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The increasing demand for high-performance computing necessitates efficient cooling of central processing units (CPUs) to ensure optimal functionality and prevent overheating. Nanofluids, colloidal suspensions comprising scattered nanoparticles in a base fluid, have emerged as a promising solution due to their distinct thermal properties and potential for enhanced heat transfer. Thus, the main objective of the current study is to evaluate the thermal performance and efficacy of nanofluids as coolants for desktop PC CPU cooling system. To achieve this, an extensive experimental setup was devised to analyze the heat transfer characteristics of nanofluids under diverse operating conditions. Different types of deionized water based-nanofluids, which are Al2O3, CuO and Fe2NiO4 with nanoparticle mass concentration of 0.3% were blended for 3 hours using magnetic stirrer and followed by 6 hours of ultrasonic bath at a constant temperature of 50⁰C. The stability of the prepared nanofluid will be monitored and enhanced through this method of preparation. The thermal performance of desktop PC CPU is evaluated based on the highest operating temperature of the processors under the maximum load of computer usage. For performance comparison, a conventional coolant deionized water was utilized as a reference. Among all the nanofluids used, Fe2NiO4−H2O demonstrates the most efficient cooling performance. Its temperature gradually decreases from the peak value to 45°C under the same operating conditions with other type of nanofluids used. This significant temperature reduction can be linked to the superior thermal conductivity of Fe2NiO4 nanoparticle. This finding underscores the potential of nanofluids as an advanced cooling solution for desktop PC CPU system. [ABSTRACT FROM AUTHOR]

Thanks to the unique architectural construction, nano-sized activated carbon materials demonstrate superior performance as supercapacitor electrode materials compared to conventional carbon-based materials. In this work, we demonstrated biowaste-derived tubular-like porous architecture synthesis through the KOH activation with different mass ratios (precursor/KOH) viz. 1:0.20, 1:0.25, and 1:0.30 by using a one-step pyrolysis strategy. The young coconut husk (YCH) waste was used as a carbon resource. All the synthesized samples were characterized using several techniques, including a scanning electron microscope combined with energy-dispersive X-ray, X-ray diffraction, and X-ray diffraction, to evaluate the surface topography, elemental composition, and crystalline nature of the samples. A cyclic voltammetry and galvanostatic charge/discharge technique was employed to assess their capacitive behavior. The surface morphology of YCH-0.25 shows a tubular-like porous architecture with a diameter in the range of 26-144 nm. According to CV and GCD, curves The YCH-0.25 sample attains the optimum capacitive performance as high as 231 F g−1 and 297 F g−1, respectively. This work provides a new perspective on the future management of young coconut husk waste in terms of promising clean energy technologies. [ABSTRACT FROM AUTHOR]

Silica extracted from clay of Kendari Bay has been studied. The clay was first rinsed with deionized water and dry under daily sunlight. The dried clay was then crushed and sieved of 60 meshes. Silica was obtained by leaching method using hydrochloric acid (HCl) with concentration varied from 4M to 10M with increment of 2M. During leaching process, the mixture was left for stirring at 100°C for 5 h, rinsed until neutral pH and filtered. The samples were characterized using X-ray Fluorescence (XRF) to know chemical composition of clay, X-ray Diffraction (XRD) for structural properties and Fourier Transform Infra-Red (FTIR) for functional groups. The results showed that the optimal condition for silica extraction is 6 M of 64.588%. XRD result revealed that the Bragg peak with high intensity situated at 2 = 26,6° is identified as SiO2 with Miller index of 101 of quartz type. FTIR result shown that the peak situated on 1.050 cm−1 was identified as Si-O-Si functional groups. The, we concluded that the clay of Kendari Bay was became the source of silica. [ABSTRACT FROM AUTHOR]

For the past five years, application of magnetic adsorbent for the remediation of textile effluent is receiving significant attention due to its low cost, simple preparation, and easy recovery. In this study, a magnetic bentonite composite (MBC) was synthesized through co-precipitation technique and then used for removing Methylene Blue (MB) dye. The raw bentonite and MBC were characterized using vibrating-sample magnetometry (VSM), X-ray powder diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The FTIR analysis indicated the possible involvement of hydrogen bonding between the iron oxide and bentonite particles to form the MBC. The magnetic composite exhibited a saturation magnetization of 9.2 emu/g with high degree of crystallinity as displayed in the XRD pattern. During a preliminary adsorption study, the MBC successfully removed 100% MB from aqueous solution with a maximum adsorption capacity of 100 mg/g. Immersion of spent MBC in various desorption eluent (1 M of NaOH, NaCl, HNO3, EDTA, and deionized water) showed a negligible MB desorption. This composite exhibits great potential as a green and efficient adsorbent for future works involving dye remediation. [ABSTRACT FROM AUTHOR]

