bluuebunny/crossref_metadata_2025 huggingface dataset:
On the use of recombination rate coefficients in hydrogen transport calculations
Authors: Schmid K. , Zibrov M.
Published: June 2021

The commonly accepted picture for the uptake of hydrogen isotopes (HIs) from the gas phase across the surface into a metal with an endothermic heat of solution for HIs is that of dissociation followed by thermalisation in a chemisorbed surface state and finally overcoming a surface barrier to enter the metal bulk where the HIs occupy interstitial solute sites. To leave the metal bulk the HIs first transition to the chemisorbed surface state from which they then enter gas phase by recombining into a diatomic molecule. This model is generally attributed to the work of Pick and Sonnenberg from 1985. They clearly distinguish surface states and subsurface solute sites where the recombination flux is proportional to the square of the concentration of chemisorbed atoms due the diatomic nature of this Langmuir–Hinshelwood process. In an effort to compare their extended model with an earlier surface model by Waelbroeck, which uses an expression for the recombination flux proportional to the square of the sub-surface interstitial solute concentration, they derive an effective recombination coefficient. However, also with the so-derived Pick and Sonnenberg recombination coefficient, the Waelbroeck model is only applicable under certain conditions. But, due to its simplicity, it is often used in boundary conditions of diffusion trapping type calculations, generally ignoring whether or not these conditions are met. This paper will use the full Pick and Sonnenberg model implemented in the TESSIM-X code and in simplified algebraic approximations, to show the limits of applicability of the Waelbroeck–Ansatz in modelling hydrogen transport in metals foreseen for the first wall of magnetic confinement fusion devices.
Tensile strength of pervious concrete with different mix proportions
Authors: Karawi Rasha Jasim Al
Published: June 2021

No-fines concrete is a distinctive kind of concrete that has an amount of porosity that lets the water and any liquid sources pass immediately through it. Often, many mechanical properties of concrete refer to its strength through the testing of the compressive strength, flexural strength, and splitting tensile. Thus, this research mainly focused on the splitting tensile strength with different mix ingredients. Two series of penetrable concrete were prepared to study the effect of two parameters on such concrete. In the first group, the sand was eliminated for one sample and the styrene butadiene rubber (SBR) was added to the mix with a percentage of 5% and 8% by cement weight. The second group was to study the effect of a partial replacement of coarse aggregate with sand in three varied proportions of 15%, 30%, and 45% of the total volume of aggregate. The water/cement ratio (w/c) was chosen to be 0.38 and 0.42. The results showed that the sand content has a higher positive effect than SBR on the tensile strength of pervious concrete.
A review of slopes stability challenges and neighbour buildings
Authors: Mahmood Mohammed Shakir , Akhtarpour Ali , Alsharifi Zehraa
Published: June 2021

Due to the attraction of the hilly views and lack of flatland in some countries, there are needs to the construction near the slopes. In evaluating slope stability, attention must be considered by geotechnical engineers, particularly to geology, surface drainage, groundwater, and soil shear strength. Slope failures depend on the soil type, soil stratification, groundwater, seepage, and the slope geometry and some failures are sudden and disastrous. The analysis of slope stability is more complicated with the existence of earthquakes, neighbour buildings or structures, unsaturated-saturated soil states. This paper reviews the effect of different parameters on the stability analysis of slopes and neighbour structures. There are distinguished effects from increasing the seismic forces and wetting process on the decreasing of soil shear strength and collapsing of the slopes.
Efficiency of different methods to predict settlement of shallow foundation in cohesionless soil
Authors: Mohammed Zainab R , Abdul-Husain Husain A
Published: June 2021

During the last decades, many methods have been developed to predict the settlement of shallow foundations on cohesionless soils based on the results of SPT. However, such prediction methods with the required degree of accuracy and consistency have not yet been developed. The current study is an attempt to evaluate the performance of some of these methods and obtain the most efficient one. This goal has been performed by evaluating and ranking eight common methods. These methods are Terzaghi and peck, Meyerhof 1, Bowles (1986), Parry, Schultze and Sherif, Meyerhof 2, Burland and Burbidge and Anagnostopoulos et al.. A total number of 189 cases published in the literature were adopted to carry out the ranking analysis of the selected methods. The concept of rank analysis depends in general on four approaches. These approaches are Nash-Sutcliffe efficiency, arithmetic average & standard deviation, accumulative probability analysis, and Log-Normal distribution of the ratio between the predicted and measured settlement. The results of the analysis revealed that the Anagnostopoulos et al. method have got the first rank with a rank index of 6 while Terzaghi and peck have achieved the last rank with rank index of 27. Therefore, Anagnostopoulos et al. method can be used to estimate the settlement of shallow foundations based on the results of SPT with high confidence.
Seismic effect on uplift bearing capacity of pile embedded in dry sand
Authors: Abdul Hussein Haider N. , Mohammed Shafiqu Qassun S. , Khaled Zeyad S. M.
Published: June 2021

