Arnold Alguno

Mindanao State University - Iligan Institute of Technology | MSUIIT · Department of Physics

We report on the performance of solar cells with stacked self-assembled Ge dots in the intrinsic region of Si-based p-i-n diode. These dots were epitaxially grown on p -type Si(100) substrate via the Stranski–Krastanov growth mode by gas-source molecular beam epitaxy. Enhanced external quantum efficiency (EQE) in the infrared region up to 1.45 μm w...

Kinetics of the step flow growth on the (16×2) reconstructed Si(110) surface has been studied experimentally and with computer simulations. It is shown that during Si growth under DC heating vicinal steps on the (16×2) reconstructed Si(110) surfaces undergo a kinetic step bunching and develop extended segments preferentially oriented along the (16×...

The dark current–voltage (J–V) characteristics and the conversion efficiency of the solar cells with embedded stacked Ge islands in the intrinsic layer were investigated. These islands were grown by molecular beam epitaxy on Si substrates. We used a two-diode model to analyze the dark J–V characteristics of Ge island solar cells. Results showed tha...

We report on the effects of spacer thickness on the external quantum efficiency (EQE) of the solar cells with Ge islands embedded into the intrinsic region of the Si-based p-i-n diode. The EQE response of the solar cells in the near-infrared region is dependent on the spacer thickness that separates the layers of self-assembled Ge islands. It was f...

We fabricated Si-based solar cell with stacked Ge islands grown via the Stranski-Krastanov growth mode in the intrinsic layer of pin diodes. The onset of the external quantum efficiency in the near infrared regime was extended up to approximately 1.4 mum for the solar cells with stacked Ge islands. The quantum efficiency was found to increase with...

As a result of the high surface energy, noble metal nanoparticles (NPs) tend to agglomerate and destabilize during catalytic reactions and, hence, proved uneconomical, which is not conducive to improved activity. Therefore, the sustainable reduction and stabilization of precious metal NPs are highly demanded to achieve high activity. Herein, Pt NPs...

Polyurethane coating has been widely used as a protective coating due to its wide range of mechanical strength, excellent abrasion resistance, toughness, low-temperature flexibility, and chemical resistance, simplicity in production and application, and superior protection on corrosion to mild steel. No studies have been reported utilizing coconut-...

In the Philippines, bananas are one of the most exported agricultural products, with up to 6 million metric tons of annual harvest. Because of this, harvesting bananas generates waste like banana pseudo-stems. Banana pseudo-stems offer a good source of nanocellulose, and it was found that these have very similar chemical compositions to jute and si...

In this study, an eco-friendly coconut oil-based polyol blend was synthesized for bio-based waterborne polyurethane (WBPU) and WBPU-silane composite coatings. It was demonstrated that an increase in silane content incorporated into the WBPU matrix significantly enhanced the corrosion protection of WBPU coatings. Results also show a fourfold increas...

The effects of nanocellulose extracted from pineapple leaf fiber on the physico-chemical and thermal properties of epoxy nanocomposite are reported. Nanocellulose was added to the epoxy in different amounts of loadings (0.5, 1.0, 1.5, and 2.0 wt.%) to prepare nanocomposites. The physico-chemical and thermal properties of the nanocellulose reinforce...

We report on microscopic structural characterizations of multicrystalline SiCe (mcSiGe) bulk crystal, which contains microscopic compositional distribution, and discuss possible influence on solar cell applications. By combining microscopic Raman spectroscopy and energydispersive xray analysis, the existence of built-in strain and its spatial distr...

This study presents a novel polyurethane-activated carbon composite (PACC) as an effective and sustainable adsorbent for treating lead-ion-contaminated waters. The PACC was characterized using SEM-EDX, FTIR, BET, XRD, and TGA to evaluate its physicochemical and thermal properties. Furthermore, the PACC was employed in an experimental column adsorpt...

In the present study, the dynamic behavior of rotating carbon fiber reinforced polymer (CFRP) composite tapered plates reinforced with graphene nanoparticles has been investigated using a finite element (FE) formulation. The mechanical properties of CFRP laminates containing 0–0.5 wt% graphene nanoparticles were assessed using ASTM standard tests....