Electrical discharge coating (EDC) is a well-known technique among researchers for modification of metallic surfaces. This process is capable of producing a hard coating layer, biocompatible and high corrosion resistance at low operating cost. Unfortunately, the process develops unfavourable microcracks and porosity on the substrate surface attributed by heat generation. Thus, in this study, the effect of several parameters to the microdefects' formation was investigated through an experimental work based on fractional factorial design. This work was conducted on a nickel-titanium (NiTi) shape memory alloy by varying the EDC parameters, namely; polarity, discharge duration, peak current, pulse interval, gap voltage and additive Ti nano powder concentration in deionized water (DI water). ANOVA results exhibited that the discharge duration has dominated the microcracks and porosity fraction on the substrate surface due to the impact of high intensity of discharge energy. Although, the Ti nano powder mixed in the DI water had capability to reduce the microcracks formation, the porosity fraction during at high gap voltage setting was elevated with the Ti nano powder mixed. [ABSTRACT FROM AUTHOR]

In the present study Si2N2O is prepared from stoichiometric mixture of Si3N4 and SiO2 through slip casting and reaction sintering method. Si3N4 and SiO2 powders were characterized for crystallographic phase and particle size distribution. The dispersion behavior of Si3N4 in deionized water (DIW) was estimated through zeta potential measurement. High zeta potential values of >45 mV at pH 10 and above indicate good dispersion. The slips of Si3N4 and SiO2 having solid loading of 69 to 72 Wt.% when slip cast into plaster molds give green density of 53±1%. On reaction sintering in the temperature range of 1550°C to 1650 ⁰C in nitrogen atmosphere the products have density of 63 to 80% and apparent porosity 12 to 33%. The samples sintered at 1650 ⁰C for 1 h and 2 h show 3-point flexural strength of about 80-100 MPa and porous microstructure. [ABSTRACT FROM AUTHOR]

The operation of pilot conversion plant in Serpong Nuclear Area to produce nuclear grade uranium dioxide from yellow cake generated liquid waste containing uranium. This uranium liquid waste remains problematic because the existing treatment processes for radioactive waste in the radioactive waste processing installation is yet to accommodate liquid waste which contained uranium. Therefore, the study for treatment of this kind of waste is necessary to support the radioactive waste management and to maintain the sustainability of the operation of the pilot conversion plant. The objective of this work is to recover uranium in the liquid waste by precipitation, thus decreasing the concentration of uranium in the liquid waste. The study was carried out by simulation using PHREEQC code and direct precipitation experiment with NaH2PO4 and NaOH as precipitating agents. The aqueous uranium in the liquid waste was precipitated with the addition of each of precipitating agent in a beaker glass to produce uranium precipitates. After the precipitation, the precipitates and the supernatant were separated by centrifugation. The uranium precipitates obtained from the experiment were washed with deionized water and ethanol. Then, a small portion of the precipitates was taken and coated with sputtered gold prior to analysis using SEM-EDS. The supernatant, meanwhile, was filtered and the concentration of uranium in the filtrate was determined using ICP-OES. The results shows that uranium precipitates with NaH2PO4 were crystalline, whereas with NaOH were amorphous. The initial concentration of uranium in the liquid waste was 2878 mg/l, whereas after the precipitation the concentration became approximately 1 mg/l. These values correspond to 99.9% aqueous removal by precipitation with those precipitating agents which indicates that this method is promising to be further developed for uranium liquid waste treatment. [ABSTRACT FROM AUTHOR]

