ANALISA PENGARUH WAKTU PEMANFAATAN SOLAR CELL & LUAS HEADSINK TERHADAP SUHU

Kotak pendingin atau juga dikenal cooler box adalah tempat tempat untuk menyimpan es batu atau minuman dingin. Saat didalam rumah kita bisa memanfaatkan kulkas untuk menyimpan es batu atau minuman dingin. Namun saat kita beraktivitas diluar rumah sering kebingungan untuk menjaga es batu atau minuman dingin tersebut,maka dari itu cooler box hadir untuk menunjang aktivitas diluar rumah serta jauh dari sumber listrik.Disebabkan kotak pendingin berguna untuk menyimpan es atau minuman, banyak orang-orang menggunakan kotak tersebut untuk berbagai macam diantaranya untuk menyimpan daging,ikan,dan lain sebagainya.Tingkat kesegaran ikan akan semakin cepat menurun atau ikan akan mudah membusuk pada suhu tinggi namun sebaliknya jika suhu rendah dapat menghambat pembusukan(Suparno et al.1993).Maka dari pada itu banyak orang – orang berangsur menggunakan kotak pendingin untuk menyimpan ikan,karena didalam kotak pendingin dapat mengurangi bakteri pembusukan di suhu badan ikan.Dalam penelitian ini kami membuat kotak pendingin yang terbuat dari sytrofroam dengan bantuan alat seperti solar cell,battery,fan,heatsink,dan thermoelectric atau peltier.Kami menganalisa heatsink variable 8 x 10cm,9 x 10 cm, serta 10 x 12 cm selama 1 jam, 2 jam, serta 3 jam.Berdasarkan hasil yang diperoleh dari penelitian ini pada variable 8 x 10 cm dengan waktu 1 jam,dengan waktu tersebut menghasilkan 𑄠konveksi yang sama dengan 𑄠radiasi.sehingga variable 8 x 10 lebih efektif dari pada variable yang lainnya

Jurnal Arkeologi Siddhayatra Vol.9 No.2 Tahun 2004

Dalam edisi kali ini menampilkan empat buah artikel pertama oleh Tony Djubiantono dari Asdep Arkenas di Jakarta dengan melakukan penelitian di kawasan situs Keratuan Balaw Bandar Lampung yang pada akhir kesimpulannya bahwa di situs Keratuan Balaw merupakan pemukiman pada masa lalu dan ada kemungkinan mengaeah kepada periodesasi yang lebih tua karena adanya temuan serpihan rijang dan obsidian. Selanjutnya Sondang M Siregar menulis dengan judul "Fondasi Bangunan Candi Tuo Sumay" yang menginformasikan bahwa agama Buddha telah masuk dan berkembang di Desa Tuo Sumay yang dalam pendirian angunan tersebut senantiasa menerapkan konsel dalam agama Budha. Kristantina dan Siswanto membahas tentang situs Goa Puteri antara legenda yang berkembang di masyarakat dan dari kecamatan arkeologi sebagai salah satu Goa hunian masa lalu yang sarat mengandung data kepurbakalaan. Artikel terakhir ditulis Triwurjani dari Asdep Arkenas yang mengangkat topik "Tata Letak Hunian Megalitik DAS Sekampung di Propinsi Lampung" yang menyatakan bahwa bentuk pemukiman DAS Sekampung memperlihatkan 2 macam bentuk, yakni ada bentuk pemukiman dengan gundukan tanah dan parit dan ada yang tidak

Mars Earth Return Vehicle (MERV) Propulsion Options

The COMPASS Team was tasked with the design of a Mars Sample Return Vehicle. The current Mars sample return mission is a joint National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) mission, with ESA contributing the launch vehicle for the Mars Sample Return Vehicle. The COMPASS Team ran a series of design trades for this Mars sample return vehicle. Four design options were investigated: Chemical Return /solar electric propulsion (SEP) stage outbound, all-SEP, all chemical and chemical with aerobraking. The all-SEP and Chemical with aerobraking were deemed the best choices for comparison. SEP can eliminate both the Earth flyby and the aerobraking maneuver (both considered high risk by the Mars Sample Return Project) required by the chemical propulsion option but also require long low thrust spiral times. However this is offset somewhat by the chemical/aerobrake missions use of an Earth flyby and aerobraking which also take many months. Cost and risk analyses are used to further differentiate the all-SEP and Chemical/Aerobrake options

Human Exploration Using Real-Time Robotic Operations (HERRO)- Crew Telerobotic Control Vehicle (CTCV) Design

