bluuebunny/crossref_metadata_2025 huggingface dataset:
Exciton transport in amorphous polymers and the role of morphology and thermalisation
Authors: Campaioli Francesco , Cole Jared H
Published: November 2021

Understanding the transport mechanism of electronic excitations in conjugated polymers is key to advancing organic optoelectronic applications, such as solar cells, organic light-emitting diodes and flexible electronics. While crystalline polymers can be studied using solid-state techniques based on lattice periodicity, the characterisation of amorphous polymers is hindered by an intermediate regime of disorder and the associated lack of symmetries. To overcome these hurdles we have developed a reduced state quantum master equation approach based on the Merrifield exciton formalism. This new approach allows us to study the dynamics of excitons’ centre of mass and charge separation (CS), going beyond the standard model of charge-neutral Frenkel excitons. Using this model we study exciton transport in conjugated polymers and its dependence on morphology and temperature. Exciton dynamics consists of a thermalisation process, whose features depend on the relative strength of thermal energy, electronic couplings and disorder, resulting in remarkably different transport regimes. By applying this method to representative systems based on poly(p-phenylene vinylene) (PPV) we obtain insight into the role of temperature and disorder on localisation, CS, non-equilibrium dynamics, and experimental accessibility of thermal equilibrium states of excitons in amorphous polymers.
Shell-shaped condensates with gravitational sag: contact and dipolar interactions
Authors: Arazo Maria , Mayol Ricardo , Guilleumas Montserrat
Published: November 2021

We investigate Bose–Einstein condensates in bubble trap potentials in the presence of a small gravity. In particular, we focus on thin shells and study both contact and dipolar interacting condensates. We first analyze the effects of the anisotropic nature of the dipolar interactions, which already appear in the absence of gravity and are enhanced when the polarization axis of the dipoles and the gravity are slightly misaligned. Then, in the small gravity context, we investigate the dynamics of small oscillations of these thin, shell-shaped condensates triggered either by an instantaneous tilting of the gravity direction or by a sudden change of the gravity strength. This system could be a preliminary stage for realizing a gravity sensor in space laboratories.
Multimessenger analysis strategy for core-collapse supernova search: gravitational waves and low-energy neutrinos
Authors: Halim Odysse , Casentini Claudio , Drago Marco , Fafone Viviana , Scholberg Kate , Vigorito Carlo Francesco , Pagliaroli Giulia
Published: November 2021

Core-collapse supernovae are fascinating astrophysical objects for multimessenger studies. Gravitational waves are expected to play an important role in the supernova explosion mechanism. Unfortunately, their modeling is challenging, due to the stochastic nature of the dynamics and the vast range of possible progenitors. Therefore, the gravitational wave detection from these objects is still elusive with already advanced detectors. Low-energy neutrinos will be emitted copiously during the core-collapse explosion and can help the gravitational wave counterpart search. In this work, we develop a multimessenger strategy to look for such astrophysical objects. We exploit a global network of both low-energy neutrino and gravitational wave detectors. First, we discuss how to improve the detection potential of the neutrino sub-network by exploiting the time profile of a neutrino burst from a core-collapse supernova. We show that in the proposed approach, neutrino detectors can gain at least 10% of detection efficiency at the distance where their efficiency drops. Then, we combine the information provided by gravitational wave and neutrino signals in a multimessenger analysis. In particular, by using the clusters of low-energy neutrinos observed by LVD and KamLAND detectors in combination with the gravitational wave triggers from LIGO-Virgo detector network, we obtain an increase of the probability to detect the gravitational wave signal from a core-collapse supernova at 60 kpc, from zero to ∼33% for some specific gravitational wave emission model.
The Effect of Mask & Face Shield on the General Discomfort of the Workers in the Food Industry: A Structural Equation Modeling Approach
Authors: Pequeña Arianne R. , Prasetyo Yogi Tri
Published: November 2021

Using face mask & face shield and practicing hand sanitary measures mitigate the risk of getting COVID-19. However, different types of discomfort have been long associated with these especially among healthcare workers. An online survey with 255 respondents was conducted to investigate the discomfort felt by another group of frontliners: food & beverage company workers. Based on the SEM, it was found that exposure to PPE & sanitary protocols significantly explains general discomfort. Visual discomfort, skin irritation, and breathing difficulty contribute most to general discomfort. This study linked overall discomfort to work difficulties. Parts of the face that are most prone to discomfort were identified: ears, nose, and cheeks. For demographics, age, department, and role could affect the severity of specific types of discomfort. This study aims to be the basis for more SEM models and creation of more ergonomic PPE & sanitary protocols in the F & B industry.
Effects of size and dimension in optic relaxation in Rb vapor
Authors: Atutov S , Sorokin V
Published: November 2021

We report on an experiment in which the fluorescence decay time of 5P levels of Rb atoms in a coated vapor cell exceeds several of milliseconds that many orders of magnitude longer than normal decay time of excited of rubidium atoms. This effect has been observed by using the pump laser with fixing frequency and the periodically scan the probing laser frequency of which overlap all Rb hyperfine linens of 5P-5S transition. Long time fluorescence decay take place in wide part of the spherical high quality coated cell. In cylindrical part of the cell or in uncoated cell the long time fluorescence decay was disappeared.
Semiconductor quantum well based shutters for NIR laser mode-locking with ∼ GHz repetition rate
Authors: Rubtsova N N , Kovalyov A A , Ledovskikh D V , Preobrazhenskii V V , Putyato M A , Semyagin B R , Kuznetsov S A , Pivtsov V S
Published: November 2021

