Judul: Rancangan Konseptual Mesin Penggerak Aplikator Pupuk Butiran dengan Mekanisme Pengangkat Pelepah Daun
Abstrak: Fertilizer application is one of activities on oil palm tree cultivation. Fertilizer application is applied in nursery, pre-production plant, and production plant. Inaccuracy of spreading is one of fertilization problem such as fertilizer which was dropped on oil palm frond, especially on pre-production plant. The objective of this research is to make conceptual design of prime mover of granular fertilizer applicator with frond lifting mechanism. The design criteria were the ground pressure of machine less than 90 kPa, maximum width machine was 250 cm and 220 cm of high. The result indicate that weight of machine without fertilizer applicator was 1205.55 kg, 19.59 kPa of ground pressure, 141.3 cm of width and 174.9 cm of high. The prime mover component consist of chassis, gearbox, crawler, roller, engine, control lever, seat, lifter conveyor, and cabin chassis. The chassis was made from canal UNP S45C. Based on engineering analysis, chassis has 3.03 N/m2 of maximum shear stress and 30.92 N/m2 of maximum bending stress. Frond lifting system slope was 53.45o and operated at 0.67 m/s of forward velocity with 1.13 m/s of lifting velocity. Based on result of load static simulation from SolidWorks software, the material which used in each component is safe because the value of stress is less than material yield strength.
Keyword: Bogor Agricultural University (IPB), SolidWorks, load simulation, conveyor, fertilization

Judul: Rancang Bangun Mesin Pemupuk Kelapa Sawit dengan Metode Pembenaman ke Dalam Tanah
Abstrak: Fertilizer application methods for oil palm by spreading fertilizer on the soil surface need to be fixed, by immersion of fertilizer in the soil to make it more effective and more efficient in the use of fertilizer. The objective of this research was to design and construct a prototype of fertilizer immersion machine for oil palm, driven by a four-wheel tractor. The machine was designed using a rotor type metering device for fertilizer metering, and a rotary blades mechanism for immersion of fertilizer in the soil. The metering device and the rotary shaft were driven by the PTO of the tractor using a gear box and sprockets-chain power transmissions. The rotary unit consisted of four rotary blades mounted on two flanges which were welded to the rotary shaft with flanges spaced of 20 cm. Rotary diameter was 45 cm, working width was 20 cm, and the rotation speed was 200 rpm. The machine was mounted on a four-wheel tractor via the three point hitches. Based on the results of the design, a prototype was constructed and tested. The test results showed that the machine could immerse fertilizer into the soil at a depth of 10-15 cm and mixing with soil in fairly evenly. Fertilizing dose was about 1 kg per meter application.
Keyword: tractor, oil palm, immersion, rotary, fertilizer applicaort

Judul: Effects of Alcohol Consumption on Spatial Memory Performance and Neuron Complexity
Abstrak: Alcoholic beverages have always been a common drink all around the globe. The ethanol that is contained inside these alcoholic beverages have been known to have various negative side effects to the brain if consumed excessively. Other articles have claimed a certain moderate amount of alcohol consumption could have beneficial effects on the brain, but no exact concentration limit of consumption has been elaborated to cause damage in the hippocampal area. The objective of this research is examining the effects of alcohol towards neuron complexity and spatial memory performance. Four groups of mice were used as test subjects and were given the solution pre-orally. The first group is the control group which is given water, the second group was given 5% alcohol, the third group was given 15% alcohol, and the fourth group was given commercially sold alcoholic beverage. The mice were given said solutions in the span of 30 days. Spatial memory performance is observed by how a mice scores inside a Y-maze in the span of 5 minutes after 30 days of treatment. Neuron complexity is determined by the number of intersections of dendrites and the maximum angle of neurons inside the Dentate Gyrus (DG) and Cornu Ammonis (CA) region of the hippocampus which is observed by Golgi-Cox staining, photographed with optilab and then analyzed using the ImageJ application. alcohol consumption does not have any significant effect on spatial memory performance nor neuron complexity in the hippocampal area. These findings are not significantly different than the control group, possibly because the treatment is not chronic enough to trigger a significant physiological change.
Keyword: Ethanol, spatial memory, complexity, hippocampus