In this paper, Aactivation of 3D printed PLA/Carbon with through electroplating at various voltages is investigated. The activated electrode was employed with water electrolysis to determine the reactivity for the hydrogen production. The objectives are to activate 3D printed PLA with nickel promoter, investigate the effect of voltage on the electrode morphology and evaluate the electrocatalytic reactivity. The electrodes were designed by using Solidwork and printed by using Fused Deposition Modelling 3D printer. Electrodeposition was conducted by using different voltages to decorate the electrodes with metallic promoters in order to activate them for the Hydrogen Evolution Reaction at the cathode. The morphology of the plated electrode electrodeposition was observed by using optical microscopy (OM) and Scanning Electron Microscope (SEM). The activated electrode reactivity was then evaluated by employing electrocatalysis, i.e., hydrogen evolution reaction. The electrode plated with Ni at 15V for 60 minutes produced the highest amount of hydrogen gas compared to other. However, further investigation by prolonging the time for 5V electroplating process showed higher hydrogen gas production compared to 15V 60 minutes electroplated electrode. Low voltage resulted in good more uniform nickel coating, while high voltage caused the coating to be peeled off as observed by scanning electron microscope & optical microscope. [ABSTRACT FROM AUTHOR]

The rapid development of motorbikes lately is marked by the many variants (types). Motorcycles are the most widely used means of transportation by Indonesian people in general. The completeness system of the machine includes the ignition system, filling system, lubrication system, cooling system, starter system and fuel system. Good engine performance is supported by several factors including fuel consumption in accordance with the working conditions of the engine, proper ignition timing, high engine compression and a strong spark to burn the entire mixture of gasoline and air at the end of the compression stroke to produce the desired combustion. to find out how the AC CDI ignition system works for the Honda Astrea Grand motorcycle and the 110 cc CDI DC Shogun ignition on CAMEL IBATE vehicles. To get a more efficient/efficient fuel flow discharge. The data analysis method to determine the fuel flow rate is by testing the Camel Ibate vehicle using the Honda Grand Standard AC CDI and the 110 cc Shogun CDI-DC at 3500 Rpm, 4000 Rpm, 4500 Rpm, 5000 Rpm, 5500 Rpm, to get the time difference required in testing the fuel flow discharge with. At 3500 rpm engine speed, the time difference between AC CDI and DC CDI is 16.22 seconds. At 4000 rpm engine speed, the time difference between AC CDI and DC CDI is 17.9 seconds. At 4500 rpm engine speed, the resulting time difference between CDI AC and CDI DC is 15.64 seconds. At 5000 rpm engine speed, the time difference between AC CDI and DC CDI is 20.97 seconds. At 5500 rpm engine speed, the time difference between AC CDI and DC CDI is 13.09 seconds. [ABSTRACT FROM AUTHOR]

The major aim of this study is to compare the power generation of carbon felt electrode and carbon paper electrode operated Microbial fuel cells (MFC) using restaurant wastewater. Restaurant wastewater samples were collected from MFC with carbon felt electrode (N=13) and carbon paper electrode (N=13) operated for 10 days (G power 80%). Voltage was measured using a multimeter and current, power, power density was calculated from it for both groups. The Power generation was found to be high in MFC operated with carbon felt electrode (410 mW/m2) due to its active surface area, strong conductivity, and good biocompatibility compared to carbon paper electrode (121 mW/m2). The independent sample T-test was done which showed that the power generation of MFC operated with carbon felt electrode (p<0.001) found to be significantly higher compared with MFC operated with carbon paper electrode. The study shows that carbon felt electrode operated MFC is able to achieve higher power generation compared to carbon paper electrode. [ABSTRACT FROM AUTHOR]

In this work, palladium metal nanoparticles (PdNPs) were prepared by pulsed ablation technique in deionized water (DIW) and a pulsed Nd-YAG laser with two wavelengths (532 nm - 1064 nm) was used and three energies were used for each wavelength (800 mJ - 900mJ -1000mJ) with a number of pulses (500 pulse) and pulse width (10 ns) and a frequency interval (6 Hz). The optical, structural and morphological properties of palladium nanoparticles (PdNPs) were studied by means of several (uv-Visible -XRD-SEM) assays. Comparison between the results based on the difference in wavelength and laser energy and the effect of the change in wavelength and energy on the properties of palladium nanoparticles (PdNPs), The resulting particles appeared in a spherical shape and tended to agglomerate and form what looked like clusters, and their size ranged between several nanometers and 30 nanometers. The particle grain size of palladium nanoparticles ranged between (17nm) at (1000mJ) at a wavelength (1064nm) and (25nm) at (800mJ) at a wavelength (532nm). [ABSTRACT FROM AUTHOR]

