Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1 - 30 of 33243

Full-Text Articles in Chemistry

Purification Of Protoporphyrin Ix Using The Fplc, Ken Overway, Laura Narby May 2027

Purification Of Protoporphyrin Ix Using The Fplc, Ken Overway, Laura Narby

Honors Projects

Protoporphyrin IX (PPIX) is the main pigment in brown eggshells, and it is embedded in the shell gland of hens during the final stages of the egg-making process. This natural dye can be used as a substitute for organic sensitizers in dye-sensitized solar cells (DSSCs). One benefit of PPIX is that it is a natural resource and has a high absorption coefficient in the visible and near-infrared region (NIR). Purified PPIX is extremely helpful in dye-sensitized solar cells because it improves electron injection efficiency, can be chemically modified to improve its absorption efficiency, and can be mixed with nanomaterials such …

Go to article

An Assessment Of Carbon Dioxide Removal Potential From Stormwater Ponds Using Concrete-Based Materials, Yu-Hsuan Tai Jan 2027

An Assessment Of Carbon Dioxide Removal Potential From Stormwater Ponds Using Concrete-Based Materials, Yu-Hsuan Tai

Theses and Dissertations (Comprehensive)

Stormwater ponds (SWPs) are engineered stormwater infrastructure known to be major greenhouse gas (GHG) emitters, including carbon dioxide (CO2). Concrete-based materials have great potential to capture CO2 as carbonate minerals (CaCO3), through aqueous carbonation, driven by their alkaline nature and high portlandite (Ca(OH)2) content. However, the mechanistic understanding of how specific parameters including mass, surface area, and degradation of calcium silicate hydrate (C-S-H) phases collectively control carbonation kinetics and CO2 uptake under dynamically evolving conditions remains underexplored. Laboratory-scale experiments were conducted to evaluate the effects of cement dosage, particle surface area, and …

Go to article

Computational Studies Of Triplet State Formation In Zinc Dipyrrin Complexes, Reuben Kwabla Adigbli Dec 2026

Computational Studies Of Triplet State Formation In Zinc Dipyrrin Complexes, Reuben Kwabla Adigbli

Electronic Theses and Dissertations

Zinc dipyrromethene complexes are promising earth-abundant photosensitizers due to their strong visible-light absorption and tunable excited states. To rationally design them for photocatalysis and photodynamic therapy, a molecular-level understanding of triplet-state formation is needed, but details of intersystem crossing remain unclear. To study the effect of π-extension, we synthesized an indole-substituted zinc dipyrrin complex: the dipyrromethane ligand was prepared from indole and mesitaldehyde, oxidized to the dipyrromethene, then coordinated with zinc. DFT and TD-DFT calculations determined ground and excited-state geometries and energies in different solvents, modeled absorption spectra, and visualized charge distributions. The results show how solvent polarity shifts energies …

Go to article

Study Of Fast Switching Metastable-State Photoacids And Controlled Drug Release From Polycaprolactone (Pcl) Vascular Scaffold, Rana Salman Abbood Abbood Dec 2026

Study Of Fast Switching Metastable-State Photoacids And Controlled Drug Release From Polycaprolactone (Pcl) Vascular Scaffold, Rana Salman Abbood Abbood

Theses and Dissertations

Metastable-state photoacid (mPAH) has become a common tool for controlling and driving chemical processes with light. mPAHs with fast reverse reactions are desirable for precise temporal control or generating quick pulses of proton concentration. In this work, different approaches towards fast reversing mPAHs are studied. Experimental and computational results showed that stabilizing the charge–transfer intermediate is an effective way to increase the rate. A novel mPAH with a reverse reaction ≈500 times faster than the most widely used mPAH in methanol has been developed. Another water-soluble mPAH exhibited a reverse reaction with a rate constant of 7.8 s−1, the fastest …

Go to article

Efficient Removal Of Methyl Orange Dye Via A Mnfe₂O₄/Go Nanocomposite With A Ctab Dual-Layer Surfactant Coating, Taher Karami, Soleiman Bahar, Reza Mostafazadeh Dec 2026

Efficient Removal Of Methyl Orange Dye Via A Mnfe₂O₄/Go Nanocomposite With A Ctab Dual-Layer Surfactant Coating, Taher Karami, Soleiman Bahar, Reza Mostafazadeh

