Laboratory Materials Research Articles

Evaluation of interferents in sampling materials for analysis of post‐explosion residues (explosive emulsion/ANFO) using gas chromatography–mass spectrometry (GC/MS)

AbstractChemical analysis aimed at identifying post‐explosion residues is critical for investigating crimes or accidents involving explosives, establishing it as a vital area of forensic chemistry. In general, only trace amounts remain in samples analyzed for this purpose, making the presence of interferents a constant concern. Therefore, understanding the materials used from collection to sample preparation is essential for this type of analysis. This study focuses on organic contaminants in collection and laboratory materials analyzed by gas chromatography/mass spectrometry (GC/MS), complementing a previous study by Mauricio et al. (2020), which addressed inorganic contaminants in materials used for similar purposes in ion chromatography (IC). No prior studies have specifically investigated the potential organic interferences introduced by various materials commonly used in forensic laboratories for sample pre‐processing, storage, and evidence collection in this context. Plastic films, bottle caps, disposable gloves, syringes, swabs, disposable cups, plastic tubes, and plastic pipettes were examined. GC/MS analyses revealed that certain materials, particularly syringe plungers, gloves, and plastic films, can interfere with the detection of post‐explosion residues from explosive emulsions and ANFO (ammonium nitrate‐fuel oil). These findings emphasize the importance of evaluating materials for potential interferences prior to sample collection and processing to minimize contamination risks. This study provides significant insights into how commonly used laboratory materials can impact forensic analysis, thereby enhancing the reliability of post‐explosion residue analysis and supporting more accurate forensic investigations.

Evaluating the Teaching of Physical Science Practical Work at a Selected Resource-Constrained Secondary School in Rundu Circuit, Kavango East Region

This study evaluated the teaching of Physical Science practical work at a resource-constrained secondary school in the Rundu Circuit, Kavango East region in Namibia. The research objectives were to assess the impact of practical work on learners’ academic performance in a resource-constrained community, identify the challenges faced by both teachers and learners in conducting practical activities, and propose strategies to address these challenges and improve the overall quality of science education. A qualitative research design was employed, with data collected through semi-structured interviews involving four Physical Science teachers. The interviews were analyzed using thematic analysis, with themes aligned to the research objectives. The findings revealed that the state of science practical work was poor due to a lack of sufficient laboratory equipment and resources. Other significant challenges identified included limited laboratory space, inadequate time allocation, overcrowded classrooms, a lack of motivation among learners, and insufficient background knowledge on practical work for learners. These challenges collectively impeded effective teaching and learning of science practical work. To overcome these issues, the study recommended providing adequate laboratory materials and constructing an additional laboratory to alleviate overcrowding. The study also further recommended the employment of laboratory technicians to assist teachers in organizing, planning and conducting practical activities more efficiently. Furthermore, the study suggested forming partnerships between schools to share laboratory facilities, as per Key Area 7 of the National Standard and Performance Indicators for Schools in Namibia, which emphasizes the importance of collaborative linkages within educational communities. By implementing these strategies, it was concluded that the quality of Physical Science practical work in resource-constrained schools could be significantly enhanced, leading to improved learner outcomes.

Simple and Cost-Effective Generation of 3D Cell Sheets and Spheroids Using Curvature-Controlled Paraffin Wax Substrates

The challenges associated with animal testing in pharmaceutical development have driven the search for alternative in vitro models that mimic human tissues more accurately. In this study, we present a simple and cost-effective method for generating 3D cell sheets and spheroids using curvature-controlled paraffin wax films, which are easily accessible laboratory materials that eliminate the need for extracellular matrix (ECM) components or thermo-responsive polymers. By adjusting the curvature of the paraffin wax film, we successfully generated human periodontal ligament fibroblast (HPdLF) cell sheets and bone marrow-derived mesenchymal stem cell (hBMSC) spheroids. Key parameters, such as cell density, substrate curvature, and incubation time, were identified as critical factors for optimizing the formation of these 3D structures. In addition, the use of quantum dots (QDs) for cell tracking enabled long-term visualization and distinction between different cell types within complex tissue-like structures. We further demonstrated that wrapping the hBMSC spheroids with HPdLF cell sheets partially replicated the connective tissue structure of the periodontal ligament surrounding the tooth root. This highlights the potential of this platform for the construction of more sophisticated tissue-mimicking assemblies. In conclusion, curvature-controlled paraffin wax films provide a versatile and practical approach for 3D cell cultures. This simplifies the generation of both cell sheets and spheroids, offering a promising tool for tissue engineering and regenerative medicine applications, where precise cell-to-cell interactions are essential.Graphical abstract

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A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.

