Science & Technology Asia

The Analysis of Safety Behavior in Construction Project

Feri Harianto, Moh Arif Rohman, I Putu Artama Wiguna, Erma Suryani — Wed, 25 Sep 2024 00:00:00 +0700

The purpose of this study was to determine the effect of using videos and safety games packaged on mobile phones on work safety behavior. The quasi-experimental research method uses learning media through videos, safety games, and work experience. The dependent variable is work safety behavior, while age and education are covariates. Sampling as respondents using purposive sampling with a sample size of 60. This analysis uses ANOVA. The result of this research is that the learning media in the form of video significantly affects the perception of work safety (sig. < 0.05). Video is the best learning media between the combination of safety game and video-safetygame in providing a perception of safety behavior with a mean = 3.494. The results of this study contribute to implementing safety training in the field. Video is a learning media that increases knowledge about work safety to reduce the incidence of work injuries.

Capacity of Decomposed Methylene Blue and Anticancer Effects of Silver Nanoparticles Using Perilla Leaf Extract

Hiep Hoang Phu, Hieu Doan Duc, Nguyet Chu Anh, Hue Do — Wed, 25 Sep 2024 00:00:00 +0700

Silver nanoparticles (AgNPs) are one of the materials with a lot of potential because of their diverse applications. AgNPs are synthesized in a variety of ways; however, with the direction of anticancer applications and decomposition of organic dyes in dyeing wastewater, AgNPs synthesized by the green method are preferred. In this study, AgNPs were synthesized using Perilla frutescens (L.) Britt extract called P. AgNPs. The Perilla frutescens (L.) Britt extract was utilized as both a surface stabilizer and a reducing agent. UV-Vis absorption spectra of the P.AgNPs was analyzed to determine how particle production is affected by the extract's pH. The shape, crystalline structure, size and size distribution of P.AgNPs were studied using TEM imaging, X-ray diffraction diagram (XRD) and dynamic light scattering (DLS). Surface functional groups and atomic composition of P. AgNPs are represented on Fourier Transformation InfraRed spectrum (FTIR) and Energy-dispersive X-ray spectroscopy (EDX). The obtained P.AgNPs are relatively uniform with an average diameter of 30 nm ± 5 nm and well distributed in the solution. P.AgNPs were deposited on activated carbon (P.AgNP-AC). P. AgNPs- AC was used to decompose methylene blue (MB) dye in the presence of H₂O₂, achieving a decomposition efficiency of up to 98. 4%. The extract or P. AgNPs exhibited potential antiproliferative activity against MDA-MB-231, HT29, and K562 cells. Interestingly, the anticancer effect of P. AgNPs was up to 2.0 times stronger than that of the leaf extract.

Comparative Analysis of α-Amylase Sequences in Selected Aspergillus Species and Analysis of Amylase Activity in Three Locally Isolated Aspergillus Species

Wed, 25 Sep 2024 00:00:00 +0700

Amylase is an important enzyme in industries where members of the Aspergillus genus are significant producers of industrial amylase enzymes; α- amylase is an endoamylase which plays a crucial role in starch hydrolysis. However, knowledge regarding the sequences and evolutionary relationship of α- amylase among sections Nigri, Flavi and Fumigati in the Aspergillus genus have remained unknown. The amylase activity of some previously isolated important Aspergillus species, namely A. niger, A. fumigatus and A. flavus, also requires further investigation. In this study, α- amylase sequences of species under three sections in the Aspergillus genus were retrieved from NCBI for sequence analysis and alignment for phylogenetic tree construction. The solid-based method was then applied to screen for amylase production and the Enzymatic Activity Index (EAI) was evaluated to analyze amylase activity. Similarities in enzyme sequences among the selected species were established through the presence of α- amylase domains and phylogenetic tree branching that rooted to a common ancestor. This study also found that the amylase activity of three selected species differed significantly, with A. flavus having the highest EAI of 1.03 ± 0.049, followed by A. niger (0.77 ± 0.049) and A. fumigatus (0.60 ± 0.103).

