Judul: Biologi dan Neraca Hayati Kutu Putih Singkong, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) pada Tanaman Talinum paniculatum
Abstrak: Kutu putih singkong, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) merupakan hama invasif baru yang berasal dari Amerika Selatan, menyebabkan kerusakan berat pada tanaman singkong di Indonesia sejak tahun 2010. Penggunaan tanaman singkong dalam pembiakan masal P. manihoti di laboratorium mengalami kendala yaitu berkembangnya tungau. Salah satu tanaman inang alternatif P. manihoti yang digunakan yaitu Talinum paniculatum (Portulacaceae). Penelitian telah dilakukan di laboratorium dengan tujuan mempelajari berbagai parameter biologi dan neraca hayati P. manihoti pada T. paniculatum. Rataan lama perkembangan telur 7 sampai 9 hari. Nimfa instar-1, -2, -3 masing-masing berlangsung 9.10, 6.80, 6.80 hari. Rata-rata lama hidup imago betina 28.98 hari, dengan rata-rata fekunditas sebesar 84.08 telur. Laju pertambahan instrinsik (rm) sebesar 0.106 keturunan betina per betina per hari. Rata-rata masa generasi (T) adalah 44.07 hari dan laju reproduksi bersih (Ro) selama periode ini sebesar 85.90. Laju pertambahan terbatas (λ) sebesar 1.11 kali per hari dan masa ganda (Dt) selama 6.86 hari. Hasil penelitian ini menunjukkan bahwa P. manihoti mampu berkembangbiak pada T. paniculatum. Oleh karena itu, T. paniculatum dapat digunakan sebagai tanaman inang alternatif untuk pembiakan massal P. manihoti di laboratorium.
Keyword: kutu putih, Phenacoccus manihoti, singkong, Talinum paniculatum

Judul: Biologi dan Neraca Hayati Kutu Putih Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) pada Tanaman Talinum triangulare.
Abstrak: Kutu putih Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) adalah hama invasif baru yang berasal dari Amerika Selatan. Hama ini menyebabkan kerusakan parah pada tanaman singkong di Indonesia sejak tahun 2010. Penggunaan tanaman singkong dalam pembiakan massal P. manihoti di laboratorium terhambat oleh infestasi tungau. Penelitian dilakukan di laboratorium dengan tujuan untuk mempelajari berbagai parameter biologi dan neraca hayati P. manihoti pada tanaman inang alternatif Talinum triangulare (Jacq.) Willd. (Portulacaceae). Masa perkembangan stadium pradewasa adalah 23,78 hari. Periode inkubasi telur adalah 8,05 hari. Nimfa instar-1, -2, -3 masingmasing 5.88, 4.68, 5.18 hari. Umur stadium dewasa adalah 21,28 hari, terdiri dari masa pra-oviposisi 8,90 hari, oviposisi 10. 78 hari dan pasca-oviposisi 1,60 hari. Rata-rata fekunditas 88 butir telur. Laju pertambahan instrinsik (rm) adalah 0,125 individu per induk per hari. Rataan masa generasi (T) adalah 36.462 hari dan laju reproduksi bersih (Ro) adalah 88.142 per generasi. Laju pertambahan terbatas (λ) adalah 1,134 per hari, dan waktu berlipat ganda (Dt) adalah 5,503 hari. Hasil penelitian ini menunjukkan bahwa P. manihoti mampu berkembang biak pada T. triangulare dengan nilai (rm) adalah 0,125. Oleh karena itu, T. triangulare dapat digunakan sebagai tanaman inang alternatif untuk permbiakan P. manihoti secara massal di laboratorium.
Keyword: kutu putih, Phenacoccus manihoti, Talinum triangulare

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