Judul: Serangan Rayap Tanah pada Areal Demplot Uji Keturunan Eucalyptus pellita di Parung Panjang, Bogor, Jawa Barat
Abstrak: Sejak penanaman yaitu bulan Maret 2021 sampai umur delapan bulan, beberapa tanaman Eucalyptus pellita di areal demplot uji keturunan mengalami kematian akibat serangan rayap tanah. Akan tetapi jenis rayap tanah yang menyerang dan berpotensi menyerang belum diketahui secara komprehensif. Penelitian ini bertujuan untuk mengevaluasi frekuensi serangan rayap tanah dan potensi serangannya pada areal demplot uji keturunan E. pellita Kawasan Hutan dengan Tujuan Khusus, Parung Panjang, Bogor, Jawa Barat serta mengidentifikasi spesies rayap tanah yang menyerang kayu umpan. Penelitian dilakukan dengan cara pengumpanan menggunakan kayu pinus (Pinus merkusii) berdasarkan American Society for Testing and Material D 1758-06. Hasil penelitian menunjukkan bahwa, frekuensi kematian tanaman E. pellita di areal demplot mencapai 16,29%, frekuensi serangan rayap terhadap kayu umpan pada areal demplot sebesar 85,45%, dan ratarata kehilangan berat kayu umpan sebesar 32,20%. Rayap yang ditemukan setidaknya ada tiga jenis yaitu Macrotermes gilvus, Microtermes insperatus, dan Shedorhinotermes javanicus.
Keyword: damage intensity, Eucalyptus pellita, Pinus merkusii, termite bait, weight loss

Judul: Keanekaragaman Spesies Rayap Tanah di Lingkungan Pemukiman Kota Bogor, Jawa Barat
Abstrak: Kebutuhan masyarakat Kota Bogor akan tempat tinggal semakin meningkat, sehingga mengubah kondisi lingkungan yang dapat memengaruhi keberadaan organisme pengganggu, terutama rayap tanah. Penelitian ini bertujuan untuk mengidentifikasi spesies rayap tanah dan keanekaragamannya di Kota Bogor, mengetahui karakteristik tanah dan cuaca, serta mengetahui intensitas kerusakan dan frekuensi serangan rayapnya. Penelitian dilakukan di 12 kelurahan contoh. Disetiap kelurahan contoh, ditanam 25 kayu umpan (2 x 2 x 46 cm) dari kayu pinus yang sebelumya telah diberi perlakuan tekanan uap air (105 ℃, 1 bar, 5 jam). Disetiap kelurahan contoh diambil tanah contoh. Data cuaca diukur di salah satu kelurahan contoh. Hasil penelitian menunjukkan bahwa spesies rayap yang ditemukan ada 3 jenis yaitu Microtermes sp., Macrotermes sp., dan Schedorhinotermes sp. Spesies rayap tanah di lingkungan pemukiman Kota Bogor didominasi oleh Microtermes sp. Karakteristik tanah dan cuaca sangat mendukung kehidupan rayap di Kota Bogor. Nilai frekuensi serangan rayap sebesar 38% (tinggi) dan nilai intensitas kerusakan kayu adalah 6-9.
Keyword: frekuensi serangan, intensitas kerusakan, karakteristik tanah, Pinus merkusii, tekanan uap panas

Judul: Exergy Analysis of Membrane Utilization for Solution Separation in LiBr-H2O Absorbtion Refrigeration System
Abstrak: Absorbtion refrigeration system provides prominent advantages in tems of environmental impact and energy consumption. Absorbtion refrigeration system uses natural refrigerant, such as water, which gives no harm to the environment. In terms of energy consumption, it requires heat to regenerate refrigerant from its absorber and provide the refrigeration effect. This form of energy is preferred since heat can be supplied from various sources, including waste heat and renewable energy, and thermodynamically categorized as low quality energy. However, effectiveness of refrigerant regeneration could only be obtained if the temperature is high enough. In this study, the heat utilization in the regeneration process will be eliminated by introducing membranes for separating the refrigerant from the absorber. Specifically, the objectives of this research are to :1) to study the absorbtion mechanism of water vapor by LiBr-H2O solution in a controlled condition, 2) to study the regeneration process of LiBr-H2O using reverse osmosis (RO) membrane and vacuum membrane distillation (VMD) when applied in LiBr-H2O absorbtion refrigeration system, 3) to perform the energy and exergy analysis in LiBr-H2O absorbtion refrigeration system using RO membrane. The membrane was used as a tool to separate the refrigerant from absorbent which performs as regeneration process in conventional absorbtion system. As separation component, RO membrane employs pressure to oppose the osmotic pressure and pass certain component through the pores. While, VMD employs vacuum pressure and thermal, so that the substance to be transported through the membrane is in form of vapor. The result shows that absorbtion rate of water vapor by LiBr-H2O solution was influenced by solution concentration, temperature, humidity and pressure. The highest absorbtion rate was 0.031 g/minute which was occurred at temperature 40°C, RH 70% and solution concentration 60%. Prediction model was developed to calculate the absorbtion parameter inspite of P-T-X diagram.The highest water vapor absorbtion in absorber using spiral wound module-based RO membrane occurred at initial concentration of 30%, wich is the highest concentration used in the experiment. Increasing of operation pressure during separation process will increase permeation flux but decrease rejection factor.Unexpectedly, permeate of the RO membrane still contain LiBr at concentration 7w/w %-9w/w%, which affect the achievable cooling temperature and cooling capacity. Optimization of regeneration using VMD was conducted with response surface methodology (RSM) and the result show that highest permeate flux (0.93 kg.m-2.s-1) can be achived at initial concentration of 47.5%, temperature of 80°C and flow rate of 1.9 L.min-1.COP obtained in absorbtion refrigeration system using RO membran with initial concentration 20% was in the range of 1.147-1.171. Exergy analysis shows that increasing pressure of RO membrane at concentration 20% increased the irreversibity.On the other hand, exergy analysis on VMD shows that higher concentration and temperature will increased irreversibility.
Keyword: refrigeration, absorbtion, reverse osmosis, vacuum membrane distillation, energy, exergy