The widespread application of engineered nanoparticles (NPs) in various industries has demonstrated their effectiveness over the years. However, modifications to NPs' physicochemical properties can lead to toxicological effects. Therefore, understanding the toxicity behaviour of NPs is crucial. In this paper, regularized regression models, such as...

Bio-derived polyol products have gained global interest as a green and sustainable substitute for fossil-based polyols in a diverse range of polyurethane (PU) applications. According to previous studies, PU properties are highly influenced by the reaction kinetics during their formation. One major factor affecting this is the reactivity of their po...

This study propounds a sustainable alternative to petroleum-based polyurethane (PU) foams, aiming to curtail this nonrenewable resource’s continued and uncontrolled use. Coconut fatty acid distillate (CFAD) and crude glycerol (CG), both wastes generated from vegetable oil processes, were utilized for bio-based polyol production for rigid PU foam ap...

The production of biodiesel generates glycerol as a by-product that needs valorization. Glycerol, when converted to polyglycerol, is a potential polyol for bio-based thermoplastic polyurethane (TPU) production. In this study, a novel polyglycerol polyester polyol (PPP) was developed from refined glycerol and coconut oil-based polyester polyol. Glyc...

To attain efficient removal of hexavalent chromium (Cr6+) from aqueous solutions, a novel polyurethane foam-activated carbon (PUAC) adsorbent composite was developed. The composite material was synthesized by the binding of coconut shell-based activated carbon (AC) onto a coconut oil-based polyurethane matrix. To thoroughly characterize the physico...

Conventional lead halides perovskites have attracted much attention to become a next‐generation solar technology. Besides their low cost and excellent efficiency, high toxic nature and device instability become the major issue to limit their wide applications. Ti‐based (Cs2TiI6) double halide perovskite solar cells (PSCs) have emerged as a potentia...

Selenium is a mineral that is essential to human health and is widely recognized for its responsibilities as a powerful anticancer vitamin and antibacterial vitamin. Selenium also plays a critical part in the production of vitamin D. The purpose of this research was to evaluate the particular effects that selenium nano-particles (SeNPs') had on the...

This study propounds a sustainable alternative to petroleum-based polyurethane (PU) foams aiming to curtail this nonrenewable resource's continued and uncontrolled use. Coconut fatty acid distillate (CFAD) and crude glycerol (CG), both wastes from vegetable oil processes, were utilized for bio-based polyol production for rigid PU foam application....

Nanophotonics includes a diverse set of nontrivial physical processes, such as radiation-matter interaction, near-field optical microscopy, and the fabrication of nanophotonic materials, which extend far beyond diffraction limits. These effects have created new opportunities for a number of applications in nonlinear optics, light harvesting, media...

The unique consequence of green synthesis is that the mediator plant is able to release chemicals that are efficacious as reducing as well as stabilizing agents. In this work, the fruit pulp and leaf essences of Cassia fistula have been used to manufacture silver nanoparticles through the green synthesis technique. The sculpturing of nanoparticles...

Conventionally, designing rigid polyurethane foams (RPUFs) with improved physico-mechanical properties from new, bio-based polyols is performed by modifying foam formulations via experimentation. However, experimental endeavors are very resource-dependent, costly, cumbersome, time-intensive, waste-producing, and present higher health risks. In this...

This study reports the synthesis of ferric vanadate (FeVO4) via a facile hydrothermal method, focusing on demonstrating its exceptional electrochemical (EC) properties on detecting low-density ascorbic acid (AA). The phase purity, crystallinity, structure, morphology, and chemical compositional properties were characterized by employing X-ray diffr...

The conventional Bi 2 Te 3 thin film can be used for thermoelectric power factor. However, the poor efficiency of Bi 2 Te 3 thin film severely limits its wide range of applications. In this study, we have reported the Sr doped Bi 2 Te 3 thin film coated on a glass substrate via a simple thermal evaporation route. The synthesized thin films have bee...