The growing rate of occurrence of earthquakes in Iraq and the whole region has driven to conduct this experimental research aiming at evaluating the uplift capacity of piles under seismic influence. Shaking table was especially manufactured to simulate the seismic loading resulting from Halabjah earthquake with high accuracy. Pullout tests were carried out on piles embedded in dry sand to determine the ultimate uplift load capacity before and after applying the seismic loading for different length to diameter ratios (L/D) of pile model 20, 25 and 30 and for loose and dense dry sand. It has been found that the maximum pull-out load of the pile after applying only Halabjah seismic loading was reduced between (8.16%) and (10.46%) in loose dry sand. However, there is no clear effect on tension pile capacity in dense dry sand except in pile of L/D=30, that bearing capacity increased by about 15.94%. And when apply combined loading of Halabjah seismic loading and uplift loading equal to one-third of maximum tension capacity the reduction of maximum pull-out capacity was between (55.02% to 73.22%) in loose sand while in dense sand there is a reduction about 50% for pile with L/D=20 and 25% and a low reduction of 8.06% for pile with L/D=30.
Pavement condition index (PCI) for some highways collector selected in Najaf city implemented with PAVER software
Authors: Kareem Saba Abbas , Shubber Khawla H. H.
Published: June 2021

Pavements are the main assets of highway infrastructure. Pavement Condition Index (PCI) is a numerical index used to describe the general condition of a pavement. This paper is another trial in monitoring and find pavement condition index (PCI) by applying PAVER software version 5.2. This work aims to evaluate (PCI) of a flexible pavement of some miner collector highways in the north sector in Najaf city divaricate from both sides of Najaf- Karbala suburban main collector highway in its part away from Al- Askariin intersection towards Karbala. These highway sections are Al-Rahma, Al Hizam Al Akhdar, and Al Muearid, Al Shamalii garage highways which cover a total length approximately 11.54 km in both direction of traffic movement (diverging from Najaf- Karbala highway and return to it). Field survey data such as highway section geometric design and distresses type, dimension, and severity, were collected depending on sample size and number of samples extracted, and then entered into the PAVER program to calculate PCI. The result of PAVER shows Results approved that Al-Rahma and Al Shamalii garage highways sections are in satisfactory level, while Al Muearid highway section in (fair) and Al Hizam Al Akhdar in worst case (poor). In addition to that, reasons of these defects had been figuring out according to results obtained.
Optimization of replacement fines in roads base materials by cement/ lime
Authors: Jasim Heydar A , Mahdi Zaid A , Al-Obaedi Jalal T S
Published: June 2021

The road networks in Iraq suffer from the increase in the proportion of highly carriage trucks and vehicle growth rates, which requires improving the layer’s characteristics and using protective methods accomplished with suitable costs to achieve high quality and fewer cost treatments. This paper investigates the effect of modifying sand -gravel soil as a base layer by using cement or/ lime as a replacement to the original filler. The mechanical properties of the mix were evaluated based on compaction, CBR, and compression strength tests. The results for the CBR test suggested that there was an increase in bearing ratio when replacing a percent of filler by cement or lime as compared with the origin material, and the percent of replacement by cement or lime was 30% of origin filler. The results for the compression strength show that there is an increase with increasing percent of filler replacement by Cement, on the contrary, the Lime increase reveals a decrease in strength. The replacement with cement was better than that of lime. Lime should be used in less than 30% from point of view cost and strength. The findings of this paper suggested that adopting the method will result in decreasing the thickness of the pavement layer. The best results obtained when adopting 100% replacement by cement (10% by total weight) which gave the best reduction in the required thickness by about 62%. Regarding the lime use, the results revealed optimal percent of lime to be used is about 3% of total weight.
Assessment the performance of asphalt mixtures modified with waste tire rubber at high temperatures
Authors: Al-Rubaie Ali H. , Joni Hasan H.
Published: June 2021

Quality of roads pavement can consider as one of the essential criteria for the good transportation system. So, to reduce the problems of fatigue crack and rutting of roads, several actions have been taken including the improving of pavement quality and the structure design methods. The increasing in the attention of traffic engineers in the last few years to modify and improve the asphalt performance through providing a different type of additives and replace the raw materials of asphalt mixture with recycled materials, in order to improve the environmental as well as reduce the cost of modified pavement mixture. There were several types of research investigated the validity of using the waste material products in the mixtures of asphalt pavements, since these replacement materials could improve the performance of roads pavement, the researches that adopted the influence of usage recycle waste materials to improve performance of the asphalt of the road still limited compared with other construction fields. This paper briefly discussed the modified asphalt mixtures performance and the most used recycled material which is crumbs rubber used as modifier in the HMA. By using various proportions of crumbs rubber (2.5, 5, 7.5, 10, 15 and 20% by weight of asphalt), and investigate the effect of adding rubber crumbs waste on the most important dynamic and mechanical properties of asphalt mixtures, which is the rutting resistance. It aims also to understand the benefits and disadvantages of using recycled tire rubber and develop the idea on good inclusion of waste material in the road pavements.
Mechanical strength and hydraulic properties of modified porous concrete mixtures
Authors: Almansori Hussein J. , Al-Sibahy Adnan , Al-Humeidawi Basim
Published: June 2021

