Results Of Measurements Research Articles

ABOUT ONE METHOD OF STUDYING THE COEFFICIENT OF THERMAL EXPANSION OF POLYMERS

The problem of studying the deformation response of film samples made of UV-curable polymers to temperature changes is considered. It is difficult to obtain massive samples of these polymers due to the peculiarities of their polymerization. This paper suggests a methodology for tests that allows us to determine the temperature dependence of the coefficient of linear thermal expansion (CTE) in a wide range, including the relaxation transition. As measuring equipment was used a dynamic mechanical analyzer TA Instruments Q800 DMA with liquid nitrogen cooling system GCA, which allows varying temperature and its rate of change in wide ranges, controlling and measuring forces and displacements with high accuracy. The proposed approaches are applicable to any film samples and provide an opportunity to establish functional dependences of CTE not only on temperature, but also on its rate of change. At the same time, in contrast to traditional methods, the described procedures allow obtaining correct data under the conditions of relaxation transitions taking into account the influence of the temperature change rate on these processes. Considerable attention is paid to calibrate the measuring equipment, in particular, the measurement and compensation of the temperature deformation of the tooling. The measurements results are compared with known literature sources, manufacturers data, the results of measurements of samples with known characteristics and with the results obtained on a horizontal dilatometer. It is shown that the proposed method of measurements is correct and has a number of advantages over traditional methods of research when working with film samples or in cases where it is necessary to take the effect of the rate of temperature change on CTE into account.

Statistical Methods in the Analysis of the Effect of Carbonisate on the Hardness of Epoxy-Resin-Based Composites

This research concerns the manufacture and characterisation of epoxy composites with the addition of carbonisate, obtained by the pyrolysis of MDF (medium-density fibreboard) furniture board waste. The laminated composites were made by hand lamination, with the carbonisate used as a filler to improve the mechanical properties of the composite. The carbonisate was obtained by the thermal decomposition of MDF waste in an anaerobic environment by pyrolysis, which is an efficient method of waste management and material recycling. The resulting carbonisate was integrated into an epoxy resin matrix to investigate its potential as a reinforcing agent. The article describes a study on the hardness of epoxy-resin-based composites to which carbonisate was added in different fractions and percentages. The aim of the research was to test the possibility of using char as a component in improving the mechanical properties of epoxy composites with a view towards creating a durable recycled material with optimal parameters. As part of the study, a statistical analysis of the results of hardness measurements was carried out to accurately assess the effect of the quantity and size of the carbonate particles on the mechanical properties of the materials. The analysis identified significant differences between samples and verified the repeatability of the results. It was found that the addition of carbonisate to the A0 base sample (without the addition of carbonisate) leads to a significant hardening of the material. This was confirmed by the higher medians of samples A01 (carbonisate 5% with a 0.5 mm fraction), A02 (carbonisate 7.5% with a 0.5 mm fraction), and A03 (carbonisate 5% with a 1.0 mm fraction) compared to the base sample. The most homogeneous hardness was shown in sample A02, with the highest concentration of results and the lowest values of standard deviation and spread. The results indicated that the addition of carbonate significantly increased the hardness of the composite materials, with optimal stability achieved at 7.5% (by weight) of carbonate with a 0.5 mm fraction. The conducted research precisely determined the influence of the amount and characteristics of carbonisate particles on the mechanical properties of the materials, which enables the more effective designing of future composites. The statistical results provide a reliable basis for evaluating the potential applications of these materials in various industrial sectors, such as construction, automotive and aerospace, where high hardness and durability are important.

The Effect Of Co2-Brine-Rock Interaction Towards Sand Onset Modeling In Dolomite-Rich Sandstone: A Case Study In Air Benakat Formation, South Sumatera, Indonesia