The emissions of lethal organic pollutants, e.g., toxic dyes, from various industries result in the contamination of water, and hence, it is highly desirable to eradicate these pollutants. Herein, the catalytic reduction of hazardous methylene blue (MB) and rhodamine B (RhB) dyes has been evaluated (using sodium borohydride (NaBH4) as a reductant)...

This study reports light energy harvesting characteristics of bismuth ferrite (BiFeO3) and BiFO3 doped with rare-earth metals such as neodymium (Nd), praseodymium (Pr), and gadolinium (Gd) dye solutions that were prepared by using the co-precipitation method. The structural, morphological, and optical properties of synthesized materials were studie...

In this research, the frst work was carried out to manufacture MgO-based metal matrix composite containing 3 wt%. Sintering parameters, such as temperature, pressure, and time were subjected to Taguchi analysis to identify the most signifcant efect on magnesium oxide physical and mechanical characteristics. Te impact of each sintering parameter exp...

Teaching research in the Philippines is compartmentalized based on strands such as capstone and science investigatory project. Despite the difference in nomenclature, the process of teaching and even the competencies are somewhat the same. The main discrepancy of teaching research is on asking for specific construct when students do not have the su...

The use of titanium dioxide (also known as titania) in solar cells, biomaterials, and photocatalytic processes has generated an ever-increasing amount of interest. Titania is widely used in a variety of applications because it is nanocrystalline, chemically stable, has a high refractive index, is mechanically hard, and transmits visible light well....

Coconut oil (CO) has become one of the most important renewable raw materials for polyol synthesis due to its abundance and low price. However, the saturated chemical structure of CO limits its capability for functionalization. In this study, a novel reaction mechanism via the sequential glycerolysis and amidation of CO triglycerides produced an am...

Carbon nanotubes (CNTs) and graphene, in particular, have been the subject of many recent studies since their discovery in the early 2000s. Because of their unusual properties, carbon nanotubes (CNTs) have piqued the interest of scientists across a wide range of disciplines. An Al matrix was reinforced with powder metallurgy-fabricated B4C and CNT...

PCM (phase-change memory) is a memory innovation that has gained prominence as a capacity-class memory for computer systems. It is made up of a tiny functional amount of phase-change material that is located in the middle of two electrodes. In PCM, data is kept by utilizing the difference in electrical resistance between a crystalline phase, which...

For the safe and economical construction of embankment dams, the mechanical behaviour of the rockfill materials used in the dam's shell must be analyzed. The characterization of rockfill materials with specified shear strength is difficult and expensive due to the presence of particles greater than 500 mm in diameter. This work investigates the fea...

The utilization of vegetable oil in producing bio-based polyol, as an alternative replacement to petroleum-based polyol in making polyurethane (PU) foam has gained a lot of interest due to its finite supply and low production cost. In this study, bio-based polyol using coconut oil as raw material produced PU foam as thermal insulation material. The...

Silver nanoparticles were synthesized using locally purchased honey and silver nitrate solution. This method provides a simplistic and straightforward approach to the formation of silver nanoparticles. The silver nanoparticles with varying amounts of silver nitrate solution were characterized using ultraviolet-visible spectroscopy and Fourier trans...

Silver nanoparticles have been well known to possess efficient antibacterial properties. Many studies conducted on silver nanoparticles synthesized in different routes, from physical methods to chemical techniques to biological synthesis. In this study, the biological route was utilized using Psidium guajava leaves extract mixed with silver nitrate...

Innovative technologies enable businesses to stay competitive in the marketplace while also increasing profits in the manufacturing of nanocomposites for water treatment. The aforementioned driving factors resulted in the adoption of a number of innovative technologies, and no other trend has had a greater impact in recent years than Industry 4.0....

The composite was made using the stir cast manufacturing method. Many parameters, like stirring speed, stirring time, ZrO2% reinforcement, and cast temperature, are evaluated in a Taguchi experimental design to see how they affected the composite properties. In terms of composite properties, ZrO2% reinforcement and the stir speed have the most sign...

