Experimental Research Research Articles

Assessing the Potential Dangers of Cell Phone Use to Human Health: A Review of the Evidence on Cancer Risk

Cell phones have become ubiquitous in modern life, leading to concerns about potential health risks associated with prolonged exposure to radiofrequency electromagnetic fields (RF-EMF) emitted by these devices. This review examines the current scientific evidence on the potential link between cell phone use and cancer risk, focusing on epidemiological studies, experimental research, and mechanistic investigations. Epidemiological studies, including large-scale cohort studies and case-control studies, have produced mixed results, with some indicating possible associations between cell phone use and specific cancers such as glioma and acoustic neuroma, while others find no significant link. Experimental research has explored potential biological mechanisms, such as oxidative stress and DNA damage, but definitive connections to cancer remain elusive. Regulatory perspectives and public health recommendations emphasize cautious use, particularly among vulnerable populations. Despite extensive research, significant gaps remain, including limited long-term data and inadequate exploration of new technologies like 5G. Future research should address these gaps through long-term, interdisciplinary studies and improved exposure assessment methods. This review highlights the complexity of the issue and underscores the need for ongoing research to provide clearer insights and inform public health guidelines. Keywords: Cell phone use, cancer risk, radiofrequency electromagnetic fields (RF-EMF), epidemiological studies.

Pengaruh Penerapan Model Pembelajaran Project Based Learning (PJBL) Terhadap Hasil Belajar Siswa Pada Mata Pelajaran IPS Kelas VIII di Mts Al – Mabrur Bone Raya Kabupaten Bone Bolango

The aim of this research is to find out whether the project based learning model can improve the learning outcomes of class VIII students in social studies subjects at MTs Al - Mabrur Bone Raya, Bone Bolango Regency. This research uses a quantitative approach and Quasi Experimental research in the form of Pretest Prottest Control Group Design. In this design there are two groups taken as samples. Then they were given a pretest and posttest to find out whether there were differences between the experimental and control groups with a sample size of 34 students. The data collection techniques used in this research are observation, tests, documentation and research data analyzed descriptively and inferentially with the t test. The research results show that there is a positive and significant influence between the Project Based Learning Model on the Learning Outcomes of Class VIII Students in Social Sciences Subjects at MTs Al - Mabrur Bone Raya, Bone Bolango Regency. The research hypothesis test shows a significant value of 0.0000.05, with the criterion that if the sig value is smaller than 0.05 then H0 is rejected then H1 is accepted. Based on these criteria, it can be concluded that H0 is rejected and H1 is accepted, which means that there is an influence of the project based learning (Pjbl) learning model on the learning outcomes of class VIII students in social studies subjects at MTs Al - Mabrur Bone Raya, Bone Bolango Regency.

Pengaruh Model Pembelajaran Project Based Learning Berbantuan Media Prezi terhadap Keterampilan Menulis Teks Biografi Siswa Kelas X SMAN 1 Batipuh

One important aspect of Indonesian language learning is the development of writing skills. Writing skills can be taught through Indonesian language learning because of the independent curriculum, especially on biography texts. Efforts to improve student writing learning outcomes by choosing a learning model in the form of a project-based learning model . The purpose of this study was to analyze the effect of the project-based learning model on the writing skills of biographical texts of SMA Negeri 1 Batipuh class students. The method used in this research is quantitative method by using quasi experimental research. The sample used was selected based on purposive sampling technique. The sample in this study amounted to 60 students. The data in this study are in the form of scores converted from scores based on two tests of biography text writing skills on the sample.Based on data analysis and discussion, it can be concluded three things First, students' biography text writing skills without using the project-based learning model obtained an average of 74.87 with LDC qualifications (More than Sufficient) Second, students' biography text writing skills using the project-based learning model obtained an average of 83.47 with Good (B) qualifications. Third, the use of project-based learning model affects the biography text writing skills of students in class X SMA Negeri 1 Batipuh with a level of 95%.

Experimental and numerical investigation on the cavitation erosion effect and resonance effect of submerged water jets

ABSTRACT To analyse the cavitation erosion effect and resonance effect of submerged water jets generated by organ-pipe nozzles, experimental and numerical research is conducted in the nozzles with five different diffuser angles. The cavitation erosion intensity and the flow characteristics of submerged jets are obtained by the erosion test, high-speed photography and Large Eddy Simulation. The experimental and numerical results illustrate that the nozzle with a 60° diffuser angle is capable of producing a strong cavitation erosion effect. Compared to the fully developed submerged jet, the axial pressure oscillation of axially confined submerged jets is stronger, indicating that it has a strong resonance effect. The stress wave generated by cavitation modulates the jets after reflection from the impact wall. This modulation results in the excitation of the original main frequency oscillation of organ-pipe nozzle jets, which then gives rise to multiple frequency oscillations, thereby forming the strong resonance effect.