Research outputs 2022 to 2026

This study investigated the adsorption of methyl orange (MO) from aqueous solutions using a novel MnFe₂O₄/GO nanocomposite coated with cetyltrimethylammonium bromide (CTAB). The dual-layer surfactant modification facilitates both electrostatic and lipophilic interactions. This enhancement significantly improves dye removal efficiency. The adsorption process was monitored using spectrophotometry at 464 nm, with various characterization techniques confirming the structural and magnetic properties of the nanocomposite. The optimized parameters for maximum adsorption include a 2-minute ultrasonic dispersion, pH 6.8, and a surfactant-to-adsorbent ratio of 1, achieving a maximum adsorption capacity of 285.7 mg/g. The kinetic data followed a pseudo-second-order model, whereas the adsorption isotherm …

Go to article

Reduced Mediators Released By Cyanobacteria During Exoelectrogenesis Detected Using Differential Pulse Voltammetry, Laura T. Wey, Monica Brachi, Yagut Allahverdiyeva, Shelley D. Minteer Dec 2026

Reduced Mediators Released By Cyanobacteria During Exoelectrogenesis Detected Using Differential Pulse Voltammetry, Laura T. Wey, Monica Brachi, Yagut Allahverdiyeva, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Cyanobacteria generate electrical current through exoelectrogenesis (extracellular electron transfer) downstream of photosynthesis, yet the identity of the endogenous redox mediator(s) responsible remains unresolved. Here, we apply differential pulse voltammetry (DPV) to detect and characterise redox-active species released by Synechocystis sp. PCC 6803 under illumination. To enable sensitive detection, we developed an electrolyte intermediate between BG11 (Blue-Green-11) growth medium and MOPS (3-(N-morpholino)propanesulfonic acid) buffer that minimises background electrochemical interference while maintaining short-term cellular functionality. DPV revealed multiple light-enhanced oxidation peaks (0.1–0.65 V vs. saturated calomel electrode (SCE)) that were not resolvable using cyclic voltammetry, providing evidence that cyanobacteria release reduced compounds …

Go to article

A Review Of Gallium And Germanium Recovery From Industrial Solid Residues, Ernest V. Oteng, Marthias Silwamba, Lana Alagha, Alex Luyima Nov 2026

A Review Of Gallium And Germanium Recovery From Industrial Solid Residues, Ernest V. Oteng, Marthias Silwamba, Lana Alagha, Alex Luyima

Mining Engineering Faculty Research & Creative Works

The global demand for critical elements such as gallium (Ga) and germanium (Ge), and the shift toward circular mining has accelerated the development of new extraction and recovery processing these metals from industrial solid residues. This transition is driven by a substantial surge in demand for advanced technologies and the depletion of primary ore. Consequently, industrial solid residues, particularly zinc processing residues, smelter slags, flue dusts, and coal fly ash, are emerging as viable alternative sources. These residues incorporate Ga and Ge through isomorphic substitution in phases such as ferrites, silicates, and glassy aluminosilicates, and are enriched by industrial processes, …

Go to article

Optimizing Multi-Layer/Multi-Physics Passive Adaptive Thermal Enclosures For Climate-Responsive Energy Regulation: A Numerical Study, Rajae Bousselham, Mingjiang Tao, Sergio Granados-Focil, Adriana Hera, Steven Van Dessel Nov 2026

Optimizing Multi-Layer/Multi-Physics Passive Adaptive Thermal Enclosures For Climate-Responsive Energy Regulation: A Numerical Study, Rajae Bousselham, Mingjiang Tao, Sergio Granados-Focil, Adriana Hera, Steven Van Dessel

Chemistry

Adaptive facades regulate heat transfer by adjusting their thermal behavior in response to environmental conditions. Passive adaptive systems, including stimuli-responsive thermal storage materials, tunable radiative coatings, and variable-conductivity layers, offer significant potential for material-based thermal regulation. However, their combined potential remains unexplored, as most studies examine individual mechanisms in isolation. As a result, trade-offs among energy savings, material usage, design complexity, and climate responsiveness are often underrepresented, overlooking coupled interactions in multilayer assemblies limiting their effectiveness. This study develops a transient three-dimensional numerical framework coupling heat transfer with multi-objective optimization to evaluate trade-offs between minimizing annual energy consumption and enclosure …

Go to article

Radiological And Chemical Safety Assessment Of Drinking Water From Treatment Plants And Rivers In Kut City, Iraq, Ahmed A. Alswaty, Hadi D. Alattabi Oct 2026

Radiological And Chemical Safety Assessment Of Drinking Water From Treatment Plants And Rivers In Kut City, Iraq, Ahmed A. Alswaty, Hadi D. Alattabi

Karbala International Journal of Modern Science

Climate change and increasing anthropogenic activities, particularly wastewater discharge into rivers, have raised pollution levels in the water sources of Kut City, necessitating an assessment of the radiological and chemical safety of drinking water at the city's treatment plants. Thirteen water samples were collected, comprising ten treated and three raw water samples from the source rivers. An HPGe detector was used to measure the radionuclides 214Bi, 214Pb, 212Bi, 212Pb, 40K, and 137Cs. All measured radionuclides were below the minimum detectable activity (MDA). ICP-OES analysis supported these findings, as U concentrations in most samples were …