The exceptional and specific reactivity of mercury ions (Hg²⁺) toward plasmonic silver nanoparticles (AgNPs) in aqueous media has motivated the need to develop innovative, low-cost, portable, and robust sensors to help address the detrimental effects of heavy metal contamination particularly in rural communities. In this paper, we present the plasm...

The optoelectronic properties of the ternary Cd0.25Zn0.75Se alloy are reported under the influence of a high pressure ranging from 0 to 25 GPa, within a modified Becke–Jhonson potential using density functional theory. This alloy has a cubic symmetry, is mechanically stable, and its bulk modulus rises with pressure. It is observed to be a direct ba...

The microstructure and mechanical properties of an MMC based on AA 7075 and strengthened through silicon carbide (SiC) as well as boron carbide (B4C) elements were studied. The (SiC + B4C) combination was used in various weight percentages of 4, 8, 12, and 16% to create the hybrid composites utilizing the traditional stir casting procedure. XRD and...

Organic dyes used in the food and textile industries are the primary sources of environmental contamination due to their high toxicity and nonbiodegradability. This paper describes the synthesis of cellulose nanocrystals/zinc oxide (CNC/ZnO) nanocomposite via the sol-gel method. Various characterization techniques such as FTIR spectroscopy, UV-Vis...

Industry 4.0, with the widespread use of IoT, is a significant opportunity to improve the reliability of industrial equipment through problem detection. It is difficult to utilize a unified model to depict the working condition of devices in real-world industrial scenarios because of the complex and dynamic relationship between devices. The scope o...

The synthesis and design of non-precious and efficient sonophotocatalyts by an environment friendly technique are requisites for solar energy conversion and environmental remediation. This work reports the preparation of Ag/ZnO microspheres with different Ag contents through deposition-precipitation method for pollutant degradation and CO 2 convers...

The need to monitor the presence of cyanide (CN−) in water is necessary to minimize the risks to aquatic ecosystems and human health. In this paper, a paper-based analytical device (PAD) was fabricated by immobilizing silver nanoparticles (AgNPs) on filter paper (FP) for the semi-quantitative colorimetric detection of CN− in water. The average diam...

Water contamination is a significant issue in the modern day, caused by the textile dying business, and it has a detrimental impact on living organisms. We report on the manufacture of gold-doped ZnO nanospheres using a simple heat treatment approach and the use of ZnO nanoparticles as photocatalysts for the degradation of methyl orange dye. To inc...

In today’s world of electronics, nanomaterial applications pose a challenge. The spin coating approach was used to create nanostructured ZnO with wurtzite structure in a recent study. Antimony doping, aluminum, and antimony codoping with 2.0 percent were used to make these films. The impact of doped and codoped films on structural, optical properti...

Rockburst phenomenon is the primary cause of many fatalities and accidents during deep underground projects constructions. As a result, its prediction at the early design stages plays a significant role in improving safety. The article describes a newly developed model to predict rockburst intensity grade using Adaptive Boosting (AdaBoost) classifi...

High-performance plastics or engineering polymers have been actively studied for various microelectronic applications as the demand for faster processing speeds increases. Taking advantage of its high Young’s modulus ideal for inter-layer dielectric applications, polyurethane (PU), a class of linearly-segmented polymer primarily made by reacting is...

Protein is the material foundation of living things, and it directly takes part in and runs the process of living things itself. Predicting protein complexes helps us understand the structure and function of complexes, and it is an important foundation for studying how cells work. Genome-wide protein interaction (PPI) data is growing as high-throug...

In researching social network data and depression, it is often necessary to manually label depressed and non-depressed users, which is time-consuming and labor-intensive. The aim of this study is that it explores the relationship between social network data and depression. It can also contribute to detecting and identifying depression. Through coll...

Biosensors are a group of measurement systems and their design is based on the selective identification of analyses based on biological components and physical and chemical detectors. Biosensors consist of three components: biological element, detector, and converter. The design of biosensors in various fields of biological sciences, medicine has e...