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THE KINETICS OF PRECIPITATE COARSENING IN ZIRCALOY-2
No full textZircaloy-2 has been used as fuel element cladding material in both light and heavy water power reactors. The aims of the experiment are to study the kinetics of precipitate coarsening during isothermal a-annealing and to characterize the nucleation and growth of precipitate affected by the variations of cold work and heat treatment. The results of the experiment show that all specimens annealed at 650°C have the average precipitate diameter less than 0.1 um whereas those at 750°C have the average size larger than 0.1 .tm except for one annealed for less than 5 hours. The average size of precipitates is 0.07 um for specimens deformed before 0-quenching and 0.168 .tm for specimens deformed after 0-quenching. The deformed specimens after 13-quenching have more homogeneous size distribution than that of undeformed specimens and specimens deformed before 0-quenching. The kinetics of precipitate coarsening depends on the changes in annealing temperature and time, and cooling rate from the 0-phase region. The nucleation and growth of precipitates have been influenced by the variations of cold work and heat treatment
SYNTHESIS AND CHARACTERIZATION OF LiFePO4/PPy/CLAY COMPOSITE AS CATHODE MATERIAL FOR Li-ION BATTERY
No full textSYNTHESIS AND CHARACTERIZATION OF LiFePO4/PPy/CLAY COMPOSITE AS CATHODE MATERIAL FOR Li-ION BATTERY. Conductor polymers have been used previously as a conducting agent or carbon source in various sol-gel and solid state methods to increase the conductivity of LiFePO4. The composite of LiFePO4/PPy/Clay were synthesized by mixing LiFePO4 and clay with a Ppy solution. The characterizations were done by using X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM) and LCR meter respectively. From XRD analysis it could be deduced that LiFePO4 has an ordered olivine structure with a Pnma space group. The SEM images provide clear evidence that small crystal particles of LiFePO4 either coat the surface of the clay particles or lie among them. These LiFePO4 particles have a small particle size (100–500 nm). With the increasing of LiFePO4 content, these small crystal particles at the surface or among the clay particles are increased. Increasing the PPy content to increase the conductivity of the material obtained. With the addition of clay from 5 to 10 wt. %, the DC conductivity of the blends is clearly observed to increase up to three orders of magnitude
EFFECT OF ANNEALING CYCLES ON DEEP DRAWABILITY OF LOW CARBON TITANIUM ADDED STEEL
No full textEFFECT OF ANNEALING CYCLES ON DEEP DRAWABILITY OF LOW CARBON TITANIUM ADDED STEEL. Maximum mechanical properties and deep drawability of low carbon titanium added steels was obtained after heat treatment with simulation batch annealing cycles in an industrial process. The effect of holding times and holding temperatures on deep drawability were studied using tensile test for measuring normal anisotropy (r-value) and strain hardening exponent (n-value). Scanning electron microscope were employed for observation of microstructure in steel sheets. X-ray diffraction with pole figure techniques were also used for measuring texture of annealing. Results showed that as the temperature was increased up to 900 oC, both r and n values increased gradually and peaked in the temperature of 850 oC. This results showed that formability of sheet materials increased until batch annealing temperature reach 850 oC as increasing the ratio of intensities {111} /{100}. The largest mean r value of almost 2.6 was obtained in slow heating at holding temperature of 850 oC with n value of 0.27
PEMBUATAN DAN KARAKTERISASI SEL BATERAI SEKUNDER BAHAN SUPERIONIK AeRbAg4I1RbI3
No full textPEMBUATAN DAN KARAKTERISASI SEL BATERAI SEKUNDER BAHAN SUPERIONIK AeRbAg4I1RbI3. Bahan elektrolit padatan berbasis perak RbAg4I5 telah digunakan sebagai elektrolit untuk pembuatan sebuah sel baterai sekunder (rechargeable) dengan Ag sebagai anoda dan RbI3 sebagai katoda. Telah dilakukan pengukuran karakteristik pengisian-peluwahan (charge-discharge) dan polarisasi terhadap baterai pada kondisi tekanan atmosfir biasa dan temperatur ruang. Dapat disimpulkan bahwa konfigurasi sel Ag/RbAg4I5/ Rb13 dapat berfungsi sebagai baterai sekunder. Sel dapat berfungsi dengan balk pada rapat arus hingga 230 RA/cm1
Double Emulsion Based Alginate/Chitosan Prepared by Ultrasound for Bioactive Encapsulation
