bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effectiveness of Kaempferia galanga extract for the prevention of saprolegniasis on catfish Clarias gariepinus eggs
Authors: Humsari Arvilia , Rosidah , , Junianto , 
Published: August 2017

ABSTRACTSaprolegniasis is a disease caused by the infection of Saprolegnia sp. Saprolegniasis can attack catfish eggs causing a decrease in hatching rate. There are some plants which have an antifungal potential, e.g. cutcherry Kaempferia galanga L. This study aimed to obtain the effective concentration of cutcherry rhizome extract for the prevention of saprolegniasis, resulting in a high hatching rate. This study applied five treatments: the extract at concentrations of 0 mg/L; 20 mg/L; 40 mg/L; 60 mg/L; and 80 mg/L applied to catfish eggs. The method applied was the immersion of eggs in cutcherry extract for one hour. The results showed that the immersion method applied in the application of cutcherry rhizome extract could reduce saprolegniasis. This was indicated by the decrease of saprolegniasis compared to control. The use of cutcherry rhizome extract (the treatment at concentrations of 20 mg/L; 40 mg/L; 60 mg/L; and 80 mg/L) could prevent saprolegniasis with saprolegniasis levels of 43.5%; 27.5%; 19.5%; and 18.5%, respectively. Keywords : catfish eggs, cutcherry rhizome extract, saprolegniasis ABSTRAKSaprolegniasis merupakan suatu penyakit yang timbul karena infeksi Saprolegnia sp. Saprolegniasis dapat menyerang telur ikan lele yang menyebabkan turunnya daya tetas telur. Terdapat beberapa tanaman yang memiliki daya antifungi seperti tanaman kencur Kaempferia galanga L. Penelitian ini bertujuan untuk mendapatkan konsentrasi ekstrak rimpang kencur yang efektif untuk pencegahan penyakit saprolegniasis sehingga menghasilkan daya tetas telur yang tinggi. Penelitian menggunakan lima perlakuan yaitu dosis ekstrak 0 mg/L (kontrol); 20 mg/L; 40 mg/L; 60 mg/L; dan 80 mg/L dengan menggunakan telur ikan lele sangkuriang. Metode yang digunakan yaitu perendaman telur dalam ekstrak kencur selama satu jam. Hasil penelitian menunjukkan bahwa metode perendaman ekstrak rimpang kencur dapat mengurangi saprolegniasis. Hal ini ditunjukkan dengan semakin menurunnya saprolegniasis jika dibandingkan kontrol. Penggunaan ekstrak rimpang kencur (perlakuan 20 mg/L; 40 mg/L; 60 mg/L; dan 80 mg/L) dapat mencegah saprolegniasis berturut-turut 43,5%; 27,5%; 19,5%; dan 18,5%. Kata kunci : telur ikan lele, ekstrak rimpang kencur, saprolegniasis
Growth, biomass, and chlorophyll-a and carotenoid content of Nannochloropsis sp. strain BJ17 under different light intensities
Authors: Fakhri Muhammad , Arifin Nasrullah Bai , Hariati Anik Martina , Yuniarti Ating 
Published: August 2017

