Pemetaan Kesehatan Tanaman Jeruk Dengan Metode Supervised Classification Berdasarkan Hasil Citra Drone

Luas tanaman jeruk dilaporkan mengalami penurunan di beberapa daerah. Hal tersebut disebabkan oleh beberapa hal, diantaranya serangan penyakit dan kurangnya perawatan. Badan Pusat Statistik (BPS) hanya menyediakan data luasan produksi saja sehingga informasi tentang luasan tanaman yang sakit belum ada. Pemantauan kondisi tanaman dapat menggunakan penginderaan jauh. Penelitian ini bertujuan untuk mengembangkan metode penginderaan jauh dengan drone untuk mendeteksi kesehatan tanaman jeruk. Lokasi percobaan dilakukan di Banyuwangi dengan menggunakan drone phantom 4 dengan kamera RGB. Hasil foto dianalisa menggunakan software agisoft photoscan dalam beberapa tahap, yaitu: align photos, build dense cloud, build digital elevation model, build orthomosaic dan export geotiff. Ratusan foto akan menjadi satu kesatuan gambar dengan proses tersebut. Hasil proses gambar tersebut kemudian di analisa di software QGIS dengan metode Supervised Classification. Percobaan dilakukan pada tanaman muda dan dewasa. Dengan metode tersebut klasifikasi kesehatan tanaman jeruk dewasa dapat dibagi menjadi tiga, yaitu : sehat, sakit dan mati. Hasil ini kemungkinan bias lebih sedikit dibandingkan pada tanaman muda.

Proplyds in the Flame Nebula NGC 2024

A recent survey of the inner 0.35 × 0.35 pc of the NGC 2024 star forming region revealed two distinct millimetre continuum disc populations that appear to be spatially segregated by the boundary of a dense cloud. The eastern (and more embedded) population is ∼0.2 − 0.5 Myr old, with an ALMA mm continuum disc detection rate of about 45 per cent. However this drops to only ∼15 per cent in the 1 Myr western population. When these distinct populations were presented it was suggested that the two main UV sources, IRS 1 (a B0.5V star in the western region) and IRS 2b (an O8V star in the eastern region, but embedded) have both been evaporating the discs in the depleted western population. In this paper we report the firm discovery in archival HST data of 4 proplyds and 4 further candidate proplyds in NGC 2024, confirming that external photoevaporation of discs is occurring. However, the locations of these proplyds changes the picture. Only three of them are in the depleted western population and their evaporation is dominated by IRS 1, with no obvious impact from IRS 2b. The other 5 proplyds are in the younger eastern region and being evaporated by IRS 2b. We propose that both populations are subject to significant external photoevaporation, which happens throughout the region wherever discs are not sufficiently shielded by the interstellar medium. The external photoevaporation and severe depletion of mm grains in the 0.2-0.5 Myr eastern part of NGC 2024 would be in competition even with very early planet formation.

Growth and structure of multiphase gas in the cloud-crushing problem with cooling

ABSTRACT We revisit the problem of the growth of dense/cold gas in the cloud-crushing set-up with radiative cooling. The relative motion between the dense cloud and the diffuse medium produces a turbulent boundary layer of mixed gas with a short cooling time. This mixed gas may explain the ubiquity of the range of absorption/emission lines observed in various sources such as the circumgalactic medium and galactic/stellar/active galactic nucleus outflows. Recently, Gronke & Oh showed that the efficient radiative cooling of the mixed gas can lead to continuous growth of the dense cloud. They presented a threshold cloud size for the growth of dense gas that was contradicted by the more recent works of Li et al. & Sparre et al. These thresholds are qualitatively different as the former is based on the cooling time of the mixed gas whereas the latter is based on the cooling time of the hot gas. Our simulations agree with the threshold based on the cooling time of the mixed gas. We argue that the radiative cloud-crushing simulations should be run long enough to allow for the late-time growth of the dense gas due to cooling of the mixed gas but not so long that the background gas cools catastrophically. Moreover, the simulation domain should be large enough that the mixed gas is not lost through the boundaries. While the mixing layer is roughly isobaric, the emissivity of the gas at different temperatures is fundamentally different from an isobaric single-phase steady cooling flow.

Tentative detection of HC5NH+ in TMC-1

Using the Yebes 40m radio telescope, we report the detection of a series of seven lines harmonically related with a rotational constant B0 = 1295.81581 ± 0.00026MHz and a distortion constant D0 = 27.3 ± 0.5Hz towards the cold dense cloud TMC-1. Ab initio calculations indicate that the best possible candidates are the cations HC5NH+ and NC4NH+. From a comparison between calculated and observed rotational constants and other arguments based on proton affinities and dipole moments, we conclude that the best candidate for a carrier of the observed lines is the protonated cyanodiacetylene cation, HC5NH+. The HC5N/HC5NH+ ratio derived in TMC-1 is 240, which is very similar to the HC3N/HC3NH+ ratio. Results are discussed in the framework of a chemical model for protonated molecules in cold dense clouds.