The HERRO concept allows real time investigation of planets and small bodies by sending astronauts to orbit these targets and telerobotically explore them using robotic systems. Several targets have been put forward by past studies including Mars, Venus, and near Earth asteroids. A conceptual design study was funded by the NASA Innovation Fund to explore what the HERRO concept and it's vehicles would look like and what technological challenges need to be met. This design study chose Mars as the target destination. In this way the HERRO studies can define the endpoint design concepts for an all-up telerobotic exploration of the number one target of interest Mars. This endpoint design will serve to help planners define combined precursor telerobotics science missions and technology development flights. A suggested set of these technologies and demonstrator missions is shown in Appendix B. The HERRO concept includes a crewed telerobotics orbit vehicle as well three Truck rovers, each supporting two teleoperated geologist robots Rockhounds (each truck/Rockhounds set is landed using a commercially launched aeroshell landing system.) Options include a sample ascent system teamed with an orbital telerobotic sample rendezvous and return spacecraft (S/C) (yet to be designed). Each truck rover would be landed in a science location with the ability to traverse a 100 km diameter area, carrying the Rockhounds to 100 m diameter science areas for several week science activities. The truck is not only responsible for transporting the Rockhounds to science areas, but also for relaying telecontrol and high-res communications to/from the Rockhound and powering/heating the Rockhound during the non-science times (including night-time). The Rockhounds take the place of human geologists by providing an agile robotic platform with real-time telerobotics control to the Rockhound from the crew telerobotics orbiter. The designs of the Truck rovers and Rockhounds will be described in other publications. This document focuses on the CTCV design

Cold Gas Outflows, Feedback, and the Shaping of Galaxies

There is wide consensus that galaxy outflows are one of the most important processes determining the evolution of galaxies through cosmic time, for example playing a key role in shaping the galaxy mass function. Our understanding of outflows and their drivers, however, is in its infancy --- this is particularly true for the cold (neutral atomic and molecular) phases of outflows, which present observational and modeling challenges. Here we outline several key open questions, briefly discussing the requirements of the observations necessary to make progress, and the relevance of several existing and planned facilities. It is clear that galaxy outflows, and particularly cold outflows, will remain a topic of active research for the next decade and beyond

Advanced Lithium Ion Venus Explorer (ALIVE)

The COncurrent Multidisciplinary Preliminary Assessment of Space Systems (COMPASS) Team partnered with the Applied Research Laboratory to perform a NASA Innovative Advanced Concepts (NIAC) Program study to evaluate chemical based power systems for keeping a Venus lander alive (power and cooling) and functional for a period of days. The mission class targeted was either a Discovery ($500M) or New Frontiers ($750M to $780M) class mission. Historic Soviet Venus landers have only lasted on the order of 2 hours in the extreme Venus environment:temperatures of 460 degrees Centigrade and pressures of 93 bar. Longer duration missions have been studied using plutonium powered systems to operate and cool landers for up to a year. However, the plutonium load is very large. This NIAC study sought to still provide power and cooling but without the plutonium. Batteries are far too heavy but a system which uses the atmosphere (primarily carbon dioxide) and on on-board fuel to power a power generation and cooling system was sought. The resuling design was the Advanced Long-Life Lander Investigating the Venus Environment (ALIVE) Spacecraft (S/C) which burns lithium (Li) with the CO2 atmosphere to heat a Duplex Stirling to power and cool the lander for a 5-day duration (until the Li is exhausted). While it does not last years a chemical powered system surviving days eliminates the cost associated with utilizing a flyby relay S/C and allows a continuous low data rate direct to earth (DTE) link in this instance from the Ovda Regio of Venus. The five-day collection time provided by the chemical power systems also enables science personnel on earth to interact and retarget science - something not possible with an approximately 2-hour spacecraft lifetime. It also allows for contingency operations directed by the ground (reduced risk). The science package was based on that envisioned by the Venus Intrepid Tessera Lander (VITaL) Decadal Survey Study. The Li Burner within the long duration power system creates approximately 14000 W of heat. This 1300 degree Centigrade heat using Li in the bottom "ballast" tank is melted to liquid by the Venus temperature, drawn into a furnace by a wick and burned with atmospheric CO2. The Li carbonate exhaust is liquid at 1300 degrees Centigrade and being denser than Li drains into the the Li tank and solidifies. Since the exhaust product is a dense liquid no "chimney" is required which conserves the heat for the stirling power convertor. The Duplex Stirling provides about 300 W of power and removes about 300 W of heat from the avionics and heat that leaks into the 1-bar-insulated payload pressure vessel kept at 25 degrees Centigrade. The Na K radiator is run to the top of the drag flap.The ALIVE vehicle is carried to Venus via an Atlas 411 launch vehicle (LV) with a C3 of 7 km2/s2. An Aeroshell, derived from the Genesis mission, enables a direct entry into the atmosphere of Venus (-10 degrees Centigrade, 40 g max) and 6 m/s for landing (44 g) using a drag ring. For surface science and communication, a 100 WRF (WebEx Recording Format), X-Band 0.6-meter pointable DTE (Direct-to-Earth) antenna provides 2 kbps (kilobits per second) to DSN (Deep-Space Network) 34-meter antenna clusters.Table 1.1 summarizes the top-level details of each subsystem that was incorporated into the design. Cost estimates of the ALIVE mission show it at approximately$760M which puts it into the New Frontiers class.The ALIVE landed duration is only limited by the amount of Li which can be carried by the lander. Further studies are needed to investigate how additional mass can be carried, perhaps by a larger launcher and larger aeroshell