Go to article

Ph-Compensated Hydrogen Peroxide Quantification Using A Dual-Modal Fiber-Optic Probe, Homayoon Soleimani Dinani, Bohong Zhang, Maryam Karimi, Rex E. Gerald, Shelley D. Minteer, Jie Huang Oct 2026

Ph-Compensated Hydrogen Peroxide Quantification Using A Dual-Modal Fiber-Optic Probe, Homayoon Soleimani Dinani, Bohong Zhang, Maryam Karimi, Rex E. Gerald, Shelley D. Minteer, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

We report a dual-modal fiber-optic probe that integrates electrochemical quantification of hydrogen peroxide (H₂O₂) with co-localized fluorescent pH sensing for pH-indexed interpretation of the H₂O₂ response. H₂O₂ is a reactive oxygen species involved in oxidative stress, inflammation, and cellular signaling, and local pH modulates both its production and electrochemical response. Many electrochemical H₂O₂ sensors exhibit pH-dependent sensitivity, creating ambiguity unless pH is measured and used for compensation, which is difficult in small, heterogeneous, or rapidly changing microenvironments. A three-electrode configuration—working (WE), counter (CE), and Ag/AgCl pseudo-reference (pRE) electrodes—is fabricated directly on the cylindrical surface of a 710-µm-diameter optical fiber using …

Go to article

Size-Tunable Tellurium Quantum Dots By Glancing Angle Deposition, S. M. Sayem, Salim Hussain, Fernando Maia De Oliveira, Ranjitha Kumarapuram Hariharalakshmanan, Gregory Guisbiers, Tansel Karabacak Oct 2026

Size-Tunable Tellurium Quantum Dots By Glancing Angle Deposition, S. M. Sayem, Salim Hussain, Fernando Maia De Oliveira, Ranjitha Kumarapuram Hariharalakshmanan, Gregory Guisbiers, Tansel Karabacak

Faculty Scholarship

Tellurium has a unique helical crystal arrangement and pronounced anisotropy that influence its electronic and optical properties at the nanoscale. This study reports the synthesis of pure tellurium quantum dots (Te QDs) on silicon wafer using glancing angle deposition (GLAD). Quasi-hemispherical dots with lateral sizes ranging from 9 to 28 nm and vertical dimensions of 6 to 10 nm were produced as a function of the deposition duration. A comparison of the dot sizes with the Bohr radii of the charge carriers indicated a regime of strong to intermediate confinement. Structural analyses confirmed the polycrystalline nature and trigonal phase of …

Go to article

Microwave Spectrum And Iodine Nuclear Quadrupole Coupling Constants Of Difluorodiiodomethane, Cf2i2, Michael J. Carrillo, Michael J. Tubergen, Garry S. Grubbs, S. A. Cooke, Stewart E. Novick Oct 2026

Microwave Spectrum And Iodine Nuclear Quadrupole Coupling Constants Of Difluorodiiodomethane, Cf2i2, Michael J. Carrillo, Michael J. Tubergen, Garry S. Grubbs, S. A. Cooke, Stewart E. Novick

Chemistry Faculty Research & Creative Works

The high-resolution rotational spectrum of difluoro diiodomethane is reported for the first time. A molecular-beam broadband Fourier transform microwave spectrometer recorded the spectrum over the frequency range of 5.9–18.1 GHz. The rotational constants, centrifugal distortion constants, nuclear quadrupole coupling constants, and nuclear spin-rotation constants for the two equivalent iodine nuclei were determined from fitting 1378 hyperfine transitions of 163 rotational transitions: A = 2743.79691(18)MHz, B = 587.83103(5) MHz, C = 528.72470(5) MHz, χaa = −1213.287(6) MHz, χbb – χcc = −885.210(5) MHz, and χab = 1437.721(5) MHz. 31 dipole-forbidden/quadrupole-allowed transitions, arising from the large nuclear quadrupole coupling effect of iodine, …

Go to article

Implementation Of The Problem-Based Learning Model On The Topic Of The Immune System To Enhance The Critical Thinking Skills Of Grade Xi B Students At Sman 1 Tojo, Nani Sofyanti, Sutrisnawati Sutrisnawati, Vita Indri Febriani, Mohammad Jamhari, Bustamin Bustamin, Raya Agni Sep 2026