Development of a Simple Tool to Enhance Driver Identification in Motorcycle Accidents, Covering both Collision and Non-collision Subtypes

Wed, 25 Sep 2024 00:00:00 +0700

In Lampang province, Thailand, motorcycle-related road traffic collisions are common, and the differentiation between drivers and passengers is crucial for legal proceedings. This study aimed to develop and validate two multivariable predictive models that differentiate between motorcycle drivers and passengers based on demographics and fracture patterns. Retrospective data from patients involved in motorcycle accidents from January 2014 to December 2017 at Lampang Hospital were used to construct models. Model 1 focused on motorcycle collisions with other vehicles, while Model 2 focused on non-collision motorcycle accidents. Predictor selection was done through multivariable logistic regression using a stepwise backward elimination method. A total of 1,816 patients with fractures from motorcycle accidents were included, with 1,583 categorized as drivers and 233 as passengers. The final model identified six significant predictors: age categories, gender, pelvis and lumbar spine fractures, wrist and hand level fractures, femur fractures, and lower leg fractures. Both models demonstrated acceptable discriminative abilities, indicating their potential as userfriendly tools for medical and legal adjudication following motorcycle accidents.

Computational Screening of Rheum palmatum Phytochemicals as Potential Anti-Diabetes Agent via Sodium-Glucose Transport Protein 2 Inhibition

Wed, 25 Sep 2024 00:00:00 +0700

Diabetes mellitus is a debilitating condition that affects people all over the world. Diabetes mellitus can be brought on by a number of different factors, the most common of which include being overweight and leading an unhealthy lifestyle. There have been a number of attempts made to cure diabetes, however these therapies are not precise and can cause adverse reactions. The quest for novel pharmaceuticals derived from plants with therapeutic properties is something that really has to be done in order to cut down on the use of synthetic drugs and the negative consequences that come along with them. In light of this, the purpose of this research was to investigate the potential of the bioactive molecules of Rheum palmatum to serve as an anti-diabetic therapeutic candidate by inhibiting Sodium Glucose Transport Protein 2. Computational prediction consisting of protein and ligand optimization, molecular docking, and visualization was applied in this study. The generation of therapeutic candidates from the bioactive chemicals in R. palmatum showed promise based on computational analysis. In comparison to the control medication, the physcion8-glucoside, laccaic acid, chrysophanol, rhein, and aloe emodin showed reduced binding affinity scores. When compared to the standard anti-diabetic medicine, the binding location and other physicochemical parameters following molecular docking produced excellent and competitive results.

In Silico Identification of Bajakah Root (Spatholobus littoralis Hassk) Alkaloid Compounds to Stimulate Lipolysis Through Inhibition of Phosphodiesterase-4

Khoirul Rista Abidin, Ariffialdi Nurhidayatulloh, Nurmah — Wed, 25 Sep 2024 00:00:00 +0700

Modulating the nucleotide cycle signaling of phosphodiesterases (PDEs) can facilitate thermogenesis. When it comes to obesity therapy, utilizing herbs as part of non-pharmacological treatment methods is highly recommended due to the lower risks involved compared to pharmacological methods. Bajakah root, a typical plant found in West Kalimantan, also known by its Latin name, Spatholobus littoralis Hassk (S. littoralis Hassk), is currently being extensively researched. Isorhynchophylline and rhynchophylline are common alkaloids found in S. littoralis Hassk. The objective of this study was to explore the potential of these two alkaloids through an in silico approach. Chem3D Pro software was used to prepare ligands with energy conformations for accurate docking results via AutoDock Vina software. The visualization was carried out in Biovia Discovery Studio. The lowest binding energy values were obtained for the PDE4C isoform, with values of -9.14, -7.61, and -5.61 kcal/mol, respectively. The interaction between isorhynchophylline and PDE4C had the lowest binding energy. In silico studies suggest that two alkaloid components, isorhynchophylline and rhynchophylline, found in S. littoralis Hassk have the potential to increase lipolysis activity.

Antibiofilm Activities of Quercetin on ESKAPE Pathogens: An in-silico Analysis

Rina Rani Ray — Wed, 25 Sep 2024 00:00:00 +0700

The treatment of ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) is difficult due to their antibiotic resistance, which is mostly attributed to the biofilm matrices produced by these bacteria. These biofilms are notoriously difficult to counter though some natural compounds show promise. Quercetin, a plant-derived flavanol is found to have antibiofilm activities against these ESKAPE pathogens. In this study, molecular docking experiments demonstrated a strong affinity between quercetin and biofilm forming proteins of ESKAPE pathogens, namely 3TIP, 3ZYB, 5KED, 5FCE, 5D6H and 6YF6, which indicates that quercetin could be effective for eradicating ESKAPE pathogens. Optimization of parameters for best molecular interaction was studied using Box Behnken Response Surface Methodology.

