Judul: Penyusunan tabel volume sortimen jati (Tectona grandis, L.f.) di kph Pemalang perum perhutani unit I Jawa Tengah
Abstrak: Forest inventory is an activity related to tree stand potency prediction, including timber potency. As it is in Jati forest, the purpose of inventory is estimating the quality and quantity of timber potency. Table volume classification is needed to make tree volume prediction less complicated. There are one or more variables that usually used in tree table volume prediction. Because timber values are different in each sorts, Jati timber value is depend on its’ sorts type. Therefore, volume information of each sort type is absolutely required. Spread diagram from the sample tree were conducted to determine the models that will be used to predict the tree volume, whether it is linear (single and multiple) or non-linear. Based on the diagram, tree table volume prediction model can be determined. Tree volume prediction models, according to Spurr (1952), i.e: 1. Berkhout Model : V = a Db 2. Shumacher Hall Model : V = b0 Db1 Tb2 3. Stoate Model : V = b0 + b1 D2 + b3 D2 T + b4 T The Spurr models above can be transformed into linier regression models through the use of logarithmic transformation. Berkhout model type, which is often used in tree volume prediction, needed to be transformed into logarithmic equation. Conversely, Schumacher Hall and Stoate equation are already in linear type that logarithmic transformation is unneeded. Jati volume prediction at KPH Pemalang by using Berkhout model without transformation delivered better accuracy compare to another models with transformation. Best Jati volume prediction model determined at KPH Pemalang is Modified Geometric model : V = 13.432379 D (-29.5999/D). D in the equation determined as diameter breast height, within range 18-70 cm. Jati volume prediction per sort at KPH Pemalang can be determined based on the proportion of sort volume to total tree volume. The tree volume can be attained from model V = 13.432379 D^(-29.5999/D).
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Judul: Penyusunan Model Penduga Volume Jati (Tectona grandis L.f) di BKPH Wilangan Selatan, KPH Saradan, Perum Perhutani Divisi Regional Jawa Timur
Abstrak: Kegiatan inventarisasi hutan bertujuan memperoleh data dan informasi kondisi sumber daya hutan yang nantinya akan digunakan sebagai acuan dalam perencanaan hutan. Penentuan volume pohon atau tegakan secara langsung terkadang sulit dan tidak praktis dilakukan di lapangan. Oleh karena itu, diperlukan ketersediaan alat bantu dalam inventarisasi hutan untuk mempercepat kegiatan dan memperkecil kesalahan dalam pengukuran yang dikenal dengan tabel volume pohon. Penelitian ini bertujuan menyusun model penduga volume terbaik untuk pohon jati (Tectona grandis L.f) kelas hutan tanaman bertumbuhan kurang (TBK) di BKPH Wilangan Selatan. Sebanyak 62 pohon contoh digunakan untuk penyusunan model dan 31 pohon contoh untuk validasi model yang dipilih secara purposive dari petak-petak kelas hutan TBK. Pengukuran diameter dan tinggi pohon menggunakan Criterion RD 1000 dan pita ukur. Model penduga volume terbaik untuk pohon jati kelas hutan TBK adalah model Berkhout (V = 0.000302Dbh2.18) dengan R2 adj sebesar 87.3% dan simpangan baku sebesar 0.078. Model persamaan regresi penduga volume yang sudah ada tidak berbeda nyata dengan model terbaik yang didapatkan.
Keyword: TBK forest class, Tectona grandis L.f, volume estimator model

Judul: Durability of Specific Immunoglobulin (Ig) Y Againts Influenza and Covid-19 in Sunscreen
Abstrak: The benefit of specific immunoglobulin Y (Ig Y) as an active ingredient in personal care products such as sunscreen has not been properly studied. Our study aims to evaluate the reliability of specific IgY against influenza and the COVID-19 virus in a sample sunscreen product. Specific IgY influenza and COVID-19 viruses were inserted in the sample sunscreen at two concentrations of 0.1% and 0.25%. Three treatments were observed: control (C) sunscreen without IgY, treatment 1 (T1) sunscreen with 0.1% IgY, and treatment 2 (T2) sunscreen with 0.25% IgY. Organoleptic observations were carried out to monitor changes in aroma, color, and texture, and sunscreen sampling was done every week for 6 weeks. The durability of IgY was evaluated using an enzyme-linked immunosorbent assay (ELISA) and a neutralization assay. Organoleptic observation from weeks 1 to 6 showed consistency in its aroma, color, and texture. Enzyme-linked immunosorbent assay and neutralization assay (NA) results of the T1 and T2 groups showed negative results except for sample T1 at week 5, which showed a positive result in the Influenza A ELISA. Based on the results, it seems that IgY concentrations of 0.1% or 0.25% were not optimal. However, this negative result might be due to low concentration of the IgY and the presence of beeswax, which inhibits IgY and causes it to dissolve in distilled water, thus preventing it from being detected in the assay.
Keyword: Immunoglobulin Y, Sunscreen, Influenza, COVID-19, Biological Activity