Implementation Of The Problem-Based Learning Model On The Topic Of The Immune System To Enhance The Critical Thinking Skills Of Grade Xi B Students At Sman 1 Tojo, Nani Sofyanti, Sutrisnawati Sutrisnawati, Vita Indri Febriani, Mohammad Jamhari, Bustamin Bustamin, Raya Agni

Jurnal Pendidikan Sains

Critical-thinking skills are essential competencies for students in 21st-century learning. Preliminary classroom observations in Class XI B at SMAN 1 Tojo indicated that instruction remained predominantly teacher-centered and provided limited opportunities for students to engage in activities involving interpretation, analysis, evaluation, and inference. This study aimed to improve students’ critical-thinking skills through the implementation of Problem-Based Learning (PBL) on the immune system topic. The study employed a Classroom Action Research (CAR) design conducted over two cycles, involving 28 students in Class XI B. Data were collected using a teacher activity observation sheet and critical-thinking skills tests assessing four indicators: interpretation, …

Go to article

Bioherbicidal Potential Of Noni Fruit (Morinda Citrifolia) Extract Against Water Hyacinth (Eichhornia Crassipes), Nur Rahma Afriani, Paulus Hengky Abram, Vanny M Agustina Tiwow, Reny Reny Sep 2026

Bioherbicidal Potential Of Noni Fruit (Morinda Citrifolia) Extract Against Water Hyacinth (Eichhornia Crassipes), Nur Rahma Afriani, Paulus Hengky Abram, Vanny M Agustina Tiwow, Reny Reny

Jurnal Pendidikan Sains

Noni fruit (Morinda citrifolia) contains secondary metabolites that may have potential bioherbicidal activity. This preliminary laboratory experiment aimed to identify flavonoids and tannins in noni fruit extract and to describe the phytotoxic responses of water hyacinth (Eichhornia crassipes) exposed to different extract concentrations. Noni fruit was extracted with 96% ethanol by maceration and concentrated using a rotary evaporator. The extract was qualitatively screened for flavonoids and tannins and applied to water hyacinth at concentrations of 0%, 10%, 20%, 30%, and 50% (v/v), with three plants per treatment. Plant responses were observed for 25 days and analyzed …

Go to article

Evaluating The Nash Reaction As A Sustainable Alternative To The Snar Reaction In The Synthesis Of Pharmaceutical Intermediates, Allison L. Ryerson, James K. Bashkin, Jessica R. N. Thompson, Adam Weiss, Huy Q. Nguyen Sep 2026

Evaluating The Nash Reaction As A Sustainable Alternative To The Snar Reaction In The Synthesis Of Pharmaceutical Intermediates, Allison L. Ryerson, James K. Bashkin, Jessica R. N. Thompson, Adam Weiss, Huy Q. Nguyen

Undergraduate Research Symposium

Nucleophilic aromatic substitution (SNAr) reactions are one of the most widely used reaction classes in pharmaceutical production today, used for example to produce nitroaryl amine intermediates. In comparison to the traditional SNAr pathway, the nucleophilic aromatic substitution of hydrogen (NASH) provides a greener alternative in pharmaceutical production by using cheaper starting materials, eliminating more hazardous solvents, and reducing toxic waste.

Go to article

Synthesis And Charge Transport Characterization Of 9,9'-Bifluorenylidene-Based Conjugated Molecules For Single-Molecule Conductance, Zach Moughamian, Jahnavi Badiganti, Jinjia Xu Sep 2026

Synthesis And Charge Transport Characterization Of 9,9'-Bifluorenylidene-Based Conjugated Molecules For Single-Molecule Conductance, Zach Moughamian, Jahnavi Badiganti, Jinjia Xu

Undergraduate Research Symposium

Molecular electronics explores the use of individual molecules as functional components in nanoscale electronic devices. In this project, fluorenone-based π-conjugated molecules including 9,9'-bifluorenylidene-S and triphenylamine-substituted derivatives were synthesized to investigate structure-property relationships relevant to molecular charge transport. The synthesized compounds were obtained in 13% and 27% yield respectively. ¹H NMR spectroscopy confirms characteristic aromatic resonances in the 7-9 ppm region consistent with the conjugated framework. UV–Vis spectroscopy reveals absorption maxima at 459 nm and 470 nm, indicating extended π-conjugation and donor-acceptor effects. Single-crystal X-ray diffraction confirms the structure of 9,9'-bifluorenylidene-S, which crystallizes in the monoclinic system (space group P2₁/c). In …

Go to article

Enantioselectivity Of The Photochemical Continuous-Flow Isomerization Of Humulones, Gregory M. Giovine, Trevor Smith, Bruce Hamper Sep 2026

Enantioselectivity Of The Photochemical Continuous-Flow Isomerization Of Humulones, Gregory M. Giovine, Trevor Smith, Bruce Hamper