Temporary dense seismic network during the 2016 Central Italy seismic emergency for microzonation studies

In August 2016, a magnitude 6.0 earthquake struck Central Italy, starting a devastating seismic sequence, aggravated by other two events of magnitude 5.9 and 6.5, respectively. After the first mainshock, four Italian institutions installed a dense temporary network of 50 seismic stations in an area of 260 km2. The network was registered in the International Federation of Digital Seismograph Networks with the code 3A and quoted with a Digital Object Identifier ( https://doi.org/10.13127/SD/ku7Xm12Yy9 ). Raw data were converted into the standard binary miniSEED format, and organized in a structured archive. Then, data quality and completeness were checked, and all the relevant information was used for creating the metadata volumes. Finally, the 99 Gb of continuous seismic data and metadata were uploaded into the INGV node of the European Integrated Data Archive repository. Their use was regulated by a Memorandum of Understanding between the institutions. After an embargo period, the data are now available for many different seismological studies.Publishedid 1825T. Sismologia, geofisica e geologia per l'ingegneria sismicaJCR Journa

Workshop on identification of future emerging technologies in the ocean energy sector

As part of the Commission's internal Low Carbon Energy Observatory (LCEO) project, the Joint Research Centre (JRC) is developing an inventory of Future Emerging Technologies (FET) relevant to energy supply. A key part of the LCEO initiative is the consultation of external experts, addressing both those with in-depth experience in specific fields and those with a broad perspective on relevant science and engineering aspects. In this context, on March 27, 2018 the JRC organised a Workshop on Identification of Future Emerging Technologies for Ocean Enery, on it premises in Ispra. The workshop was organized on the idea of a colloquium between international experts to discuss about future emerging technologies considering different aspects such as their technology readiness level (TRL) , the potential advantages and challenges affecting their development, and evaluating the possible speed of development . A number of different technological solutions were discussed, identified directly by the invited experts on the condition that they respected the following criteria: • To be a technology for energy supply/conversion in the field of ocean energy. • To be a radically new technology/concept, not achievable by incremental research on mainstream technologies (this should match the concept of the Future Emerging Technology in the Horizon 2020 work program http://ec.europa.eu/programmes/horizon2020/en/h2020-section/future-and-emerging-technologies). • To be in an early stage of development: their Technology Readiness Level should not be more than 3. Questionnaires were sent to experts for the identification of ocean energy FETs. The templates can be found in Appendix B. The structure of the workshop was builtupon the inputs received from the experts and on in-house analysis undertaken by the JRC. The aim of this document is to gather, organize and highlight all the knowledge and information, provided by the external and internal experts, which were discussed during the workshop.JRC.C.7-Knowledge for the Energy Unio

Inventory of current EU paediatric vision and hearing screening programmes

Background: We examined the diversity in paediatric vision and hearing screening programmes in Europe. Methods: Themes relevant for comparison of screening programmes were derived from literature and used to compile three questionnaires on vision, hearing and public-health screening. Tests used, professions involved, age and frequency of testing seem to influence sensitivity, specificity and costs most. Questionnaires were sent to ophthalmologists, orthoptists, otolaryngologists and audiologists involved in paediatric screening in all EU fullmember, candidate and associate states. Answers were cross-checked. Results: Thirty-nine countries participated; 35 have a vision screening programme, 33 a nation-wide neonatal hearing screening programme. Visual acuity (VA) is measured in 35 countries, in 71% more than once. First measurement of VA varies from three to seven years of age, but is usually before the age of five. At age three and four picture charts, including Lea Hyvarinen are used most, in children over four Tumbling-E and Snellen. As first hearing screening test otoacoustic emission (OAE) is used most in healthy neonates, and auditory brainstem response (ABR) in premature newborns. The majority of hearing testing programmes are staged; children are referred after one to four abnormal tests. Vision screening is performed mostly by paediatricians, ophthalmologists or nurses. Funding is mostly by health insurance or state. Coverage was reported as >95% in half of countries, but reporting was often not first-hand. Conclusion: Largest differences were found in VA charts used (12), professions involved in vision screening (10), number of hearing screening tests before referral (1-4) and funding sources (8)