Carbon Capture Utilization Storage (CCUS) into geological storage (e.g., Enhanced Oil or Gas Recovery) provides a solution to reduce CO­2 emissions. However, it still remains a potential operational problem, such as sand problem phenomena in producer wells. This study observes the phenomenon of sand problems in production wells possibly triggered by CO2-brine-rock interactions on CO2 injection in rich dolomite sandstone reservoir. This research performs several experimental works (i.e., time-lapse dry mass measurements, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and elastic wave measurements) by using CO2-brine-rock batch experimental setup as well as geochemical simulation to observe mineral dissolution, pore structures alteration as well as rock physics alteration due to CO2-brine-rock interactions. We used an outcrop sample of dolomite-rich sandstone from the Air Benakat Formation, South Sumatera, Indonesia. Our experimental and simulation works show that dolomite dissolution (dolomite reduction of ~4% after 14 soaking days), secondary porosity development (11% of visible porosity improvement), as well as rock strength reduction, occur indirectly (shown by elastic wave velocity, i.e. and reduction of ~3.8% and ~4.4%, respectively) due to CO2-brine-rock interactions. Subsequently, the results of elastic wave velocity measurements were then used to modify a considerable sand onset prediction (sand-free envelope) model. The modified model showed that the production well was more prone to sand problems due to CO2-brine-rock interactions. Thus, it is concluded that the sand onset prediction model with considering CO2-brine-rock interactions could help to design a better sand management strategy in producer wells.

Verification of uranium composite materials using active interrogation techniques for safeguards purposes

Abstract The uranium isotope characterization for nuclear safeguards and security purposes was conducted using both passive and active non-destructive techniques. The interrogated samples were natural uranium (NU), low-enriched uranium (LEU), and depleted uranium (DU) all in the form of uranium dioxide. The obtained spectra using both techniques were accumulated using a high-efficiency HPGe detector. Improving detector efficiency was developed using the neural network (NN) method based on the obtained intrinsic calibration data. The obtained enrichment results of passive measurements showed good agreement with certified samples to within 1.12% in the case of LEU, 1.03% in the case of NU, and 1.04% in the case of DU.
Active interrogation of the samples was done using the neutron spectrum of a 5 Ci 241Am-Be neutron source. Seven short-lived fission products (FPs) (101Tc, 97Nb, 105Ru, 92Y, 91Sr, 92Sr, and 88Kr) were chosen as indicators to provide a complete characterization of isotopic mass determination, uranium content, and enrichment. Isotopic masses of the samples were calculated using thermal and fast interrogations. A comparison of the obtained results of 238U mass was found to agree within 0.2% with certified value based on fast interrogation, and within 0.3% of 235U mass based on thermal interrogation.

THE EFFECT OF DIFFERENT SALINITY ON GROWTH RATE AND SURVIVAL RATE OF POST-LARVA (PL-9) VANNAME SHRIMP ( Litopenaeus vannamei )

Vannamei shrimp (Litopenaeus vannaemi) is one of the largest fisheries commodities in Indonesia. The first step in the success of vannamei shrimp cultivation is seeding. The success of the hatchery will support efforts to provide quality shrimp seed . The research method used is experimentation with descriptive quantitative data analysis. Calculation using a completely randomized design test with the help of SPSS. The results of water quality measurements showed an average temperature of 26.26oC - 28.8oC. The pH ranges between 7.32-7.68. For DO it ranges from 5.2 mg/l -6.6 mg/l. For Ammonia it ranges from 0.2 ml/lt - 0.54 ml/lt. Water quality measurements were carried out for 14 days in the morning and evening. Based on these results, it can be concluded that the growth rate, survival rate, and biomass increase value, the salinity value in treatment 1 (26 ppt) shows the highest compared to the salinity values in the other treatments. Meanwhile, the value of water quality measurements based on SNI 8678-4:2021 shows that the temperature is still below standard, the pH scale is still atstandard, the DO value is still at standard value, and the value for ammonia exceeds standard limits .

Methane emissions at pressure-regulating stations in China: A comparative analysis of various quantitative methods.