Undergraduate Research Symposium

Humulones, the primary natural product present in the historically significant hop flower, represent a largely unexplored candidate for structure-based pharmaceutical design.  Showing promising biological activity as an anti-bacterial and anti-inflammatory agent, humulones are of interest both for their bioactive properties and for their long-established tolerability and natural abundance.  Humulones undergo a characteristic isomerization reaction, where the six-membered substituted phloroglucinol ring contracts to a five-membered ring isohumulone, under a variety of conditions, including those enabled by brewing conditions (thermal, metal-catalyzed) and by exposure to UV light.  Optimization of the photocatalyzed isomerization of n-humulone to n-isohumulone in flow conditions resulted in a …

Go to article

Feasibility Of Acetylated Icacina Trichantha Oliv. Tuber Starch As Viscosity And Fluid Loss Control Agents In Water-Based Drilling Mud. A Comparative Assessment With Commercial Starch, Kennedy I. Ogunwa, Theresa O. Uchechukwu, Ozioma Achugasim, Leo C. Osuji, Onyewuchi Akaranta Sep 2026

Feasibility Of Acetylated Icacina Trichantha Oliv. Tuber Starch As Viscosity And Fluid Loss Control Agents In Water-Based Drilling Mud. A Comparative Assessment With Commercial Starch, Kennedy I. Ogunwa, Theresa O. Uchechukwu, Ozioma Achugasim, Leo C. Osuji, Onyewuchi Akaranta

Tanzania Journal of Science

The need for sustainable, non-food drilling fluid additives has prompted the feasibility assessment of acetylated Icacina trichantha tuber starch as a viscosity modifier and fluid loss control agent in water-based muds. Native starch was acetylated to obtain two derivatives (Degree of Substitution DS = 0.38 and 0.68) and characterized using FTIR, swelling power, and physicochemical analyses. Drilling mud performance was assessed through rheology, gel strength, filtration loss, sorptivity, and model fitting. Acetylation improved swelling and reduced gelatinization temperature. The optimal formulation, Mud-ITO-ACS2 (DS = 0.68), exhibited the most favorable performance, combining low plastic viscosity (6 cP vs 9 cP for …

Go to article

Effect Of Acid Pretreatment On The Adsorption Of Phenol Red By Cellulose Isolated From Sandbox (Hura Crepitans L.): Kinetics, Isotherms And Thermodynamics, Muibat O. Alabi-Abass, Najeem A. Adesola Babarinde, Adeola A. Ibikunle, Nurudeen O. Sanyaolu Sep 2026

Effect Of Acid Pretreatment On The Adsorption Of Phenol Red By Cellulose Isolated From Sandbox (Hura Crepitans L.): Kinetics, Isotherms And Thermodynamics, Muibat O. Alabi-Abass, Najeem A. Adesola Babarinde, Adeola A. Ibikunle, Nurudeen O. Sanyaolu

Tanzania Journal of Science

The removal of synthetic dyes from wastewater remains an urgent environmental concern due to their persistence and toxicity. This study evaluates cellulose from Hura crepitans (HC) and its acid-modified form (AHC) for the adsorption of phenol red (PR) dye from aqueous solutions. The adsorbents were characterized using FTIR to identify functional groups responsible for dye binding, XRD to determine the crystalline structure, SEM to examine surface morphology, and BET/BJH analyses to measure surface area and pore distribution. Acid modification enhanced surface roughness, porosity, and the abundance of active functional sites, leading to improved adsorption efficiency. Optimal conditions were pH 9.0 …

Go to article

The Use Of Gadgets And Learning Motivation Among Grade Xi Students In Biology Learning At Sma Negeri 5 Palu, Yulia Citra, Mohammad Jamhari, Masrianih Masrianih, Lestari M.P Alibasyah, Mursito S. Bialangi, Yulia Windarsih Sep 2026

The Use Of Gadgets And Learning Motivation Among Grade Xi Students In Biology Learning At Sma Negeri 5 Palu, Yulia Citra, Mohammad Jamhari, Masrianih Masrianih, Lestari M.P Alibasyah, Mursito S. Bialangi, Yulia Windarsih

Jurnal Pendidikan Sains

This study aims to describe the profile of gadget use and learning motivation among Grade XI students in biology learning at SMA Negeri 5 Palu and to explore students’ and teachers’ experiences of gadgets as learning support tools and potential sources of digital distraction. A qualitative descriptive design was employed, supported by descriptive questionnaire profiling. A total of 74 students completed a 50-item questionnaire on gadget use and learning motivation, while 10 students and two biology teachers participated in semi-structured interviews. Questionnaire data were analyzed using frequencies and percentages, while interview data were analyzed thematically. The descriptive findings showed that …

