Concentric circles and spiral configurations for large correlator arrays in radio astronomy

Aperture synthesis arrays are commonly used in radio astronomy to take images of radio point sources, with the planned Square Kilometre Array (SKA) being the most common example. One approach to enhancing the quality of the images is to optimize an antenna array configuration in a possible SKA implementation. An ideal arrangement must ensure optimal configurations to capture a clear image by either decreasing the sidelobe level (SLL) in the l-m domain or increasing the sampled data in the spatial-frequency domain. In this paper a novel configuration is considered to optimize the array by considering all possible observation situations through the positions of the antenna array elements via a mathematical model that we call geometrical method (GM). To demonstrate its efficiency, the technique is applied to developing an optimal configuration for the elements of the Giant Metrewave Radio Telescope (GMRT). The effect of these changes, particularly in the forms of circular and spiral arrangements, is discussed. It is found that a spiral configuration results in fewer overlapping samples than the number of antennas placed along three arms of the GMRT with fewer than 11% and 27% overlapping samples in the snapshot and 6 hr tracking observations, respectively. Finally, the spiral configuration reduces the first SLL from -13.01 dB, using the arms of the current GMRT configuration, to - 15.64 dB.Web of Science1564art. no. 17

Dampak El Nino terhadap Produksi dan Pendapatan Agroindustri Berbasis Singkong di Desa Karang Anyar Kecamatan Gedongtataan Kabupaten Pesawaran

This study aims to study the impact of El Nino on the production and revenues of cassava based on agroindustry in Karang Anyar Village, Gedongtataan Sub-district of Pesawaran District. The location was chosen purposively. The sample size was 37 kelanting industries and 13 cassava chips industries. The data of this research were collected from February to March 2016. The data was analyzed by income analysis and income statement analysis in addition to the middle test value. The study showed that there was significant difference on average production of cassava based on agroindustry between normal and El Nino seasons. There was also significant different on average income of cassava based on agroindustry between normal and El Nino season. There was significant difference on average total cost of cassava based on agroindustry between normal and El Nino seasons and there was significant difference on input and output prices of cassava based on agroindustry between normal and El Nino season

Faktor yang Mempengaruhi Sikap Skeptisme Profesional Seorang Auditor pada Kantor Akuntan Publik di Sumatera

Penelitian ini bertujuan untuk mengetahui faktor yang mempengaruhi sikap,skeptisisme professional seorang auditor pada Kantor Akuntan Publik di Sumatra.Populasi penelitian ini adalah seluruh auditor yang bekerja pada Kantor AkuntanPublik (KAP) dan terdaftar pada Direktori Akuntan Publik Indonesia (IAPI) 2009 diwilayah Sumatera dan seluruh populasi dijadikan sampel. Data yang terkumpuldianalisa dengan menggunakan regresi berganda (multiple regression) denganbantuan SPSS 15.00. Hasil analisa menunjukkan bahwa pengalaman, kesadaranetis, situasi audit serta profesionalisme berpengaruh signifikan terhadap skeptisisme22professional auditor. Dari pengujian koefisien determinasi (R ) diperoleh hasil Rsebesar 0.737 (73.70%). Berarti bahwa 73.70% skeptisisme professional auditordipengaruhi oleh pengalaman, kesadaran etis, situasi audit serta profesionalismedan masih ada 26.30% variabel lain yang mempengaruhi skeptisisme professionalauditor

Development of Wet Noodles Based on Cassava Flour

Cassava is one of Indonesia\u27s original commodities and contains good nutrition and has high productivity and a relatively low price. Cassava flour has a high potential as a substitute for imported wheat flour that is widely used in noodle production. The main purpose of this research was to develop wet noodles from cassava flour that can compete with wet noodles from wheat flour. The research consisted of experiments with several variations of composition and production method for producing cassava flour-based wet noodles. The best result was then examined for its nutritional value, economical value, and market response, and also a comparison was made between the prepared wet noodles and the standard noodles made from wheat flour. The analysis was based on five characteristics: taste, texture, chewiness, aroma, and appearance. Relations between these characteristics with composition, materials used, and methods applied are discussed. The developed cassava flour-based wet noodle meets physical, nutritional, and economical standards. Raw materials of the noodle were cassava flour and a wheat flour composite with a 5:1 ratio, egg, gluten, soda-ash, water, and vegetable oil, while the process was completed in multiple stages. Market response showed that the cassava flour-based wet noodles were 80% similar to wheat-flour noodles

Ultramafic xenoliths from the Bearpaw Mountains, Montana, USA: evidence for multiple metasomatic events in the lithospheric mantle beneath the Wyoming craton