History of hydrological research in Slovakia and its links to water management

ABSTRACT The article outlines the development of water resources management and research in hydrology in Slovakia in the last century when the centralised water resources planning provided a robust framework for the development of hydrological research. We first present facts about the organisation of research in hydrology from 1948 to 1990, which dealt with various problems of practical relevance. Experimental research and its international outreach in the collaborative programs of the Danube countries or the UNESCO water programmes are described. Then, the main achievements related to experimental hydrological research in two small research catchments with long histories of operation, the Mošteník Brook and the Bystrianka Creek catchments, are presented. Short biographies of researchers who significantly contributed to the overall development of water management or hydrological research in small catchment in Slovakia are provided.

Numerical study of P3HT-based hybrid solid-state qantum dot solar cells with CdS quantum dots employing different metal oxides using SCAPS-1D

This study presents a comprehensive numerical investigation into solid-state quantum dot solar cells (SSQDSCs) utilizing P3HT poly(3-hexylthiophene) as both a hole transport and absorber layer employing SCAPS-1D simulation software, the research explores the performance of cells composed of FTO (Fluorine-doped Tin Oxide) as the front contact, integrated with different metal oxides (Titanium dioxide (TiO2), zinc oxide (ZnO), and tin dioxide (SnO2), CdS (Cadmium sulfide )quantum dots, P3HT, and Pt (platinum )as the back contact namely Hybrid solar cell. The thickness of each layer is systematically optimized, and the influence of various CdS quantum dots sizes is thoroughly examined. The study also dived into the characterization of interface defects at the P3HT/CdS junction, involving modifications to the electron affinity of P3HT. Additionally, the impact of metal work function variations was also investigated analyzing at each case critical parameters such as open-circuit voltage (VOC), short-circuit current density (JSC), fill factor (FF), power conversion efficiency (PCE) and quantum efficiency. The results demonstrate that optimization of these parameters has the potential to elevate solar cell efficiency to 18%. These simulation findings offer valuable insights for comparative analysis and a deeper understanding of the challenges encountered in experimental research.

Experiment research on the control method of automatically retained entry by roof cutting pressure relief within thick hard main roof longwall top coal caving panel

Experiment research on the control method of automatically retained entry by roof cutting pressure relief within thick hard main roof longwall top coal caving panel

Evolution of Microstructure and Hardness during Carburization Heat Treatment of Heavy-duty Gear Steels: Numerical Prediction and Experimental Study

Abstract In order to solve the problems of long process cycle, low efficiency and high cost in the carburization heat treatment process of 18Cr2Ni4WA heavy-duty gear steel. The carbon concentration distribution of 18Cr2Ni4WA steel under conventional carburizing process at 930℃ was studied by combining numerical simulation with experimental research. The results show that the carbon concentration distribution predicted by the simulation is in good agreement with the experimental results. The microstructure of the surface layer after low-temperature tempering consists mainly of fine acicular tempered martensite, while the core consists mainly of lath tempered martensite and bainite. The increase in hardness after carburization is mainly attributed to the solid solution strengthening of the carbon atoms. The increase in hardness after cryogenic treatment is mainly attributed to the precipitation strengthening of the carbides. In addition, compared to the conventional carburization at 930°C, the high temperature carburizations at 950°C and 970°C reduced the carburization time by 37.2% and 53.5%, respectively.

LncRNA MEG3: Targeting the Molecular Mechanisms and Pathogenic causes of Metabolic Diseases.

Non-coding RNA is a type of RNA that does not encode proteins, distributed among rRNA, tRNA, snRNA, snoRNA, microRNA and other RNAs with identified functions, where the Long non-coding RNA (lncRNA) displays a nucleotide length over 200. LncRNAs enable multiple biological processes in the human body, including cancer cell invasion and metastasis, apoptosis, cell autophagy, inflammation, etc. Recently, a growing body of studies has demonstrated the association of lncRNAs with obesity and obesity-induced insulin resistance and NAFLD, where MEG3 is related to glucose metabolism, such as insulin resistance. In addition, MEG3 has been demonstrated in the pathological processes of various cancers, such as mediating inflammation, cardiovascular disease, liver disease and other metabolic diseases. To explore the regulatory role of lncRNA MEG3 in metabolic diseases. It provides new ideas for clinical treatment or experimental research. In this paper, in order to obtain enough data, we integrate and analyze the data in the PubMed database. LncRNA MEG3 can regulate many metabolic diseases, such as insulin resistance, NAFLD, inflammation and so on. LncRNA MEG3 has a regulatory role in a variety of metabolic diseases, which are currently difficult to be completely cured, and MEG3 is a potential target for the treatment of these diseases. Here, we review the role of lncRNA MEG3 in mechanisms of action and biological functions in human metabolic diseases.