Fast semiconductor shutters based on coupled wells were designed in the search for reliable, compact and cheap key element of GHz repetition rate NIR lasers passive mode-locking. Stable 0.98 GHz repetition rate 200-fs Yb:KYW laser pulses were demonstrated for SESAM including semiconductor reflector and a layer of quantum wells. The damage threshold estimate for the SESAM is ∼ 8.87 mJ/cm2. Other type of shutter – DSAM – was developed with dielectric reflector and the layer of quantum wells transferred over reflector. The measured recovery time was about 2-3 ps for both types of saturable absorbers. The efficiency relative to the incident pump power was 57% for the SESAM and 19% for the DSAM. Average output power of 2.54 W for the all-semiconductor shutter (SESAM) and of 0.92 W for the dielectric mirror with a saturable absorber (DSAM) were obtained. Actual state of the art for the shutters design is considered.
Key-Point Interpolation: A Sparse Data Interpolation Algorithm based on B-splines
Authors: Wang Bolun , Jiang Xin , Huo Guanying , Su Cheng , Yan Dongming , Zheng Zhiming
Published: November 2021

B-splines are widely used in the fields of reverse engineering and computer-aided design, due to their superior properties. Traditional B-spline surface interpolation algorithms usually assume regularity of the data distribution. In this paper, we introduce a novel B-spline surface interpolation algorithm: KPI, which can interpolate sparsely and non-uniformly distributed data points. As a two-stage algorithm, our method generates the dataset out of the sparse data using Kriging, and uses the proposed KPI (Key-Point Interpolation) method to generate the control points. Our algorithm can be extended to higher dimensional data interpolation, such as reconstructing dynamic surfaces. We apply the method to interpolating the temperature of Shanxi Province. The generated dynamic surface accurately interpolates the temperature data provided by the weather stations, and the preserved dynamic characteristics can be useful for meteorology studies.
Analysis of Opening Angle for Radial Magnetic Field Compensation Windings of Double-layer Ferromagnetic Cylindrical Shells
Authors: Zuo Chao , Chen Meng , Xiao Hanchen , Geng Pan
Published: November 2021

A double-layer ferromagnetic cylindrical shell causes a magnetic anomaly in its surrounding space under the action of the geomagnetic field. Aiming at the problems of poor compensation uniformity and obvious local magnetization caused by the single-branch winding compensation method, a double-branch winding solution is proposed. By establishing a double-layer ferromagnetic cylindrical shell model, the radial magnetization characteristics of the cylindrical shell under the action of the vertical geomagnetic field was analyzed, and the opening angle of double-branch winding was studied. By optimizing the opening angle of compensation windings in the three proposed configuration schemes with respect to the minimum abnormal magnetic field, the optimal ranges of opening angle for the double-branch compensation windings were determined.
Hybrid Reconstruction and Evaluation of 3D Model of Equipment Parts for Virtual Maintenance System
Authors: Chu Weijun , Sun Xiangyu
Published: November 2021

The research and application of reverse engineering technology are more and more extensive, but its process is still not fully mature. Aiming at the complexity of equipment parts and the diversity of accuracy requirements, the method of hybrid reconstruction and evaluation of 3D model of equipment parts for virtual maintenance system is illustrated. The general process is given. Taking the two-stage bevel gear worm reducer as the research object, the research on three-dimensional scanning, data processing and model reconstruction is carried out. This paper focuses on the reconstruction process and methods such as regional division, solid model construction based on maximum outer contour, creation of basic surface, patch fitting and so on by taking the bevel gear in the reducer as an example. Finally, 3D comparison, 2D comparison, cross-section accuracy and size of the reconstructed solid model are evaluated. The results show that the hybrid reconstruction method has strong adaptability and high efficiency. Reverse modeling and forward design are organically combined to give full play to their advantages, and the hybrid reconstruction method can effectively reverse the original design intention of the product and improve the parameterization ability of reverse modeling. It can meet the requirements of different precision models developed by virtual maintenance system, structural wall chart and atlas, multimedia and so on.
Modelling and Implementation of a Knowledge Question-answering System for Product Quality Problem Based on Knowledge Graph
Authors: Liu Hanxu , Dong Fangxu , Wang Meiqing , Lin Qiu
Published: November 2021

Aiming at the problem of difficulty in understanding the semantics of the problem in the traditional quality problem management system, the knowledge retrieval technology of product quality problem based on the knowledge graph is carried out. The process model for knowledge retrieval of quality problem based on semantic templates is constructed. A domain corpus is built, which consisting of thousands of quality problem handling records. The TF-IDF (Term Frequency-inverse Document Frequency) algorithm was used to extracted the vocabulary from the quality problem analysis reports. A natural language question semantic classification process model based on Naive Bayes classifier is established to improve the accuracy of semantic template matching. On the basis of theoretical study, a quality problem knowledge question-answering system-QQ-KQAS based on knowledge graph is developed, and the effectiveness of the proposed method is verified through examples.
Research on System Development and Application of Electrical Equipment Intelligent IoT Platform
Authors: Chen Xinsheng , Sun Meng , Li Ling , Chen Xi , Wang Sheng
Published: November 2021