As a key component of the distribution system, metering and pressure-regulating (M&R) stations provide an opportunity for effective mitigation of methane emissions. Given that these stations are readily accessible, above-ground facilities, routine methane emission monitoring can identify issues and with repair or upgrades this can lead to reduced methane emissions. This practice has become an important measure for addressing climate change. China aims to actively promote the monitoring, evaluation, and inventory improvement of distribution systems. In this study, methane detection and analysis were conducted at 11 pressure regulation-metering stations operated by a company in North China and Central China. Methane emissions were estimated using the dynamic flux chamber method, the inverse Gaussian plume modeling method (OTM33A), and the stochastic Lagrangian (LS) inverse modeling method. The results of the dynamic flux chamber method indicate that flanges, instrumentation and meters, and connectors are the primary sources of methane emissions at pressure-regulating stations, with emission factors of 0.0034kg/h (CI: 0.0030-0.0038kg/h), 0.0022kg/h (CI: 0.0018-0.0025kg/h), and 7.1e-04 (CI: 6.3e-04-8.0e-04) kg/h, respectively. The correlation between detected concentration and emission rate was weak. The cumulative fluxes calculated by the three methods were 0.109kg/h (CI: 0.094-0.125kg/h), 0.143kg/h (CI: 0.015-0.337kg/h), and 0.125kg/h (CI: 0.035-0.218kg/h). The results of controlled tests and field measurements suggest that the LS method offers a more reliable and physically accurate analysis of methane fluxes for pressure regulating-metering stations with limited measurement distances (typically less than 30m) and small continuous emissions. The emission factor for the pressure-regulating stations in this study is 0.013kg/h (CI: 0.008-0.023kg/h) using the bootstrap Monte Carlo method. This research provides guidance for operators to implement fixed monitoring, which is crucial for building emission inventories and ensuring production safety.

Ideal EduTech Model based on Qur’anic Perspective (Implementation at The Center for Education and Training of Administrative)

This Qur’an-based ideal Edutech model research aims to identify the best studies and practices in facilitating learning and improving work performances by creating, using, and managing processes and proper technologies. The research used a qualitative descriptive method as the research method. As for the Qur’anic interpretation method, at-Tafsir al Maudhu’i (thematic interpretation) was used since it is considered capable of addressing contemporary issues and providing a comprehensive perspective of the Qur’an in solving problems that continue to emerge along with the times. The results of satisfaction evaluation and measurement of training participants in 2023 scored 89,56 signifying the improvement after the implementation of Edutech. It showed, through the library research, several ideal models of the implementation of the Qur’an based Education Technology, such as prophet Yusuf model in the implementation of the resilience of Pusdiklat Tenaga Administrasi (The Center for Education and Training of Administrative Staff), and the Quran-based ADDIE model (analysis, design, development, implementation, and evaluation). The advantage of this research lies in Quran-based Edutech, as many verses of the Quran encourage the implementation of innovation and creativity by utilizing technology in education.

Effect of composition of multicomponent supports on properties of supported Nickel catalysts

Ni catalysts supported on combinations of alumina, magnesia, zirconia with rare earth supports are studied for the steam reforming of ethanol (ESR). The composition of the supports is systematically varied to identify the role of individual components and their contribution when they are combined. Supports containing magnesia or zirconia show contrasting behavior of acidity, XRD crystallite size of NiO, reducibility, dispersion of Ni(0), OSC, coking and metals sintering characteristics. Catalyst activity and deactivation are strongly influenced due to these differences. HRTEM indicates the redispersion of Ni(0) during reduction of NiO on catalysts containing magnesia. Magnesia and alumina-magnesia based catalysts show hindered reduction of nickel and highest intrinsic activity (H2 yields). But sintering of Ni is their nemesis. Moderate interaction of Ni with zirconia-based supports (H2-TPR) lends sintering stability in ESR. Quaternary Alumina-Magnesia-Zirconia catalysts imbibe advantages of individual components and are overall best with fair H2 yield, good stability and regenerability. Long duration (80 hours) performance tests give holistic results because they encompass multiple factors influencing deactivation. Intrinsic chemical reactivity (as opposed to) active metal dispersion is important while comparing the activity of catalysts with different compositions. Degree of reducibility of nickel is an important consideration while measuring metal dispersion by chemisorption. Metal reducibility by H2-TPR, dispersion measurement by chemisorption and particle size determination by HRTEM are used as complementary techniques for rationalizing results of metal dispersion measurement.

