Generation of Continuous Hybrid Zig-zag and Contour Paths For 3D Printing

The generation of the printing paths is a decisive step in additive manufacturing (AM). There is a variety of patterns that offer different characteristics, but those that are strictly continuous become especially relevant in certain types of AM by extrusion, with materials like bioinks, carbon or clays, since they do not allow the retraction of the material and travelling movements result in the generation of artefacts. In this work, we present (1) a method that generates continuous paths to fill 2D polygons with a hybrid zig-zag and contour pattern with any direction and line separation,which is based on the extension of an algorithm that decomposes the 2D area to be filled into convex areas, (2) a method to join the subpolygon trajectories such that a continuous path that fills the whole polygon is obtained, and (3) a publicly available dataset of 2D polygons that are relevant to test the performance of the algorithms.

Analysis of Morphometric Changes in Tondano Lake Based on Bathymetric Maps

This study aims to analyze changes in the morphometry of the lake bottom in a period of ten years, namely from 2006 to 2016. The analysis of morphometric changes is carried out by comparing two bathymetric maps from the mapping in 2006 and 2016. The morphometric aspects studied include the water surface area stated in km2, the volume of water (in m3) and the depth of the lake (in m). The results showed that within 10 years the surface of the lake water has decreased by 1.03 km2, while the total volume of lake water has increased by 10.41 m3. The average depth of the lake in a period of 10 years has barely changed significantly, only silting of about 0.01 meters. Judging from the contour pattern, it shows that there is a tendency for siltation to move not only towards the south but also towards the east. That means more sediment contributions come from the western region. The rain catchment area on the west side of the lake has a larger area when compared to the east side (Eris District). The sediment potential is greater from this area.

Kajian Penggunaan Ruang dan Kesehatan Lingkungan Suku Saga di Kabupaten Ende

Saga Village, Ende Regency, East Nusa Tenggara has a traditional house that becomes its identity, namely Sa’o. Unlike ordinary traditional houses, Sa’o has a customary leader in each house. Thus, the house is not just a place to live but also shows the social hierarchy. Visually, the floor plan is a square with a very steep roof angle so that the roof is visible. The philosophy follows the analogy of the human body, that is, lewu (pedestal/ foot), one (wall/ body), gara (roof/ head). On the macro scale, the Saga settlement pattern follows the contour pattern. There are about 20 houses with the same typology. The use of space in cultural activities is not yet identified. Besides, the position of the contoured landscape without shade and surrounded by forests has a vulnerability to several diseases. The link between space use and environmental health also has not yet been explained. Continuing from previous research on space cosmology, the micro aspect in this study deals with the physical identification of traditional houses. In contrast, in the macro aspect, it discusses the use of space for cultural activities and aspects of environmental health. The data collection was carried out through focus group discussions (FGD) and analyzed using a descriptive qualitative method with an ethnographic approach. The results of this study are descriptions of spaces used for cultural activities at a particular time and place as well as efforts to improve public environmental health. In conclusion, Saga people have local wisdom in terms of traditional architecture, in addition to the intangible form of inherited traditions and efforts to improve environmental health.