With the increasingly development of the new information and communication technologies, China has proposed the integration of new information technology, electrical equipment, and intelligent Internet of Thing (IoT) system to accelerate the innovative development of the manufacturing industry. However, the information isolation and data scattering cause the poor services of electrical equipment. Aiming at the question, the preliminary construction of electrical equipment intelligent IoT Platform (EIP) is carried out in this article through system analysis and system design, which helps enterprises to improve the quality of manufacturing, realizing the transformation and upgrading and healthy development of the enterprise. At the same time, through the accumulation of heavy and complicated IoT big data, the quality evaluation and total life cycle management of electrical equipment are strongly supported to enhance the level of supply chain operations management, which lays a more solid foundation for the electrical equipment manufacturing industry to enhance the core competitiveness and for China to accelerate the realization of high-quality development by the intelligent manufacturing.
The Effects of U-233 Impurity on U-232 and Tl-208 Buildup in Experimental Power Reactor with Thorium-Based Fuel
Authors: Dwijayanto R A P , Suwoto  , Zuhair  , Su’ud Z
Published: November 2021

The existence of Tl-208 in thorium fuel cycle is a double-edged sword. Tl-208 is a high-energy 2.6 MeV gamma emitter, which acts as an effective proliferation barrier while simultaneously complicating the handling of the spent fuel. To ensure the safety of the latter, the buildup of both Tl-208 and its parent, U-232, are necessary to be understood. This paper attempts to analyse the buildup of U-232 and Tl-208 in the Reaktor Daya Eksperimental (Experimental Power Reactor/RDE) fuel based on thorium cycle, using various U-233 isotopic vectors. The simulation result shows that U-232-contaminated fresh fuels ended up with higher Tl-208 and U-232 activities at the end of cycle (EOC) compared with uncontaminated fresh fuel. However, their U-232 build-up rate are lower and even negative at one case. Then, lower U-233 purity caused a higher U-232 and Tl-208 activities at EOC. This result implies a considerable difference of isotope buildup between the various U-233 vectors. Consequently, the thorium cycle-based RDE spent fuel handling should consider the isotopic vector of U-233 used in fresh fuel.
Laser blow-off with photodiode detection system at the helically symmetric experiment
Authors: Castillo J.F. , Clark C. , Bader A. , Likin K.M. , Anderson D.T. , Geiger B. , Kumar S.T.A. , Swee C.
Published: November 2021

A laser blow-off (LBO) system has been installed in the HSX stellarator to investigate impurity transport. A Nd:YAG laser is used to ablate a target area on a glass slide that has been coated with a thin film of aluminum and rapidly deposits a small, controlled quantity of aluminum atoms into HSX plasma. To study the radial propagation and confinement of the injected aluminum impurities, time-resolved emission measurements are made using a 20 channel AXUV photodiode detection system. The LBO system has achieved its design purpose, most notably the ability to make controlled impurity injection without significant perturbation to the background plasma. A detailed description of the setup as well as initial results of operation are presented.
Dynamics of KPI lumps
Authors: Chakravarty Sarbarish , Zowada Michael
Published: November 2021

A family of nonsingular rational solutions of the Kadomtsev–Petviashvili (KP) I equation are investigated. These solutions have multiple peaks whose heights are time-dependent and the peak trajectories in the xy-plane are altered after collision. Thus they differ from the standard multi-peaked KPI simple n-lump solutions whose peak heights as well as peak trajectories remain unchanged after interaction. The anomalous scattering occurs due to a non-trivial internal dynamics among the peaks in a slow time scale. This phenomena is explained by relating the peak locations to the roots of complex heat polynomials. It follows from the long time asymptotics of the solutions that the peak trajectories separate as

O

(

|
t
|

)

as |t| → ∞, and all the peak heights approach the same constant value corresponding to that of the simple one-lump solution. Consequently, a multi-peaked n-lump solution evolves to a superposition of n one-lump solutions asymptotically as |t| → ∞.
Mini review: Characteristics of upwelling in several coastal areas in the world
Authors: Umasangaji H , Ramili Y
Published: November 2021

This paper provides an overview of the upwelling processes and the controlling factors as an effort to reveal the characteristics and the intensities of upwelling events in several parts of the world. This review aimed at identifying the characteristics of upwelling and how the global climate controlling this physic phenomenon such as ENSO, IOD and Kelvin Wave. Several places in the Southeast Asia experienced high intensities of upwelling when El Nino events such as in South of Java, East Coast of Malaysia Peninsula and in Vietnam Coastal area. The results of this review found that area with the most intensive and productive upwelling in the world is South American waters and Banguela Upwelling System (BUS) in the African Coast. However, several other areas also show intensive and high productivity of upwelling, such as off the southern coast of Java Island in Indonesia and the Banda Sea and its surroundings. It is found that upwelling with stronger intensity can result in increase of mortality of certain organisms such as scallops. Additionally, increase of nutrients in a waters is often accompanied by an increase in several species of toxic algae that are harmful to the local fishery system (harmful algae blooms, HABs).
Spatial distribution of nutrients in Maumere Bay, East Nusa Tenggara
Authors: Meirinawati H , Prayitno H B
Published: November 2021

