bluuebunny/crossref_metadata_2025_split huggingface dataset:
PERENCANAAN PEMELIHARAAN MOTOR DIESEL DENGAN METODE RCM (RELIABILITY CENTERED MAINTENANCE) PADA PLTG TELUK LEMBU PEKANBARU
Authors: Darno  
Published: March 2021

Teluk Lembu Gas Power Plant (PLTG) is one type of power plant that uses the power of burning fuel and high pressure air. To be able to meet the needs of electrical energy on the island of Sumatra, especially in the Riau region,electricity production must not experience a decrease in productivity due to equipment damage. Obstacles that arise are frequent downtime unexpectedresulting in the production of electricity is interrupted or even to cause derating caused by damage to the operational when the engine is running. This study aims to provide recommendations for equipment maintenance andtime intervals optimal inspectionin the generator system. The research method used is Reliability Centered Maintenance (RCM) withanalysis quantitative. Where are the stages of implementing the RCM method, namely determining thecomponents criticalin the PLTG generator engine, determining thevalues, determining the Mean Time to Failure (MTTF) and Mean Time to Repair (MTTR)time interval optimal maintenance, and making a table of causes of damage to thecomponents generator engine. After analyzing it, it was found that thecomponent criticalof PLTG Teluk Lembu is the Diesel Motor. This is obtained based on the component with the highest frequency of damage, namely 13 damage during a period of 1 year. From the results of data processing, it is obtained that the MTTF value is 0.92441 hours and the MTTR value is 0.89014 hours. Theinspection time interval optimalis 25 days, so it is advisable to carry out Corrective and Preventive maintenance activities for Diesel Motorcycles periodically every 25 days (PM 25D) in order to increase the reliability of the Diesel Motor
STUDI KERUSAKAN HIGH PRESSURE TURBINE VANE PESAWAT ATR72-500 WINGS AIR DI BANDARA SULTAN SYARIF KASIIM II PEKANBARU
Authors: Desmico Ekta W Muhammad , Ridwan Abrar 
Published: March 2021

The aircraft can fly as there is a thrust from the engine that causes the aircraft to have speed. The components of the aircraft engines are compressor, combustion chamber, turbine and propeller. High pressure turbine vanes is a component in the Hot section or turbine section that serves to direct the hot gas flow from the combustion chamber to the turbine. The purpose to be achieved in this research is to analyze and find out the cause of high pressure turbine vane damage and know the gas engine efficiency PW127. Cause of damage due to treatment not done according to the schedule until the phenomenon of overtemperature after combustion chamber and the content of impurities in the water laundering results. After the Brayton cycle calculation is obtained the temperature value of the turbine entry 1563oC (1836 K). These results exceed the turbine inlet temperature according to manual maintenance engine. Based on laboratory test, the content of 250 mg/m2 sulfur and 1800 mg/m2 chloride is obtained. This content causes damage by erosion or corrosion of high pressure turbine vane components. The value of gas efficiency is 42% according to the outside Air tempetarure. The thermal efficiency of gases will increase with increasing temperature conditions.
The Effect of Flow on the Resonance Absorption of Slow MHD Waves in Magnetic Flux Tubes
Authors: Sadeghi Mohammad , Bahari Karam , Karami Kayoomars 
Published: March 2021

Abstract
In this paper, we study kink and sausage oscillations in the presence of longitudinal background flow. We study the resonance absorption of kink and sausage modes in the slow continuum, under magnetic pore conditions, in the presence of flow. We determine the dispersion relation, and solve it numerically to find the frequencies and damping rates of the slow kink and sausage surface modes. We also obtain an analytical solution for the damping rate of the slow surface mode in the long wavelength limit. We show that in the presence of plasma flow, resonance absorption can result in strong damping for forward waves, and can be considered as an efficient mechanism to justify the extremely rapid damping of slow surface sausage waves observed in magnetic pores. Moreover, the plasma flow reduces the efficiency of resonance absorption to damp backward waves. With respect to pore conditions, resonance instability is avoided in our model.
[C ii] and CO Emission along the Bar and Counter-arms of NGC 7479*
Authors: Fadda Dario , Laine Seppo , Appleton Philip N. 
Published: March 2021