Effect of Ag–Te alloys on pH sensitivity of Ag2O–TeO2 glass/stainless steel enamel

Glass pH sensors are unsuitable for in vivo biomedical, clinical, or food applications because of brittleness of glass, the difficulty in measurement of small volumes and complex matrices, and the need for calibration. Herein, a novel enamel reference electrode for pH sensors is developed using a binary xAg2O·(100–x)TeO2 glass/stainless steel (SUS) electrode. Subsequently, the effects of Ag2O content on the precipitated crystalline phases and pH sensitivity of Ag2O–TeO2 glass/SUS electrodes are examined. The results indicate that the xAg2O·(100–x)TeO2 glass/SUS samples exhibit relatively low pH sensitivity. The pH sensitivities of the samples can be classified into two distinct groups. The first group, comprising samples with an Ag2O content of 25 mol% or more, exhibits a pH sensitivity higher than 10 %. The second group, comprising samples with an Ag2O content of 22 mol% or less, exhibits a pH sensitivity of less than 10 %. The pH sensitivity tends to decrease with increase in stutzite fraction in Ag–Te alloys. Results of X-ray diffraction measurements and transmission electron microscopy observations indicate that the hessite and stutzite Ag–Te alloys, which are minor and conductive, are the primary contributors to the low pH sensitivity observed. Moreover, the pH sensitivity of xAg2O·(100–x)TeO2/SUS is observed to be between those of the Ag–Te alloy and the Ag2O–TeO2 glass matrix. We propose occurrence of an electrical shunt should occur between the Ag–Te alloy and the Ag+-ion conductive Ag2O–TeO2 glass matrix. Regarding xAg2O·(100–x)TeO2 glass/SUS, the 20Ag2O·80TeO2 glass/SUS to 21Ag2O·79TeO2 glass/SUS compositions represent promising candidates as for KCl-leakage-free reference electrodes for pH sensors.

Analysis of the Alignment of Bauran System Features Based on Outcome-Based Education Rules Using Feature-Oriented Domain Analysis

Implementing information systems in higher education curriculum design is a crucial tool for academics, enabling them to design, develop, and evaluate the curriculum more dynamically, responsively, and structurally. However, it is not just about having a tool. It is about ensuring that the tool aligns with curriculum design standards. This study, therefore, measures and analyses the conformity of the Bauran system as a curriculum management information system with the established stages and standards of curriculum design. The analysis is based on the Indonesia National Standards for Higher Education (Standar Nasional Pendidikan Tinggi (SN DIKTI)) by referring to the Guidebook for Higher Education Curriculum Development in Indonesia and best practices in the implementation of Outcome-Based Education (OBE) curriculum design. The method used in this research is feature-oriented domain analysis (FODA), which includes context analysis, domain modeling, and architecture modeling. Experts in the field of OBE curriculum then validate the results of feature measurement and mapping. The study compares 27 Bauran features to 10 stages in the curriculum design guidebook and nine stages in the OBE curriculum design flow. The analysis results show that the Bauran system has implemented 10 out of 10 stages (100%) of curriculum design according to the curriculum design guidebook. However, Bauran has only implemented 8 out of 9 stages (89%) in the OBE curriculum flow. These findings not only provide feature recommendations for future Bauran development and other higher education curriculum management systems but also highlight the potential of the Bauran system for future development.

Modification as a Method of Regulation of Energy Characteristics and Functionalization of Solid Surfaces

The surfaces of solids (gold, silver, polymers) were modified with adsorption layers of various compounds. Optimal modification conditions were determined using methods of contact angle measuring and quartz crystal microbalance. The degree of filling of surfaces with the adsorption layer was calculated and the data obtained were compared with the results of direct measurements of adsorption. The surface energy of the modifying layers was determined and the potential applications of modified solids as functional materials are demonstrated.

Stability of Ionogels upon Contact with Water: Effect of Polymer Matrix Hydrophobicity and Ionic Liquid Solubility

New composite materials (ionogels) have been obtained based on imidazolium ionic liquids immobilized in highly porous polymers, i.e., polyamide 6,6 (nylon 6,6) and low-density polyethylene. A method has been proposed for determining the rate of ionic liquid removal from an ionogel upon contact with water, with this method being based on continuous measuring the conductivity of an aqueous phase. The results of the conductometric measurements have been confirmed by high-performance liquid chromatography data. It has been shown that the stability of ionogels upon contact with water is determined by both the hydrophobicity of a polymer matrix and the solubility of an ionic liquid in water. The highest degree of ionic liquid removal (more than 80%) has been observed for composites based on porous polyamide 6,6 (hydrophilic matrix) and dicyanimide 1-butyl-3-methylimidazolium (completely miscible with water). Ionogels based on lowdensity polyethylene (hydrophobic matrix) and bis(trifluoromethylsulfonyl)imide 1-butyl-3-methylimidazolium (poorly soluble, 1 wt %, in water) have shown the highest stability (washout degree of no more than 53% over 24 h). The method proposed for analyzing the rate of ionic liquid dissolution in water has been used to discuss the mechanism of this process.

