The effect of subcooling and length of hydrophobic-spot periphery on nucleate pool boiling heat transfer from TiO 2 -coated surface with and without PTFE (polyetatafluoroethylene) hydrophobic circle spots at intermediate heat flux has been examined. The experiments are performed with liquid subcooling ranging from 0-20 K and heat transfer block used were TiO 2 -coated copper block with a PTFE hydrophobic circle spot with various diameters with total area of PTFE being constant. Bubble nucleation and behavior were observed by using high-speed camera. The results showed that the heat transfer performance of surfaces with PTFE hydrophobic circle spot is better than superhydrophilic surface in overall condition. Furthermore, the heat transfer performance decreases under subcooled condition for all surfaces. Increase in peripheral length of hydrophobic-spot enhances the heat transfer performance.

The monitoring results of the Lancang Kuning University management study program show that 30% of the graduates of the management study program work as young entrepreneurs. The research used is survey research using questionnaires distributed to alumni through an online questionnaire of 69 people from 214 people taken randomly in 2017 and analyzed the data by descriptive analysis. This research showed that the performance of young educated entrepreneurs with average scores reached 3.11 is in quite good category. When viewed from the above average value on the indicator Persistence in facing business challenges so far, then the enthusiasm in running a business so far and the mental readiness to face business competition during this time and the ability to communicate in establishing relationships with business partners. For values below the average lies in the development of business so far and government support so far. This shows that the business being run is still not well-developed and this shows that the performance is still low and also related to government support is still lacking. Inhibiting factors of the performance of young educated entrepreneurs from the respondents' answers about these conditions include: lack of business capital, then the economic conditions of the community that are less supportive so that the purchasing power of the people decreases and the problem of business skills owned by young entrepreneurs and the level of intense competition and the quality of service products produced in business as well as marketing and business premises.

No abstract

Corncobs are a waste product from corn farming that are abundant in Indonesia. Corncobs have a high cellulose content, more than 40%, which made it useful for synthesizing CMC. CMC is a cellulose derivative that is widely used in many industries such as food, pharmaceutical, detergent, textile, cosmetic product and binder. In this paper, we use CMC that are synthesized from corncobs as binder in the electrodes of lithium ion battery. The steps of synthesizing CMC from corncobs started with the isolation of the cellulose, then followed by the processes of alkalization, carboxymethylation and finally the purification. FTIR spectrum shows that CMC are successfully synthesized. The presence of strong absorption band at 1613 cm-1 is related to the stretching vibration of the carboxyl group (COO-). The absorption in the 1300–1450 cm-1 region is due to symmetrical deformations of CH2 groups. While the broad absorption around 3427 cm-1 is due to the stretching of the hydroxyl groups (-OH). Test on three samples of different sizes, (mesh-100, mesh-60 and mesh-40) gives CMC purity values of 98.69%, 98.56% and 97.77%, respectively. In the application of CMC as anode binder, the best composition is 4% CMC, where it gives the highest conductivity of 0.587 S/cm. Voltammogram measurement with a scan rate of 50 mV/s in the voltage range of -1 to 1 Volt gives the capacitance value of 2237 μF.