Go to article

The Application Of The Group Investigation (Gi) Model Of Cooperative Learning To Improve Students’ Understanding Of Biodiversity In Year 10 At Sman 2 Mori Atas, Nadia Rosmita Lumako, Mohammad Jamhari, Yulia Windarsih, Lilies Lilies, Rafiqa Rafiqa, Amalia Buntu Sep 2026

The Application Of The Group Investigation (Gi) Model Of Cooperative Learning To Improve Students’ Understanding Of Biodiversity In Year 10 At Sman 2 Mori Atas, Nadia Rosmita Lumako, Mohammad Jamhari, Yulia Windarsih, Lilies Lilies, Rafiqa Rafiqa, Amalia Buntu

Jurnal Pendidikan Sains

Biology instruction at SMAN 2 Mori Atas was predominantly conducted through conventional teaching practices. Preliminary observations revealed that students had difficulty understanding biodiversity concepts, and several students did not meet the minimum passing criterion of 70. These conditions highlighted the need for learning activities that promote active investigation, discussion, and conceptual connections. This classroom action research examined the use of the Group Investigation (GI) cooperative learning model to improve Grade 10 students’ classroom engagement and conceptual understanding of biodiversity, as assessed through Higher-Order Thinking Skills (HOTS) questions based on the Structure of Observed Learning Outcomes (SOLO) taxonomy. The study involved …

Go to article

The Effect Of The Problem-Based Learning Model On Biology Learning Outcomes In The 8th Grade Science Class At Smp Negeri 19 Palu, Delfi Srieviyani, Mursito S. Bialangi, Masrianih Masrianih, Abd Hakim Laenggeng, Vita Indri Febriani, Bustamin Bustamin Sep 2026

The Effect Of The Problem-Based Learning Model On Biology Learning Outcomes In The 8th Grade Science Class At Smp Negeri 19 Palu, Delfi Srieviyani, Mursito S. Bialangi, Masrianih Masrianih, Abd Hakim Laenggeng, Vita Indri Febriani, Bustamin Bustamin

Jurnal Pendidikan Sains

Research background: The low student achievement in biology at SMP Negeri 19 Palu specifically regarding the human respiratory system is attributed to the conventional teaching methods still employed by teachers. Purpose and scope of the article: This study examines the effect of the Problem-Based Learning (PBL) model on students’ learning outcomes in biology, specifically regarding the human respiratory system. Method: This study used a quasi-experimental design with a quantitative approach. The research design employed was a nonequivalent control group design using two groups: an experimental group (Class VIII D) consisting of 25 students who received the PBL model, and a …

Go to article

Evaluation Of Carcinogenic Contaminants (Nitrates, Ammonium, Bromates, And Chloroform) In Baghdad Drinking Water And Their Removal Using Orange Peel Powder As A Bio Sorbent, Estabraq Ali Hameed, Hiba N. Sami, Eman Waleed Hayder Sep 2026

Evaluation Of Carcinogenic Contaminants (Nitrates, Ammonium, Bromates, And Chloroform) In Baghdad Drinking Water And Their Removal Using Orange Peel Powder As A Bio Sorbent, Estabraq Ali Hameed, Hiba N. Sami, Eman Waleed Hayder

Karbala International Journal of Modern Science

The present study was carried out for six months to detect the presence of some important chemical contaminants (bromate, nitrate, chloroform, and ammonium) in the drinking water of Baghdad at ten sampling sites. The study suggested the use of orange peel powder (OPP) as a cheap and eco-friendly biosorbent. X-ray diffraction (XRD) was used to confirm the amorphous nature, surface and structural characteristics of OPP. Further, SEM investigation also showed very microporous surface. FTIR (Fourier Transform Infra-Red Spectroscopy) analysis confirmed the presence of active carboxyl (-COOH) and hydroxyl (-OH) binding sites. Baseline studies show that the levels of nitrate and …

Go to article

Nontarget Analysis Of The Volatile And Semivolatile Chemical Profile Of Wildland Firefighter Gear: Insight Into Occupational Exposure And Health Implications, Patrica Ivy Agorsor, Husam Kafeenah, Margaret D. Taiwo, Robin M. Verble, Michael O. Eze Sep 2026

Nontarget Analysis Of The Volatile And Semivolatile Chemical Profile Of Wildland Firefighter Gear: Insight Into Occupational Exposure And Health Implications, Patrica Ivy Agorsor, Husam Kafeenah, Margaret D. Taiwo, Robin M. Verble, Michael O. Eze

