Judul: Determination of footprint area model using body weight and height as prediction parameters
Abstrak: Prediksi ketenggelaman roda merupakan hal penting untuk diperhitungkan dalam studi kinerja sebuah kendaraan off-road yang beroperasi pada suatu lahan agar tercapai efisiensi dan efektifitas kinerja kendaraan. Hal tersebut seyogyanya dapat diukur dengan alat/metode yang sederhana seperti ketenggelaman telapak kaki agar petani lebih mudah dan cepat dalam memprediksi ketenggelaman roda kendaraannya. Parameter yang diperlukan untuk memprediksi ketenggelaman telapak kaki adalah berat badan dan luasan telapak kaki, sedangkan untuk memprediksi luasan telapak kaki diperlukan parameter berat dan tinggi badan. Penelitian ini bertujuan untuk membuat model luasan telapak kaki (A) subjek laki-laki dan perempuan dengan parameter berat badan (W) dan tinggi badan (H).
Keyword: sinkage, human foot sinkage, footprint area model

Judul: Pendugaan Kedalaman Tekan Roda Traktor Roda Empat Berbasis Uji Kedalaman Tekan Telapak Kaki Manusia
Abstrak: Load of a tractor on certain terrain condition may cause sinkage, which results motion resistance on its four wheels. This motion resistance reduces its mobility and decreasing work capacity. This research was aimed to predict the sinkage of a fourwheel tractor based on human footprint approximation. The parameters examined for the sinkage prediction were pressure and the physical properties of soil. Based on the observations, water content can be used as representative of other soil properties. Through linear regression analysis, some equation models for predicting human footprint and tractor sinkage were obtained. The equation models employed water content and normal pressure as the independent variables. Those models were then compared with the observed tractor’s sinkage to find the best fitted model. Equation model zkskid = 12.804 - 0.275(ka) + 6.56(P) through male subject and zkdkab = 18.028 - 0.262(ka) - 7.304(P) through female subject were the best fitted model that can be used for sinkage prediction of four-wheel tractors.
Keyword: soil, equation model, sinkage, footprint, tractor, Bogor Agricultural University (IPB)

Judul: Phycocyanin Extract From Spirulina platensis for as an Antioxidant and Biopigment for Spherificated Caviar Product
Abstrak: Fikosianin merupakan pigmen alami berwarna biru cerah yang kaya manfaat dengan kandungan antioksidan yang tinggi. Antioksidan memiliki peran yang sangat penting untuk mencegah kerusakan tubuh pada level molekuler yang disebabkan oleh radikal bebas. Radikal bebas dapat mengakibatkan kerusakan DNA, pembelahan sel abnormal (kanker), penuaan dini, inflamasi, penyakit jantung, dan beragam efek negatif lainnya. Pigmen fikosianin tersedia secara melimpah pada Spirulina platensis yang merupakan ganggang hijau biru (mikroalga) yang mudah dikultivasi dan dikondisikan serta dapat tersedia sepanjang tahun. Sebagai pigmen alami, fikosianin cenderung tidak stabil terpapar oksigen, cahaya, suhu, dan pH tertentu. Pemanfaatan pigmen fikosianin harus mampu menjaga kestabilan kandungan bioaktif pigmen dan tetap menarik bagi konsumen. Pengolahan pigmen fikosianin sebagai food additive pewarna pada produk spherificated caviar dapat dilakukan. Spherificated caviar dibuat dengan teknik spherification yang berfungsi sebagai penyalut yang melindungi bahan inti. Tujuan dari penelitian yaitu mempelajari pengaruh penambahan pigmen fikosianin kedalam produk spherificated caviar terhadap stabilitas kandungan antioksidan pigmen serta penerimaan konsumen terhadap produk. Metode yang dilakukan meliputi ekstraksi pigmen fikosianin dengan metode maserasi, kemurnian pigmen, analisis aktivitas antioksidan, dan uji organoleptik. Hasil menunjukan ekstrak pigmen dalam jangkauan warna biru kehijauan, pemurnian ekstrak menghasilkan angka 1,541 dengan kategori food grade. Analisis antioksidan menghasilkan nilai IC50 2,81 untuk ekstrak, dan nilai IC50 10,54 setelah diolah menjadi produk, keduanya termasuk kedalam kategori antioksidan kuat. Variasi konsentrasi pigmen fikosianin tidak memberi perbedaan nyata terhadap penerimaan konsumen dalam atribut warna, rasa, dan tekstur produk. Kata kunci: antioksidan, fikosianin, pigmen, spherificated caviar, Spirulina platensis, Phycocyanin is a bright blue natural pigment that has great beneficial and rich in antioxidant content. Antioxidant has an important role in preventing molecular damage on the body that is caused by free radicals. Free radicals could cause DNA damage, abnormal cell growth (cancer), premature aging, inflammation, heart diseases, and other negative effects. Phycocyanin pigment is found abundance in Spirulina platensis which is a blue green algae (microalgae) that is easy to cultivated and conditioned, also able to produce throughout the year. As a natural pigment, phycocyanin is prone to be unstable when exposed to oxygen, light, and to a certain temperature and pH. The utilization of phycocyanin pigment as colorant food additive in spherificated caviar product could be considered. Spherificated caviar is made with spherification technique that acts as coat / encapsulating that protects the main substance. The objective of this research is to study the effect of adding phycocyanin pigment into spherificated caviar product and also consumer preference of the product. Methods that are used including phycocyanin extractions with maceration method, phycocyanin pigment purity ratio, antioxidant activity analysis, and organoleptic test. The result shows phycocyanin pigment extraction produce bluish green colour, phycocyanin purification resulting in 1,541 value which belongs in the food grade category. Antioxidant analysis resulting in IC50 value of 2, 81 for phycocyanin extract, and IC50 value of 10,54 after being processed into spherificated caviar product, both value fall under very strong antioxidant category. Variants of phycocyanin pigment concentration added into the product did not affect consumer preferences in color, taste, and texture of the product. Keywords: antioxidant, phycocyanin, pigment, spherificate caviar, Spirulina platensis
Keyword: antioxidant, phycocyanin, pigment, spherificated caviar, spirulina platensis