ABSTRACT Nannochloropsis sp. has been identified as sources of live feed and pigment in aquaculture. To increase the production, the optimal environmental conditions for microalgae are required. Light intensity is one of the important factors that significantly affects the biomass and pigment of microalgae. The study aimed to determine the effect of light intensity (1,500; 3,000; and 4,500 lux) on growth, biomass production, chlorophyll-a, and carotenoid content of Nannochloropsis sp. strain BJ17. The results showed that different light intensities significantly affected the growth, biomass, chlorophyll-a and carotenoid contents of Nannochloropsis sp. strain BJ17. Increasing light intensity resulted in the increase of the growth rate, biomass, chlorophyll-a, and carotenoid contents of Nannochloropsis sp. strain BJ17. The cell achieved the highest specific growth rate of 1.729 %/day and the cell concentration of 43.333×106 cell/mL at a light intensity of 4,500 lux. The highest chlorophyll-a and carotenoid concentrations of algae were obtained at 4,500 lux (8.304 μg/mL and 3.892 μg/mL, respectively). This study suggested that increasing light intensity led to the increase in the growth, biomass, chlorophyll-a, and carotenoid content of Nannochloropsis sp. strain BJ17. Keywords: carotenoid, chlorophyll, biomass, growth rate, light intensity ABSTRAK Nannochloropsis sp. diketahui sebagai sumber pakan alami dan pigmen pada budidaya perikanan. Budidaya pada kondisi lingkungan yang optimal diperlukan untuk meningkatkan produksi mikroalga. Intensitas cahaya merupakan salah satu faktor esensial yang secara signifikan mempengaruhi biomassa dan pigmen mikroalga. Tujuan penelitian ini adalah untuk menentukan pengaruh intensitas cahaya yang berbeda (1.500, 3.000, and 4.500 lux) terhadap pertumbuhan, produksi biomassa, klorofil-a, dan karotenoid Nannochloropsis sp. strain BJ17. Hasil menunjukkan bahwa intensitas cahaya yang berbeda berpengaruh secara signifikan terhadap pertumbuhan, biomassa dan klorofil-a dan karotenoid Nannochloropsis sp. strain BJ17. Semakin tinggi intensitas cahaya maka laju pertumbuhan, biomassa, kandungan klorofil-a dan total karotenoid Nannochloropsis sp. strain BJ17 semakin tinggi. Laju pertumbuhan spesifik tertinggi 1,729%/hari dan konsentrasi sel maksimum tertinggi 43,333×106 sel/mL dihasilkan pada intensitas cahaya 4.500 lux. Konsentrasi klorofil-a (8,304 μg/mL) dan karotenoid (3,892 μg/mL) tertinggi juga diperoleh pada intensitas cahaya 4.500 lux. Studi ini menunjukkan bahwa peningkatan intensitas cahaya berperan dalam meningkatkan pertumbuhan, produksi biomassa, klorofil-a, dan karotenoid Nannochloropsis sp. strain BJ17. Kata kunci: karotenoid, klorofil, biomassa, pertumbuhan, intensitas cahaya
Survival and growth responses of snakehead fish Channa striata Bloch. juvenile in aerated and unaerated acid sulfate water
Authors: Purnamawati , , Djokosetiyanto Daniel , Nirmala Kukuh , Surawidjaja Enang Harris , Affandi Ridwan 
Published: August 2017