Abstract
We present new SOFIA [C ii] and ALMA CO
J=1→0 observations of the nearby asymmetric barred spiral galaxy NGC 7479. The data, which cover the whole bar of the galaxy and the counter-arms visible in the radio continuum, are analyzed in conjunction with a wealth of existing visible, infrared, radio, and X-ray data. As in most normal galaxies, the [C ii] emission is generally consistent with emission from cooling gas excited by photoelectric heating in photodissociation regions. However, anomalously high [C ii]/CO ratios are seen at the two ends of the counter-arms. Both ends show shell-like structures, possibly bubbles, in Hα emission. In addition, the southern end has [C ii]-to-infrared emission ratios inconsistent with normal star formation. Because there is little H i emission at this location, the [C ii] emission probably originates in warm shocked molecular gas heated by the interaction of the radio jet forming the counter-arms with the interstellar medium in the galaxy. At two other locations, the high [C ii]/CO ratios provide evidence for the existence of patches of CO-dark molecular gas. The [C ii] and CO observations also reveal resolved velocity components along the bar. In particular, the CO emission can be separated into two components associated with gas along the leading edge of the bar and gas trailing the bar. The trailing gas component that amounts to approximately 40% of the gas around the bar region may be related to a minor merger.
Dust Growth in Molecular Cloud Envelopes: A Numerical Approach
Authors: Beitia-Antero Leire , Gómez de Castro Ana I. 
Published: March 2021

Abstract
Variations in the grain size distribution are to be expected in the interstellar medium (ISM) owing to grain growth and destruction. In this work, we present a dust collision model to be implemented inside a magnetohydrodynamic (MHD) code that takes into account grain growth and shattering of charged dust grains of a given composition (silicate or graphite). We integrate this model in the MHD code Athena and build on a previous implementation of the dynamics of charged dust grains in the same code. To demonstrate the performance of this coagulation model, we study the variations in the grain size distribution of a single-sized population of dust with radius 0.05 μm inside several dust filaments formed during a 2D MHD simulation. We also consider a realistic dust distribution with sizes ranging from 50 Å to 0.25 μm and analyze the variations in both the size distribution for graphite and silicates and the far-ultraviolet extinction curve. From the obtained results, we conclude that the methodology here presented, based on the MHD evolution of the equation of motion for a charged particle, is optimal for studying the coagulation of charged dust grains in a diffuse regime such as a molecular cloud envelope. Observationally, these variations in the dust size distribution are translated into variations in the far-ultraviolet extinction curve, and they are mainly caused by small graphite dust grains.
Presolar Silicate and Oxide Grains Found in Lithic Clasts from Isheyevo and the Fine-grained Matrix of Northwest Africa 801
Authors: Sanghani Manish N. , Marhas Kuljeet Kaur , Hsiao Silver Sung-Yun , Peeters Zan , Shang Hsien , Lee Der-Chuen , Bizzarro Martin 
Published: March 2021

Abstract
We report on the discovery of 33 oxygen-anomalous grains from the CH3/CBb3 chondrite Isheyevo and the CR2 chondrite Northwest Africa (NWA) 801. Oxygen isotopic compositions indicate the origin of the majority grains in stellar outflows of low-mass (∼1.2 to ∼2.2 M
⊙), solar-metallicity red giant or asymptotic giant branch stars, while highly 17O-enriched grains probably have nova origins. Isotopic compositions of the eight 18O-rich grains, including an extremely 18O-rich grain (∼16 times solar 18O/16O ratio), are reproduced by zone mixing of SNe II ejecta. Close-to-normal silicon, magnesium, and calcium isotopic compositions of grains are consistent with the isotope exchange in the interstellar medium or the meteorite parent body, while two grains with Si isotopic anomalies and one grain with Mg isotopic anomalies reflect the Galactic chemical evolution. An Isheyevo clast showed several hot spots with moderate to high 15N enrichments, including a hot spot with an extreme 15N excess of (7225 ± 316)‰. However, no correlation between 15N enrichment and presolar oxygen-rich grain abundance is found. Grains with elliptical shapes probably indicate primary condensation feature. Two complex grains possibly display decoupling of the isotopic and elemental compositions in the grain formation environments. The low silicate-to-oxide abundance ratio for the fine-grained chondrule rims in NWA 801 likely reflects the preferential destruction of silicates due to terrestrial weathering. In NWA 801, the presolar O-rich grain abundance in fine-grained chondrule rims is higher than in the interchondrule matrix, similar to the trend observed for some aqueously altered chondrites of petrologic type 2.
Spectroscopy of the 2015 Outburst of AG Pegasi
Authors: Mistry Dharmesh , Steele Iain A. 
Published: March 2021