The availability of nutrients in the marine environment is very important for primary production and as indicator of the health condition in waters. East Nusa Tenggara Province is one of the province that has a potential fishery, especially in Maumere Bay of Sikka Regency. Therefore, it is necessary to monitor the water quality and spatial distribution of nutrients in that area. This study aims to determine water quality, assess water trophic status, and determine limiting factors in Maumere Bay. Sampling was conducted in August 2017 at 14 research stations and 1 daily station. The results showed that the relationship between DIN, DIP, and DSi at the daily station was a weak correlation. DIN reaches maximum concentration after 8 hours, whereas DIP and DSi reach maximum concentration after 12 hours. The average DIN, DIP, and DSi were 1.082 μmol L−1, 0.123 μmol L−1, and 4.544 μmol L−1, respectively. The average DIN/DIP ratio was 11.554. It can be concluded that Maumere Bay is an oligotrophic area and phosphate as a limiting nutrient for phytoplankton growth.
Seasonal variations of water quality at Doreri Gulf, Manokwari, West Papua
Authors: Sembel L , Setijawati D , Yona D , Risjani Y
Published: November 2021

The character of Manokwari City’s coastal waters is strongly influenced by activity on the mainland. The degradation in Sawaibu Gulf’s water quality has an impact on water quality nearby, as well as the waters of the Field Work Center (BLK), Lemon Island, and Tanjung Manggewa, which is part of Doreri Gulf. The purpose of this study was to determine the water quality in Doreri Gulf according on location and season. In February-April (rainy season) and August-October (dry season) 2020, the research was carried out within Doreri Gulf, Manokwari, West Papua. Turbidity, salinity, pH, temperature, and dissolved oxygen are amongst the variables analyzed. Its statistical analyses were performed descriptively using standard deviation and ANCOVA to correlate seasons and locations. Temperature, DO, and pH were highest at location 2; salinity showed highest at location 3; and turbidity were highest at location 1. Low concentrations of DO, pH, and salinity were measured at location 1; temperature showed highest at location 3; and turbidity were highest at location 1. The dry season would have the highest temperature, DO, pH, and salinity concentrations, meanwhile the rainy season had enough highest turbidity. The study confirms that there are no variations in water quality between location of each variable and that seasonal factors comprise the majority of differences in water quality.
Radioactivity level of coastal sediments and water across the Sangihe Island as the outlying islands of Indonesia
Authors: Yahya M N , Untara  , Makmur M , Prihatiningsih W R , Putra D I P , Priasetyono Y
Published: November 2021

Indonesia as an archipelagic country is very concerned about maritime development, the outlying islands are the entrance for potential threats of radioactive distribution from global waters. Furthermore, the outlying islands have functions such as territorial defence, security, and sovereignty, economic and ecological. As environmental protection, level of natural and anthropogenic radioactivity was performed due to potential threats. The activity concentration of natural (226Ra, 232Th, and 40K) radionuclides inshore sediments samples are range from 3.44 ± 0.01 Bq kg−1, 5.13 ± 0.03 Bq kg−1 and 151.42 ± 0.04 Bq kg−1 respectively and average concentration level of anthropogenic of 137Cs in sediment and seawater obtained were 0.35 Bq kg−1 and 0.83 Bq m3 respectively. The concentrations value of NORM was lower compare to another region but the ratio sequence 226Ra<232Th<40K relatively have same pattern. The presence of fission product 137Cs in this region comes from global fallout since no nuclear activities in Indonesia and the level of 137Cs are almost same as the estimation the concentration 137Cs in the Pacific Ocean and comparable with other studies. Radioactivity levels in all samples are under the value of radiological hazard index (0.004-0.039, trace hold h-index=1) and annual effective dose rate are in save level (0.01 mSv/y, recommended limit AED=1mSv/year). The level of NORM radioactivity is locally and varied for each region meanwhile anthropogenic radioactivity are global and comparable since there are no nuclear activity in Indonesia.
Assessment of coastal water productivity of Fitu Village, Ternate Island based on its zooplankton community structure
Authors: Yuliana  , Mutmainnah
Published: November 2021

Zooplankton has an important role in waters, especially in the food chain, this organism is the first consumer that plays a major role in bridging the transfer of energy from the main producers to living things at a higher trophic level. The aim of the study was to analyze the coastal waters condition of Fitu Village, Ternate Island based on zooplankton community structure, carried out at 4 stations, and 4 sampling periods. Zooplankton samples were taken by filtering method. The results showed that there were 10 zooplankton genera from 4 classes, namely Ciliates (3 genera), Crustacea (4 genera), Hydrozoa (1 genus), and Rotifera (2 genera). The abundance of zooplankton found ranged from 2271 to 11562 ind.l−1, the highest at station 1 period IV and the lowest at station 4 period I. The value range of zooplankton biological indices were diversity index (H’) = 1.12 - 1.87, evenness index (E) = 0.64 - 0.93, and the dominance index (D) = 0.17 - 0.42. The waters of Fitu are included in the category of waters that have a low fertility level with a diversity index value (H’) of 1.12 - 1.87.
The development of the reproductive organs of the hybrid grouper cantik (Epinephelus fuscoguttatus x E. polyphekadion)
Authors: Muzaki A , Sembiring S B M , Permana G N , Mahardika K , Haryanti
Published: November 2021