ABSTRACT The aim of the research was to analyze survival rate, specific growth rate, albumin, and feed efficiency and physiological (blood glucose, cortisol, dan haemoglobin) responses of snake head fish juvenil that reared at aerated and unaerated of tidal land water have been conducted in the laboratory. Experiments using completely randomized design with aerated and unaerated as a treatment, and each treatment has twelve replications. The snakehead fish juvenil wich length 2.4±0.2 cm and weight of 0.21±0.05 g reared in the aquarium that are size 30×25×35 cm (water volume 25 L) with a stocking density 2 juvenile/L, for 40 days. The fishes were fed with commercial feed with protein content about 40%, feeding two times a day (morning and afternoon) were at satiation. Replacement of water done every two days about 10% of the total water volume in the aquarium. The results showed that unaerated median significantly affected to biometric and physiological response of juvenile of snake head fish. The media un-aerated gives the best results shown by the higher value of survival (92%), specific growth rate (6.73%/ day), feed efficiency (78.22%), protein retention (41.91%), energy retention (30.81%) value of albumin (6.60 g/100 mL) and the haemoglobin (5.58 g/dL), and have the lowest value of cortisol (21.49 ng/L) and blood glucose (43.36 mg/100 mL). Keywords: acid sulfate water, growth rate, aeration, Channa striata ABSTRAK Penelitian ini bertujuan untuk menganalisis respons kelangsungan hidup, pertumbuhan spesifik, albumin, dan efisiensi pakan dan fisiologis (kortisol, glukosa darah, dan hemoglobin) juvenil ikan gabus yang dipelihara dengan dan tanpa aerasi pada media air rawa pasang surut. Penelitian menggunakan rancangan acak lengkap dengan aerasi dan tanpa aerasi sebagai perlakuan, dan masing-masing perlakuan memiliki 12 ulangan. Juvenil ikan gabus berukuran panjang 2,4±0,3 cm dan bobot 0,21±0,03 g dipelihara dalam akuarium 30×25×35 cm (volume 25 L) dengan padat tebar 2 ekor/L, selama 40 hari. Ikan diberi pakan berupa pakan komersial dengan kadar protein ±40%, pemberian pakan dua kali sehari (pagi dan sore) at satiation. Penggantian air dan penyiponan dilakukan dua hari sekali sebanyak 10% dari volume total dalam akuarium. Hasil penelitian menunjukkan bahwa perlakuan tanpa aerasi berpengaruh nyata terhadap respons biometrik dan fisiologis juvenil ikan gabus. Media tanpa aerasi memberikan hasil yang lebih baik ditunjukkan oleh kelangsungan hidup (92%), laju pertumbuhan spesifik (6,73%/ hari), efisiensi pakan (78,22%), retensi protein (41,91%), retensi energi (30,81%), kadar albumin (6,60 g/100 mL), dan hemoglobin (5,85 g/dL) yang lebih tinggi, sedangkan kadar kortisol (219 ng/L) dan glukosa darah (43,36 mg/100 mL) yang terendah. Kata kunci: media sulfat masam, pertumbuhan, aerasi, Channa striata
Application of gamal Gliricidia sepium leaves compost as depuration agent of leads (Pb) in the body organ of red tilapia Oreochromis sp.
Authors: Robin , , Nirmala Kukuh , Harris Enang , Affandi Ridwan , Jusadi Dedi 
Published: August 2017

ABSTRACT This study was aimed to perform depuration of Pb contained in tilapia body. The experiments were conducted in aquarium using compost of Gliricidia sepium leaf at a concentration of 10g/L, 20 g/L, 30 g/L, 40 g/L, and 0 g/L (control). The result showed that Pb level in fish muscle immersed with compost of Gliricidia leaf at a dose of 30 g/L for five days successfully decreased to a safe limit for human consumption (<0.3 mg/kg). However, decrease of Pb level in fish liver and kidney to finally reach the safe limit required seven days. Decreasing level of lead in the organs of experimental fish along with the increasing level of Pb in compost and maintenance media indicated that Pb accumulated in fish were released into the maintenance media by compost through chelation process. To conclude, compost of G. sepium leaves can be used as the material for depuration of Pb in the body of tilapia Keywords: humic acid, fulvic acid, depuration, Gliricidia leaves, lead, red tilapia ABSTRAK Penelitian ini bertujuan untuk mendepurasi Pb yang terkandung di tubuh ikan nila. Percobaan dilakukan di dalam akuarium menggunakan kompos daun gamal pada konsentrasi 10 g/L, 20 g/L, 30 g/L, 40 g/L, dan 0 g/L (kontrol). Hasil penelitian menunjukkan bahwa, Pb di daging ikan yang direndam dengan kompos daun gamal pada konsentrasi 30 g/L selama lima hari, kadarnya menurun hingga batas aman untuk dikonsumsi manusia (<0,3 mg/ kg). Penurunan Pb di hati dan ginjal untuk mencapai kadar aman membutuhkan waktu yang lebih lama, yakni tujuh hari. Seiring dengan menurunnya kadar Pb dalam organ ikan uji, kisaran Pb dalam kompos dan media budidaya meningkat, menunjukkan bahwa Pb dari tubuh ikan dilepaskan ke media budidaya dan terjadi proses khelat oleh kompos. Dengan demikian, kompos daun gamal bisa digunakan sebagai bahan pendepurasi Pb dari tubuh ikan nila. Kata kunci: asam humat, asam fulvik, depurasi, daun gamal, timbal, nila merah
Supplementation of astaxanthin and vitamin E in feed on the development of gonads white shrimp broodstock Litopenaeus vannamei Boone 1931
Authors: Maulana Fajar , Arfah Harton , Istifarini Mita , Setiawati Mia 
Published: August 2017