Computational Investigation of a Multiphase Turbo Expander for Heat Pumps and Refrigeration Cycles

The design and development of an innovative Tesla style turbo expander for two-phase fluids is proposed, as a substitute for the lamination valve of a traditional Heat Pump cycle. Thereby enhancing the overall performance of the Heat Pump, by recovering mechanical work to offset the compressor requirements. The major challenge in such configurations is the reliable operation of the expander, when phase change occurs across it, from a purely liquid flow to a mainly vapour flow by volume with a dense cloud of liquid droplets. To investigate the phase change, a modelling approach is adopted which is routinely applied to modelling fuel-flashing in direct injection diesel engines, where the phase change deviates strongly from equilibrium. The Homogeneous Relaxation Model (HRM) is employed, which utilizes an Eulerian approach. The proposed computational model is firstly validated against experimental results available in the literature. A sensitivity analysis of the phase change model relaxation parameter is performed. It was found that a value 10 times lower than the published value gave closer agreement to the measured results. It is believed that this result is due to the roughened walls of the experiment, which would produce more nucleation sites for vapour bubble formation. This suggests that this model maybe is sensitive to the geometry of the turbine. Following this validation, the detailed flow profile in the proposed Tesla turbo-expander is investigated. Two different expander designs are considered in this project, one working with water [4,20] and the other with butane (R600). This study focuses particularly on the butane expander design. The expander performance is evaluated for rotational speeds up to 32’000 RPM. Results on the turbo-expander under investigation, showed that the presence of a dense cloud of liquid droplets produces a significant pressure drop across the turbine rotor, which increases with RPM, postponing the phase change. High volume-fraction of liquid was predicted to penetrate deeper inside the rotor above 16’000 RPM for the butane expander. The resulting lower liquid flow velocity relative to the rotor disk speed at the inlet of the rotor is predicted to significantly degrade the performance of the turbine at high rotational speeds. Decreasing the nozzle throat area improves the situation, by initiating the phase change further upstream and increasing the RPM operational range by 50%. Angling the nozzle radially inward by 10° was found to not have a great impact on the performance of the turbine. It was determined from this study that it is critical to predict correctly where the phase change starts, in order to accurately predict the performance of the turbine. Important is to remove as much liquid as possible from the flow, before it enters the rotor, to minimize the impact of the phase change on the turbine performance.

PEMANFAATAN FOTO UDARA FORMAT KECIL UNTUK PEMETAAN BIDANG TANAH DI SUB DAS BOMPON

Remote sensing technology such as small format aerial photography (SFAP) from unmanned aerial vehicle (UAV) or drone can be a solution in accelerating the land parcel mapping in Indonesia. This study aims to determine the level of geometric and planimetric accuracy of SFAP data output in land parcel mapping and describe the step of data processing. The results showed that in land parcel mapping, the main SFAP output data is orthophoto. Therefore, the processing should not need to do the dense cloud process, the orthophoto build process can use DEM from sparse cloud for time efficiency and reduce the relief displacement effect. The orthophoto geometry accuracy is CE90 of 0.44, so it is very well used for mapping 1: 2500 scale, while DSM has a LE90 value of 2.80. Planimetry accuracy of the land parcel distance has met the tolerance standard, while planimetry accuracy of the land parcel area there is 1 parcel that does not meet the tolerance standard. However, in general, SFAP can be used as a basis for land parcel mapping in slightly hilly areas such as Bompon watershed.Keywords: Small format aerial photo, land parcel, geometric accuracy, planimetric accuracy Teknologi penginderaan jauh seperti foto udara format kecil (FUFK) dari pesawat nir awak bisa menjadi solusi dalam percepatan pemetaan bidang tanah di Indonesia. Penelitian ini bertujuan untuk mengetahui tingkat ketelitian geometrik dan planimetrik data keluaran FUFK dalam pemetaan bidang tanah serta mendeskripsikan tahapan-tahapan pengolahan datanya. Hasil penelitian menunujukkan bahwa dalam pemetaan bidang tanah, data keluaran FUFK yang utama adalah ortofoto. Oleh karena itu sebaiknya proses pengolahan tidak perlu melakukan proses dense cloud, proses build orthophoto bisa menggunakan DEM dari sparse cloud untuk efisiensi waktu serta mengurangi efek relief displacement. Ketelitian geometri ortofoto yaitu CE90 sebesar 0,44, sehingga sangat baik digunakan untuk pemetaan skala 1:2500, sedangkan DSM memiliki nilai LE90 sebesar 2,80. Ketelitian planimetrik terhadap jarak bidang tanah telah memenuhi standar toleransi, sedangkan ketelitian planimetrik terhadap luas bidang tanah terdapat 1 bidang yang tidak memenuhi standar toleransi. Walaupun begitu, secara umum FUFK bisa digunakan sebagai dasar pemetaan bidang tanah di wilayah yang sedikit berbukit seperti Sub DAS Bompon.Kata Kunci: Foto udara format kecil, bidang tanah, ketelitian geometrik, ketelitian planimetrik.

Copper-Alloy Surfaces and Cleaning Regimens against the Spread of SARS-CoV-2 in Dentistry and Orthopedics. From Fomites to Anti-Infective Nanocoatings

The latest diffusion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease (COVID-19), has involved the whole world population. Even if huge efforts to control the pandemic have been done, the viral spread is still continuing. COVID-19 is reported as a zoonosis jumped from bats and pangolins to humans. After infection in humans, SARS-CoV-2 is found in the nasopharyngeal and salivary secretions. The virus has also been detected in the blood plasma of infected patients. The viral spread occurs through droplets exhaled from the nose and mouth of the infected people when they breath or talk, or through droplets propelled as a dense cloud by chough or sneeze. The virus can also be delivered as an aerosol from blood plasma, through surgical procedures. Following these ways, the virus can disperse in the air, then reaching and settling on the exposed surfaces. How long the virus will survive on a surface depends on the material the surface is made from. Infection via high-touch surfaces should be prevented. Copper alloy coatings, combined with efficient hygienic/disinfectant procedures and careful surgical practice, could be helpful to health protection in dental practice and can also be adopted in orthopedic traumatology.