Enhanced Electrical Performance of InAs Nanowire Field-Effect Transistors Based on the Y2O3 Isolation Layer.

Nanowire (NW) field-effect transistors (FETs) have great potential in next-generation integrated circuits. InAs NWs are suitable for N-type transistors because of their excellent electrical properties. However, unlike the Si/SiO2 system, the loose and defective native oxide of InAs is unable to passivate the channel surface and serve as an efficient isolation layer (IL) in the gate stack. Here, we, for the first time, demonstrate that using a stable dielectric Y2O3 to replace the native oxide IL can effectively passivate the NW surface, isolate the channel surface from high-k HfO2, and improve the electrical properties of InAs NW FETs significantly. First, top-gate devices with Y2O3 IL outperform the devices with native oxide or chemically generated oxide of InAs as the IL, exhibiting a small subthreshold swing (SS) of 77 mV/dec, a large on-off ratio, a high field-effect mobility (μFE) of 1845 cm2/V·s, and an extremely low interface trap density (Dit) of 9.1 × 1011 eV-1 cm-2. Double-gate FETs with Y2O3 IL also show excellent gate control (drain-induced barrier lowering (DIBL) down to 35 mV/V) and a high μFE of 2711 cm2/V·s (the highest in the multigate structure). In addition, InAs NW FETs with Y2O3 IL show greater stability after long-term air exposure than those with native oxide IL, demonstrating retained on-off ratio, DIBL, transconductance, and even smaller SS (from 89 to 77 mV/dec). Finally, the results of low-temperature measurement suggest that Y2O3 IL can effectively improve interface qualities. Our results indicate that Y2O3/HfO2 InAs NW FETs have great potential in digital units of integrated circuits for future nodes. Our strategy for improving the interface between InAs NW and the dielectric layer is also valuable for other III-V NW devices.

Stereooptical Methods of Sea Surface Processes Registration

This work presents the optical methods for measurements of physical parameters on sea surface also covered by ice by using stereo cameras. New method of images with sea ice processing is offered. It can detect areas of open water and sharp edges on ice, which influence on radar signal refraction. This method is based on area of interest detection on optical images, statistical parameters for each area calculation, classification and local level definition to recognize needed structures. By using stereo system perspective distortions can be corrected and physical parameters of wind waves and sea ice can be calculated. This method was probe on stereo images obtained from 90th voyage of R/V «Akademik Mstislav Keldysh» in the Laptev Sea.The results of ripple waves velocity measurements in case on open water by using development previously stereo method is presented. Comparison with Doppler shift of microwave signal is made.The methods presented in this paper are of interest in field experiments simultaneously with the use of coherent radar stations for the quantitative interpretation of radar data, as well as for remote monitoring of the sea surface and ice conditions methods development.

100% humidity independent PTR-MS: Novel method and proof-of-concept**Dedicated to Tilmann D. Märk on the occasion of his 80th birthday.

Abstract It has been well-known and studied that the quantification of various compounds with Proton-Transfer-Reaction – Mass Spectrometry (PTR-MS) is dependent on the sample gas humidity. For example, if the formaldehyde concentration in outdoor air remains constant, but the weather and thus the humidity changes, the measured signal intensity for protonated formaldehyde will change. Established countermeasures against this effect include labor-intensive calibrations at different humidity levels and subsequent data correction, the use of filters or membranes to dry the sample air, which will also trap analytes of interest, and the introduction of excessive amounts of humidity into the PTR reaction region to reduce the relative but not the absolute humidity changes caused by the sample gas, which alters the well-defined ion chemistry and again limits quantification accuracy. 
Here, we present a novel solution to the humidity dependence problem that comes virtually without any drawbacks, does not require any additional labor by the user, and does not diminish analytes of condensable nature. A target humidity for the PTR reaction region is chosen before the actual measurement. Via the controlled injection of water vapor into the reaction region, the humidity is kept constant throughout the analysis, independent of the sample gas constitution. Therefore, it can be excluded that any changes in the acquired ion signal intensities are artifacts caused by changing sample humidity, and, if required, calibration measurements only have to be performed at one humidity level. 
We introduce the instrumental adaption necessary for using the novel method and subsequently present proof-of-concept results of measurements in a laboratory, as well as in a "real-life" environment, utilizing two different PTR-MS instruments. 