USING 5E INSTRUCTIONAL MODEL WITH ICT SUPPORT IN TEACHING LOWER SECONDARY STUDENTS ON THE TOPIC OF LIGHT REFLECTION

The educational process has become more accustomed to active classroom engagement. Physics teaching should focus more on young pupils’ investigative journey. This research investigates the effect of the ICT-based 5Es instructional model on the conceptual understanding and science process skills of grade 6 pupils on light reflection. The 5E Model stands for Engage, Explore, Explain, Elaborate, and Evaluate. The study used a mixed-method design involving 24 students participating in a 5E-based intervention. The pre- and post-test results showed a significant improvement in conceptual knowledge and science process skills. Statistical analysis using paired t-tests and Cohen's d found that the 5E Model has significantly improved students' conceptual understanding of the topic and their science process skills. The study also used a phenomenological analysis and identified three critical themes that contributed to the success of the intervention. These themes were high interest and excitement in using laboratory materials, collaboration among students in exploring light reflection, and teacher scaffolding and facilitation to help students overcome challenges. The 5Es Model, which involves engaging, examining, explaining, elaborating, and evaluating stages, was highly influential in keeping students interested and enthusiastic throughout the learning process. The study confirms that the 5Es instructional model positively impacts students’ science process skills and conceptual understanding. Using both quantitative and qualitative analyses provides a thorough understanding of the intervention’s effectiveness and offers recommendations for improving the implementation of the 5Es Model in science education. This study recommended providing professional development opportunities for teachers to enhance their skills in implementing the 5Es instructional model. Regular workshops, collaborative sessions, and opportunities for knowledge exchange can equip teachers with up-to-date teaching strategies and insights.

Geo Talk Media: Microlearning-Based Innovative Learning Media To Foster Student Interest In Natural Resources Material At The South Malang Nature Laboratory.

One of the innovative learning media that can be applied is learning video. Geo Talk Media is an innovation in education that combines the microlearning approach with multimedia technology by utilising natural resources as a laboratory in South Malang. This research aims to produce microlearning-based video learning media. The main focus of this platform is to foster student learning interest in Natural Resources material, especially those in South Malang. The type of research used is Research and Development (RnD), using the ADDIE development model. The instrument used is an open questionnaire with qualitative descriptive data analysis and a closed questionnaire with quantitative descriptive data analysis. The research subjects were geography teachers and students of class X SMAN 1 Kepanjen. The results showed that the micro-learning approach of Geo Talk learning video media can foster student learning interest in natural resources material in the South Malang laboratory. Proven by the percentage level of 87.12% with very feasible criteria. This research is important because it can overcome the problems that are often found, namely the limited focus of students in understanding the material provided, so that the advantages of this media are effective in helping facilitate student understanding of the material taught with a microlearning approach, and can provide new experiences for students.

Development of a new inversion-voltammetric technique in determining inorganic iodine in Laminariae thalli L. for the quality control of raw materials in factory laboratories

Objectives. To develop and validate a methodology for determining inorganic iodine in Laminariae thalli L., corresponding to the norms of the State Pharmacopoeia of the Russian Federation, 15th edition (SPh 15). The methodology needs to be valid and suitable for the quality control of pharmaceutical raw materials in factory laboratories.Methods. Cathode inversion voltammetry was used as an instrumental method for determining inorganic iodine using a graphite electrode capable of sorbing electroactive ion associates of surfactant–iodine.Results. When compared with the titrimetric technique recommended by SPh 15, the proposed technique is more selective, sensitive and less time-consuming. The efficiency and metrological characteristics of the technique were confirmed by validation in accordance with the requirements of SPh 15.Conclusion. The paper presents a new method for determining the gross content of inorganic iodine in Laminariae thalli L. This technique can be used not only in scientific research, but also in the routine quality control of medicinal plant raw materials in control and analytical laboratories engaged in pharmaceutical quality control.

Validation of the HemoCue Hb 801 portable haemoglobin analyser for fish blood.