This study presents a comprehensive experimental investigation on the behavior of porous concrete mixtures intended to be used as surface road layer containing mineral admixture. Silica fume and/or fly ash were used to formulate modified concrete mixes at ratios ranged from 10% to 20%. A systematic change in 50% of the 9.5 mm aggregate particles size was adopted throughout single size coarse aggregate of 5mm. This in turn produces two groups of concrete mixes and eight individual mixtures. The compressive and tensile strengths, voids content and permeability characteristics were measured and the obtained results were compared with relevant guide of porous concrete. The results showed that a moderate strength of 24 MPa can be obtained at early ages. For the same concrete mixture, the values of voids content and permeability were 21.7% and 19.3 mm/s, respectively. Such kind of concrete can be used in construction of roads and it helps in water draining purposes.
The effect of elimination the left-turn movements on the intersections Capacity-A simulation study
Authors: Al-amedy Tabarak A , Al-Obaedi Jalal
Published: June 2021

Left-turn movement is an important element to determine the capacity of intersections due to high conflicts points. Therefore, finding the alternatives for such left turn movements may increase the intersection throughput and make it safer. This study discusses the effect of eliminating the left turn movements on the intersection capacity by adding U-turn sections after each approach to apply the left turning away of the intersection. This means that the left turn traffic will pass the intersection using through movements, use the added U- turns and use the intersection again to reach the destination direction using right turns. To apply such scenario, traffic simulation has been applied as a tool using Paramics traffic simulator which is one of the most confident tools over the world. Simulation models have been developed using Paramics considering both signalized and un-signalized intersections with different effective green times. The results suggested that applying such alternatives will significantly increase the intersection capacity. However, further research is needed to examine the geometric layout that would be useful for such alternatives and to confirm the validity of the findings by validation the developed simulation models.
Operational assessment of biological wastewater treatment using advanced return-mass reactors based on principal component cluster analysis
Authors: Najy Rana Hasan , Al-Obaid Basim Hussein Khudair , Salman Mohammed Sadeq
Published: June 2021

In this study, field results data were conducted, implemented in 64 biofilm reactors to analyses extract organic matter nutrients from wastewater through a laboratory level nutrient removal process, biofilm layer moving process using anaerobic aerobic units. The kinetic layer biofilm reactors were continuously operating in Turbo 4BIO for BOD COD with nitrogen phosphorous. The Barakia plant is designed to serve 200,000 resident works on biological treatment through merge two process (activated sludge process, moving bed bio reactio MBBR) with an average wastewater flow of 50,000 m3/day the data were collected annually from 2017-2020. The water samples were analysis in the central laboratory of the wastewater treatment plant in Barakia region by the Directorate Sanitation in Najaf is influential, wastewater at the treatment plant for Al-Bio-shaft saw major water quality parameters. The data was analysis of using a principal component approach a cluster study of the return-mass reactors. The results showed that the biological oxygen dem (BOD5, 126 mg / L), chemical oxygen dem (COD, 222 mg/L), total solids, total suspended solids (TSS, 223 mg/L) a pH of 7.6 over a period of 4years, also the optimum removal rate was 89 %of the BOD, under optimum conditions, 78 % of the chemical oxygen occurred in the air reactor by nitrification with an average ammonium removal yield of 67 %. The cluster analysis results showed that the years (2018, 2017, 2020) are a good level of treatment compared to 2020. The final effluent quality (an average value of three years) complies with the stringent regulations proposed by the Iraqi National Stards established by Regulation 25 of 1967 BOD / COD ratio were calculated Influence is 0.63 in total wastewater.
Evaluate the performance of horizontal flow wetlands as an option for tertiary treatment of secondary sedimentation basins
Authors: Qasid Dounia Jamiel , Ali Sura kareem , Ahmed Mahmood Dhiab
Published: June 2021

Constructed wetlands (CWs) are simple low-cost wastewater treatment units that use natural process to improve the effluent water quality and make it possible for its reuse.in this study used the horizontal flow system for the tertiary treatment of wastewater effluent from secondary basins at Al-Rustamiya wastewater treatment plant / old project / Baghdad / Iraq. the Phragmites Australis plant was used for wastewater treatment and the horizontal subsurface flow system was applied. the experimental study was carried out in February 2020 to October 2020. the parameters were monitored for a period of five weeks, Concentration-based average removal efficiencies for HSSF-CW were COD,53% [NO]_3,41.3% [PO]_4,52% and TSS, 54.2%. Thus, constructed wetland can be considered as a sustainable alternative to the tertiary conventional treatment of wastewater, thus making it possible for reuse..
A state of the art review of fiberless and steel fiber reinforced high strength concrete columns behavior under various loadings
Authors: Al-Qabbani Hussein K , Aljazaeri Zena R , Al-Hadithy Laith K
Published: June 2021