<p class="Pa3"><strong>ABSTRACT </strong></p><p> </p><p>Increase production high quality of white shrimp <em>Litopenaeus vannamei</em> broodstock can be done with the addition of vitamin E or astaxanthin. A dose used was 350 ppm vitamin E, 500 ppm astaxanthin, combination of 350 ppm vitamin E, and 500 ppm astaxanthin, combination of 175 ppm vitamin E and 250 ppm astaxanthin. The purpose of this research was to evaluate the effect of astaxanthin and vitamin E supplementation with different dose in the feed on gonad maturity of white shrimp broodstock. Feeding of vitamin E and astaxanthin was performed in three times, at 06.00, 12.00 and 20.00 by as much as 2% of the shrimp weight. The results showed that combination of 175 ppm vitamin E and 250 ppm astaxanthin giving highest relative survival (100.00±0.00%), growth rate of broodstock shrimp (1.07±0.26%/day), the fastest maturity of first gonads level achieved 14 days (19.45 ±4.81%), maturity of fourth gonads level achieved 41 days, levels of spawning (33.33±8.33%), fecundity (87,000±2,000 eggs) and hatching rate (49±1.53%).</p><p> </p><p class="Pa5">Keywords: astaxanthin, <em>Litopenaeus vannamei</em>, vitamin E.</p><p> </p><p> </p><p class="Pa3"><strong>ABSTRAK </strong></p><p> </p><p class="Pa5">Meningkatkan kualitas induk udang vaname <em>Litopenaeus vannamei </em>dapat dilakukan dengan penambahan vitamin E atau astaxanthin pada pakan. Tujuan penelitian ini adalah untuk mengetahui pengaruh pemberian astaxanthin dan vitamin E dengan dosis berbeda dalam pakan terhadap tingkat kematangan gonad calon induk udang vaname. Dosis yang digunakan 350 ppm vitamin E, 500 ppm astaxanthin, 350 ppm vitamin E, dan 500 ppm astaxanthin, 175 ppm vitamin E dan 250 ppm astaxanthin. Pemberian pakan dengan penambahan vitamin E dan astaxanthin dilakukan sebanyak tiga kali, yaitu jam 06.00, 13.00, dan 20.00 WIB sebanyak 2% dari bobot udang. Hasil menunjukkan bahwa perlakuan terbaik didapatkan pada pemberian kombinasi 175 ppm vitamin E dan 250 ppm astaxanthin dengan tingkat sintasan induk udang 100,00±0,00%, laju pertumbuhan spesifik induk udang 1,07±0,26%/hari, kematangan gonad pertama tercepat dicapai pada 14 hari sebanyak 19,45±4,81%, kematangan gonad keempat didapat pada hari ke-41, tingkat pemijahan 33,33±8,33%, fekunditas 87.000±2.000 telur, dan derajat penetasan telur mencapai 49±1,53%.</p><p> </p><p>Kata kunci: astaxanthin, udang vaname <em>Litopenaeus vannamei</em>, vitamin E</p>
Repositories of Open Educational Resources: An Assessment of Reuse and Educational Aspects
Authors: Santos-Hermosa Gema , Ferran-Ferrer Núria , Abadal Ernest 
Published: August 2017