Haemoglobin concentration ([Hb]) assessment in fish blood has become a routine parameter to measure the health and welfare status of the animals. The original method (haemoglobincyanide method, best known as the Drabkin method) for measuring Hb in human and animals is not well suited for work outside of a laboratory setting. It is relatively time consuming, contains hazardous cyanide elements, and requires specific laboratory material. As an alternative to the Drabkin method, portable analysers have been developed for human blood, but they need to be first validated for fish blood before being used in experiments. In this study, the performance of the new HemoCue Hb 801 portable haemoglobin analyser was compared to the validated Drabkin method to determine [Hb] in three fish species. Hb readings between the two methods were not different for any of the species tested (rainbow trout, Onchorynchus mykiss, Atlantic wolffish, Anarhichas lupus, and Nile tilapia, Oreochromis niloticus). Therefore, this new portable device can be readily used to measure Hb in fish blood. Unlike the previous model from HemoCue, the Hb 201+, this device does not need an incubation time or a correction factor, representing a major gain of time and precision.

Understanding Human Health Impacts Following Microplastic Exposure Necessitates Standardized Protocols.

Microplastics (MPs; 1 µm to 5 mm) are a persistent and pervasive environmental pollutant of emergent and increasing concern. Human exposure to MPs through food, water, and air has been documented and thus motivates the need for a better understanding of the biological implications of MP exposure. These impacts are dependent on the properties of MPs, including size, morphology, and chemistry, as well as the dose and route of exposure. This overview offers a perspective on the current methods used to assess the bioactivity of MPs. First, we discuss methods associated with MP bioactivity research with an emphasis on the variety of assays, exposure conditions, and reference MP particles that have been used. Next, we review the challenges presented by common instrumentation and laboratory materials, the lack of standardized reference materials, and the limited understanding of MP dosimetry. Finally, we propose solutions that can help increase the applicability and impact of future studies while reducing redundancy in the field. The excellent protocols published in this issue are intended to contribute toward standardizing the field so that the MP knowledge base grows from a reliable foundation. © 2024 Wiley Periodicals LLC.

Identification of Laboratory Management Systems at Senior High Schools In Mataram City

The Laboratory for Biology serves an effective educational facility for learning of biology, where biology subject often requires lab activity. Proper management of the laboratory is a crucial aspect for the smooth execution of practical activites by both teachers and students. The objective of this research was to determine the biology laboratory management system at SMA Negeri 3 Mataram. This research is descriptive research using observation and interview methods. The data collected in two types, the primary data is observation questionnaire and the result of interview to the biology teachers of SMAN 3 Mataram. The development of the observation questionnaire for the standardization of biology laboratory refers to the National Education Minister’s Regulation No. 24 of 2007, and the laboratory management standards refer to The Minister of Education and Culture’s Regulation No.8 of 2018. There are ten aspects considered in the observation of the biology laboratory, including the evaluation of the laboratory space, the completeness of laboratory equipment and materials, and the cleanliness of the laboratory. Based on the research found that eight aspects were categorized as very good, and two aspect were categorized as as good. The completeness of laboratory tools and materials, as well as laboratory safety, need to be improved.

PERBANDINGAN UJI KUAT TEKAN BETON MENGGUNAKAN AGREGAT KASAR PECAH MANUAL DENGAN AGREGAT KASAR PECAH PADA MESIN

Construction requires strong and abundant materials, so various concrete mixing innovations are needed, such as the use of a variety of coarse aggregate materials. This research aims to determine the characteristics, comparison of concrete compressive strength tests and split tensile strength tests of manually broken coarse aggregate concrete with machine broken coarse aggregate using the SNI method at the Structure and Materials Laboratory of the Muhammadiyah University of Parepare. The research results show that the characteristics of manually broken and machine broken coarse aggregates meet laboratory material testing standards. The compressive strength value of manually broken coarse aggregate concrete is 24.63 Mpa and machine broken coarse aggregate concrete is 25.19 Mpa. The splitting tensile strength value of manually broken coarse aggregate concrete is 4.778 Mpa and machine broken coarse aggregate concrete is 5.444 Mpa. The use of machine-broken coarse aggregate produces higher compressive and tensile strength values for concrete compared to manually broken coarse aggregate