Penetration test and numerical simulation of scaled earth penetrator for coral aggregate seawater concrete cylindrical target

In order to study the mechanical properties of coral aggregate seawater concrete (CASC) subjected to the penetration of scaled earth penetrator, firstly, the penetration depth and damage of CASC and ordinary sand-gravel concrete under the same conditions were compared by experimental research, and the influence of concrete strength and projectile velocity on penetration performance was analyzed. Then, the three-dimensional mesoscopic model is used to simulate the test conditions, and the failure process and failure mechanism are analyzed. The results show that under the same penetration conditions, as the strength of CASC increases, the crater diameter becomes larger, which is consistent with the conclusion of ordinary concrete (OPC). During the penetration process, the CASC and the mortar are destroyed as a whole. At the same time, as the penetration speed of the projectile increases, the width of the crack on the surface of the target increases. When the projectile velocity is low, the anti-penetration performance of CASC with the same strength is not as good as that of OPC with the same strength. For the target with a thickness of 25 cm, the penetration depth of the concrete target with the same strength will increase with the increase of the velocity of the projectile. When the velocity of the projectile is constant, the penetration depth of CASC will decrease with the increase of the strength. The numerical simulation results obtained by using the K & C mesoscopic model are in good agreement with the experimental results, indicating that the model and its model parameters have high reliability in the analysis of CASC penetration mechanical properties.

Thermo-economic performance analysis and multi-objective optimization of viscosity ratio and thermal conductivity ratio of copper oxide–palm oil nanolubricants

Through experimental research, this work explores the thermophysical properties, cooling efficiency, and economic viability of copper oxide–palm oil nanolubricants in tribology applications. The viscosity and thermal conductivity of the nanolubricants were tested at three different volume concentrations (0.1, 0.3, and 0.5 vol. %) throughout a temperature range of 30 °C to 80 °C at intervals of 10 °C. Researchers looked attentively at how the viscosity and thermal conductivity ratios of the nanolubricants were affected by temperature and volume concentration. A significant increase in thermal conductivity was noted with increasing concentration and temperature. On the other hand, as temperature increased, viscosity reduced and was dependent on volume concentration. The property enhancement ratio was used to evaluate the nanolubricants' cooling capacity before an economic analysis of their cooling efficacy was conducted. Based on experimental data, the study led to the creation of novel correlations between the viscosity ratio and thermal conductivity ratio. These models showed a high degree of agreement (R2 values of 99.47% for the thermal conductivity ratio and 97.78% for the viscosity ratio) between the expected and actual outcomes. The ideal values of the viscosity and thermal conductivity ratios were 1.10 and 1.62, respectively. These values corresponded to a critical temperature of 37.32 °C and a volume concentration of 0.16 vol. % for nanoadditives. The findings offer valuable insights into optimizing nanolubricants for enhanced cooling performance in tribological systems, with potential applications in improving energy efficiency and reducing operational costs in industrial processes.

Experimental research on nonlinear vibration characteristics of double-layer mining string for deep-sea hydrate extraction under internal and external flow excitation