No full textWater-in-oil-in-water (W/O/W) emulsion is an effective technology for encapsulating bioactivity but has poor stability. This study aims to evaluate the effect of ultrasonication on the preparation of double emulsions with varying alginate/chitosan ratios (1:1, 1:2, 2:1) and sonication times between 0 and 7 minutes. The results showed that a sonication time of 7 minutes resulted in the best storage stability (0.00–1.02%) and thermal stability (17.13–23.21%), a significant decrease in droplet size (2.08–2.87 μm), and higher emulsion activity index (EAI) (16.11–38.10 m2/g) and emulsion stability index (ESI) (63.28–89.74 min) values. The alginate/chitosan ratio of 2:1 also gave the most optimal results with storage stability of 4.58%, thermal stability of 36.23%, droplet size of 2.08–4.14 μm, and EAI and ESI values of 16.12 m2/g and 48.42 min. The ultrasonic-assisted alginate/chitosan double emulsion method effectively improved the stability and bioavailability of bioactive and presents significant potential for food and pharmaceutical applications
Spatial Analysis of Physical Parameters Influencing Water Quality: A Case Study in Seloromo Reservoir, Central Java, Indonesia
No full textReservoirs are vital water resources that have an essential role from the perspective of living things. Utilization of reservoirs by humans frequently causes problems in the reservoir ecosystem, such as water pollution. Seloromo Reservoir was the second reservoir built to support various activities such as agriculture, fisheries, and tourism. Complex activities can influence the quality of reservoir water because sources of pollution are absorbed and flow into the water body. For this reason, monitoring is essential to determine factors that affect water quality of the reservoir. The aim of this research is to analyze the water quality of Seloromo Reservoir by testing physical parameters such as water temperature, degree of acidity (pH), Electrical Conductivity (EC), Total Dissolved Solid (TDS). In order to show the spatial distribution of each physical characteristic, grab samples were collected and measured in real time using a water checker. The results will be shown on a map. Spatial distribution maps were created by using the Inverse Distance Weighted (IDW) method which provides the simplest formulation and accurate results. Results show that human activities such as agriculture, livestock, and tourism around the reservoir and inputs from the river inlet indicate the condition of water quality in Seloromo Reservoir. Spatial distribution maps of physical parameters show that the northern area is more affected than the southern area of the reservoir. Local communities have an important role in conserving the water resources in this reservoir. Consequently, the research can contribute new knowledge about the condition of the reservoir and provide additional reference in establishing policies
Pengaruh kewirausahaan sosial terhadap peningkatan kesempatan kerja di Kota Cimahi
No full textThis research aims to understand the impact of the development of micro, small, and medium enterprises (MSME) in social entrepreneurship in Cimahi City, as well as factors that influence the job creation in this region, including education level, gender, and business environment. This study collected the data using mixed methods through FGDs (Focus Group Discussions) and questionnaire distribution to 107 regional social and conventional entrepreneurs. The results of the data analysis show that social entrepreneurship has a greater impact on job creation than conventional entrepreneurship. Male social entrepreneurs with higher education levels can create relatively more job opportunities. Furthermore, entrepreneurs who make their business a primary occupation also tend to employ more workers. While a more competitive business climate increases job opportunities, this study found that social entrepreneurs with high levels of innovation tend to be labor-saving, hence creating fewer job opportunities. The study concludes that developing MSMEs in social entrepreneurship is essential to reducing regional unemployment
Jam kerja berlebih pada lansia di Indonesia: Analisis data Survei Sosial Ekonomi Nasional tahun 2023
No full textThe rising percentage of older people working for excessive hours in Indonesia requires attention as this situation may worsen their health. This study aims to analyze the variables that influence older people to work excessive hours in Indonesia in 2023. This study uses data from the 2023 National Socio-economic Survey (Susenas) with 71,367 samples and applies the binary logistic regression method for analysis. Results showed that 26.92% of older people worked excessive hours, predominantly young elderly, those with education levels higher than elementary school, those without health insurance, urban residents, those working in the trade sector, those with more than four household members, and those with savings. Furthermore, significant factors are influencing the excessive working hours among older people include age, health insurance ownership, area of residence classification, employment sector, and household size. The study suggests that the government and companies need to collaborate to create elderly-friendly working environments