Abstract
Between 2015 September and 2016 January, we obtained 18 spectra of the 2015 classical outburst of AG Pegasi—a symbiotic star consisting of a white dwarf (WD), red giant, and surrounding nebula. Modelling the flux contributions of these components reveals that nebular emission, from the reprocessing of high energy WD photons, dominates the 3200–6300 Å range. Nebular emission rises and falls in line with changes seen in the WD, whose properties have been derived using Hβ and He ii (4686 A) line flux, and emission measure calculations. WD parameters follow changes seen in visual band light curves. During the second peak of the outburst, WD temperatures reach 166,000 ± 6000 K, with a luminosity and radius of 14,000 ± 2000 L
⊙ and 0.149 ± 0.014 R
⊙ respectively. These features are consistent with an expansion of the WD pseudo-photosphere due to an accretion rate exceeding that required for stable hydrogen burning.
Vitamin D Correlation with Echocardiographic Function in Patients of Congestive Heart Failure
Authors: Mohanty Vivek , Pathania Monika , Bhasi Ankith 
Published: March 2021

Background:
The association between vitamin D and heart failure, especially left ventricular (LV) function, is still not clear.

Objectives:
We aimed to study the correlation between 25-hydroxy vitamin D levels and parameters of cardiac systolic and diastolic functions in patients with LV systolic heart failure.

Materials and Methods:
Ninety patients of heart failure coming to our hospital with systolic heart failure (LV ejection fraction <40%) were included. Venous sample were taken for measurement of 25-hyrdoxy vitamin D levels. Transthoracic echocardiography was done for all patients, and parameters of LV systolic and diastolic functions were taken.

Results:
Compared to patients having vitamin D <20 ng/ml, patients having vitamin D levels ≥20 ng/ml had higher early diastolic mitral annular velocity (e'), significantly lower ratio of early diastolic mitral inflow velocity (E) to e' (E/e'), significantly shorter isovolumetric relaxation time (IVRT) suggestive of better diastolic function. Furthermore, patients having vitamin D <20 ng/ml had higher LV end-systolic volume, LV end-systolic diameter, larger LV end-diastolic diameter, higher interventricular septum thickness, higher LV wall thickness, and higher LV mass.

Conclusion:
Reduced vitamin D (<20 ng/ml) was associated with worse systolic function in terms of systolic volume and diameter, diastolic function in terms of lower e′, higher E/e′, and longer IVRT.
Biosorption of lead by bacteria isolated from abattoir wastewater
Authors: Abioye O. P , Nnadozie H.O , Aransiola S.A , Musa O. I. 
Published: March 2021

Six bacteria were isolated from abattoir wastewater collected from Minna central abattoir. Lead tolerant bacteria were isolated from the wastewater. The isolates were then characterized on the basis of their colonial appearance and reaction to various biochemical tests. The lead tolerance profile of the isolates was carried out using agar diffusion method, with concentrations of Lead nitrate ranging from 50-250 mg/L. Two resistant isolates identified as species of Bacillus and Neisseria were selected for biosorption studies. Lead concentration was determined using Atomic Absorption Spectrophotometry. The lead biosorption capacity of the two isolates was studied by inoculating 2 mL of 24 hours old bacteria suspension in 50mL Nutrient broth, containing varying concentrations of lead (500 and 1000 mg/L) at varying pH (7 and 8), with representative samples being withdrawn at day 4, 8 and 12. The results showed that highest biosorption rate was recorded on day 10, at pH 7, in solution containing 500 mg/L of lead with 75.3% and 66% by Bacillus sp. and Neisseria sp. respectively. These results show that Bacillus sp. had better sorption capacity than Neisseria sp. Both organisms can be used for the removal of lead.
Keywords: Wastewater, Biosorption, Abattoir, heavy metal, Bacteria
Level of Depression and Suicidal Ideation among BSN Students
Authors: Balay-odao Ejercito M. , Marbella Ivy May , Balisong Juana 
Published: March 2021

Undergraduate college students have been identified as at-risk population for development of suicidal ideation and depression. Student nurses are among those who experience depression and anxiety due to stressful life events. The stressful situations encountered by student nurses are multifaceted. Thus, this study explored the level of depression and suicidal ideation of BSN students and the effect of gender and year level. The need to explore these two salient factors was prompted by the need to promote and to improve school of nursing services, student safety, and decrease cases of depression and suicidal ideation among students. The study utilized a descriptive design. There were 326 student nurses who participated in the study. The questionnaire which was used for this study was based on 2 standardized self – report questionnaire. The findings showed that most of the students experienced mild to severe depression. Most of the students however, do not have suicidal ideation behavior, but almost one third of the students have a high risk for suicidal ideation behavior. Furthermore, the findings showed that gender and year level have no significant effect on the level of depression among BSN Students. Gender and year level have no significant effects in the level of suicidal ideation among student nurses. These findings can help guide the development of a school-based, prevention and promotion mental health program.
Biodegradation of Chlorobenzoic Acid Substitutes, Particularly, 2- Chlorobenzoic Acid by Aeromonas hydrophila
Authors: Tarawneh Khaled , AL-Quraishi Farah , Qaralleh Haitham , Al Tarawneh Amjad , Al-limoun Muhamad , Khleifat Khaled 
Published: March 2021

