The use of such cross sections was fundamental to verify the original pictorial film and restoration re-paintings before the conservation intervention in the same years.In this paper, the results of analytical insights on Raffaello pictorial palette are presented. The information is obtained by the analysis of the old ICR stratigraphic sections, through the use of Scanning Electron Microscope with Energy Dispersive X-Ray analysis (SEM-EDX) and micro-Raman (632.8 nm), while Surface Enhanced Raman Scattering (SERS) analysis through colloidal paste has been tested for the identification of organic lake-pigments present in low concentration and for the successful recognition of copper resinate, whose SERS spectrum is here reported for the first time, according to our knowledge. This combined diagnostic approach has made it possible to recognize the pigments employed in the different pictorial layers, such species in traces and those from organic materials, responding to open questions arising previous non-invasive analyses and highlighting further aspects of the illustrious master refined painting technique.

Hazard Analysis and Fire Risk Assessment in a Chemical Lab Based on the Example of Hydrogen Peroxide Production Unit

Hazard Analysis and Fire Risk Assessment in a Chemical Lab Based on the Example of Hydrogen Peroxide Production Unit

From a Hazardous Waste to a Commercial Product: Learning Circular Economy in the Chemistry Lab

From a Hazardous Waste to a Commercial Product: Learning Circular Economy in the Chemistry Lab