Efficient supplementary materials flourish the structural performance and sustainability of reinforced concrete structures. Steel fiber is one of these materials that have significant influence on enhancing tensile and flexural strengths and ductility of high strength reinforced concrete columns. This paper presents a review study on the structural performance of steel fiber reinforced concrete columns. The studied case was related to the columns that subjected to concentric or eccentric compression loads or combined compression loads and cyclic lateral loads. The current survey is divided into two branches; the first is related to fibreless HSC columns, while the other is specialized by SFRHSC ones. In addition to the prime actuator (steel fiber content), the investigated parameters were included concrete strength, transverse reinforcement properties, and axial load ratio. The results of this investigation showed that the positive influence of adding steel fiber on improving the flexural strength, fatigue life and resistance, delaying spalling failure of the exterior concrete shell and outward buckling of the longitudinal steel reinforcing bars. The optimum volume fraction of steel fiber used is 0.5% to 2% (by weight) and when 2% of steel fibers are introduced into the concrete mix, the columns’ cover didn’t spall away.
The behavior of reinforced concrete columns exposure to eccentric loads at high temperature
Authors: Al-Naqeeb Faaiza , Al-Thairy Haitham
Published: June 2021

This paper aims to investigate the influence of high temperature on the reinforced concrete columns’ behavior and load-carrying capacity when subjected to eccentric loads. Experimental tests were conducted on four RC column specimens reinforced by steel bars and subjected to four levels of temperatures: 20 ºC, 400 ºC, 500 ºC, and 650 ºC. One of these specimens was exposed to ambient temperature and considered as the control specimen. After exposure to elevated temperature, all columns were axially loaded by compression force using an eccentricity ratio (e/h) equal to 0.5. The experimental test findings demonstrated a remarkable decrease in the RC column’s ultimate carrying capacity when subjected to elevated temperature. The columns’ ultimate load capacity decreases by about 14.286 %, 28.571 %, and 42.857 % at elevated temperature magnitude of 400 ºC, 500 ºC, and 650 ºC respectively, compared with the control column at ambient temperature. Also, an increase in fire temperature resulted in a reduction in the load capacity with an increase in lateral and axial deflection of tested columns.
Early Age Temperature Distributions in Concrete Bridge in the Middle of Iraq (Experimental Study)
Authors: Laibi Noor M. , Shallal Muhaned A.
Published: June 2021

The temperature difference between the inside and outside of the concrete bridge causes the appearance of early cracks in the concrete bridge. The thermal cracks are appeared on surfaces or inside the bridge body. The sources of the thermal loads come from solar radiation, air temperature, wind speed, and the heat of hydration of cement after pouring concrete (at the early edge of concrete). Concrete T-section used to study the temperature distribution at the early edge, fourteen thermocouples used to measure the temperature during the day; these thermocouples were placed in the different location inside the concrete bridge as well as on its surface. The temperature-time curves were obtained for each thermocouple, from these curves it was found that the effect of cement hydration on the internal temperature was during the first 48 hours, while the effect of solar radiation was evident during daylight hours on the top surface of the model. The effect of solar radiation continues while the effect of cement hydration vanished after 48 hours.
Effect of using column capital on the punching shear strength of flat slab-edge column connection under eccentric loading
Authors: Jasim Attaa H. , Ammash Haider K.
Published: June 2021

The influence of column capital on punching resistance at the edge column is virtually not fully studied. This is a significant omission, as column capital under eccentric loading can arise in flat slab buildings under lateral loading from wind and earthquakes. This paper deals with the effect of using reinforced concrete column capital on the punching shear strength of the flat slab-edge column connection under eccentric loading. The study involves testing experimentally six reinforced concrete flat slab-edge column models with dimensions (1000×1600×100 mm) with two different dimensions of column capital (300×400 mm, and 500×800 mm) in addition to reference model without columns capital (column dimension 200×200mm). Two specimens as a control without columns capital where the first specimen under axial load according to column section but another under eccentric loading with eccentricity (e=half width of column). The effect of size of the column capital and were studied experimentally. We observed an increase in punching resistance by (17.02% and 27.66%) respectively over that of the reference specimen under axial load, and about (18.18% and 25%) respectively over that of the reference specimen under eccentric loading.
Assessment of the flexural capacity of composite reinforced concrete beams using experimental tests and finite element analysis
Authors: Witwit Dolfocar Ali Usamah , Jasim Prof. Dr. Nabeel Abdulrazzaq
Published: June 2021

One of the main governing matters points in studying the composite reinforced concrete beams (CRC) is the force transmission mechanism at the interface between the concrete and the steel section. In this research, a new connection method for CRC beams consisting of reinforced concrete and steel T-section is studied. In this method, the stirrups are utilized to perform as shear connectors. The experimental part of the study includes studying the flexural behavior of the CRC beam with different degrees of interaction. The theoretical part of the study includes constructing a three-dimensional finite element model using ABAQUS software and validating the model using the experimental results. The model was verified by comparing the critical local and global responses of the CRC beams such as the beam deformation, load at which the steel T-section reached yield point, and concrete cracking and crushing. The model showed a good correlation for the estimation of ultimate load with an accuracy of 105% was achieved.
Investigation of temperature gradients in composite girders in the southern region of the black sea
Authors: Mussa Faten I. , Abid Sallal R.
Published: June 2021