Comparison of 5G‐IoT antenna performance by using four distinct dielectric materials to verify their efficiencies

SummaryThe characterization of four different materials, Taconic (D1), FR4 (D2), Lab material (D3), and Created material (D4) using the ring resonator technique, is presented in this study along with a comparison of antenna performance using standard and measured dielectric constant ( ) and loss tangent ( ) values. This article discussed the comparison of antenna performances on four distinct dielectric materials to verify their efficiencies. Standard values of for the reported materials are 2.20, 4.40, 2.33, and 10.45 for D1, D2, D3, and D4, respectively, with corresponding values of 0.0009, 0.02, 0.0012, and 0.00032. The and for the materials D1, D2, D3, and D4 are calculated as 2.10, 4.56, 2.51, and 9.89 and 0.00094, 0.01927, 0.0013, and 0.0003025, respectively, using a ring resonator. The materials are utilized as the substrate for a printed single layer Y‐Shape 5G‐IoT antenna in order to validate the measured results. According to the findings of this study, the measurement of using the resonator approach exhibited errors of 4.54%, 3.63%, 7.82%, and 5.33%, respectively, while the has errors of 04.44%, 03.65%, 08.33%, and 5.47% for materials D1, D2, D3, and D4, respectively. The outcomes of this work include the numerical calculation of the and of four materials and the validation of the measured values using a Y‐Shape 5G‐IoT antenna in the millimeter‐wave 5G frequency bands. Additionally, the values calculated mathematically are compared with the values obtained from the conventional ring resonator.

Teachers’ Experiences with the Use of Virtual Laboratories in the Teaching of Physics in Rwandan Secondary Schools: A Survey Design

Laboratory experimentation providing students with hands-on experiences can greatly enhance the teaching and learning of physics. However, traditional hands-on laboratories are very expensive, limiting the possibilities for practical activities. In addition, limited time for laboratory practices prevents teachers and students from conducting laboratory activities properly. A possible solution to these limitations could be the use of virtual laboratories (VLs). The present study was conducted to explore the availability of teaching resources to support experimental work, the use of these resources including VLs and the challenges teachers face in using VLs. An online survey with 107 secondary school physics teachers was used to collect data. The study is framed by the Concerns-Based Adoption Model for teacher use of curriculum innovations. Regarding VLs, a mere 6% of teachers reported regular use, revealing a significant gap in adoption. Challenges identified included a lack of awareness, limited information and communications technology tools and insufficient supporting resources. Cross-item analysis revealed that only 25% of 107 teachers reported having a well-equiped physics laboratory, 45% work without a physics laboratory but with science kits or improvised materials, while 30% have no access to a physics laboratory, science kits or improvised local materials. Thus, for teachers without access to a physics laboratory, science kits or improvised local materials, VLs represent a crucial opportunity to provide learners with a complete laboratory experience. The study recommends tailoring continuing professional development support to address teachers’ concerns regarding the use of VLs. This includes enhancing awareness and providing information for teachers without access to well-equipped physics laboratories, while addressing management concerns for those with or without such resources.

Production of a guide in Brazilian Sign Language for chemical laboratory utensils

The inclusion of deaf people in the Brazilian educational system is guaranteed by the use of Brazilian Sign Language (Libras). It is important that the learning process of these students, especially when dealing with abstract concepts such as those related to Chemistry, is offered based on teaching tools that cover this language. The objective of this work was to develop a guide with signs in Libras, already existing in the literature, of chemistry laboratory materials as a didactic device aiming to promote inclusion and facilitate access to experimental chemistry teaching for deaf students. The work began with meetings to plan the preparation of the booklet and choose the most common materials in laboratory classes (analytical balance, volumetric flask, beaker, burette, Erlenmeyer flask, funnel, suction bulb, volumetric and graduated pipettes, beaker and glass clock) accompanied by searching for the corresponding sign in Libras. The guide was created considering the five Libras parameters: point of articulation, movement, facial/body expression, configuration and orientation of the hands. Therefore, the material created constitutes a facilitator and important tool for interaction between teacher and student in laboratory classes, resulting in a more dynamic and efficient teaching and learning process for the target audience.