Biological Sciences Faculty Research & Creative Works

Prescribed fire releases a complex mixture of volatile and semivolatile organic compounds to the environment. Firefighters are directly exposed to these hazardous mixtures through occupational activities. This study investigated the volatile and semivolatile chemical contamination profile of firefighter protective gear and the effectiveness of laundering as a decontamination strategy. Our results revealed that firefighter gear accumulated a broad spectrum of combustion-derived contaminants, predominantly composed of polycyclic aromatic hydrocarbons and derivatives, phenolic compounds, and aromatic hydrocarbons. Representative compounds identified included toluene, biphenyl, naphthalene, 1-methynaphthalene, 2-methylnaphthalene, acenaphthene, phenol, alkylated phenols, and chlorinated phenols. Quantitative analysis revealed representative combustion-derived compounds at concentrations (mean …

Go to article

Efficient Acidic H2O2 Electrosynthesis Over Co Atoms Anchored On Nitrogen-Doped Hierarchical Porous Carbon, Xiao Huang, Zi-Hao Zhan, Hao-Xu Niu, Guan-Yu Luo, Jin-Tao Huang, Bo-Xuan Jin, De-Li Wang Sep 2026

Efficient Acidic H2O2 Electrosynthesis Over Co Atoms Anchored On Nitrogen-Doped Hierarchical Porous Carbon, Xiao Huang, Zi-Hao Zhan, Hao-Xu Niu, Guan-Yu Luo, Jin-Tao Huang, Bo-Xuan Jin, De-Li Wang

Journal of Electrochemistry

The two-electron oxygen reduction reaction (2e− ORR) presents a promising route for the on-site production of hydrogen peroxide (H2O2), offering a green alternative to energy-consuming anthraquinone process. However, the high selectivity toward the competing 4e− ORR over the desired 2e− pathway leads to low Faradaic efficiency for H2O2, posing a critical challenge in catalyst design. In this work, a nitrogen-doped hollow hierarchical porous carbon with anchored Co atoms (CoN/HPC) was constructed for high-performance H2O2 production. The as-prepared Co-N/HPC catalyst showed excellent 2e− ORR performance, achieving …

Go to article

Engineering Small-Sized Cations With Strong Solvation For High-Voltage Supercapacitors, Tong Huo, Pan Liu, Hao Chen, Peng Zhang, Zhen-Lei Chen, Guo-Fu Sun, Zhi-Qiang Shi, Jing Wang Sep 2026

Engineering Small-Sized Cations With Strong Solvation For High-Voltage Supercapacitors, Tong Huo, Pan Liu, Hao Chen, Peng Zhang, Zhen-Lei Chen, Guo-Fu Sun, Zhi-Qiang Shi, Jing Wang

Journal of Electrochemistry

Supercapacitors (SCs) have attracted much attention in the field of energy storage due to their high power density and long cycle life. However, their relatively low energy density limits their application in a wider range of fields. Methods to increase energy density include enhancing specific capacitance and extending operating voltage window. Herein, we report a novel electrolyte salt, tetramethylammonium bis(fluorosulfonyl)imide (TMA-FSI), the resulting electrolyte formed with propylene carbonate (PC), designated as TMF, exhibited a wide electrochemical stability window (ESW) of 5.09 V. On the one hand, we found that the small size of TMA+ enables it to enter the …

Go to article

Dense Platinum Nanoparticles Confined In Mn-N-C Nanocages For Robust Heavy-Duty Pemfcs, Lei Zhao, Zhen-Min Cao, Jia-Yu Zuo, Ming-Liang Yang, Hong-Yan Qiao, Jun-Song Chen, Rui Wu Sep 2026

Dense Platinum Nanoparticles Confined In Mn-N-C Nanocages For Robust Heavy-Duty Pemfcs, Lei Zhao, Zhen-Min Cao, Jia-Yu Zuo, Ming-Liang Yang, Hong-Yan Qiao, Jun-Song Chen, Rui Wu

Journal of Electrochemistry

High-loading Pt cathodes are essential for heavy-duty proton exchange membrane fuel cells but suffer from a critical tradeoff between ionomer sulfonate poisoning and nanoparticle instability. Herein, we report a spatial confinement strategy to encapsulate dense Pt nanoparticles (~51.8 wt%) within Mn/N-co-doped mesoporous carbon nanocages (denoted as Pt-MnNC). This architecture excludes bulky ionomers to create an ionomer-shielded environment against sulfonate poisoning, while Mn-Nx-mediated strong metal-support interactions anchor the Pt nanoparticles to prevent agglomeration and further boost durability. In the 5 × 5 cm2 membrane electrode assembly tests, the Pt-MnNC catalyst delivers an exceptional power density of 1.26 W·cm …