Based on an experimental composite concrete slab-steel beam girder and using a verified finite element thermal model, a case study analysis was performed to evaluate the temperature gradients in composite girders in the Black Sea’s Turkish city Samsun. The case study was conducted based on extreme data records of approximately 50 years. The extreme daily solar radiation and air temperature difference were utilized in finite element thermal analysis for six months that represent the different seasons of the year. The investigated months were the hot months (April, June, and July) and cold months (October, November, and December). The study focused on the vertical temperature gradients (along the vertical centerline of the girder) and the lateral temperature gradients (along the horizontal centerline of the topping concrete slab). The finite element results showed that the maximum vertical temperature gradient occurred in June and was 13.55 °C, while the maximum lateral temperature gradient occurred in December and was 10.11 °C. The results also showed that different behaviors of the positive vertical gradient were recorded for the cold months than those for the hot months. Similarly, the distributions of the positive lateral gradients were different for the two groups of months. These differences were attributed to the different sun movements and solar radiation striking angles in summer and winter.
Application of dynamic calibration and control waveform optimization techniques in the fast sweeping reflectometer upgrade on the HL-2A tokamak
Authors: Yang Z.C. , Jiang M. , Shi Z.B. , Zhong W.L. , Shi P.W. , Liu Y. , Wen J. , Fang K.R.
Published: June 2021

High temporal-spatial density profiles, measured by the frequency modulated continuous wave (FMCW) reflectometer, are crucial for the study of particle transport and confinement, especially for the transient events. However, the conventional calibration methods and control waveform of the voltage controlled oscillator (VCO) source constraint the increase of the sweeping frequency (time resolution) and the accuracy of the probed location of the FMCW. In this work, two methods of dynamic calibration of the VCO are proposed to reduce the measurement error due to the high sweep rate, and the results are found to be consistent with each other. In addition, the control waveform of VCOs are re-designed considering the VCO calibration results and dispersions of the waveguide and cables. Therefore, the sweep/dead time has been shortened to be 10 μs/50 ns from 25 μs/5 μs and the accuracy of the detection location has been improved significantly. The density profiles and density fluctuations during the tearing modes are presented which demonstrate the capability of the upgraded reflectometer.
The impact of leuprolide acetate-loaded calcium phosphate silicate cement to bone regeneration under osteoporotic conditions
Authors: Meng Lisha , Li Yajin , Wang Yu , Zhang Jingshu , Zhang Yubiao , Chen Yadong , Gong Tianxing
Published: June 2021

Osteoporosis is detrimental to the health of skeletal structure and significantly increases the risks of bone fracture. Moreover, bone regeneration is adversely impaired by increased osteoclastic activities as a result of osteoporosis. In this study, we developed a novel formulation of injectable bone cement based on calcium phosphate silicate cement (CPSC) and leuprolide acetate (LA). Several combinations of LA-CPSC bone cement were characterized and, it is found that LA could increase the setting time and compressive strength of CPSC in a concentration-dependent manner. Moreover, the in vitro results revealed that LA-CPSC was biocompatible and able to encourage the osteoblast proliferation via the mTOR signalling pathway. Furthermore, the LA-CPSC was implanted in the osteoporotic rats to evaluate its effectiveness to repair bone fractures under the osteoporotic conditions. The biomarker study and micro-CT analyses indicated that LA-CPSC could effectively reduce the osteoclast activities and promote the bone regeneration. In conclusion, our study demonstrated that LA-CPSC injectable bone cement should be a viable solution to repair bone fractures under the osteoporotic conditions.
Composition, density and spatial distribution of zooplankton on 1st transition season (March to May) in Inner Ambon Bay Waters, Indonesia
Authors: Pello F S , Latumeten J , Tetelepta J M S
Published: June 2021

Inner Ambon Bay is part of Ambon Bay that covered an area about 11.03 km2. It is semi-closed and become a small pelagic fish fishing ground, especially anchovy. The anchovy is a zooplankton predator, hence, the abundance of anchovy is dependent on the abundance of zooplankton. The research aims to analyze the composition, density, and spatial distribution of the zooplankton during the 1st transition season (March to May). Data of zooplankton composition were attained from sampling by using plankton net at ten observation stations, meanwhile, data of densities were obtained using a scientific hydroacoustic system on six parallel transect lines and one cross-parallel transect line. The study shows that the zooplankton community is dominated by Copepod and meroplankton. The highest density was found in March, while the lowest density was in April. Vertical distribution of zooplankton shows that the highest density was found near the surface (0-4 m) and decrease to a deeper water column. On the horizontal distribution, lower densities (0 – 400 ind./m2) occupy a wider area, they are evenly distributed in western, middle, and eastern, in the contrary, higher densities (3,000-4,000 ind./m2) occupy smaller space viz. in the southwest and east of Inner Ambon Bay.
Species diversity, density, phosphate concentration and the utilization of algae as a food material
Authors: Litaay C , Arfah H , Rugebregt M J , Opier R D A
Published: June 2021