Discovery of COVID-19 Protein Inhibitors in Phenolic Acids of Azadirachta indica (Neem) using Docking and Pharmacokinetics

Miah Roney, AKM Moyeenul Huq, Mohd Fadhlizil Fasihi Mohd Aluwi — Wed, 25 Sep 2024 00:00:00 +0700

COVID-19, a viral infection caused by the coronavirus SARS-CoV-2, is one of the world's most challenging diseases to cure. The fact that COVID-19 does not currently have any pharmaceutical treatments means that a concentrated effort must be made to discover the muchneeded remedies for this illness. The most attractive antiviral targets of SARS-CoV-2 are the spike protein and main protease (M^pro). In this work, sixteen phenolic acids of Azadirachta indica were docked into the active site of the spike protein and M^pro. The resulting compounds were then subjected to pharmacokinetic studies to establish the lead compounds. Based on the results, ferulic acid was found to be a promising candidate for further research into its potential as a SARS-CoV-2 inhibitor due to its positive anticipated pharmacokinetics and pharmacological properties.

The Immediate Effects of Conventional and High-Power Pain Threshold Ultrasound on Myofascial Pain Syndrome among Young Thai Adults

Sukwida Manorangsan — Wed, 25 Sep 2024 00:00:00 +0700

The study aimed to compare the immediate effects of conventional ultrasound (Con-US) and high-power pain threshold ultrasound (HPPT-US) on pain and neck range of motion (ROM) in young Thai adults with active trigger points of myofascial pain syndrome (MPS). Sixty participants were randomly allocated into two groups: Con-US (mean age 20.97±1.16 years) and HPPT-US (mean age 21.47±1.28 years). Each group underwent a single ultrasound session lasting 5 minutes. Parameters assessed pre- and post-treatment included pain intensity, neck ROM, pressure pain threshold (PPT), and pressure pain tolerance (PPTo). The average intensity dose for Con-US was 1.0 W/cm², while for HPPT-US it was 0.83 W/cm². Both techniques improved pain parameters, but there was no significant interactive effect between group and time. The single moderate-intensity session of HPPT-US may not have a lasting impact on pain tolerance due to the lack of a cumulative effect. Further studies with increased treatment sessions and higher intensity ultrasound are recommended.

Green Synthesis of Silver Nanoparticles using Ulva intestinalis with Cytotoxic and Antioxidant Activity

Irwan Irwan, Ilham Zulfahmi, Nursafiah, Ruslaini, Eli Nurliza — Wed, 25 Sep 2024 00:00:00 +0700

The cost-effective and biosafe synthesis of ”green” nanoparticles is becoming increasingly popular. Therefore, this study aimed to explore the potential of green algae (Ulva intestinalis) extract as a reducing and stabilizing agent for producing silver nanoparticles (AgNPs). U. intestinalis contains numerous secondary metabolites that play a crucial role in the formation of AgNPs. Characterization was confirmed using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and a particle size analyzer (PSA). The cytotoxic and antioxidant effects of the product were determined using the Brine Shrimp Lethality Test (BSLT) and 1,1-diphenyl-2 picrylhydrazyl (DPPH) assay. The results showed that the AgNPs had a spherical shape, with size variations of 4040 nm (19%), 771 nm (78.6%), and 97.3 nm (2.4%). The obtained AgNPs were found to have higher cytotoxic and antioxidant activity than the U. intestinalis extracts with an LC50 value of 128.2 𝜇g/mL (toxic category) and IC50 = 100.4 𝜇g/mL (strong category). This study proved that the AgNPs produced herein have the potential to be used for anticancer and antioxidant purposes.

Generalized Penon Involutive Weak Globular Higher Categories

Paratat Bejrakarbum, Paolo Bertozzini — Wed, 25 Sep 2024 00:00:00 +0700

This research examines a generalization of the concept of an involutive weak globular 𝜔-category through Penon’s approach. We first introduce the notion of a globular cone, then equip it with compositions, identities, and self-duality. Next, a free reflexive self-dual globular-cone 𝜔-magma and a free strict involutive globular-cone 𝜔-category along with a specified contraction over a given globular cone are established. An algebra for the monad induced by the free-forgetful adjunction arising from the previously constructed structure naturally defines an involutive weak globular-cone 𝜔-category. We finally provide crucial examples of involutive weak globular-cone 𝜔-categories.