Ultramafic xenoliths in Eocene minettes of the Bearpaw Mountains volcanic field (Montana, USA), derived from the lower lithosphere of the Wyoming craton, can be divided based on textural criteria into tectonite and cumulate groups. The tectonites consist of strongly depleted spinel lherzolites, harzburgites and dunites. Although their mineralogical compositions are generally similar to those of spinel peridotites in off-craton settings, some contain pyroxenes and spinels that have unusually low Al2O3 contents more akin to those found in cratonic spinel peridotites. Furthermore, the tectonite peridotites have whole-rock major element compositions that tend to be significantly more depleted than non-cratonic mantle spinel peridotites (high MgO, low CaO, Al2O3 and TiO2) and resemble those of cratonic mantle. These compositions could have been generated by up to 30% partial melting of an undepleted mantle source. Petrographic evidence suggests that the mantle beneath the Wyoming craton was re-enriched in three ways: (1) by silicate melts that formed mica websterite and clinopyroxenite veins; (2) by growth of phlogopite from K-rich hydrous fluids; (3) by interaction with aqueous fluids to form orthopyroxene porphyroblasts and orthopyroxenite veins. In contrast to their depleted major element compositions, the tectonite peridotites are mostly light rare earth element (LREE)-enriched and show enrichment in fluid-mobile elements such as Cs, Rb, U and Pb on mantle-normalized diagrams. Lack of enrichment in high field strength elements (HFSE; e.g. Nb, Ta, Zr and Hf) suggests that the tectonite peridotites have been metasomatized by a subduction-related fluid. Clinopyroxenes from the tectonite peridotites have distinct U-shaped REE patterns with strong LREE enrichment. They have 143Nd/144Nd values that range from 0·5121 (close to the host minette values) to 0·5107, similar to those of xenoliths from the nearby Highwood Mountains. Foliated mica websterites also have low 143Nd/144Nd values (0·5113) and extremely high 87Sr/86Sr ratios in their constituent phlogopite, indicating an ancient (probably mid-Proterozoic) enrichment. This enriched mantle lithosphere later contributed to the formation of the high-K Eocene host magmas. The cumulate group ranges from clinopyroxene-rich mica peridotites (including abundant mica wehrlites) to mica clinopyroxenites. Most contain >30% phlogopite. Their mineral compositions are similar to those of phenocrysts in the host minettes. Their whole-rock compositions are generally poorer in MgO but richer in incompatible trace elements than those of the tectonite peridotites. Whole-rock trace element patterns are enriched in large ion lithophile elements (LILE; Rb, Cs, U and Pb) and depleted in HFSE (Nb, Ta Zr and Hf) as in the host minettes, and their Sr–Nd isotopic compositions are also identical to those of the minettes. Their clinopyroxenes are LREE-enriched and formed in equilibrium with a LREE-enriched melt closely resembling the minettes. The cumulates therefore represent a much younger magmatic event, related to crystallization at mantle depths of minette magmas in Eocene times, that caused further metasomatic enrichment of the lithosphere

Attacks on quantum key distribution protocols that employ non-ITS authentication

We demonstrate how adversaries with unbounded computing resources can break Quantum Key Distribution (QKD) protocols which employ a particular message authentication code suggested previously. This authentication code, featuring low key consumption, is not Information-Theoretically Secure (ITS) since for each message the eavesdropper has intercepted she is able to send a different message from a set of messages that she can calculate by finding collisions of a cryptographic hash function. However, when this authentication code was introduced it was shown to prevent straightforward Man-In-The-Middle (MITM) attacks against QKD protocols. In this paper, we prove that the set of messages that collide with any given message under this authentication code contains with high probability a message that has small Hamming distance to any other given message. Based on this fact we present extended MITM attacks against different versions of BB84 QKD protocols using the addressed authentication code; for three protocols we describe every single action taken by the adversary. For all protocols the adversary can obtain complete knowledge of the key, and for most protocols her success probability in doing so approaches unity. Since the attacks work against all authentication methods which allow to calculate colliding messages, the underlying building blocks of the presented attacks expose the potential pitfalls arising as a consequence of non-ITS authentication in QKD-postprocessing. We propose countermeasures, increasing the eavesdroppers demand for computational power, and also prove necessary and sufficient conditions for upgrading the discussed authentication code to the ITS level.Comment: 34 page

Nitrate in Groundwater and its Associated Health Risk: A Cross-Sectional Study in Mukim Salor, Kota Bharu, Kelantan, Malaysia

Background: Mukim Salor is an agricultural area in the district of Kota Bharu, Kelantan state, Malaysia. Farmers there use nitrogen-based fertilizers for paddy and vegetable planting. The use of these types of fertilizers may lead to contamination of nitrate in groundwater by the process of leaching into the soil. Kota Bharu is one of the areas in this country where the population still rely on groundwater as their main source of potable water. Daily use of water contaminated with nitrate may give rise to problems including “methe­moglobaenamia” or blue baby syndrome and shortness of breath. At the moment, there are no data available on nitrate levels or hazard index associated with nitrate exposure in groundwater in Mukim Salor. This study aimed to determine nitrate levels in groundwater and to perform health risk assessment from nitrate exposure among residents in Mukim Salor, a subdistrict in the district of Kota Bharu, Kelantan, an east coast state in Peninsular Malaysia. Subjects and Method: This cross-sectional study was conducted among residents from Mukim Salor, Kelantan, Malaysia. Fifty (50) respondents were chosen based on the inclusion and exclusion criteria and they were initially interviewed in order to obtain demographic data and groundwater usage information. Groundwater samples were taken from each of the respondent’s house who used groundwater exclusively for drinking and cooking. The samples were then analyzed using a HACH brand DR 1900 direct reading spectro­photometer. Risk assessment on exposure to nitrate was also calculated. Results: Nitrate levels ranged from 0.1 to 2.8 mg/L, with a mean of 1.08 + SD 0.64 mg/L. Nitrate levels in the area of study did not exceed the standard set by the health authorities (<10 mg/L) and there was no significant risk of nitrate contamination in ground water (where HI<1). Conclusion: Residents in Mukim Salor, Kelantan, Malaysia, were exposed to low levels of nitrate in groundwater. Keywords: Agriculture, nitrate, groundwater, methemoglobinaemia, health risk assessment, Mukim Salor