Judul: Characteristics of Pine Stands (Pinus merkusii Jungh. et de Vriese) Resin Production in KPH Pati
Abstrak: Getah pinus memiliki nilai ekonomi yang tinggi dan potensial untuk dibudidayakan. Pengusahaan getah pinus oleh KPH Pati tidak lepas dari informasi yang menunjang peningkatan produktivitas getah. Tujuan penelitian ini mengidentifikasi karakteristik tegakan pinus (Pinus merkusii Jungh. et de Vriese) penghasil getah di KPH Pati. Pemilihan pohon contoh dilakukan dengan metode purposive sampling. Pengamatan kondisi lingkungan dilakukan dengan metode deskriptif berupa observasi dan dokumentasi. Rata-rata produktivitas getah pinus pada anak petak 36E dan 70A sebesar 0,716 kg/bulan/pohon dan 1,320 kg/bulan/pohon. Pohon pinus pada anak petak 36E memiliki diameter batang kecil, sedangkan pohon pinus pada anak petak 70A memiliki diameter batang besar. Peubah diameter setinggi dada, tinggi total, jumlah bidang sadap, tinggi bidang sadap, kedalaman bidang sadap, dan ketinggian tempat tumbuh memiliki tingkat keeratan hubungan sangat lemah terhadap produktivitas getah. Kerapatan tegakan pada anak petak 36E tinggi sedangkan kerapatan tegakan pada anak petak 70A jarang. Getah pinus yang tertampung pada wadah penampung getah terlihat tercampur dengan air dan kotoran., Pine resin has a high economic value and potential to be cultivated. Pine resin business by KPH Pati cannot be separated from information that supports the increase in resin productivity. The goal of this study to identify the characteristics of pine stands (Pinus merkusii Jungh. et de Vriese) resin producing in KPH Pati. The selection of sample trees was carried out by purposive sampling method. Observation of environmental conditions is carried out by descriptive methods are observation and documentation. The average pine resin productivity in anak petak 36E and 70A was 0,716 kg/month/tree and 1,320 kg/month/tree. The pine trees in anak petak 36E have a small diameter, while the pine trees in anak petak 70A have a large diameter. The diameter, total height, number of tapping fields, height of the tapping field, depth of field of tapping, and height of the growing place have a very weak level of closeness to resin productivity. The density of stands in anak petak 36E is high, while the density of stands in anak petak 70A is rare. Pine resin that is accommodated in a resin-holding container looks mixed with water and dirt.
Keyword: Descriptive, Purposive Sampling, Resin Productivity

Judul: Produktivitas Penyadapan dan Pengumpulan Getah Pinus (Pinus merkusii) di RPH Wagir, BKPH Kepanjen, KPH Malang
Abstrak: Salah satu upaya meningkatkan produktivitas getah pinus yaitu dengan melakukan perhitungan untuk mengetahui besaran produktivitas. Faktor-faktor yang memengaruhi produktivitas penyadapan dan pengumpulan juga harus diketahui agar dapat menjadi evaluasi untuk meningkatkan produktivitas. Tujuan dari penelitian ini menganalisis nilai produktivitas dari penyadapan dan pengumpulan getah pinus dan menganalisis pengaruh kemiringan lahan, diameter, dan waktu kerja. Metode penelitian menggunakan time study. Hasil dari penelitian yang dilakukan diperoleh produktivitas penyadapan dan pengumpulan pada KU VI curam sebesar 21,262 pohon jam-1 dan 29,188 kg jam-1. KU VI datar produktivitas penyadapan sebesar 7,736 pohon jam-1 dan pengumpulan sebesar 15,344 kg jam-1. Produktivitas penyadapan dan pengumpulan KU IV curam sebesar 22,607 pohon jam-1 dan 34,371 kg jam-1. Produktivitas penyadapan dan pengumpulan pada KU IV datar sebesar 20,906 pohon jam-1 dan 30,839 kg jam-1. Faktor yang memengaruhi produktivitas pada penyadapan dan pengumpulan yaitu waktu kerja yang memiliki hubungan sangat kuat dan berbanding terbalik. Kemiringan lahan tidak memiliki hubungan terhadap produktivitas penyadapan dan pengumpulan. Diameter tidak memiliki hubungan juga terhadap produktivitas pengumpulan., One of the efforts, to increase the productivity of pine resin, is to do calculations to find out the amount of productivity. Factors that affect tapping and collection productivity should be identified so that they can be used as an evaluation in order to increase productivity. The purpose of this study is analyze the productivity of tapping and collecting pine resin and analyze the effect of the slope, diameter, and work time. This study method is time study. The result of the research conducted obtained tapping and collection productivity at KU VI steep is 21,262 trees hour-1and 29,188 kg hour-1. KU VI flat the productivity that is tapping of 7.736 trees hour-1and collection of 15.344 kg hour-1. The productivity of KU IV steep tapping and collecting is 22,607 trees hour-1 and 34,371 kg hour-1. In addition, the productivity of tapping and collection at KU IV flat is 20,906 trees hour-1 and 30,839 kg hour-1. The factors which affect productivity in tapping and collection are that working time which has a very strong and inversely significant correlation. The slope has no significant correlation to productivity in tapping and collection. The diameter has no significant correlation to productivity in the collection.
Keyword: pine resin, time study, working time, productivity

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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