SISTEM INFORMASI MANAJEMEN LABORATORIUM PADA JURUSAN FARMASI POLITEKNIK KESEHATAN KEMENKES JAMBI

Laboratory Management is a systematic process that involves collecting, storing, maintaining, processing, retrieving, and validating data required by the laboratory to make informed management decisions. The Department of Pharmacy at Politeknik Kesehatan Kementerian Kesehatan (Poltekkes Kemenkes) Jambi needs a management system that can handle a significant amount of data. The current laboratory management system is not digitalized, which has led to inadequate documentation of inventory data, borrowing and returning of lab equipment and tools, as well as other relevant information related to schedules and student final projects. Therefore, the objective of this research is to develop a web-based information system for laboratory management. The system will assist laboratory staff in managing data and information related to practicums and laboratory activities. Input data are inventory of laboratory tools and materials data, lab schedule data, and lab activity data. The system output will provide tool and material inventory data reports, as well as reports on the use and borrowing of tools and materials. This research has resulted in the development of a Laboratory Management Information System that assists laboratory managers in managing inventory and laboratory activity data.

Monitoring changes in hydric properties of treated stone material with conservation products by time-sequential IR thermography

A methodological approach for a semi-quantitative non-destructive testing (NDT) of the effects on hydric properties after the application of different conservation treatments (commercial ethylsilicate and siloxane compounds with consolidant, water repellent or consolidant + water repellent properties) is presented in this study. The NDT used for this purpose is a simplified method of time-sequential infrared thermography (IRT) on stone (granite and marble, treated and untreated) from the Roman theatre of Merida (Spain), which was listed by UNESCO as World Heritage Site in 1993.As water evaporation modifies temperature intensely, IRT enables monitoring the response of the stone samples during water absorption-evaporation processes. The comparative analysis between treated and non-treated specimens was performed by calculating the rate of surface apparent temperature change (ΔoC/h) value. The capillary rising test, monitored by IRT, clearly showed a different response of the samples treated with water-repellent treatments, proving their efficiency. Samples treated with organosilicic compounds showed a large and rapid drop in apparent surface temperature, indicating that water accesses rapidly.Results from the evaporation test also show this difference. The surface apparent temperature increased immediately in samples with water-repellent treatments, in which water does not enter inside stone, but remains on the surface. Samples with ethyl silicate, again, show a greater difference with respect to untreated samples, taking longer to recover surface apparent temperature, because the water is retained inside the stone for longer.This study proved simplified time-sequential IRT as a reliable technique for assessing the efficacy of conservation treatments applied to stone materials in laboratory.

Assessment and strengthening of grandstand of horse racecourse in Budapest—A national monument

AbstractThe racecourse “Kerepesi Ügető” in Budapest was closed in 2000, and all of its buildings were demolished except for the Class II Grandstand, which had been declared a national monument earlier. Our task was to perform a comprehensive static investigation of this grandstand and to develop a methodology for structural strengthening in order to preserve this monument for future generations. Investigations included in situ measurements, laboratory material tests, and finite‐element analysis of the structure. According to the results of static calculations, the method of strengthening was proposed, which included the injection of cracks, integration of new structural elements, application of concrete jacketing, and bonded carbon‐fiber‐reinforced polymer sheets. The applied strengthening and renovation method extended the lifespan of the grandstand by 50 years.

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NatPro LabPro: An innovative laboratory package in plant extract screening for scientific research projects

Challenges in teaching science require innovative approaches—creating new methods and materials to improve student learning experiences. Innovations are essential for national development, fostering growth and positive change. This study focused on developing and evaluating an Innovative Laboratory Package (ILP) designed for science projects in natural product screening. It used a developmental research design and followed the ASSURE instructional model. The study identified that the least common lab tests conducted by students and teachers on natural products included basic pharmacological-toxicological, antioxidant, and cytotoxic assays of plant extracts. Access to laboratory materials and financial support presented moderate challenges for the participants. Laboratory analysts rated the ILP as outstanding, and STEM teachers highly evaluated its content, structure, coherence, learning activities, usefulness, appearance, organization, and innovativeness. Teachers reported that using the ILP provided new, meaningful, and engaging experiences, promoted critical thinking and scientific attitudes, allowed easy and flexible experiments, and equipped students with new scientific skills in a cost-effective way. The ILP could enhance science projects and develop research expertise in plant screening for both students and teachers. The findings can help curriculum developers create innovative learning resources and prioritize curriculum innovations.