Observation of the reproductive organs of the hybrid grouper cantik was carried out. Cantik grouper is the result of cross-breeding between female tiger grouper Epinephelus fuscoguttatus and male camouflage grouper E. polyphekadion. This study aimed to determine the development of the reproductive organs of cantik grouper. The observed test fishes were 3 fishes of Cantik grouper with a total length of 42 - 49 cm and a bodyweight of 1.45 - 2.26 kg. The parameters observed were the concentarion of estradiol and testosterone in the blood using the ELISA kit, gonad development, and histological maturity level of the gonads. The results showed that the hormone testosterone found in the sample cantik no 1 was 9353 pg/ml, while the hormone estradiol was found in all samples of beautiful grouper in the range of 291 - 1133 pg/ml. From the dissected fish, the gonads had developed and weighed 3.12 - 56.01 g and one sample had a fecundity of 265,800 eggs with an egg diameter of 360-520 micron. Gonadal histology shows oosit development at maturity levels I, II, and IV. This indicates that the crossbreeding between female tiger grouper and male camouflage grouper produces hybrid grouper cantik that are fertile, which is shown by their reproductive organs to have developed well.
Spirulina water extract and Lactobacillus bulgaricus FNCC– 0041, Streptococcus thermophilus FNCC–0040 secretion as immunostimulants in gnotobiotic Artemia challenge tests against pathogenic Vibrio parahaemolyticus, V. vulnificus, and V. harveyi
Authors: Yudiati E , Sedjati S , Azhar N , Oktarima WA , Arifin Z
Published: November 2021

Spirulina water extract (SWE) has a good potency as an immunostimulant. Lactobacillus bulgaricus & Streptococcus thermophilus are lactic acid bacteria (LAB) that produce exopolysaccharide exudate. Vibriosis is a common infectious disease for aquatic cultivans caused by Vibrio spp. This study determines the ability of SWE in combination with L. bulgaricus & S. thermophilus as immunostimulant (Artemia challenge test) assay against Vibrio parahaemolyticus, V. vulnificus, and V. harveyi. Factorial Design with two factors namely SWE doses (0, 300, 600, and 900 ppb) and Vibrio spp. treatment (non-Vibrio spp., Vibrio harveyi (Vh), Vibrio parahaemolyticus (Vp), Vibrio vulnificus (Vv), Vh-Vp, Vv-Vp, Vp-Vh, and Vp-Vv-Vh) were applicated. SWE was diluted and LAB at a concentration of 108 cell/mL were fermented in three days at 30°C. Ten newly hatched Artemia nauplii were enriched with fermented and non-fermented SWE for one hour, then challenged with 108 cell/mL Vibrio spp. The survival of Artemia was recorded every 6 hours. Results showed that the survival rate of Artemia enriched with 300 ppb concentration of SWE and LAB was significant than control (p<0.05). It is concluded that there is a positive effect on the bioencapsulation of the minimum concentration of SWE and LAB secretion to accelerate Artemia’s immune response.
The effect of probiotics on digestive enzyme activity during larvae and juvenile stage of Yellow Fin Tuna (Thunnus albacares)
Authors: Haryanti  , Gunawan  , Setiadi A , Sembiring S B M , Permana I G N , Hutapea J H , Sugama K
Published: November 2021

Yellow fin tuna fry production technology is not successful yet. This was assumed related to the biological and physiological characteristics of the fish. The physiological approach to regulating digestion through probiotics is needs to be studied. The aim of this study was to examine the effect of probiotics bacterial strains of the enzymatic activity in digestion system for the larvae to juvenile stages of yellow fin tuna, Thunnus albacares. The experiment was initiated by culturing 3 probiotic isolates (Bacillus subtilis strain TA-1, Bacillus amyloliquefaciens strain TN-2, Bacillus subtilis strain TO-4) and apply to the larval rearing of yellow fin tuna. In the experiment the treatments applied were supplemented probiotics and without probiotic, each treatment was held with 2 replications. Fish samples were collected every day and analyze the gene expression profile associated with digestion enzyme synthesis by total RNA isolation and cDNA synthesis followed analysis of its by using the RT –qPCR method. The results showed that the growth response of T. albacares tuna larvae reared with probiotics tended to be faster (P<0.05) than the control (without probiotics). The supplementation of probiotic could improved the expressed digestibility of the target genes associated with enzymatic synthesized. Amylase enzymatic synthesized increase 200-1200 times in larvae 10 –17 Day After Hatch (DAH), while in the lipase enzymatic activity started with 13 DAH ( 25 time) and 16 – 21 DAH by 150-300 times. In trypsin the highest enzymatic activity was at 16 DAH, which was 200 times. While in control, the expression of enzymatic synthesis of amylase, lipase, and trypsin was relatively low.
SwissADME predictions of pharmacokinetics and drug-likeness properties of small molecules present in Spirulina platensis
Authors: Riyadi P H , Romadhon  , Sari I D , Kurniasih R A , Agustini T W , Swastawati F , Herawati V E , Tanod W A
Published: November 2021

