Judul: Karakteristik pertumbuhan anakan bambu tali (gigantochlos apus kurz.) perbanyakan split
Abstrak: Bambu tali (Gigantochloa apus Kurz.) memiliki prospek yang cukup baik karena kegunaannya yang bermacam-macam yaitu sebagai bahan baku pokok dalam pembuatan kerajinan, anyaman baik yang berupa alat-alat rumah tangga maupun hiasan. Sejalan dengan peningkatan jumlah penduduk dan perkembangan industri yang menggunakan bambu sebagai bahan baku, kebutuhan akan komoditi ini meningkat, sementara itu, pasokan bahan baku bambu masih tergantung pada sumber alam, padahal sumber alam tersebut dan sumber- sumber yang ada pun semakin menurun kuantitas maupun kualitasnya sebagai akibat intensitas eksploitasi sehingga perlu dilakukan pembudidayaan bambu secara intensif. Dalam rangka pembudidayaan bambu tersebut telah banyak dilakukan upaya pembiakan secara vegetatif dengan cara stek bonggol maupun stek batang. Perbanyakan secara vegetatif merupakan cara yang efektif dalam perbanyakan bambu tali. Pembangunan persemaian bambu dilakukan untuk meningkatkan keberhasilan penanaman di lapangan. Tunas-tunas hasil pembiakan vegetatif berkembangbiak menghasilkan tunas-tunas baru dalam polybag dan dapat digunakan sebagai bahan tanaman dengan cara split. Dalam pertumbuhan tunas tersebut, terdapat suatu perilaku yang menarik, yaitu pertumbuhan tunas pertama, kedua, ketiga dan seterusnya menunjukkan adanya perbedaan. Perbedaan tersebut adalah adanya peningkatan ukuran diameter dan panjang tunas dari tunas pertama, kedua dan seterusnya. Pola pertumbuhan tunas ini perlu diteliti lebih lanjut dalam rangka pengembangan pengetahuan tentang biologi bambu tali untuk menunjang perbanyakannya Penelitian ini bertujuan untuk mengetahui kecepatan tumbuhnya tunas, kecepatan munculnya tunas dan karakteristik pertumbuhan tunas bambu tali (Gigantochloa apus Kurz.) antara buluh induk dan buluh-buluh anak.
Keyword: Bamboos

Judul: Pertumbuhan Tiga Spesies Bambu Dengan Berbagai Media Tanam
Abstrak: Bambu termasuk jenis rerumputan dari famili Poaceae, yang tumbuh menyerupai pohon berkayu dengan batang bulu berongga. Hal tersebut dikhawatirkan penurunan potensi dan keanekaragaman jenis bambu dapat terjadi. Oleh karena itu, perlu dilakukan pemenuhan bibit bambu. Tujuan dari penelitian ini adalah mengetahui media yang paling cocok untuk mendukung percepatan pertumbuhan dan mengetahui dari ketiga spesies bambu mana yang paling cepat tumbuh. Penelitian dilakukan selama 12 minggu, pada bulan April hingga Juli 2023. Jenis data yang digunakan yaitu jumlah cabang, jumlah daun, dan persentase hidup. Analisis data menggunakan uji ANOVA kemudian dilakukan uji lanjut BNT (Beda Nyata Terkecil) dengan metode RAK (Rancangan Acak Kelompok). Hasil dari penelitian menunjukkan bahwa media tanam yang paling baik untuk pertumbuhan yaitu campuran media tanam tanah dengan pupuk kandang. Spesies bambu yang berpengaruh nyata pada pertumbuhan stek cabang bambu adalah bambu buluh (Schizostachyum brachycladum). Persentase hidup keberhasilan pertumbuhan stek cabang bambu dimiliki oleh bambu buluh (Schizostachyum brachycladum) dan bambu ater (Gigantochloa atter), yaitu 58%. Kata kunci: bambu, media tanam, pertumbuhan, stek cabang, Bamboo is a type of grass from the Gramineae family, that grows to resemble a woody tree with hollow bristle stems. It is feared that there may be a decrease in the potential and diversity of bamboo species. Therefore, it is necessary to fulfil bamboo seedlings so that the existence of bamboo species is maintained. The purpose of this study was to determine the most suitable medium to support the acceleration of growth and to determine which of the three species of bamboo is the fastest growing. The study was conducted for 12 weeks, from April to July 2023. The type of data used is the number of branches, the number of leaves, and the percentage of life. Data was analyzed using the ANOVA test, and then further tests were run using the SMD (Smallest Mean Difference) test with the RGD (Random Group Design) method. The results of the research show that the best planting medium for growth is a mixture of soil and manure. The bamboo species that has a significant effect on the growth of bamboo branch cuttings is reed bamboo (Schizostachyum brachycladum). The survival percentage of successful growth of bamboo branch cuttings belongs to reed bamboo (Schizostachyum brachycladum) and ater bamboo (Gigantochloa atter), namely 58%. Keywords: bamboo, branch cuttings, growth, growing medium
Keyword: Bamboo, Branch cuttings, growth

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