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: Serangan Rayap Tanah terhadap Tegakan Pohon di Kebun Raya Bogor
Abstrak: Pelestarian dan perlindungan terhadap pohon-pohon yang tersimpan di Kebun Raya Bogor (KRB) perlu dilakukan untuk menghindari kerusakan oleh berbagai macam penyakit maupun serangga perusak termasuk rayap. Penelitian bertujuan menganalisis frekuensi serangan rayap dan mengidentifikasi jenis rayapnya, menganalisis preferensi rayap terhadap jenis pohon, serta tingkat kerusakan pohon akibat serangan rayap di KRB. Penelitian dilakukan dengan menggunakan metode jalur sampling dengan Intensitas Sampling 20%. Hasil penelitian menunjukkan bahwa sebanyak 213 (100%) pohon contoh di KRB terserang rayap. Spesies rayap tanah yang ditemukan sekurang-kurangnya terdapat empat spesies yaitu Coptotermes curvignathus Holmgren, Macrotermes gilvus Hagen, Odontotermes javanicus Holmgren dan Nasutitermes matangensis Haviland. Rayap M. gilvus banyak ditemukan pada pohon Pterocarpus indicus, Dysoxylum spp., Shorea spp., dan Dimocarpus spp.. Rayap O. javanicus banyak ditemukan pada pohon Vitex cofassus, Dehaasia incrassata, Heritiera spp., dan Cordia spp.. Rayap N. matangensis banyak ditemukan pada pohon Canarium indicum, Dysoyylum spp., dan Sindora spp.. Rayap C. curvignathus banyak ditemukan pada pohon Araucaria columnaris, Agathis sp., dan Pinus spp. Tingkat kerusakan pohon contoh akibat serangan rayap sebesar 10-90%., Preservation and protection of trees stored in the Bogor Botanical Gardens (KRB) need to be done to prevent damage by various kinds of diseases and destructive insects including termites. This study aimed to analyze the frequency of termite attacks and to identify the type of termites, to analyze termite preferences for tree species, as well as the degree of tree damage due to termite attacks in KRB. The research was conducted using the path sampling method with a sampling intensity 20%. The results showed that as many as 213 (100%) sample trees in KRB were attacked by termites. There are at least four subterranean termite species found, namely Coptotermes curvignathus Holmgren, Macrotermes gilvus Hagen, Odontotermes javanicus Holmgren, and Nasutitermes matangensis Haviland. Termites M. gilvus are found in Pterocarpus indicus, Dysoxylum spp., Shorea spp., and Dimocarpus spp. Termites O. javanicus are found in Vitex colossus, Dehaasia incrassata, Heritiera spp., and Cordia spp. Termites N. matangensis is found in Canarium indicum, Dysoxylum spp., and Sindora spp. Termites C. curvignathus can be found in Araucaria columnaris, Agathis sp., and Pinus spp. The level of damage to sample trees due to termite attacks is 10-90%.
Keyword: Attack frequency, subterranean termites, termite preferences, tree health

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