Identifikasi Zona Pengurangan Air Tanah Berdasarkan Model 3d Gaya Berat Mikro Antar Waktu

Penelitian ini dilatar belakangi oleh Kenyataan bahwa di kota Semarang telah terjadi penurunan muka air tanah di beberapa lokasi. Penelitian menggunakan metoda gaya berat mikro antar waktu (time lapse selama kurun waktu Desember 2003 hingga Juni 2004 di daerah Semarang. Tujuan penelitian adalah untuk mengaplikasikan metoda gaya berat mikro dalam menentukan zona pengurangan air tanah dataran aluvial Semarang dan melakukan pemodelan 3D menggunakan program Grav3D untuk identifikasi zona pengur angan air tanah dataran aluvial Semarang. Akusisi metoda gaya berat dilakukan dengan menggunakan alat gravitimeter Lacoste & Romberg tipe G1158 dan G1118 yang dilengkapi dengan alliod 100 untuk mengukur gaya berat tiap stasiun dan gravitimeter Lacoste & Romberg tipe G508 untuk mengukur efek pasang surut terhadap gaya berat. Pemodelan 3D anomali gaya berat mikro time-lapse efek dinamika fluida mampu mengidentifikasi 9 zona pengurangan air tanah yakni sekitar masjid Ataqwa, PRPP, Tugu Muda , Simpang Lima, Jl. Majapahit, Genuk, Tanah Mas, Tanah Putih dan daerah sekitar kelurahan Sendangguwo. The background of this research is that Semarang has experienced the ground water level degradation in some areas. The method used in this research was time lapse microgravity during December 2003 to June 2004. The purpose of the research is to apply the microgravity method in determining the reduction zone of groundwater and alluvial plains Semarang using a 3D modeling by usingGrav3D program to identify the reduction of groundwater zone of alluvial plains in Semarang. The acquisition method of gravity wass done by using a Lacoste & Romberg gravitimeter G1158 and G1118 type equipped with alliod 100 to measure the gravity of each station and Lacoste & Romberg gravitimeter G508 type to measure the tidal effect of the gravity. The 3D modeling microgravity anomaly time-lapse effects of fluid dynamics is able to identify 9 groundwater reduction zones which is about, Ataqwa mosque, PRPP, Tugu Muda, Simpang Lima, Jl. Majapahit, Genuk, Tanah Mas, Tanah Putih, and around Sendangguwo area

The neural correlates of dreaming.

Consciousness never fades during waking. However, when awakened from sleep, we sometimes recall dreams and sometimes recall no experiences. Traditionally, dreaming has been identified with rapid eye-movement (REM) sleep, characterized by wake-like, globally 'activated', high-frequency electroencephalographic activity. However, dreaming also occurs in non-REM (NREM) sleep, characterized by prominent low-frequency activity. This challenges our understanding of the neural correlates of conscious experiences in sleep. Using high-density electroencephalography, we contrasted the presence and absence of dreaming in NREM and REM sleep. In both NREM and REM sleep, reports of dream experience were associated with local decreases in low-frequency activity in posterior cortical regions. High-frequency activity in these regions correlated with specific dream contents. Monitoring this posterior 'hot zone' in real time predicted whether an individual reported dreaming or the absence of dream experiences during NREM sleep, suggesting that it may constitute a core correlate of conscious experiences in sleep

Climate change and human occupation in the Southern Arabian lowlands during the last deglaciation and the Holocene

Paleohydrological and archaeological evidence from the Southern and South-Eastern Arabian Peninsula reveal strong relations between phases of human settlements and climate change linked to the Indian monsoon system. During the early to mid-Holocene, large fresh-water lakes extended in the lowland deserts of Ramlat as-Sab'atayn (Yemen) and Wahiba Sands (Oman), which were very similar to those occurring in the North, in the Rub' al-Khali (Saudi Arabia), at that time. Many archaeological sites, characterized by scattered stone artefacts, ostrich-eggshells and bones around hearths, are related to this lacustrine phase, which culminated around 10 000-8000 cal yr B.P. in the lowland deserts before the lakes progressively dried up. The last record of fresh-water bodies' extensions date back 7300 cal yr B.P. at Shabwa (Yemen) and 7500 cal yr B.P. at al-Haid (Oman). Then, fresh-water was probably available only from seasonal run-off from adjacent highlands, where paleolakes persisted into the late Holocene. Dry climate conditions in the inland desert of Yemen during the late Holocene coincide with a phase of intensive human inhabitation as testified by development of irrigation in the piedmontane areas, numerous necropolises of built collective burials and houses