Comparison of Biosorbent and Biochar Derived from Banana Pseudo Stem Waste for Crystal Violet Removal from Synthetic Wastewater

Wed, 25 Sep 2024 00:00:00 +0700

Crystal violet (CV), a toxic carcinogenic dye commonly used for dyeing and colouring, is difficult to remove from effluents due to its complex structure. Currently, adsorption utilizing green adsorbent derived from abundant, low-cost agricultural wastes is an efficient and simpler technique than other dye removal methods. This study aims to evaluate the potential of banana pseudo stem (BPS) as biochar and biosorbent feedstock for CV dye removal. Batch experiments were conducted to investigate the effect of various adsorption parameters with one factor at a time (OFAT) analysis. The adsorbent characterization with the FTIR identified the presence of carboxylic, hydroxyl and amine groups, while SEM images showed rough, irregular pore structures, which resulted in dye molecules’ strong adsorption onto the adsorbent surface. Using BPS biosorbent and BPS biochar, the highest CV removal of 91.9% and 93.7% was achieved at the same optimum adsorption conditions; pH 3, 2 g/L adsorbent dosage and 60 mg/L initial concentration. The adsorption on BPS biochar reached an earlier equilibrium time (90 min) as compared to the BPS biosorbent (110 min). The calculated maximum adsorption capacity, q𝑚, using the Langmuir model is 59.52 mg/g and 71.94 mg/g for BPS biosorbent and BPS biochar, respectively. Isotherm adsorption data for both adsorbents were better fitted to the Freundlich model. Therefore, the prepared BPS biochar has great potential as a promising adsorbent for removing CV dye from an aqueous solution.

Dynamic Network for Air Freight Forwarder’s Stochastic Capacity Management

Kannapha Amaruchkul — Wed, 25 Sep 2024 00:00:00 +0700

A freight forwarder, a key player in the air cargo service chain, collects individual packages from shippers and transports consolidated shipments to air carriers, some of which have long-term block space agreements with the forwarder. If, on any day, the total demand from the consolidated shipment exceeds the allotment specified in the block space agreement, the forwarder may need to purchase additional space in the spot market, where the freight rate is often higher. Alternatively, the forwarder may opt to delay some shipments, storing them overnight at a warehouse and incurring inventory holding costs. On the other hand, if the total demand is less than the allotment, the forwarder is required to pay at least the minimum charge. For each destination and each day of the week, demand exhibits significant week-to-week variation, while the capacity supply on each day of the week remains fixed over the contract duration. In the long-term problem, the forwarder must decide on the allotment before knowing the random daily demand. In the short-term problem, it determines how to allocate the realized demand to multiple carriers with different freight rates. The problem is formulated as a two-stage stochastic program, embedding the multi-day network of time-varying demand. The proposed solution is compared to the current approach in a case study, utilizing historical demand data from one of Thailand’s largest forwarders. Based on the top four destinations from April 2020 to July 2021, our proposed solution yields significant cost savings.

Ground Water Quality Assessment with Reference of TDS and EC

Vinod Kumar Kushwah, Kunwar Raghvendra Singh — Wed, 25 Sep 2024 00:00:00 +0700

Groundwater is one of the natural water resources for domestic activities like bathing, washing, drinking, etc. , and agriculture purposes. Due to rapid growth in population, industrialization, urbanization intensive agriculture practices and over exploitation, the quality and quantity of groundwater are deteriorating. The objective of this investigation was to analyze the electrical conductivity (EC) and total dissolved solids (TDS) as water quality parameters. Twenty sampling sites of groundwater of Mathura district were gathered from various sources, including hand pumps and tube wells. According to this study, 40 percent of the samples were found within the acceptable limit for drinking, which is 500– 1000 mg/ L as defined by World Health Organization (WHO, 2017) and Bureau of Indian Standards (BIS, 2012), while sixty percent were above the allowable limit. Therefore, most samples of the groundwater in Mathura, Uttar Pradesh, do not meet the drinking water standards. These results indicate that the quality of water is not suitable for potable and irrigation purposes. Exceeding the suggested TDS thresholds in water can elevate the consumption of detrimental minerals such as lead, arsenic, and fluoride, as well as salts, which can lead to long- term gastrointestinal and cardiovascular problems after prolonged consumption. This research investigation provides insight into the pristine state of ground water quality in the study area and is hence relevant for water quality assessments in various domestic regions.