Go to article

Characterization Of Combined Adsorption Using Fermi Levels, Molecular Dynamics, And Monte Carlo Simulations To Prevent Cu–Zn (111) Alloy Corrosion, Mushtaq Jerri Meften, Ammar Abdul Jabbar Kadhim, Mohammed Shafeeq Abed Sep 2026

Characterization Of Combined Adsorption Using Fermi Levels, Molecular Dynamics, And Monte Carlo Simulations To Prevent Cu–Zn (111) Alloy Corrosion, Mushtaq Jerri Meften, Ammar Abdul Jabbar Kadhim, Mohammed Shafeeq Abed

Makara Journal of Science

Experimentally developing corrosion inhibitors requires a significant amount of money and time. In silico advancement empowers selecting inhibitor molecules based on their properties derived from theoretical studies, thereby reducing costs. Our main approaches include theoretical studies such as Fermi levels, electrostatic potential surface (EPS), Fukui indices, molecular dynamics stimulations, and Monte Carlo as indispensable tools to investigate the adsorption mechanisms of molecules 6-((5-(((3S,5R)-2-oxo-5-((2-(pyrazin-2-yloxy) thiazol-5-yl) thio) tetrahydro-2H-thiopyran-3-yl) oxy)isothia-zol-3-yl)thio) nicotinic acid (PTT), and (S)-2-((5-((6-((3-(2-thioxoethoxy)-1,2,4-thiadiazol-5-yl)thio)-1,6-dihydropyra-zin-2-yl)oxy)-1,3,4-thiadiazol-2-yl) thio) acetaldehyde (TTD) on the Cu/Zn (111) alloy. We electronically characterized PTT and TTD, which were proven effective inhibitors. Notably, all results suggested that the two exhibited high …

Go to article

Lignin Valorization To Phenolic Compounds Over Metal Oxide-Modified Hierarchical Zsm-5 Zeolites Derived From Indonesian Minerals, Arnia Putri Pratama, Iman Abdullah, Yuni Krisyuningsih Krisnandi Sep 2026

Lignin Valorization To Phenolic Compounds Over Metal Oxide-Modified Hierarchical Zsm-5 Zeolites Derived From Indonesian Minerals, Arnia Putri Pratama, Iman Abdullah, Yuni Krisyuningsih Krisnandi

Makara Journal of Science

Lignin, a key component of lignocellulosic biomass, offers significant potential as a renewable raw material for the sustainable production of aromatic chemicals. To investigate its heterogeneous catalytic depolymerization, benzyl phenyl ether (BPE) was used as a model compound. Hierarchical ZSM-5 catalysts were synthesized and modified with metal oxides (NiO and CuO). Belitung kaolin and Bayat natural zeolite, natural minerals from Indonesia, were used as silica and alumina sources to synthesize hierarchical ZSM-5 zeolite (labeled as ZSM-5N), which was compared with hierarchical ZSM-5 synthesized using pro-analysis precursors (labeled as ZSM-5S). Comprehensive physicochemical characterization using FTIR, XRD, BET, XRF, SEM-EDX, and NH₃-TPD …

Go to article

Therapeutic Outcomes Of Oral Antibiotics For The Treatment Of Methicillin-Resistant Staphylococcus Aureus Urinary Tract Infections: A Multisite, Retrospective Cohort Study Of Linezolid, Trimethoprim–Sulfamethoxazole And Doxycycline, Ryan Mccall, Elena Gatskevich, Steven E. Fiester, Michael Floren, Elisabeth Chandler Sep 2026

Therapeutic Outcomes Of Oral Antibiotics For The Treatment Of Methicillin-Resistant Staphylococcus Aureus Urinary Tract Infections: A Multisite, Retrospective Cohort Study Of Linezolid, Trimethoprim–Sulfamethoxazole And Doxycycline, Ryan Mccall, Elena Gatskevich, Steven E. Fiester, Michael Floren, Elisabeth Chandler

Chemistry Publications

Background: Methicillin-resistant Staphylococcus aureus (MRSA) urinary tract infections (UTIs), while relatively uncommon, pose a unique challenge in treatment as only specific intravenous (IV) options are typically utilized, with the efficacy of oral antimicrobials being poorly defined. Methods: The multi-site retrospective cohort study described herein therefore aims to characterize outcomes associated with oral administration of linezolid, trimethoprim-sulfamethoxazole (TMP-SMX), or doxycycline for the treatment of MRSA UTIs. Study participants were adults with culture-positive MRSA UTIs receiving one of the three oral therapies. Exclusion criteria included polymicrobial UTI, concomitant MRSA outside the urinary tract, receipt of non-study anti-MRSA agents for greater than or …

Go to article

Next Last