The vibration mechanism of the deep-sea hydrate mining string is extremely complex due to the combined effects of internal gas–liquid solid multiphase flow, structural contact collision, soil creep effect, and external ocean random load. Based on this, using the principle of similarity, a simulation experimental platform for the vibration of double-layer mining riser in deep-sea hydrate wells under internal and external flow excitation is developed, considering the vortex-induced effect of external flow field on the mining riser in the ocean section (which can simulate a maximum ocean flow velocity of 0.5 m/s), the three-phase flow-induced effect of gas–liquid–solid inside (which can simulate a maximum flow velocity of 2.0 m/s), and the coupling effect of mining string–conductor anchor node (CAN)–seabed. The influence of particle size, phase ratio, three-phase flow, and external flow velocity on the vibration response characteristics and nonlinear behavior of mining string are investigated. It is found that the vibration of vertical string is significantly affected by external ocean currents and internal three-phase currents. The vibration displacement amplitude of the horizontal section (average 0.08 mm) is significantly smaller than those of the vertical section (average 70 mm). The strong vibration positions of the vertical and horizontal sections of the mining string are different, in that the vertical section is mostly located below the middle section (just at 1800–2400 mm), while the horizontal section is mostly located at the three-phase inlet (just at 500 mm). The vertical section of the mining string presents a motion trajectory of oblique straight line, wide oblique straight line, or approximately wide oblique straight line, while the horizontal section is mostly a chaotic trajectory or an “8”-shaped chaotic trajectory. The decrease in particle mesh size and the increase in solid-phase proportion are reflected in the difficulty and accumulation of particle transport, leading to an increase in vibration displacement, as well as a decrease in vibration displacement amplitude and vibration energy. When the particle size set as 50 mesh, the displacement of mining string is largest, just for 110 mm of vertical section and 0.08 mm of horizontal section. The increase in the proportion of gas phase will lead to changes in the flow state of multiphase flow, which will affect the vibration displacement amplitude of the mining string to varying degrees. The increase in three-phase flow velocity further induces vibration of the mining string, and when the flow velocity is between 1.5 and 1.75 m/s, it will resonate with the string system, resulting in a sudden increase in the amplitude of vibration displacement. The research results can effectively guide operations and improve the service life of deep-sea hydrate mining riser.

Experimental Research on FSW and SFSW Welding of EN AW 7075 Aluminum Alloy

Experimental Research on FSW and SFSW Welding of EN AW 7075 Aluminum Alloy

Experimental research on the degradation law of the bond performance between steel bars and concrete with rust expansion cracking

Experimental research on the degradation law of the bond performance between steel bars and concrete with rust expansion cracking

Plastic waste in dense asphalt mixes for road pavements

Recycling plastic waste in asphalt pavements records increasing statistic figures of application during the last decade worldwide. Due to environmental constraints, but also, to some beneficial properties of plastic waste, recycling in asphalt tends to become current practice, in several countries. In the Aristotle University of Thessaloniki (AUTH), the first attempt to produce asphalt mix using plastic waste consisted of mixing recycled plastic flakes with non-modified binder. Following an asphalt mix design in the laboratory, the whole mass of conventional aggregates was replaced by PET flakes. Recycled PET flakes were chosen to be introduced in the asphalt mix since they are hard, resilient and water repellent. Bitumen emulsion was first preferred as a binder to produce a cold asphalt mix. At a second stage of experimental research, plastic flakes replaced a part of the limestone sand while conventional asphalt 50/70 was used as a binder. At this stage, the experimental research provided more encouraging outcomes. Stability of asphalt mixes decreases as the plastics content in the mix increases, but all recorded values were still within limits of acceptance. At a third stage of research, LDPE recycled material of fine gradation was used to replace a part of the asphalt binder in dense mixes. The objective was to produce a modified binder and a more durable asphalt structure. Test results showed a significant improvement of the performance of asphalt mixes, in terms of strength and deformability of the asphalt mix structure. The research is completed by comparing the conventional techniques with the outcomes of the recycling process and by delineating potential fields of application of the recycled plastics in asphalt pavements.

Analysis of thermophysical properties of polyethylene glycol/SiO2/graphene shape-stabilized phase change materials through experimental research and molecular dynamics simulation

Analysis of thermophysical properties of polyethylene glycol/SiO2/graphene shape-stabilized phase change materials through experimental research and molecular dynamics simulation

Experimental research on the bubble dynamic characteristics during carbon capture in the novel prepared functionalized porous ionic liquids

Porous ionic liquids have received widespread attention as one of the novel CO2 absorbers to reduce CO2 produced by the combustion of fossil fuels. Based on this, the CO2 capture experiments are conducted in ionic liquids ([TEP][MIm] and [TEP][FA]), and the porous ionic liquid (ZIF-8/[TEP][MIm]). The dynamic characteristics of CO2 bubbles in different concentrations of ZIF-8/[TEP][MIm] liquid are researched. The results show that the CO2 capture capacity of the aqueous solution with a concentration of [TEP][MIm] of 20 wt% reaching 2.06 mol/mol ILs. The optimal addition amount of ZIF-8 in the porous ionic liquid using the ethylene glycol as a cosolvent is 1.0 g/100 g, and the maximum CO2 capture amount is about 2.22 mol/mol. Furthermore, the aspect ratio and cross-sectional ratio of CO2 bubbles generated by the four nozzles decrease with the increase of ZIF-8 and [TEP][MIm] concentrations, and the difference between the extreme values of CO2 equivalent diameter under experimental conditions is about 0.513 cm. In addition, the Eo number decreases with the rise of CO2 bubble, and the maximum different value is about 2.94. This work explores the dynamic characteristics of CO2 bubbles in ZIF-8/[TEP][MIm] within a bubbling tower, aiming to optimize the CO2 capture process and provide a valuable reference for advancements in the carbon capture, utilization, and storage technology.