Design of Multiband Patch Antenna for WLAN Applications

Ritisha V. Bhatt, G.D. Makwana — Wed, 25 Sep 2024 00:00:00 +0700

This article proposes a compact slot-loaded multiband rectangular-shaped microstrip patch antenna. The proposed antenna of overall dimensions 30 × 30 × 1.56 mm3 radiates at 3.3 GHz, 5.8 GHz, 7.2 GHz, and 9.01 GHz to accommodate WiMAX and WLAN wireless applications. The antenna is mounted on Rogers AD255C substrate with the relative permittivity E𝑟=2.5 and loss tangent tan𝛿 < 0.002. The simulation results of return loss, gain, and bandwidth are examined for the proposed antenna. The proposed simple and low profile antenna offers simulated return loss of -19.40 dB, -12.76 dB, -27.57 dB, -31.62 dB, VSWR of 1.7, 1.2, 1.1, 1.4, and Gain of 5.25 dBi, 7.17 dBi, 5.09 dBi 6.06 dBi at resonant frequencies.

Rainfall Data Assessment from X-Band Polarimetric Radar for Small Drainage Area

Wed, 25 Sep 2024 00:00:00 +0700

For disaster monitoring and mitigation, an X-Band polarimetric radar can provide one or two minutes of rainfall data in small areas. However, this weather radar is not available in tropical nations such as Malaysia, which has suffered from flash floods and flooding, particularly during the monsoon season. As a result, this study evaluates rainfall estimation strategies for small drainage regions as part of a proposal for a new framework of rainfall estimation in Malaysia that employs X-Band polarimetric radar. It begins with raw data conversion, then clips the DEM, selects the drainage area in Kagoshima, and finally plots the hyetograph for rainfall events. The extraction of X-Band polarimetric rainfall data from AMeDAS ground data was investigated. The statistical validation results reveal a relatively positive association between X-Band polarimetry and AMeDAS, with an R2 value of around 24% for model fit. Furthermore, using QGIS to compare rainfall distribution results for both data sets reveals that AMeDAS data does not accurately reflect actual rainfall monitored by XBand polarimetric radar because there are no AMeDAS stations in the drainage area, and the X-Band polarimetric radar distribution image is also real-time. All drainages were classified as heavy rain in the upper stream, indicating the precise location of the highest intensity and the possibility that the area closest to the drainage would experience a disaster such as a flood. This paper concludes with suggestions for future works.

Preparation of Navigation Plan for Scenic Routes Between Airports at Bangkok(VTBD) and U-Tapao (VTBU) and Validation using Flight Simulator

Mari Prabu Govindan — Wed, 25 Sep 2024 00:00:00 +0700

A navigation plan is an integral part of the airline dispatch operations which helps and guides the pilot by providing all of the information needed for the safe flight to reach a destination. It must be framed with the utmost focus to provide the most accurate data and information so that the pilot can follow the scheduled time. There are n- number of possible routes to reach a destination with a flight. In this research, a flight plan for finding the most scenic route between Don Mueang International airport(VTBD) and U Tapao International airport(VTBU) is done along with the simulation of the route with the help of a flight simulator. Here visual flight rules are used to make flight plans for a Cessna 172R aircraft and the navigation plan is completely simulated with redbird 2 flight simulator.

Real-Time Classification Improvement of Indonesian Sign System Letters (SIBI) Using K-Nearest Neighbor Algorithm

Wed, 25 Sep 2024 00:00:00 +0700

Indonesian Sign Language (SIBI) is a vital means of communication for individuals with hearing impairments. The automatic translation from spoken language to SIBI presents challenges in accurately predicting sign characters. The information transfer process becomes biased when system predictions are incorrect. The current approach lacks accuracy due to data variations that may lead to character similarities. This research addresses this issue with an improved method incorporating linguistic features and contextual information. A novel approach is introduced to enhance SIBI character predictions using the K-Nearest Neighbor (K-NN) algorithm. The K-NN algorithm is employed to predict the most suitable SIBI character based on the similarity of linguistic features between input speech and existing data. This research compares distance metrics such as Euclidean, Manhattan, and Chebyshev to determine the optimal number of nearest neighbors (K) for achieving the most accurate outcomes. Experimental results employing 200 data points per label yielded satisfactory average predictions for each label. The experiments underscore the effectiveness of the K-NN model utilizing the Chebyshev distance metric with K=7 on the 200 data labels, as it provided excellent probability results for each label.