Spirulina platensis is a microalga that is easy to cultivate. Spirulina platensis contains high antioxidants sourced from chemical compounds. Antioxidants can protect against oxidative stress and degenerative diseases. This study aimed to evaluate the chemical profiles of S. platensis using Gas Chromatography-Mass Spectrometry (GC-MS) and predict its biological activity using computational analysis (Absorption, Distribution, Metabolism, Excretion) using SwissADME. The GC-MS analysis of S. platensis extracts yielded twenty-four compounds. Spirulina platensis extracts contain twelve compounds with percentage more than 1%, namely Dodecanoic acid, ethyl ester (27.71%); Ethyl linoleate (19.47%); Octadecenamide (10.99%); Octadecane (9.02%); Methyl gamma-linolenoate (8.04%); 2-Hexadecen-1-ol, 3,7,11,15-tetramethyl-, [R-[R*,R*-(E)]]- (6.92%); Neophytadiene (3.21%); Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethyl ester (2.68%); Ethyl 9-hexadecenoate (2.05%); 9-Octadecenoic acid (Z)- (1.47%); 3,7,11,15-Tetramethyl-2-hexadecen-1-ol (1,44%); 9-Octadecenamide (1.15%); and 2-Hexadecene, 3,7,11,15-Tetramethyl-2-hexadecene- 1-ol (1%). The dominant compound was dodecanoic acid, ethyl ester. The potential biological activity of dodecanoic acid, ethyl ester, is antimicrobial, antioxidant, anti-cancer, anti-candida, mycelial growth inhibition. All compounds in the extract of S platensis met the druglikeness according to Lipisnki’s rules using SwissADME. SwissADME emerged to be simple, robust and accurate method to understand the ADME properties of the compounds present in Spirulina platensis phytoconstituents. The ADME analysis results indicated that S. platensis extracts could be developed as traditional medicine and nutraceutical products.
Isolating and characterizing bacteria in the intestine of wild sandfish, Holothuria scabra as probiotics candidate
Authors: Sembiring S B M , Hutapea J H , Giri I N A , Hadisusanto S , Pratiwi R , Haryanti
Published: November 2021

The research aims to isolate bacteria as potential probiotics for rearing of sandfish, H. scabra. The procedures were isolating bacteria from nature sandfish’s intestines, characterizing, identifying, enzymatic hydrolysis activity and pathogenic testing, and in vivo testing of candidate probiotics. Identification of probiotic bacteria was based on 16S rRNA encoding gene sequence. Similarity identification was conducted by using BLAST on NCBI. The enzymatic activity test was carried out through Extra Cellular Product (ECP) of isolated bacteria. The in vivo test was done in twelve 1.2 m3 tanks. Initial mean body weight of juvenile was 6.0 ± 4.3 g and total length 4.3 ± 0.6 cm. The results, there were three isolated bacteria as candidates of probiotics with code M-4, Q-1, and E-2 which had high ability in hydrolyzing gelatin, casein, amylase, lecithin, and lipase enzymes. The M-4 was identified as Gamma proteobacterium with a 99% similarity, Q-1 and E-2 were identified as Bacillus subtilis and Bacillus sp with 98% and 97% similarity. The in vivo trial of probiotic candidate in feed for juvenile gave higher survival rate 95% compare to control 91%. The growth performance was (7.3 ± 2.1 g; 4.5 ± 0.7 cm) in probiotic which higher compare to control (6.0 ± 1.8g; 4.3 ± 0.8 cm).
Using tuna fish bone waste as mineral sources in feed formulation of tilapia (Oreochromis niloticus)
Authors: Syazili A , Ahmad K , Umakaapa I
Published: November 2021

Fish bone is a solid waste that usually found in traditional fish markets of Ternate. The bone fraction contains high minerals such as calcium, phosphorus, and collagen proteins which are important for fish growth. Tuna fish bone waste was processed into dry fish feed and mixed into feed formulation of Tilapia. Four different dose of tuna fish bone powder were applied namely 0%, 1%, 3%, and 5% as mentioned treatment A, B, C, and D. Fish diet were given to Tilapia juvenile for 42 days. Results show that the body weight and specific growth rate are highest in fish which given 3% dose of tuna fish bone than other treatments. It reaches 38.66 g and 9.617% BW/day. The lowest FCR is 1.34 in treatment C and the survival rate is not significantly different among treatments (p>0.05).
Effect of different seedling weights on Kappaphycus alvarezii growth
Authors: Irfan M , Abdullah N , La Ujiara W
Published: November 2021

Seaweed K. alvarezii is one of leading commodities in aquaculture because this seaweed species produces carrageenan which has high economic value. This study aimed to determine effect of different seedling weights on the growth of seaweed K. alvarezii, and to determine which seedling weight had the best effect on seaweed growth. Planting process was carried out using longline method. Size of longline construction used was 10 m x 20 m, with a length of 20 m and a distance of 1 m between each ropes. Each rope line contained about 66 clumps of seedlings with a distance between clumps of 15 cm. Thallus weight used was 30 gr, 50 gr, 70 gr for each treatment. The highest mean value of absolute weight growth of seaweed K. alvarezii was found in treatment C (thallus weight 70 gr) with an average value of 99.27 gr, followed by treatment A (thallus weight 30 gr) of 51.95 gr and the lowest value found in treatment B (thallus weight 50 gr) of 51.65 gr.
Study on milky haemolymph diseases infection in wild and cultured of spiny lobster, Panulirus homarus in Indonesia
Authors: Koesharyani I , Lasmika N L A , Sugama K
Published: November 2021

