Judul: Rancang Bangun dan Pengujian Penetrometer Digital dengan Perekam Data Berbasis Android.
Abstrak: Penetrometer statis didesain untuk mengukur gaya yang dibutuhkan untuk menekan probe kerucut kedalaman tanah dengan kecepatan konstan. Output datanya adalah gaya persatuan luas tanpa faktor sifat tanah lain seperti kadar air. Kadar air tanah merupakan faktor penting yang memengaruhi tahanan penetrasi tanah. Metode pengukuran kadar air yang umum menggunakan metode gravimetri yang membutuhkan waktu cukup lama untuk mendapatkan data kadar air tanah. Maka dari itu dibutuhkan penetrometer yang dapat sekaligus mengukur kadar air dengan baik. Tujuan dari penelitian ini adalah merancang, membangun dan menguji penetrometer digital dilengkapi pembacaan kadar air dengan perekam data berbasis android. Penelitian ini dibagi ke dalam 2 tahap utama, yaitu: tahap I (desain konseptual) dan tahap II (pembuatan prototipe dan pengujian). Tahap I merupakan tahap yang diawali dengan identifikasi masalah hingga didapatkan produk berupa gambar teknik. Tahap II merupakan tahapan yang terdiri dari pembuatan prototipe, uji fungsional, uji kinerja alat, pengolahan data dan analisis data. Analisis data yang dilakukan yaitu dengan menggunakan regresi linear serta pengolahan data berupa ketelitian dan ketepatan. Data yang dianalisis adalah data hasil pengujian fungsional dan pengujian kinerja. Loadcell dan HX711 digunakan sebagai sensor gaya, HC-SR04 dan DHT11 digunakan sebagai sensor kedalaman dan kit sensor kadar air tanah termodifikasi digunakan sebagai sensor kadar air. Hasil kalibrasi dan validasi sensor didapatkan nilai R2 = 0.9994 dan R2 = 0.9995 untuk sensor gaya, R2 = 0.9999 dan R2 = 0.9999 untuk sensor kedalaman, R2 = 0.9098 dan R2 = 0.9255 untuk sensor kadar air tanah. Hasil pengujian kinerja penetrometer di laboratorium secara terpadu didapat nilai R2 = 0.9224 untuk cone index, R2 0.9836 untuk sensor kedalaman dan R2 = 0.7576 untuk sensor kadar air. Hasil pengujian kinerja di lahan kering secara terpadu di dapatkan nilai nilai R2 = 0.9583 untuk cone index, R2 = 0.9994 untuk sensor kedalaman dan R2 = 0.6673 untuk sensor kadar air. Hasil pengujian di lahan sawah didapatkan nilai R2 = 0.9583 untuk sensor gaya, R2 = 0.9941 untuk sensor kedalaman dan R2 = 0.7696 untuk sensor kadar air. Hasil analisis regresi pada proses kalibrasi ulang didapat persamaan penduga kadar air dengan nilai R2 = 0.8590 untuk pengujian di laboratorium, R2 = 0.7201 untuk pengujian di lahan kering, R2 = 0.9058 untuk pengujian di lahan sawah. Berdasarkan data yang didapatkan maka penetrometer yang dirancang dapat digunakan sebagai alternatif instrumen ukur tahanan penetrasi yang dilengkapi dengan data kadar air.
Keyword: penetrometer digital, loadcell, sensor kedalaman, sensor kadar air tanah

Judul: Desain Penetrometer Digital Berbasis Mikrokontroler ATmega 8535
Abstrak: Until recently, most of soil strength measuring instrument still use spring scales penetrometer such as mechanical penetrometer. Mechanical penetrometer was difficult to use and has recording in accuracy because manual reading of spring scales and distance simultaneously. Moreover, mechanical penetrometer need three operator for operation. Therefore, digital penetrometer was developed to solve this problem. Penetrometer digital consists two main components : a electronics components and a mechanical components penetrometer. A mechanical component consists of a handle ring tranducer, penetrometer rod, and cone. Electronic components consists of sensor temperature LM35, strain gage, depth sensor , amplifier, microcontroller ATmega 8535, LCD screen, and battery 9 volts. Methodology use in this research was engineering design based on functional and structural design. Ergonomic of the developed digital penetrometer were condidered based on the Indonesians average anthropometries. Measurement principles the digital penetromter consist of: Compressive force was measured using strain gage sensors mounted on the ring transducer. Shinkage ring transducer strain gage sensor response by the form of the resistance value, because it is too small it takes amplifier, then processed by the microcontroller to be converted into units of kgf. Depth data obtained using ultrasonic sensors ranger. Ultrasonic signal transmission on soil will be reflected and received again by ultrasonic. From measuring the reflection will be further processed by a microcontroller and converted into units of cm. The data read by the LM35 temperature in the form of resistance. After that, change the resistance of the voltage to the microcontroller unit Celsius degree. The third sensor measurement results will be displayed through the LCD and stored in the EMS flash memory. Dimension of the digital penetrometer was 94 cm length, 12 millimeters rod diamater. Penetration of the developed penetrometer was done manually, while measurement of force was done by ring transduser, while depth of penetration was measured by ultrasonic sensor. Result of measurment was displayed on the LCD screen and recorded on EMS data flash memory.
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Judul: Lejeuneaceae Subfamily Ptychanthoideae (Hepaticae) in  West Java
Abstrak: Subfamily Ptychanthoideae of the family Lejeuneaceae (Hepaticae) in West Java is still poorly known. Publications on this subfamily are out of dated and written in the 19th or early of 20th century. The last taxonomic treatment of Ptychanthoideae of West Java was in 1933, many species names have changed since then. Studies on Ptychanthoideae of West Java are urgently needed. Studies on the Ptychanthoideae were based on the specimens collected from West Java. A total number of 361 of specimens deposited in the Herbarium Bogoriense (BO), Herbarium Biotrop (BIOT), Gottingen Herbarium (GOET) and Bangi Herbarium (UKMB) were examined, those are old and several recent specimens collected in West Java. Recent collections were made from Telaga Warna, Ciater, Gunung Halimun Salak National Park, Cibodas Botanical Garden, Bodogol Education Center and Conservation (Gunung Gede Pangrango National Park), University of Indonesia Campus Depok, including several collections from Banten Province. Twenty four species of Lejeuneaceae subfamily Ptychanthoideae are known from West Java, belonging to 8 genera namely Acrolejeunea (Spruce) Schiffn. (2 species), Archilejeunea (Spruce) Schiffn. (1 species), Lopholejeunea (Spruce) Schiffn. (10 species), Mastigolejeunea (Spruce) Schiffn. (3 species), Ptychanthus Nees (1 species), Schiffneriolejeunea Verd. (1 species), Spruceanthus Verd. (2 species) and Thysananthus Lindenb. (4 species). Two new records of Ptychanthoideae: Mastigolejeunea indica Steph. and Thysananthus minor Verdoorn are reported for Java. A determination key to the species is presented including their descriptions and illustrations.
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