UAV Mission Computer Operation Mode Optimization Focusing on Computational Energy Efficiency and System Responsiveness

The rising popularity of UAVs and other autonomous control systems coupled with real-time operating systems has increased the complexity of developing systems with the proper robustness, performance, and reactivity. The growing demand for more sophisticated computational tasks, proportionally larger payloads, battery limitations, and smaller take-off mass requires higher energy efficiency for all avionics and mission computers. This paper aims to develop a technique for experimentally studying the indicators of reactivity and energy consumption in a computing platform for unmanned aerial vehicles (UAVs). The paper provides an experimental assessment of the ‘Boryviter 0.1’ computing platform, which is implemented on the ATSAMV71 microprocessor and operates under the open-source FreeRTOS operating system. The results are the basis for developing algorithms and energy-efficient design strategies for the mission computer to solve the optimization problem. This paper provides experimental results of measurements of the energy consumed by the microcontroller and estimates of the reduction in system energy consumption due to additional time costs for suspending and resuming the computer’s operation. The results show that the ‘Boryviter 0.1’ computing platform can be used as a UAV mission computer for typical flight control tasks requiring real-time computing under the influence of external factors. As a further work direction, we plan to investigate the proposed energy-saving algorithms within the planned NASA F’Prime software flight framework. Such an investigation, which should use the mission computer’s actual flight computation load, will help to qualify the obtained energy-saving methods and their implementation results.

Effect of the illuminance meter used on the results of color light pollution measurements

The paper presents the results of measurements of illuminance. Twenty-two types of illuminance meter with known spectral sensitivity curves of photometric heads and eleven lamps emitting colored light were used. Laboratory measurements were conducted at a characteristic point, with a focus on assessing intrusive light, with a value of 3 lx. The considerations were supplemented with simulated illuminance calculations. For most illuminance meters, correlations were observed between the measurement results and the calculations. This allows the conclusion that, especially in the case of colored light, one of the main factors affecting the measurement result is the spectral sensitivity curve of the photometric head. The greatest discrepancies in the obtained illuminance values were found in the case of lamps emitting blue light. The paper highlights the fact that measuring low illuminance values produced by lamps emitting colored light is not an easy task. Depending on the illuminance meter used, conclusions regarding the assessment of intrusive light may vary. The aim of the paper is to indicate that not all calibrated illuminance meters are suitable for this assessment.

An Innovative Use of Hydroxyapatite (HAp) from Pokea Clam Shells (Batissa violacea var. celebensis) for Toothpaste Manufacturing

Innovation research on the use of hydroxyapatite from pokea clam shells (Batissa violacea var. celebensis) for toothpaste manufacturing has been successfully conducted. This study aims to determine how to synthesize and characterize hydroxyapatite (HAp) from pokea shells and the efficiency of its use in making toothpaste. The research process was conducted through hydroxyapatite synthesis and hydroxyapatite toothpaste formulation. The success of this synthesis was proven by the characterization of XRF spectrophotometer, FTIR spectrophotometer and digital optical microscope. The results of XRF analysis showed that the CaO content in the material was 88.21%. The results of FTIR analysis showed that in hydroxyapatite material there was absorption at wave numbers 926 cm-1 and 1024 cm-1 which showed asymmetric strain vibrations and bending vibrations of PO43- groups. The results of XRD characterization of HAp show that the diffraction peak is at an angle of 2θ = 20-57 ° with a crystal size of 46.15 nm and a degree of crystallinity of 85.43%. Digital optical microscope test results at 500x and 1000x magnification, showed hydroxyapatite has a uniform and non-porous shape. The hydroxyapatite toothpaste produced is bone white in color with menthol aroma and slightly rough texture. The resulting toothpaste is homogeneous, the diameter of the distribution that meets the quality requirements of toothpaste is 6.833 cm. The pH measurement result on toothpaste is 5.82 which meets the toothpaste quality requirements. The result of viscosity measurement on toothpaste is 20,000 cpa.s which meets the requirements of toothpaste viscosity. The foam formed is 10 mm where the height of the foam formed has met the requirements. Hydroxyapatite toothpaste has good stability and strong antibacterial activity, where the clear zone formed is 18.7 mm