Milky Haemolymph Disease in Spiny Lobster (MHD-SL) is the most pathogenic diseases in spiny lobster (Panulirus homarus). Research on MHD-SL infection has not been undertaken in Indonesia. Therefore, present study aims to determine the infection of MHD-SL lobster. In 2016 a total of 240 lobsters for 30 each both from wild and cultured sample were collected from four locations (Candi Kusuma Bay of Bali Island, Gerupuk, Awang, and Telong-Elong Bays of Lombok Island) and in 2019, 50 lobster samples were collected for artificial infection study. While in January 2020, another 40 lobsters were collected from 2 different sites of culture (coastal and offshore cages) within Telong Elong Bay to determine infection of MHD-SL and for transmission study. The MHD-SL diseased was first check by clinical sign and confirmed by PCR-DNA molecular with specific primer of 254 bp. An experimental infection of MHD-SL was carried out by injection and cohabitation. The result showed that infected MHD-SL lobster shows inactive, loose appetite to eat, reddish and white colour of abdomen then moribund and all positive by PCR test. MHD-SL was found only in cultured lobster on the cages located at coastal water and no in the cages located at offshore within Telong-Elong Bay. In the experiment of artificial infection, either by injection or cohabitation, shows clinical sign of MHD-SL appeared at 8 days and all died after 14 days for both treatments. The present study approved that MHD-SL is pathogenic agent belonged to Rickettsia-like bacterium and infection occurred by horizontal transmission.
Growth and survival of transfection and non-transfection tiger shrimp (Penaeus monodon Fabricius) broodstock candidate in pond cultivation
Authors: Suwardi  , Suwoyo H S
Published: November 2021

Tiger shrimp (Penaeus monodon Fab.) is one of important commercial species in Indonesia. Low quality of shrimp fry due to the lack of good quality broodstock availability is shrimp cultivation problem that need to be solved. The study was aimed to evaluate growth and survival rate of broodstock candidate of transfection and non-transfection tiger shrimp. The study was conducted using four ponds with 2000 m2 in size in Takalar Regency. South Sulawesi. The treatment were A = transfection tiger shrimp broodstock candidate and B = non-transfection tiger shrimp broodstock candidate. Approximately 19.0-21.9 g/ind of shrimp were reared in 60 days in 0.25 individu/m2 (500 individu/2000 m2) stocking density. Commercial pelleted feed which content 38% of protein was fed three times a day in 5-3% of body weight dosage. Measured variables were growth performance, size distribution and survival rate. The result showed that shrimp growth were no significantly different (P>0.05), while survival rate and size distribution were significantly different (P<0.05). The dominant size of transfection shrimp was 41-50 g/ind. Whereas, non-transfection shrimp was dominated by 31-40 g/ind in size (48.39%). Survival rate of tiger shrimp broodstock candidate in this study ranged from 30.80 to 64.10%.
Characteristic and boactive potential of brewed Sargassum sp. with the additional bay leaf (Syzygium polyanthum)
Authors: Damayanti A N , Riyadi P H , Dewi E N
Published: November 2021

Brewed Sargassum sp. is a product of dried seaweed that is packaged in tea bags and then brewed. The natural fishy odor from seaweed itself makes consumer acceptance of this brewed drink relatively low. The purpose of this study was to determine the effect of the addition of bay leaves (Syzygium polyanthum) and to determine consumer acceptance using hedonic test for Sargassum sp. Samples were obtained from UD Seaweed Mandiri, Wonosari, Yogyakarta. The research method used is experimental laboratories with a completely randomized design (CRD) model. The treatment given was in the form of different concentrations of bay leaves, namely 0%, 10%, 20%, and 30%. Parameters observed were water content, ash content, image processing, hedonic, phytochemical, antioxidant activity, and bioactive components. Parametric data were analyzed using analysis of variance ANOVA and Honest Significant Difference to determine differences between treatments, while non-parametric testing included hedonic tests consisting of aroma and taste tests. The results showed that the different concentrations of bay leaves gave a significantly different effect on the hedonic parameters. Brewed Sargassum sp. with a concentration of 30% had the highest score on the hedonic test, namely 7.71 < µ < 8.11 which was included as favored by the panelists. The addition of bay leaves with a concentration of 30% resulted in an IC50 value of 13.6251 ppm. Phytochemical screening which was carried out qualitatively showed positive results for the parameters of flavonoids, phenols, tannins, and saponins. The total flavonoid content of 30% concentration is 302,333 mg QE/g and produces six compounds with bioactive components. The highest compound is pentane at 69.12%. Based on the test of bioactive components in the brewed Sargassum sp. there is a pentane compound which has the potential as an antimicrobial and anti-inflammatory.
Acceptability tilapia fish (Oreochromis niloticus) jerky: an application of the many-facets Rasch Model
Authors: Mile L , Sulistijowati R , Janrianto W , Rahman D
Published: November 2021

Tilapia fish jerky is a fish product through the process of soaking spices and drying. The soaking and drying time influenced to acceptability consideration. The purpose of this research was to observe preference organoleptic. This study used the soaking and drying time to according hedonic preferences of ten panelists evaluating four criteria. Soaking time along was 10, 15, and 20 hours. Drying time along was 5, 10, and 15 hours. Ensuring data were used by the many-facets Rasch Model. The study found as long as soaking and drying time 10 hours and 5 hours preferences panelists to color, texture, odor, and taste. Taste criteria easy to judge by panelists. Color criteria are hard to judge by panelists. Tilapia fish jerky by soaking in seasoning formula for 10 hours and drying for 5 hours can be recommended to increase consumer preference.
Bioeconomic analysis of skipjack tuna fisheries in North Gorontalo Regency, Indonesia
Authors: Auliyah N , Rumagia F , Sinohaji A , Muawanah U
Published: November 2021