<p class="3">This article provides an overview of the current state of repositories of open educational resources (ROER) in higher education at international level. It analyses a series of educational indicators to determine whether ROER can meet the specific needs of the education context, and to clarify understanding of the reuse of open educational resources (OER) provided by ROER. The aim of the study is to assess ROER by combining these two perspectives, and to form a basis for discussion among the universities that are responsible for these repositories.</p><p class="3">The method was based on content analysis and consisted of two phases: an exploration of international sources, and an analysis of 110 ROER using the proposed set of indicators. The results focus on data from the analysis of ROER websites and some models of good practices. They are presented according to three core dimensions for evaluating ROER: general factors to establish types of ROER, a focus on drivers for OER reuse, and a focus on educational aspects. It was found that most of the ROER that included one or more of the proposed reuse indicators were created exclusively for educational resources. Educational aspects are not yet firmly embedded into ROER. The few repositories that seem to have successfully included them are those that provide other educational metadata and use educational standards.</p>
Analysis of Buccal Cortical Plate Thickness for Placement of Mini-Implants – A CBCT Study
Authors: David Roopak Mathew , Ranjan Raghu , M R Dinesh , R M Dharma , B C Amaranth , Arjunan Sharmila 
Published: August 2017

<p>The purpose of this study was to quantitatively evaluate buccal cortical bone thickness in the maxilla and mandible so as to provide guidelines for mini-implant placement. Cone beam computed tomographic scans of thirty patients (Age 16-30 years) were collected from preorthodontic records. Each measurement area was coded with a number beginning in the maxillary right quadrant distal to the second molar with number 1 and ending in the mandibular right quadrant distal to the second molar with number 30. For analysis these measurement areas were also grouped as sextants. Three measurement points were then defined at 2 mm, 4 mm and 6 mm from the alveolar crest in each measurement. The measuring locations were recorded on the four quadrants, resulting in 90 locations in the buccal cortical plate of maxillary and mandibular arch. The region of interest was explored at each measuring location of the 30 sites using Galileos software. The optimal site for miniimplant placement in the anterior region is between the central and lateral incisors in the maxilla and between the lateral incisor and the canine in the mandible at the 6-mm level from the alveolar crest. At the buccal aspect of the posterior region of both jaws, the optimal sites are between between the first and second molars i.e. in the Maxillary arch at 4 mm level on the right side and left side and in the Mandibular arch at 6 mm level on the right side and left side. </p>
Bending Properties of Elephant Grass Fiber Reinforced Epoxy Resin Composites
Authors: Nurhayati Alwiyah 
Published: August 2017

Elephant grass fiber reinforced epoxy resin composites has been made and characterized on its mechanical properties that is bending properties. The specimen made by varying its filler’s volume fraction. The elephant grass fiber treated by immersing in water for 3 days continued by beating the strips gently in order to loosen and separate the fiber and scrapped with sharp knife and combed until individual fibers were obtained and cut uniformly in 2 cm length and 1 mm diameter width average. Hand lay up process used to prepare the composite specimens with 1%, 3% and 5% volume fraction. This method is the simplest method and require a low cost. The dimensions of the specimens used to carry out the test adapted from ASTM D 3379-75 for Bend testing. The results showed that filler volume fraction has effect to its bending strength. Specimen with 1% filler volume fraction has the highest bending stress whereas 5% filler volume fraction specimen has the highest elasticity modulus value.
Numerical simulation and optimization for the vibration of the seed metering device based on a novel ML-IGA method
Authors: Xu Yan Lei , Wang Qi , Zhu Long Tu , Huang Dong Yan 
Published: August 2017