IDENTIFIKASI ALUR PURBA BERDASARKAN SEISMIK PANTUL DANGKAL DI PERAIRAN BANGKA UTARA LEMBAR PETA 1114

Kondisi tektonik dan tatanan geologi yang kompleks di Indonesia menghasilkan pembentukan bermacam-macam mineral. Salah satu mineral adalah timah pada wilayah Paparan Sunda, membentang dari Semenanjung Malaya, Kepulauan Riau, Kepulauan Singkep, Pulau Bangka, Kepulauan Tujuh, dan Pulau Belitung. Jalur timah ini umumnya telah mengalami erosi kuat pada waktu yang lama. Timah letakan adalah salah satu sumber daya mineral lepas pantai yang dapat ditambang. Umumnya mineral-mineral tersebut terperangkap di dalam lapisan sedimen permukaan berumur Kuarter. Pulau Bangka merupakan salah satu daerah yang dikenal sebagai kepulauan timah. Pusat Penelitian Pengembangan Geologi Kelautan (PPPGL) pada tahun 1994 telah melakukan penyelidikan geologi dan geofisika kelautan di daerah perairan Bangka Utara (Lembar Peta 1114), dengan sekala peta 1 : 250.000. Dengan teknologi khususnya seismik refleksi dan penafsirannya, diharapkan akan ada temuan-temuan cadangan timah baru. Morfologi dasar laut daerah penyelidikan digambarkan oleh pola kontur batimetri relatif rapat di bagian barat pantai. Pola ini mencerminkan suatu sisi punggungan (homoklin) dan berarah timur laut – barat daya. Diantara PulauTujuh dan Pulau Bangka pola kontur membentuk tutupan-tutupan (closure) dan membentuk suatu kelurusan berarah timur laut – barat daya berupa cekungan-cekungan kecil merupakan alur selat P. Tujuh dan P. Bangka. Hasil penafsiran rekaman seismik refleksi kondisi geologi bawah permukaan dasar laut dapat dipisahkan menjadi dua sekuen yaitu sekuen A dan sekuen B. Sekuen B adalah sekuen paling bawah (acoustic basement) yang terdiri dari subsekuen B1, B2 dan B3, tidak semua subsekuen ini terekam karena umumnya horizon reflektornya sulit diidentifikasi dan umumnya tertutup oleh pantulan ganda (multiple). Sekuen A adalah sekuen yang diendapkan diatas sekuen B, dibedakan dengan sekuen B yang berada dibawahnya oleh bidang erosi, sekuen A ini terdiri dari subsekuen A1 dan A2. Kedua subsekuen ini jika disebandingkan secara stratigrafi berdasarkan Mangga dan Jamal serta Aleva, merupakan “Young Sedimentary Complex” terbentuk pada Kala Holosen. Kata Kunci : Identifikasi Alur Purba, Seismik Pantul Dangkal, Perairan Bangka Utara, Lembar Peta 1114. In Indonesia minerals occurrence were controlled by tectonic process and regional geological setting. One mineral is tin in the Sunda shelf, area which stretch from Malaya Peninsula, Riau Islands, Singkep Islands, Bangka Island, Tujuh Islands and Belitung Island. This tin belt was strongly eroded in the long period of time. Tin placer is an offshore mineral resource which was already exploited. Generally the mineral is trapped in the surface sediment layers, of Quartenary age. Bangka Island is well known one of many tin archipelago. Marine Geological Institute (MGI) in 1994 has done geological and geophysical mapping in North Bangka waters (Map Sheet, 1114), with map scale 1 : 250.000. The technology used especially seismic reflection and its interpretation was expected discovery of new tin reserves. Sea bottom morphology of area investigation is depicted by bathymetric contour pattern relatively closed to the western coast. This pattern is a ridge (homoklin) of northeast - southwest direction. Between Pulautujuh and Bangka Islands contour pattern is closure and elongated northeast-southwest as small basins which formed a channel between P. Tujuh and P. Bangka. The interpretation of seismic reflection record showed subsurface geology condition divided in to two sequences A and B. Sequence B is a basement acoustic consisted of subsequence B1, B2 and B3, these subsequence were not all recognised due to generally its horizon reflector is difficult to be identified and is generally covered up multiple. Sequence A was deposited above sequence B and was differentiated by erosional truncation. Sequence A is consisted of subsequence A1 and subsequence A2. Both subsequences correlated to Mangga and Jamal, and also Aleva, stratigraphically representing " Young Sedimentary Complex" formed in Holocene. Keyword : Paleochannel Identification, Shallow Reflection Seismic, North Bangka Waters, Map Sheet 1114.

Lead Contamination In Soil Of Yogyakarta City, Indonesia

This paper investigates on Pb concentrations and mobility in soil of overall Yogyakarta City, Indonesia. The objectives of this study include to investigate Pb concentrations in the surface soil throughout Yogyakarta and to study their possible sources and potential environmental impacts. The soil samples from 168 locations in Yogyakarta was obtained, representing different land use and traffic conditions. Spatial analysis and sequential extraction analysis were performed. Generally, contour pattern of Pb value clearly shows that high value is concentrated in the middle and few north part of the study area, confirmed by traffic condition in the study area. In general, the results of sequential extraction analysis shows that Pb was predominantly associated with exchangeable fraction. The presence of lead in the exchangeable fractions may pose a serious environmental concern since they are highly soluble and potentially bio-available in the soil of study area. Keywords: Soil, lead contamination, GIS, sequential extraction.