The model of the skipjack tuna resource management that can provide maximum rent can be done with a clear ownership regime (sole owner) or in the condition of MEY balance. However, the management and utilization of skipjack tuna resources must also consider the factors that can result in overfishing of both biological and economics overfishing. This study aims to assess the management and utilization of skipjack tuna fisheries resources in North Gorontalo Regency using a bioeconomic approach. Data processing is done by approaching the bioeconomic model using skipjack tuna fisheries biological and economic parameters. The results showed that the maximum rent obtained in skipjack fisheries in North Gorontalo Regency was at the MEY regime compared to the MSY and OA regime. However, based on the actual data obtained, it is known that the average production of skipjack tuna in North Gorontalo Regency has not reached the optimum catch value in the equilibrium condition of MSY (hMSY
), but in some period the actual catch value has passed the optimal catch value (hMSY
), this means that skipjack tuna has overfished (biological overfishing). While the actual production value of skipjack tuna catches in North Gorontalo Regency has passed the production of optimum MEY (hMEY
). This condition indicates that actually skipjack tuna resources have experienced an economic overfishing.
Population parameter, size distribution and sex ratio of the blue shark (Prionace glauca Linnaeus, 1758) caught in the southern of Nusa Tenggara
Authors: Chodrijah U , Faizah R
Published: November 2021

The blue shark (Prionace glauca Linnaeus, 1758) was a targeted shark caught in the artisanal fisheries in Tanjung Luar, West Nusa Tenggara. This species was caught by drifting longline. The study aims to obtain the parameter population, size distribution and sex ratio of the blue shark from these waters. The research was conducted in Tanjung Luar during 2019-2020, and a total of 1676 blue sharks were caught by drift longline. The data were analyzed by using ELEFAN II. The size blue sharks varied from 73 cm to 397 cm total length (TL), with mean length was 266 cm for males and 72-390 cm with mean length 255,61 cm TL for females. Male was dominated sex ratio. The equation growth for blue shark for male was Lt = 400 (1 – e−0.28 (t-0.2921)) and female was Lt = 390 (1 – e−0.25 (t-0.3307)) . The first captured (Lc ) length for males and females are 267.76 cm and 250.98 cm, respectively. Natural mortality (M) = 0.42/year, the fishing mortality (F ) = 0.50/year. The exploitation rate was > 0.55/year it means that utilization rate of blue sharks in Southern of Nusa Tenggara waters was susceptible to overfishing. This condition needs good management actions for this species.
Changes in livelihoods: coastal community responses to artisanal gold mining at Anggai village
Authors: Salim F D , Ma’sitasari  , Damsiki N A , Abubakar Y
Published: November 2021

This study aims to describe changes in the livelihoods of coastal communities in Anggai village as a response to artisanal gold mining. The study used a descriptive approach the selection of respondents by purposive sampling. The results showed a change in the livelihood pattern, marked by a change in job orientation shifting work orientation from being farmers/fishers as the primary/main livelihood to being miners. Internal factors driving the change were individual motivation, work duration, and offspring needs. Meanwhile, external factors included job opportunities offered/invited by relatives, simple technology that was easy to apply, and growing mobilization. Meanwhile, artisanal mining had impact in increasing community (family) income.
Traditional wisdom as a starting point for conservation: A review
Authors: Supyan  , Susanto A N , Samadan G M , Sulistiono
Published: November 2021

Traditional wisdom was established on familiarity and concern for the homeland, where people are very dependent on their local resources and they developed management values based on their cultural beliefs. Traditional wisdom and its application can be useful for ecological management plans, especially conservation programs. The application of traditional wisdom as a starting point for conservation is based on: (1) Community institutional system (2) Community collective knowledge (3) Community relationship with their environment. Traditional wisdom is part of the basic theoretical framework in strengthening research designs with specific local knowledge, including environmental relationships that occur in the area. When conservationists recognize usefulness of traditional wisdom, they can engage in knowledge exchange and foster sharing of responsibilities with indigenous peoples. This type of exchange can also provide opportunities for indigenous peoples to develop scientific infrastructure.
Biomorphometry of coconut crabs (Birgus latro) in Laigoma Island, North Maluku, Indonesia
Authors: Suryani  , Widodo M S , Yanuhar U , Suprijanto A
Published: November 2021

Coconut crab is a coastal animal that lives in costal forest on islands of tropical Indo-Pacific. Crab populations are currently under threat of extinction. Several issues contribute to this, including high levels of exploitation, degradation of their native habitat, land clearance, and plantations development. This study aimed to examine the biomorphometric of coconut crabs, which includes the composition, sex ratio, distribution, widht and weight relation, condition factors and gonad maturity level. The descriptive explorative methods was used in this research. The results showed that the composition of 156 coconut crabs consisted of 82 females. The results obtained a balanced sex ratio. The size of the carapace width obtained ranged from 40.15 to 88.55 mm, with a weight of 150-565 grams. The relationship between width and capacity is allometric. The values obtained from these factors ranged from 1.01 to 1.03 for men and 1.01 to 1.012 for females. The gonad maturity level of male and female mud crabs was dominated by TKG III and IV. This indicated that the research time was in spawning period.