The influence of nature and human activities greatly affects the distribution and diversity of algae. This study was conducted to determine the species diversity, density, phosphate concentration, and algae utilization as a food material found on the island of Ambon. The sampling location was on Ambon’s island in three locations, i.e., Tantui, Hative Besar, and Allang. For 100 m, line transects were laid perpendicular to the shore at every station. For every of the transect line, four 50 cm×50 cm quadrat was placed randomly. There was 18 genus of seaweed. Of the 22 species, 11 species from Rhodophyta (50.0 %), 5 species from Phaeophyta (22.73%), and 6 were from the class of Chlorophyta (27.3%). The highest value density is village Hative Besar that is 1219.9 gr.m−2 is from the Chlorophyta group (Enteromorpha prolifera), Tantui is 986 gr/m2 from the Rhodophyta group (Gracilaria), and Allang that is 756.18 gr.m−2 from the Rhodophyta group (Acantophora). The maximum concentration in Allang is 0.19 mg.L−1, concentration in Hative Besar is 0.18 mg.L−1, while the minimum phosphate concentration is 0.15 mg.L−1 at the Tantui location. The types of algae that can be used as food sources include Gracilaria sp., Caulerpa sp., Sargassum sp, Gelidium sp., and Ulva sp.
Biology aspect and parameter population the scalloped hammerhead (Sphyrna lewini Griffith & Smith, 1834) caught from coastal fisheries in the eastern Indian Ocean
Authors: Chodrijah U , Faizah R
Published: June 2021

The scalloped hammerhead, Sphyrna lewini, have a circumglobally distribution in tropical and warm-temperate waters. Generally, in Indian ocean this species is a bycatch of the tuna longline, however, in Tanjung Luar, this species is a target species. The life history from this species is still limited. The study aimed to assess the biology aspect and growth of the scalloped hammerhead in the period February 2013 to December 2016. The result showed that 2449 individuals were caught with size between 43-395 cm TL (average 198,03 cm) for females and males ranged between 47-340 cm TL (average 161.61 cmTL). The sex ratio that was dominated by female sharks was 2.69: 1. The clasper length and total length relationship were positive with a linear regression equation of CL = 0.0902*TL-4.4402 (R2=0.6837). It showed that the length of the claspers increases proportionally with the length of the body. Application of age at length data for produced von Bertalanffy growth model parameter estimates of female L∞ = 397 cm TL, K = 0.27 year−1, for male S. lewini was L∞ = 381 cm TL, K = 0.17/ year. The total mortality rate (Z) the scalloped hammerhead was 1.15/ years, natural mortality (M) is 037/ years and the fishing mortality (F) was 0.78/ years with exploitation rate (E) = 0.68
Management policy of small-scale tuna fisheries based on island cluster in Maluku
Authors: Tauda I , Hiariey J , Lopulalan Y , Bawole D
Published: June 2021

Tuna is one of essential economic fish commodities in Maluku which mostly caught by handline and trolling line small scale fishery with fishing vessel capacity under 5 GT. The fishing vessel numbers and fish production of this fishery are declining recently, and the catching was predominantly by small size. The highest yellowfin tuna production was found in Island Cluster 7 amounted to 9,107 tones or 31% of total yellowfin tuna production in Maluku by 2019. This study was aimed to analyze the condition of yellowfin tuna in Maluku and to propose a management policy for small-scale tuna fishery base on Island Cluster. Result shows that the production between 2013-2019 was stagnant with a declining tendency. The implementation of island cluster approach in small-scale tuna fishery management will increase the efficiency, productivity, and competitiveness on it, especially at the potential island clusters 7, 5, and 4. Of all-island clusters found, island cluster 7 having the highest performance indicator for small-scale tuna fishery.
Sea urchin identification in Kodingareng Lompo waters, Spermonde Archipelago
Authors: Moka W , Inaku D F , Rais M. , Moka W
Published: June 2021

Sea urchin, belongs to Phylum Echinoderm, Class Echinoidea. It is categorized as benthic marine invertebrates, and could be found in several ecosystem from shallow water to abyssal depth. Despite the high potential, there is no detail information of this organism in Indonesia, especially in Spermonde Archipelago, South Sulawesi Region. This study aim to identify the sea urchin species found in Kodingareng Lompo Island, Spermonde Archipelago. Kodingareng Lompo is one of the islands belong to Sangkarang Regency, Makassar city. Sampling was done during July 2020. Samples were collected randomly in seagrass bed and transition area. The morphological identification was conducted at the main island. The morphological traits of sea urchin samples collections were observed, noted, and compared with some literatures for identification. There three kind of sea urchin found in this waters:Diadema setosum, Mespilia globulusandTripneustes gratilla.
Ranching of sea cucumber in Indonesia : A study case of Holothuria atra
Authors: Hartati R , Zainuri M , Ambariyanto A , Widianingsih W , Mustagpirin  , Panji F
Published: June 2021