In this paper, Gold nanoparticles were prepared by chemical reduction method using materials Gold chloride (HAuCl4/H2O) and deionized water, This method has proven its effectiveness by obtaining gold nanoparticles with sizes (9-11) nanometers. Moreover, the resultant nanoparticles have no inclination to clump together and are distributed at the nanoscale. The process's cheap cost of execution is also encouraging. The major benefit of chemical reduction is that it is characterized by great efficiency in synthesis. [ABSTRACT FROM AUTHOR]

The article considers the electrochemical aspects of the adhesion of Micrococcus luteus 1-I on platinum, glassy carbon and carbon-paste electrodes with different surface properties. With the help of electrochemical impedance spectroscopy, equivalent circuits havebeen compiled that characterize the capacitive characteristics of the phase interfaces. A direct relationship between the capacitanceof the electric double layer and the specific surface area of the electrodes is shown. It has been shown that, on the whole, the capacitance of the electrical double layer Cdl decreases in the presence of M. luteus 1-I. Based on the data obtained, an assumption was made about the effect of cell sorption on the electrode surface area S and the thickness of the electrical double layer. The results agree well with theoretical data and are statistically significant. All of these factors may indicate the adhesion of M. luteus 1-I on the selected electrodes. [ABSTRACT FROM AUTHOR]

Indonesia is the largest nickel producers in the world in form of nickel laterite ore, its reservation about 23.67% and production about 33% of world supply chain. It is smelted as ferro nickel and nickel matte. Nickel matte, with around 77% Ni, 1% Co and 0.3% Fe, could be used as nickel source in cathode active material synthesing, NMC by using nickel sulphate route. This study dealing with synthesizes cathode active material from nickel matte. The nickel matte was converted into nickel sulfate in certain condition and catalyst and then reacting with commercials Mangan Sulphate (MnSO4) and Cobalt Sulphate (CoSO4) (technical grade) resulting NMC. The type of active material was focused on NMC 111. Then, it was dopant using lithium carbonate in varied composition, 1.35% weights to 0.4 % weights. The product of Li - NMC 111 was characterized by using AAS for ratio composition and XRD for crystallography. Based on the diffractogram, as low as LiCO3 composition will give more purity crystal and better performance in the lithium ion battery. Based on its performance, initial charging test, the lithium ion battery has working voltage in the range of 3.0 VDC and 4.2 VDC, with capacity of 0.4 mAH with stability for 30 hours of charge – discharge cycle. [ABSTRACT FROM AUTHOR]

The flexible piezoresistive sensing membrane has the tremendous opportunity in wearable and foldable devices for healthcare detection, artificial skin, human body motion, and robotics applications. The aim of this paper was to develop the polymer based piezoresistive membrane using cast solution. Poly (4-styrenesulfonic) (PSSA) were mixed with Polyvinyl alcohol (PVA) polymer by using Deionized water(DW) as a solvent, to make a series of flexible piezoresistive membranes out of PVA/PSSA and investigate their electrical characteristics across a frequency range of 20 Hz to 10 MHz. The results show that raising the concentration of PSSA from 0.2gm to 0.8gm increases the dielectric constant, conductivity, and gauge factor from 105 to 107, 10-3 s/cm to 0.1 s/cm and 2.794 to 5.092 respectively, in the proposed PVA/PSSA piezoresistive ionic membrane. The electrical properties of piezoresistive ionic membranes were analyzed using the impedance analyzer for the varying wt% of PSSA. When the wt% of PSSA was varied, it was discovered that the composition containing 0.8 gm of PSSA in PVA/PSSA based ionic membrane produces the greatest results in terms of high sensitivity and gauge factor for piezoresistive sensing applications. [ABSTRACT FROM AUTHOR]