EFFECT OF FREQUENCY OF FEEDING HI-PRO-VITE 781N-1 ON THE GROWTH OF GOLDEN FISH (Cyprinus carpio) IN THE GOLDEN FISH BREEDING CENTER OF TOMONAMO IN LETEFOHO VILLAGE SUB DISTRICT SAME, MUNCIPLAITY OF MAUNUFAHI, TIMOR-LESTE

The purpose of this study was to determine the effect of the frequency of artificial feeding Hi-Pro-Vite 781N-1 on the effective growth of goldfish (Cyprinus carpio) in Timor Leste, Timor. The study used a complete randomized design (CRD) with 3 treatments and 3 replications, in which the conditions of the test unit are carried out according to randomization for all test units. The results of the research conducted for eight weeks (56 days) regarding the frequency for artificial feeding hi-pro-vite 780N-1 were: water temperature, water oxygen, sin water, and total dissolved solids (TDS) of 42.4 ppm, and the results of water quality measurements once a week in the morning (08.00 WIB), on average (20.00 htl) and in the afternoon (05.00) for 8 weeks (58 days). The results obtained during the research week (65 days) fresh at water temperature with a value of 20.2 oC with water oxygen 2.89 pmm, water content 8.3 pmm and TDS 42.4 pmm are indeed a good tolerance for the growth of carp fry (Cyprinus caprio). The behavioral impact of feeding frequency on carp growth and health is explored to refine feeding practices that promote well-being alongside growth. The findings could benefit feed manufacturers and aquaculture stakeholders by informing product development and feeding strategies tailored to maximize growth in carp, contributing to sustainable aquaculture practices. This study offers practical guidance for optimizing feeding practices to enhance growth efficiency, which is crucial for improving fish yield and farm productivity.

Facile synthesis of CuCo2O4@CdS nanoheterostructure for asymmetric supercapacitor

The abundant active sites, high theoretical capacitance, and cost-effective synthesis of transition metal oxides@sulfides (TMOs@TMSs) have made them a highly desirable choice as active electrode materials for supercapacitors. This study demonstrated the successful fabrication of a CuCo2O4@CdS nanoheterostructure electrode using a simple and economical co-precipitation method The morphology, physicochemical properties, and electrochemical behavior of this electrode were subsequently studied. The synthesized CuCo2O4@CdS nanoheterostructure was characterized using Infrared Fourier-transform spectroscopy, X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, High-resolution transmission electron microscopy, N2 adsorption/desorption isotherms and atomic force microscopy. The electrochemical performance was studied using cyclic voltammetry, impedance spectroscopy, and galvanostatic charge-discharge (GCD) measurements with a 6 Molar KOH aqueous electrolytic solution. Results from powder X-ray diffraction pattern and energy dispersive X-ray revealed the formation of CuCo2O4@CdS nanoheterostructure. Furthermore, SEM images showed the formation of more spherical structures in nanoheterostructure. The results of optical measurements of thin films were analyzed, which showed an increase in the energy gap (Eg) of CuCo2O4 nanoparticles when combined with cadmium sulfide (CdS). Additionally, the intensity of photoluminescence of the CuCo2O4@CdS nanoheterostructure was lower compared to the pure nanoparticles. Moreover, the newly synthesized CuCo2O4@CdS nanoheterostructure showed a specific capacitance of 257.5 F g−1 at a current density of 0.5 A g−1 via a three-electrode galvanostatic charge-discharge system, respectively. In the asymmetric device, the supercapacitor yielded an optimum energy density and power density of 19.6 Wh kg−1 and 700 W kg−1 at 1 A g−1 current density, respectively. Although the capacitance retention was maintained at nearly 85.2 % after 4000 cycles at a current density of 3 A g−1.