Sea ranching is one of the promising sustainable ways to restore depleted stocks and increase production of sea cucumber. Before, only high price species were exploited but now the demand is extended to many other low-value species, such as Teripang Hitam, H. atra. The present work were aimed to observed the growth and survival of H. atra ranching using pen system. Sea pens system size of 5meter x 5meter x 1.8meter was set up in Teluk Awur Waters, Jepara, Indonesia. They were designed as mesocosms that mimic sea ranching location. Wild young H. atra (average weight of 100 g) from Panjang Island, located adjacent to Teluk Awur waters were stocked at 3 individu.m−2, reared for five months without food addition. Sea cucumber was weighed and counted monthly to determine their growth and survival rate. The results of present experiment revealed that sea cucumber increased their weight with the time of rearing, the average weight gain and survival rates were 212 g and 83% respectively. It showed that their adaptation to the new environment was went well. The sea cucumber got intake of food that naturally grew in the sea pens or transported by the sea current from surrounding area. This result showed promising application on sea ranching for marine natural conservation.
Production function model of African catfish hatchery business in Joho village, Wates, Kediri
Authors: Aisyah D , Supriyadi S , Sari M , Alfarizi W , Asshovani C
Published: June 2021

The use of production inputs on African catfish hatchery business can cause production risks also can reduce production risks. This study aims to analyze the effect of production inputs cause on production risks faced by African catfish hatchery cultivators in Joho Village, Wates, Kediri. This study took 30 respondents conducted by snowball sampling and the data analysis method used Cobb-Douglas model. Data processing tools used Microsoft Excel 2016 and R-Studio 4.0.1 statistical software. The results showed production inputs of artificial feed, broodstock, and drugs significantly affect productivity. Increased of broodstock significantly decreases production risk, and increased of medicines significantly increase production risk. The policy recommendations of this study are limiting the use of production inputs that could pose production risk, and good fish farming implementation methode based on the policy of Directorate General of Aquaculture (DJPB).
CD4 (Cluster Differentiation-4) as an immune response to the portal of entry mechanism of VNN (Viral Nervous Necrosis) infection in grouper
Authors: Yanuhar U , Anitasari S , Kusriani  , Junirahma N S , Caesar N R
Published: June 2021

Viral Nervous Necrosis (VNN) is a Nodaviridae virus that attacks groupers, especially in the larval and seed stages. VNN attacks the brain organs, rapidly attacks the grouper fish receptors and then spreads to the brain via blood circulation. The mechanism of viral infection can occur because of the bond between the VNN adhesive and its receptor molecules in the grouper organ. The aim of this study was to compare the CD4 (Cluster Differentiation-4) values of VNN-infected groupers and healthy fish using immunohistochemical (IHC) analysis. The method used in this study was experimental exploratory by comparing and analyzing the response of CD4 cells in healthy groupers with groupers infected with VNN through IHC observations. The results of IHC test showed that the immunogenic epitope of 32.5 kDa VNN protein had the ability to induce tissue receptors of Humpback grouper (Cromileptes altivelis) by forming immune cells qualitatively. There are CD4 cells that are immune to specific tissue organs, i.e. eyes of the groupers, which are labeled with anti-CD4 secondary antibodies. It seems that immunogenic protein VNN with a molecular weight of 32.5 kDa has the ability to stimulate the expression of Humpback grouper immune cells such as CD4 in tissue organs, especially the eye organs qualitatively.
Sustainable tourism development based on local participation: Case study on Dalegan District for the East Java tourism industry
Authors: Rahmawati D , Soedarso  , Suryani A , Wibowo B M , Muklason A , Endarko
Published: June 2021

Coastal areas and small islands has considerable management potential, however several studies have shown that these conditions do not make the management of coastal areas in Indonesia optimal. The purpose of this research is to try to answer important issues regarding how sustainable tourism development affects people’s lives and livelihoods. This research presents debates in sustainable tourism development by paying attention to the concept of sustainable development and investigating the main problems of developing sustainable tourism development. The methodology used in this research is qualitative by using focus group discussions (FGD) with 50 people in the village of Dalegan to obtain data from important informants. The results of the research show that the lack of attention to the environmental sector in the village makes coastal tourism objects less attractive to tourists. The development of local communities must also go hand in hand with sustainable tourism development, the relationship between government and coastal managers in Dalegan also needs strengthening. The perception of visiting experiences reinforced by the presence of local communities is essential to increase the number of tourists to create a conducive economic climate. We suggest that the socio-economy should coexist with environmental sustainability and a sustainable tourism development framework must be created to address heterogeneity and complexity in a regional scope.
Dilution and Aspect Ratio Properties on Performance of Laser Deposited Ti-Al-Si-Cu/Ti-6Al-4V Composite Coatings
Authors: Fatoba O.S. , Naidoo LC. , Akinlabi S.A. , Akinlabi E.T. , Mwema F.M. , Ikumapayi O.M.
Published: June 2021