Bacterium Aeromonas hydrophila (A. hydrophila) was isolated from the Petra Wastewater Treatment Plant effluent in southern Jordan. It was identified by using morphological and biochemical characteristics. A. hydrophila was found to be able of using chlorobenzoate compounds as carbon and energy source. These capabilities were with different biodegradation rates (4- chlorobenzoic acid 5µM/hr, 3,4-dichlorobenzoic acid 15.5µM/hr, 2- chlorobenzoic acid 41µM/hr and 3- chlorobenzoic acid 65µM/hr). The degradation ability was monitored through the release of chloride, disappearance of the substrate and finally the growth of bacterial cells on these substrates. A. hydrophila dioxygenases physiologically induced by chlorobenzoic acid compounds, were analyzed for both ortho or meta ring-cleavage of these aromatic compounds. Only 1, 2-dioxygenase activity was detected which suggest that the cleavage is through the ortho pathway. The best results of degradation of 2-CBA compound were obtained with 3mM substrate concentration, 25ºC, pH 7and 200µl inoculum size. The carbon sources affected the 2-CBA degradation differently from that on chloride and cell mass production. Nitrogen sources used reduced the degradation activity of the 2-CBA as well as in the chlorine release from 2-CBA. However, the nitrogen source L-proline had a slight enhancement effect on the biodegradation between the 40-80h.
Evaluation of Aqueous Extracts of Neem kernels and leaves for the control of spotted stem borer Chilo partellus Swinhoe, in sorghum at New Halfa, Sudan
Authors: Mohammed Hassbelrasul , Ali Ali 
Published: March 2021

A field experiment was conducted to study the effect of different concentrations of aqueous extracts of Neem kernels (NK) and Neem leaves (NL) on the incidence and damage of spotted stem borer in sorghum during 2011/12-2012/13 seasons at New Halfa Research Station farm. Sorghum variety Tabat was used. The experiment was laid in a RCB design with four replicates and seven treatments. These were: NK at kg/ 30 and 40 Liter of water, NL at kg/15 and 20 Liter of water, Furadan10% G at 15kg/F and Malathion 57% EC at 2L/F as standard and the untreated control. A liquid soap was added to Neem treatments as an emulsifying agent. Three sprayings were applied using knapsack sprayer starting two weeks after emergence with 10 days intervals. Data on percent deadheart, percent leaf damage plants, percent stem tunneling, number of borer holes per plant and grain yield were recorded. Results indicated that, all treatments were highly significantly (P>0.001) reduced stem borer damage and increased the grain yield compared to the untreated one. NK at kg/ 40 L of water was the best in reducing stem borer damage and increasing grain yield comparable to the standard treatment Furadan 10% G at 15 Kg/F.
Climate change impacts model parameter sensitivity – implications for calibration strategy and model diagnostic evaluation
Authors: Melsen Lieke Anna , Guse Björn 
Published: March 2021

Abstract. Hydrological models are useful tools for exploring the impact of climate change. To prioritize parameters for calibration and to evaluate hydrological
model functioning, sensitivity analysis can be conducted. Parameter
sensitivity, however, varies over climate, and therefore climate change could
influence parameter sensitivity. In this study we explore the change in
parameter sensitivity for the mean discharge and the timing of the discharge,
within a plausible climate change rate. We investigate whether changes in sensitivity propagate into the calibration strategy and diagnostically compare three hydrological models based on the sensitivity results. We
employed three frequently used hydrological models (SAC, VIC, and HBV) and explored parameter sensitivity changes across 605 catchments in the United
States by comparing GCM(RCP8.5)-forced historical and future
periods. Consistent among all hydrological models and both for the mean
discharge and the timing of the discharge is that the sensitivity of snow parameters decreases in the future. Which other parameters increase in
sensitivity is less consistent among the hydrological models. In 45 %
to 55 % of the catchments, dependent on the hydrological model, at
least one parameter changes in the future in the top-5 most sensitive
parameters for mean discharge. For the timing, this varies between
40 % and 88 %. This requires an adapted calibration strategy
for long-term projections, for which we provide several suggestions. The
disagreement among the models on the processes that become more relevant in
future projections also calls for a strict evaluation of the adequacy of the
model structure for long-term simulations.
PLANT OIL VALORIZATION BY CROSS-METATHESIS REACTIONS: SYNTHESIS OF FINE CHEMICALS FROM METHYL OLEATE
Authors: Trasarti Andres , Gonzalez Eduardo , Nieres Pablo , Apesteguia Carlos 
Published: March 2021