Detecting and Mitigating Flaming in Online Platforms Against Women: A Step Towards Women Empowerment

Vanathi Selvaraj, Senthil Kumar S. — Wed, 25 Sep 2024 00:00:00 +0700

The rise of information and communication technologies and social media platforms has provided unprecedented opportunities for women to thrive as entrepreneurs and participate in the public sphere. However, this has also led to increasing online abuse and harassment against women. A study was conducted to examine the psychological health status of the female population affected by online flaming behavior. A quantitative analysis was conducted on 202 female respondents in Chennai, focusing on their perceptions and experiences as victims or non-victims of this online flaming. The study found that technology adoption, such as machine learning, can help identify perpetrators, identify solutions, and formulate prevention measures to safeguard and enhance women’s status in society. The study suggests that digital social media platforms contribute to recovery from abuses through early detection and can mitigate campaigns to end online violence against women. The study aids policymakers in creating appropriate policies and regulations to address cyber abuse against women.

Molecular Interactions of Polyphenolic Compounds Binding on Antiapoptotic Wild-Type and Mutated Bcl-2 Proteins

Wed, 25 Sep 2024 00:00:00 +0700

The molecular docking approach was used to determine the binding affinities and the interactions of B-cell lymphoma 2 (Bcl-2) both of wild-type and mutated Bcl-2 (Gly101Val) in complex with five polyphenolic compounds which were reported to have biological activity
in cancer therapy: Hesperetin, Quercetin, Cleomiscosin B, 5'-Methoxy-7'-epi-jatrorin A, and Procyanidin B2. The compounds were found to act as BH3-mimetics. They bind into the hydrophobic groove of BH3 motifs. Procyanidin B2 exhibited favorable binding free energies for both wild-type and mutated Bcl-2 (-8.30 to -8.80 kcal/mol). Molecular dynamics simulations and conformational analysis investigated the dynamics of Procyanidin B2 when bound to Bcl-2 in solution. Procyanidin B2 tightly binds to the hydrophobic groove of wildtype Bcl-2 (-24.79 kcal/mol) compared to the mutated species (-17.15 kcal/mol). Mutated residue in BH3 motifs induced structural changes, widening the hydrophobic cavity. This change potentially allows interference by surrounding water molecules, thereby weakening the protein-ligand interaction.

Wear Behavior Optimization of E-Glass Reinforced Polymer Matrix Composites for Automotive Applications

Wed, 25 Sep 2024 00:00:00 +0700

The proposed study focuses on developing multiphase hybrid composites comprising Epoxy matrix and E-Glass fibers, and investigating their wear behavior under varying process conditions. The research employs the Taguchi method to optimize parameters (load, speed, sliding distance) that affect wear. Experimental tests on a specialized rig simulate wear under different conditions, and analysis tools like orthogonal arrays and analysis of variance are used to determine optimal input levels and their impact. Observed findings show that load, speed, and sliding distance significantly affect wear rate and optimal settings (20 N load, 400 rpm speed, 100 m sliding distance) minimize wear rate. For instance, at 10 N load, 200 rpm speed, and 50 m sliding distance, initial wear is 201.12 microns, projected wear rate after Taguchi optimization is about 206.9 microns. Confirmation test measures around 211.52 microns. The study highlights Taguchi’s efficiency in optimizing process parameters, aiding design for hybrid composites. This approach enhances production processes, meeting industry demand for such materials also findings offer insights into settings to achieve optimal wear rate, enhancing hybrid composite performance and manufacturing sector’s ability to meet material demands.