Tea plants were discovered thousands of years ago in South-East Asia, and humankind has been drinking tea for thousands of years due to its medical benefits to prevent and treat a lot of diseases. Tea leaves are specific for their antioxidant capacities due to the presence of a wide range of flavonoid and other phenolic compounds. In this study, spectrophotometric methods were evaluated for determining the total flavonoid contents (TFCs) and ferric reducing antioxidant power (FRAP) in various green and oolong tea products collected in two specific tea-tree plantation regions in the mountainous area (Yen Bai Province-YB, the North) and Central Highland (Da Lat-DL and Lam Ha-LH, Lam Dong Province, the South) of Vietnam. The ultrasound-assisted solid-liquid extraction at 70 °C was employed to prepare the tea extracts with 70% v/v methanol in deionized water as the extraction solvent. Quercetin and trolox were used to build up the calibration curves for TFCs and FRAP, respectively. The results indicated that oolong tea products performed lower TFCs (expressed as milligrams of quercetin equivalents per gram dried weight or mg QE g−1 DW) than green tea (68.06±0.76 to 79.89±0.48 mg QE g−1 DW vs.117.4±1.7 to 244.1±3.9 mg QE g−1 DW) due to the differences in tea plant species and the oxidation levels during the fermentation period. Among the collected dried tea products, the FRAP values (expressed as micromoles of trolox equivalents per gram or µmol TE g−1 DW) were high and followed the decreasing order of YB-Green (2138±23 to 2688±40 µmol TE g−1 DW)>DL-Green (2232±60 to 2349±63 µmol TE g−1 DW)>LH-Oolong (1745.2±5.0 to 1947±45 µmol TE g−1 DW)>DL-Oolong tea products (1551±23 to 1679±25 µmol TE g−1 DW). It could be concluded that green and oolong tea products are rich sources of flavonoids and antioxidants, and the total flavonoid contents could remarkably contribute to the antioxidant capacities (r=0.841). [ABSTRACT FROM AUTHOR]

In this paper, metal oxide nanoparticles (Titanium dioxide) were prepared by using laser ablation of titanium target immersed in deionized water, where we used the technique of laser ablation in the liquid (PLAL) because of its many advantages, including being a rapid and direct way to prepare NPs and do not require long and high reaction times, Temperature and high-pressure environment and its eco-friendly method. 0ptical and structural properties of the prepared TiO2NPs studied using Q-switched Nd: YAG laser with a wavelength of 1064nm with different energies (80, 100, 120, 140, & 160) mJ /100 pulses. In addition, the prepared TiO2NPs were characterized by UV-VIS and FTIR spectroscopies. The results showed that increasing the laser energy increases an absorbance of the prepared TiO2NPs, the energy bandgap (Eg) of the prepared TiO2NPs decreased with increased Laser energy. And from the FTIR results, the formation of TiO2NPs was confirmed and it has a bond at wavenumber ranging from (400-700 cm−1) [ABSTRACT FROM AUTHOR]

Highly branched polymers such as dendrimers have the potential to be a perfect drug delivery system. Curcumin is a hydrophobic polyphenolic therapeutic drug with anti-inflammatory and antitumor effects. Due to its hydrophobic nature, its application in pharmaceuticals is hindered. Curcumin was encapsulated within the 3rd generation polyamidoamine (PAMAM) dendrimer with its NH3+ functional groups. The complex obtained had a curcumin load of 16 µg per 1 mg of dry complex and remained stable in both deionized water and methanol, showing minimal release even after 8 hours. Interactions within the complex were studied using UV-spectrophotometry and was found that the positively charged amino group of PAMAM dendrimer forms a complex with curcumin due to their ionic interactions, which was further confirmed by FTIR and NMR spectroscopy. This interaction between them enhanced curcumin's solubility in water there by improving its bioavailability. Therefore, the strategy used in this work is a suitable drug delivery system for improving many bioactive substances. [ABSTRACT FROM AUTHOR]

The objective of this research is to find out whether the method of ionization by separating water electrolysis can be used for the preparation of alkaline water production to produce hydroxyl ions which is widely talked will be useful effect for our body. This research is also useful for finding the best type of metal that is not corroded and become harmful to human health and to study the chemical reaction involved in the system. The study also included observation of the effects of the addition 100 and 200 ppm salt into system. Method used in this experiment is by separating electrolysis chamber to produce ionized water using two electrodes chamber connected by a cotton as membrane and DC adaptor as power source. Material needed for this process are separated electrolysis equipment, water, and adaptor. The result show that alkaline water will be produce by ionization of separated water electrolysis in cathode chamber while acid water will be produced in anode chamber. Research was done with variations in electrodes and composition of salt vs. contact time. Result show that most of the electrodes were corroded by salt except of aluminum. Conclusion from the experiment show that pure titanium and aluminum is suitable to prepare alkaline water using water separating water electrolysis ionization method. Key Words: oxidation, reduction, electrolysis oxidation water, electrolysis reduction water [ABSTRACT FROM AUTHOR]