This work studies the production of high-value compounds by the cross-metathesis of methyl oleate (MO) with ethylene, cinnamonitrile and cinnamaldehyde using the 2nd generation Hoveyda-Grubbs complex (HG) as catalyst, either dissolved in toluene or supported on silica. Reactions were carried out in batch reactors between 313 and 343 K. The yield to cross-metathesis products (YC-M) for the MO cross-metathesis with cinnamonitrile and cinnamaldehyde increased with the initial molar reactant ratio (RCN/MO, RCA/MO), reaching YC-M values of 82% and 95%, respectively, at R = 7. No catalyst deactivation took place during the 400-min catalytic runs. The liquid-phase cross-metathesis of MO with ethylene (ethenolysis) was performed over HG(10%)/SiO2 catalysts, producing 1-decene and methyl 9-decenoate, a valuable intermediate for the synthesis of pheromones. At RC2/MO = 2.5, the selectivity to ethenolysis products was 77% at 82% MO conversion. The MO self-metathesis was the only side reaction observed in all the catalytic tests.
PERANCANGAN E-COMPLAINT UNTUK MENINGKATKAN MUTU PELAYANAN PADA DINAS KESEHATAN LUBUKLINGGAU MENGGUNAKAN METODE SERVQUAL
Authors: Kurniawan, Alfiarini Rahman 
Published: March 2021

Pelayanan publik berbagai konsep dan teknik baru dalam sistem survei kepuasan pelayanan telah banyak dikembangkan untuk mengantikan metode survei dengan cara manual hanya mengandalkan sosialisasi yang dimana survei dilakukan pada waktu dan tempat yang telah ditentukan. Salah satu metode survei yang sedang berkembang di masa sekarang yaitu e-complaint menggunakan metode servqual. E-complaint dapat membantu para pegawai melakukan survei dan metode servqual membantu dalam perhitungan, hal ini dapat memaksimalkan waktu survei yang dapat dilakukan kapan pun. Metodelogi penelitian yang digunakan dalam menyusun skripsi ini adalah studi pustak sedangkan tahap pengembangan sistem menggunakana metode prototype. Merancang aplikasi yang akan dibangun digunakan metode terstruktur dengan menggunakan tools UML. Aplikasi e-complaint yang akan dibangun menggunakan bahasa pemrogram PHP dan MySQL sebagai database. Hasil penelitian ini adalah akan dibangun sebuah program aplikasi e-complaint untuk meningkatkan mutu pelayana pada Dinas Kesehatan Kota Lubuklinggau. Pengujian sistem yang digunakan adalah metode Black-Box. Dengan sistem yang akan dibangun e-complaint dapat membantu melakukan survei pengisian komplain sehinggan responden tidak perlu menunggu ketika sosialisasi pada waktu yang telah di tetapkan, dan dapat mempermudah pegawai dalam pengumpulan data untuk menghitung nilai hasil komplain dalam upaya meningkatkan mutu pelayanan.
PENGUKURAN KEPUASAN PELAYANAN MENGGUNAKAN METODE SERVQUAL
Authors: Yayang Eluis Bali Mawartika  
Published: March 2021

Sebuah instansi besar yang memberikan pelayanan jasa harus terus meningkatkan kualitas pelayanannya. Namun, kepuasan pelanggan terhadap pelayanan sulit untuk diukur, sehingga para pimpinan mengalami kendala untuk mengambil keputusan dalam meningkatkan pelayanan, oleh karena itu diperlukan suatu sistem yang dapat mengukur tingkat kualitas pelayanan sehingga menjadi alat bantu dalam melakukan proses pengambilan keputusan untuk meningkatkan kualitas pelayanan. Untuk mengembangkan sistem ini menggunakan metode Servqual. Metode ini menegaskan bahwa bila kinerja pada suatu atribut (attribute performance) meningkat lebih besar daripada harapan (expectation) atas atribut yang bersangkutan, maka persepsi terhadap kualitas jasa akan positif, demikian pula sebaliknya. Sistem ini berfungsi untuk membantu pihak pengambil keputusan dalam menentukan strategi meningkatkan kualitas pelayanan yang tepat.