Experimental Study on Two-Phase Flow Pattern of Air-Mixture of Distilled Water and 2% Butanol in Horizontal Mini Channel

Eli Kumolosari, Sudarja, Indarto, Deendarlianto, Hermawan — Wed, 25 Sep 2024 00:00:00 +0700

Two-phase flow occurs in many modern mini-sized objects. The two-phase flow pattern plays a crucial role in establishing the convection coefficient (h) for both heat transfer and pressure drop (△P). The current research examined the two-phase flow pattern in a transparent mini channel with an internal diameter of 1.6 mm. The orientation of the channel was horizontal. The fluids used were air-mixture of distilled water and 2% butanol with the liquid surface tension value of 46.03 mN/m. Superficial velocities of liquid and gas were varied in the range of 0.033 - 4.935 m/s and 0.066 - 66 m/s, respectively. The flow patterns observed were churn, annular, plug-annular, bubbly, and plug. The research also generated a flow pattern map. This map then was compared to those from certain preceding researchers. The findings indicated that the flow pattern map generated in this investigation was only consistent with the one established by Triplett et al. [1] with the exception of the transition boundary from plug flow and bubbly flow to churn flow. The dissimilarity was predicted due to the distinct surface tension of liquid employed. These findings contributed to discover the flow pattern characteristics which are applicable to the cooling performance of microelectronic cooling system, the efficiency of chemical reaction, etc.

Effect of Radish (Raphanus Sativus L.) Height on Natural Drying Characteristics and Mathematical Modeling

Wed, 25 Sep 2024 00:00:00 +0700

The fresh vegetable radish (Raphanus sativus L.) is perishable due to its high water content of about 87%, and radishes spoil quickly. This study aimed to study the impact of variations in radish weight on drying time, ascertain the characteristics of radish drying with natural drying, and determine the mathematical model of radish drying. The measurements of the drying samples determined in this study for the radishes are a length of 4 cm, a width of 2 cm, and height of 0.5 cm, 1.0 cm, and 1.5 cm, which will be dried under sunlight or not exposed to sunlight. The results showed that the radish height of 0.5 cm responds to the decrease in mass during outdoor drying. The explanation of the radish drying process is arrived at by matching the research data of three model equations, namely the Newton, Page, and Henderson-Pabis models. Furthermore, the suitability was determined by the coefficient of determination (𝑅2). The Page model was the most suitable drying model to explain radish drying. The changes in the characteristics of the radish before and after the drying process were detected using a scanning electron microscope.

Impact of Power-On Duration on Chloride Migration in Reinforced Reactive Powder Concrete with Recycled Aggregates, Fly Ash and Silica Fume

Naphol Yoobanpot, Pannaphat Hengterm, Natt Makul Makul, Gritsada Sua-Iam — Wed, 25 Sep 2024 00:00:00 +0700

This study aimed to examine the chloride migration characteristics of Reinforced Reactive Powder Concrete (RRPC) that is not in a steady state. The RRPC was formulated using pozzolans and recycled concrete aggregate (RCA). The study was mostly looking at how the chloride migration coefficient changed when two important things happened: how long the power was on and how much RCA was in the RRPC mixtures. Six separate categories of RRPC mixtures were formulated, each containing different ratios of silica fume (SF) and fly ash (FA), as well as varying amounts of RCA substituting for the traditional coarse aggregate. The results of this study uncovered a significant trend in the chloride migration coefficient as the duration of power on increased from 12 to 36 h. The coefficient first showed an upward trend, then a downward trend. This trend indicates the existence of a curative and sealing mechanism within the concrete structure, which gradually improves its ability to resist the penetration of chloride over time. Adding RCA to reinforced reactive powder concrete (RRPC) mixtures also slowed down the movement of chloride, and the effect became more obvious as the RCA content increased. It also found that the effect of RCA content on chloride resistance was more noticeable during shorter durations but became less significant as the duration increased.

Modeling the Rice Self-Sufficiency in the Philippines

Benjamin D. Rubin, Francis Mayo, Renan S. Maglasang — Wed, 25 Sep 2024 00:00:00 +0700

We study the interactions between the production and consumption of rice along with the several factors which involve a number of changes to the production and consumption through system dynamics modeling. We focus on three scenarios on the system dynamics model, which entails the possible effect on rice self-sufficiency and import dependency ratio by simulating the realistic values on rice production and rice consumption based on the PSA data. Historical data from 1995 was utilized and analyzed to build the model to have meaningful information regarding how the system behaves with the various factors in the system. After the model has been validated, several scenarios are simulated and their impact analyzed on the different sustainability dimensions, specifically the Philippines' Agricultural Indicator System. Results showed that production and consumption interventions are crucial to improving the Philippines' self-sufficiency and import-dependency ratio. Keywords: Rice; Self Sufficiency; System dynamics modelling