State-of-the-art nonstationary hypersurface damage assessment approach for energy harvesters

Since EH (Energy Harvesters) constitute nowadays a vital part of renewable energy engineering, experimental research is required in addition to numerical modeling, serving reliable structural design and ensuring prolonged device service time. The performance of GPEH (GalloPing EH) has been examined in this case study, utilizing comprehensive laboratory wind tunnel tests, carried out under realistic windspeed conditions. Novel structural multivariate risks assessment methodology, presented here, being feasible for nonstationary nonlinear GPEH dynamic systems, that had been either physically measured over a representative period, providing jointly quasi-ergodic time-series, or directly numerically MCS (Monte Carlo Simulated). Based on laboratory-measured GPEH dynamics, the presented analysis demonstrates that the proposed multivariate hypersurface methodology offers robust predictions of the structural failure/damage risks. Furthermore, when dealing with raw measured timeseries, representing the high-dimensional dynamic system, existing risk assessment techniques struggle to handle nonlinear inter-correlations between GPEH critical components. This case study's main objective has been to validate and benchmark the novel multimodal risk assessment methodology, which utilizes multivariate nonstationary lab-recorded time histories to extract relevant design information from the underlying GPEH dynamics.The proposed state-of-the-art nonstationary hypersurface reliability approach being of a generic nature, offering additional capacity for damage/failure risks prognostics for a wide range of nonlinear multidimensional nonstationary systems. Forecasted damage and failure risks have been supplied with confidence bands, demonstrating the experimental setup's robustness, as well as the useful design features of the presented nonstationary hypersurface risks assessment methodology. It should be noted that the presented reliability methodology being mathematically exact, and it does not rely on simplifying assumptions.

Experimental research on the flexural properties and pore structure characteristics of engineered geopolymer composites prepared by calcined natural clay

The synthesis of high ductility geopolymer composites using excavated natural clay is an economical and environmentally friendly method to realize the utilization of excavated natural clay. This paper presents an experimental research on the flexural properties and pore structure characteristics of engineered geopolymer composites (EGC) prepared by calcined natural clay. The EGC with different slag and fiber contents were prepared and the four-point bending tests were conducted on the EGC. The effect of slag and fiber content on the flexural strength, flexural deflection and flexural toughness were discussed. The microscopic pore structure characteristics of EGC were further analyzed. The optimal mixture ratio of calcined clay-based EGC with the highest flexural toughness was proposed. The results show that fiber can significantly enhance the flexural properties and cracking control ability of EGC. The ultimate flexural strength, flexural deflection, flexural strengthening index and flexural toughness of EGC all increase with increasing fiber content. The results also show the addition of 10.0% slag can increase the flexural strength and flexural toughness, while excessive slag content reduces the flexural properties. The EGC with 10.0% slag content and 2.5% fiber content exhibits excellent flexural properties and cracking control ability. The ultimate flexural strength and flexural toughness index reach 9.75 MPa and 486.11, showing the highest flexural toughness.

An integrative literature review: design and stages of peace group counselling as peace counselor/educator strategies for fostering a peace mindset

Counsellors as peace educators are to foster a peaceful mindset to students. However, not every peace counsellor shares peaceful thinking with clients or students with problems as a gap. Peace group leaders can integrate counselling as a science with religion through the design and stages of peace group counselling (PGC). This research aims to design and organize PGC stages to facilitate peaceful thinking patterns in peace counsellors/educators (PC/E) to foster peaceful thinking patterns. Integrative literature review as a research model by collecting data through documentation with relevant books and journals, then analyzing it descriptively and qualitatively. The research findings found that the PC/E's duties as imams (group leaders) and kaffah individuals have therapeutic abilities. PC/E combines peaceful thinking with help from God. The PGC process has three stages: initial, work, and the final. The work stages combine the sub-stages of peace counselling, starting from rational, exploring the root causes of peaceful thoughts, self-reflection, seeking, and searching for peaceful thought patterns, looking for different forms and behaviors of peaceful thought patterns towards God's teachings as a novelty, and ending with evaluation and follow-up. PC/E implements the PGC design and stages so that individuals can cultivate a peaceful mindset through training and experimental research.