In spite of the fact that Laser additive manufacturing (AM) processes have a similar material additive manufacturing theory, each AM procedure has its particular features in terms of operational materials and applicable situations. In recent years, additive manufacturing techniques have been acquainted as a promising technique to generate metallic parts since they can annihilate the familiar problems associated with conventional techniques. The results of the investigation showed that as the transverse speed increases, the material that is distributed to the substrate per unit length decreases and therefore that there is an inverse relationship with clad width, melt pool depth and clad height. Hence as the scanning speed increases the width if the height is smaller and the depth of the pool will be smaller too. The results indicate that the specimens manufactured at 900 W, had a decrease in dilution by 3.83%, 1.29% for Ti-Al-11Si-5Cu and Ti-Al-12Si-2Cu respectively when the scanning speed is increased. However, for Ti-Al-13Si-6Cu, there is an increase in the dilution by 1.06%, which can be attributed to the increase of the deposit area below the substrate than above. The results evidently show that increasing the laser scanning speed, increases the aspect ratio of the specimens for laser processing condition 900 W. This relationship is observed in attribution to the clad height being reduced as the scan speed is increased. Moreover, the varying scanning speed influences the clad height more significantly than the clad width; hence, the significant increase in the aspect ratio.
Sustainability of Infrastructural Projects in Nigeria: A Critical Review
Authors: Ongbali S. O. , Akinyemi A. A. , Afolalu S. A , Leramo R. O. , Ombugadu M. G.
Published: June 2021

Government at all levels in Nigeria implement diverse projects intended for economic development and benefit of the public such as roads, electricity and water supplies, ports, transportation, telecommunications, schools, health facilities, housing, and railways among other projects. However, some of these projects fail to reach completion and commissioning and sometimes abandoned on account of numerous factors. This paper seeks to appraise the current efforts in the topic area to identify and provide a holistic document on the key factors to blame for public project failure and abandonments in Nigeria which are fragmentally documented in the literature. The finding will chart the road map for intervention by stakeholders to alleviate the problem for sustainable economic development and improve the quality of life of the citizens. It appeared from the descriptive statistical analysis of the 44-variables identified in the literature that the underlying factors causing Government project failure include lack of financial capacity, use of incompetent contractors based on political consideration, corruption, poor design and implementation, poor project planning and scheduling, inaccurate cost estimate and payment delay amid others. We recommend that the Government address the identified key variables to enhance infrastructure development to boost the economy and improve the quality of life. Additionally, further research is required to use advanced analytical tools to examine the 44-variables identified which were previously neglected to provide reliable information on the key factors causing the problem for appropriate intercession by Government and stakeholders.
Effects of intercalated water on the lubricity of sliding layers under load: a theoretical investigation on MoS2
Authors: Stella Martina , Lorenz Christian D , Clelia Righi Maria
Published: June 2021

Two-dimensional (2D) materials, such as graphene and molybdenum disulfide (MoS2) have recently become some of the most studied nano-materials due to their wide array of technological and industrial applications. Among these, they display great potential as solid lubricants. Friction properties of 2D-materials, however, are very sensitive to environmental conditions, e.g. humidity. In MoS2, for instance, humidity can hamper its tribologic performances. Past experiments and recent ab-initio molecular dynamics simulations have highlighted that, at ordinary temperatures, a possible reason for lower lubricity is the physical interaction of water with the layers. It is, therefore, crucial to better understand the microscopic mechanisms underlying this behaviour, in order to optimise the lubrication performance of these materials. In this paper we used density functional theory simulations and classical molecular dynamics simulations to provide a multi-scale description of how external load affects the energetic, structural and dynamic properties of intercalated water between MoS2 layers. As a result of combining these two different approaches, we provide an atomistic description of the role of intercalated water in modifying the frictional behaviour of physically interacting layers, e.g. MoS2. The identified interlocking mechanism, which is enhanced under load, is relevant for understanding the frictional effects observed for water confined in slit nanopores, and for nanofluidics applications.
The dynein light chain protein Tda2 functions as a dimerization engine to regulate actin capping protein during endocytosis
Authors: Lamb Andrew K. , Fernandez Andres N. , Peersen Olve B. , Di Pietro Santiago M.
Published: June 2021

Clathrin- and actin-mediated endocytosis is a fundamental process in eukaryotic cells. Previously, we discovered Tda2 as a new yeast dynein light chain that works with Aim21 to regulate actin assembly during endocytosis. Here, we show Tda2 functions as a dimerization engine bringing two Aim21 molecules together using a novel binding surface different than the canonical dynein light chain ligand binding groove. Point mutations on either protein that diminish the Tda2-Aim21 interaction in vitro cause the same in vivo phenotype as TDA2 deletion showing reduced actin capping protein recruitment and increased filamentous actin at endocytic sites. Remarkably, chemically induced dimerization of Aim21 rescues the endocytic phenotype of TDA2 deletion. We also uncovered a capping protein interacting motif in Aim21, expanding its function to a fundamental cellular pathway and showing such motif exists outside mammalian cells. Furthermore, specific disruption of this motif causes the same deficit of actin capping protein recruitment and increased filamentous actin at endocytic sites as AIM21 deletion. Thus, the data indicates the Tda2-Aim21 complex functions in actin assembly primarily through capping protein regulation. Collectively, our results provide a mechanistic view of the Tda2-Aim21 complex and its function in actin network regulation at endocytic sites.