Plastic optical fiber testing as a sensor can be applied in pH measurement using loop configuration. It was made of a plastic optical fiber material with two types of peel, namely with cladding and without cladding. Sensor testing was done by dipping the sensor into buffer solutions with varying pH values. The light intensity from the LED will experience power losses due to the effect of adding the solution refractive index around the sensor, so the phototransistor will receive smaller the light intensity. Changes of light intensity in the optical fiber causes the output voltage read on the microcontroller and the computer decreases. The best measurement was obtained at sensor type of without cladding 4 loops with sensitivity 0.035 V/pH and resolution 0.029 pH. Aplication of plastic optical fiber as sensor for pH measurement has advantages such as low cost, real time, high sensitivity, accurate and simple measurement.

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In the first days after hatch, the development of organs such as the gastrointestinal tract, and the growth performance may be affected by the time in between hatch and first feed intake. In current practice, time between hatch and moment of first feed intake may take long time because of variation in hatch time, chick handling, and transportation time. Feed deprivation, especially during the first days after hatch, depresses intestinal development on the short and long term, reflected by a lower intestinal weight, shorter length, lower enzymatic activity, altered villi and crypt cell density, and lower crypt depths and villi heights and finally, depressed growth. The objective of this study was to investigate effects of the moment of first feed intake after hatch on intestinal development and growth performance of broiler chickens. A total 60 unsexed day-old Lohmann broiler chicks were randomly assigned into 3 treatments of 20 chicks each in four replicates (5 chicks each). The treatments were time first feed and water access after hatch, including 12, 42 and 72 hours. Body weight gain and feed intake were recorded weekly and the intestinal development were sampled at 12 days for the measurement of ileum histology and length of gastrointestinal tract. Results obtained were as follows: Time between hatch and moment of first feed intake had no significant effect (P> 0.05) on width of the villi. However, the height of villi, depth of the crypt dan length of the gastrointestinal tract were significantly affected by treatment. The longer delay in the provision of feed and water in day-old chick were lower height of villi and depth of the crypt, dan shorter length of the gastrointestinal tract. Statistically, performance parameters had any difference among treatments, except for feed conversion. The final body weight and feed intake decreased with increasing time between hatch and moment of first feed intake. The results suggest that early delivery of first feed can influence development and growth of gastrointestinal tract. It is also beneficial to improve posthatch growth performance of broiler chickens.

The influence of thermal annealing to the properties of n-TiO2 thin films fabricated by sol-gel spin coating has been investigated using X-ray diffraction (X-RD) and UV-Vis optical transmittance measurements. TiO2 thin films were prepared by dissolving TiO2 Nano-powders into a solvent of ethanol and it becomes sol-gel. The sol-gel of TiO2 was deposited on indium tin oxide (ITO) substrate. Then, the TiO2 the thin films were inserted into tube furnace for annealing in the temperature range of 3000C to 5000C during 60 minutes. Based on the xray diffraction results, the crystal structure of TiO2 is anatase phase structures. The crystalline size of TiO2 films after annealing at 300°C was 46.6 nm and it slightly decreased to 46.2 nm after annealing at 500°C. The optical transmittance value of TiO2 film increased after annealing in comparison before annealing the TiO2 film.