The reported researches only analyze vibration parameters of the seed-metering device. However, they do not adopt any algorithm to conduct a multi-objective optimization for the vibration performance of the seed-metering device. In this paper, the vibration of the seed-metering device is numerically computed firstly, and the correctness of the computational model is validated by experimental test. Then, some parameters including the plate thickness, inclination angle, excitation source position and supporting leg thickness of the seed-metering device are studied. In this way, those parameters which have serious impacts on the vibration are obtained. Therefore, the vibration performance is tried to optimize using these parameters as the design variables. This paper proposes a novel multi-layer immune algorithm based on genetic algorithms (ML-IGA). In order to further verify validity of the novel ML-IGA model for optimizing the vibration of the seed-metering device, it is compared with the traditional GA model and PSO-GA model. When the iteration of ML-IGA model was conducted to the 156th generation, the predicted error is smaller than the set critical error. Compared with other two kinds of algorithms, the optimized time is reduced. Regarding optimization of the GA model, the vibration amplitudes are increased by 2.49 % and 4.22 % respectively. Regarding optimization of the PSO-GA model, the vibration amplitudes are increased by 9.74 % and 6.024 % respectively. Regarding optimization of the ML-IGA model, the vibration amplitudes are increased by 17.34 % and 6.78 % respectively. Obviously, structures with better performance can be obtained through using the novel ML-IGA model.
Research on the characteristics of dynamic behavior of basilar membrane in spiral cochlea
Authors: Tang Zhi , Shen Qiong , Xu Chang , Hou Xi , Wang Qian , Liu Zhi-hui , Li Shu-jia 
Published: August 2017

This paper used PATRAN software to establish a three-dimensional spiral cochlear model according to the actual human ears, combined with NASTRAN software to conduct a harmonic response analysis on it and studied the impact of curvature on the amplitude of basilar membrane when spiral basilar membrane was excited. The computational result of the model was consistent with the experimental result reported by previous researchers, which verified the correctness of the model established by this paper. Research found the change rule of ratio of outer radius amplitude to inner radius amplitude in the longitudinal direction of basilar membrane and the change trend of the horizontal amplitude with frequency along the basilar membrane. At high frequencies, it was found that curvature had a great influence on the horizontal amplitude of basilar membrane. In the meanwhile, the structural form of spiral basilar membrane and its change trend with frequency at the position of 12 mm reflected the basilar membrane’s amplification for sound intensity. Regarding the controversial issue in the academic at present, does travelling wave exist in basilar membrane? The theory of travelling wave in basilar membrane was supported by a lot of phase accumulation and delay as shown in phase diagram.
Numerical simulation and experimental research on aerodynamic noises of the single wheel landing gear in an aircraft
Authors: Zhou Yao-ming , Liu Yao-long , Li Shao-wei , Li Dao-chun , Jia Yu-hong 
Published: August 2017

This paper established a computational model for the flow field of landing gear and extracted the velocity and vorticity distribution of flow field. A lot of shedding vortexes presented around the torque arm and pillar of landing gear and had the greatest impact on the flow field around the landing gear. Then, the aerodynamic noise of landing gear was measured in an anechoic chamber. The working noises of landing gear were more than background noises of landing gear. Their change trends were similar. Obvious peak frequencies presented at the front end of noise spectrum. In addition, peak frequencies increased with the increase of flow velocity. There were multiple peak frequencies on the curve of spectral characteristics. These frequencies were from pure sound in noises. Pure sound did not change with the change of flow velocity. The difference value of total sound pressure level of working noises and background noises was less than 10 dB. However, the difference value was bigger and bigger with the increase of flow velocity. When flow velocity was more than 50 m/s, background noises were over 10 dB lower than the total sound pressure level of working noises. Thus, it showed that the aerodynamic noise source of landing gear could be effectively recognized by experimental equipment. In addition, the total sound pressure level of aerodynamic noises of landing gear also increased with the increase of flow velocity and was directly proportional to the 6th power of flow velocity. The main noise source in experiments was dipole source. Finally, aerodynamic noises were obtained by AML model of landing gear, and compared with experimental results, showing consistent value and change trend. It showed that the computational model of noises was reliable. Based on the computational model of noises, this paper studied the contribution of pillar and torque arm of landing gear to radiation noises. Results showed that the pillar of landing gear was the main reason for radiation noises. In the future, pillar noises will be reduced through conducting structural design for the pillar of landing gear or applying sound package, further reducing radiation noises.