scholarly journals PENGARUH SUHU AIR TERHADAP DAYA TETAS TELUR DAN PERKEMBANGAN LARVA NILA MERAH (Oreochromis sp.)

2002 ◽  
Vol 4 (2) ◽  
pp. 22
Author(s):  
Rustadi Rustadi
Keyword(s):  
Ambient Temperature ◽  
Water Temperature ◽  
Seed Production ◽  
Incubation Time ◽  
Soft Drink ◽  
Circulation System ◽  
Hatching Rate ◽  
Red Tilapia ◽  
Egg Incubation ◽  
Optimum Water

Artificial incubations of red tilapia eggs and fry were conducted in the effort to increase fish seed production and its quality. These experiments were done to determine suitable water temperature for egg incubation and larvae rearing. Four different water temperature­s, 24, 27, 30, and 33oC with variance 1oC and ambient temperature were tested in triplicates. One liter of plastic incubators made from soft drink bottles were set to water re-circulation system and provided with filter means.The fertilized eggs were stocked at 150 eggs. The hatching rate of egg increased as the increase of water temperature. The increase of water temperature decreased the incubation time of eggs, but increased hatching rate and the growth of larvae. The optimum water temperature was 29,87oC. 

Effect of temperature during embryonic development and first feeding of Trichogaster leeri larvae

Zygote ◽  
2016 ◽  
Vol 24 (5) ◽  
pp. 733-741
Author(s):  
Samuel Louzada Pereira ◽  
Dalcio Ricardo de Andrade ◽  
Marcella Costa Radael ◽  
João Carlos Fosse Filho ◽  
Rafael Vieira de Azevedo ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Water Temperature ◽  
Larval Development ◽  
Environmental Factor ◽  
Effect Of Temperature ◽  
Hatching Rate ◽  
Egg Incubation ◽  
First Feeding ◽  
Incubation Temperatures ◽  
Embryonic And Larval Development

SummaryTemperature is an environmental factor that influences the development of fish, and when changed abruptly can lead to high mortality. Some species of fish are influenced by this factor, exhibiting a longer time for embryonic development and time to first feeding. This study aims to evaluate the effect of water temperature on embryonic and larval development up to first feeding, to describe the time in hours post fertilization (hpf) of the emergence of different structures and to determine the best hatching rate and survival of animals under different treatments. Five different egg incubation temperatures were used (24, 26, 28, 30 or 32°C, respectively). The eggs were observed at regular intervals of 30 min up to 24 h, every 2 h until 48 h and every 4 h until the display of first feeding in all treatments. Embryonic development was longer for eggs incubated at 24°C and the best results for hatching rate and survival of spawning efficiency were at 28°C. We recommend that incubation of Trichogaster leeri eggs is carried out at 28°C up to the first feeding of larvae.

Impacted Stress: A Causal Agent of Reduced Whitefish (Coregonus Iavaretus) Egg Incubation Time

1988 ◽  
Vol 45 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Tor F. Næsje ◽  
Bror Jonsson
Keyword(s):  
Water Temperature ◽  
Incubation Period ◽  
Incubation Time ◽  
Natural Water ◽  
Flowing Water ◽  
Degree Days ◽  
River Temperature ◽  
Egg Incubation ◽  
Heated Water ◽  
Two Samples

The purpose of these experiments was to investigate whether whitefish (Coregonus Iavaretus) eggs subjected to induced agitation had a shorter incubation period to hatching than undisturbed incubating eggs. Eyed eggs were divided into four main groups: two incubated at river temperatures and two incubated in heated water. River temperature was 2 °C at the beginning of the experiment and increased to more than 10 °C at hatching. Heated water temperatures varied between 6.5 and 8.5 °C. One sample with four replicates at each incubating water temperature was continuously agitated with flowing water, while two samples with four replicates each were incubated undisturbed. At both temperatures, eggs kept in motion by flowing water hatched at fewer degree-days (heated water: 380 ± 6.4, natural water: 417 ± 6.6) from fertilization to 50% hatching than those laying undisturbed (heated water: 513 ± 10.5, natural water: 470 ± 7.3). Eggs agitated during incubation hatched with greater synchrony than those incubated undisturbed. Larvae incubated at river temperatures were larger than those incubated in heated water. Our findings revealed that eggs can hatch at different incubation stages during the ontogeny when exposed to varying environmental stimuli.

scholarly journals Enhancing Solar Still Performance Using Vacuum Pump and Geothermal Energy

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 539
Author(s):  
Syed Danish ◽  
Abdelrahman El-Leathy ◽  
Mohanad Alata ◽  
Hany Al-Ansary
Keyword(s):  
Heat Exchanger ◽  
Wind Speed ◽  
Ambient Temperature ◽  
Water Temperature ◽  
Analytical Model ◽  
Vacuum Pump ◽  
Vacuum Pressure ◽  
Geothermal System ◽  
Outlet Temperature ◽  
Solar Still

Improvement in the performance of a solar still is investigated with the integration of a geothermal cooling system and a vacuum pump. Geothermal cooling is simulated to provide a cold, effective underground water temperature, which could reach 15–25 °C below ambient. Cooling is achieved by circulating water underground. As a result of this circulation, the cold fluid from the ground flows into a counter flow shell and tube heat exchanger. A vacuum pump is used to keep the solar still at a certain vacuum pressure. The sizes of the geothermal system and solar still are designed in such a way that the water outlet temperature from the ground and its flow rate are capable of condensing the entire vapor produced by the still. An analytical model was developed and then solved using the Newton–Raphson method for solving non-linear equations. A prototype was built to validate the analytical model. The results were in close agreement. A 305% increase in daily water productivity resulted from the proposed enhancements. After experimental validation, the effects of various parameters such as vacuum pressure, ambient temperature, and wind speed on the yield of geothermal solar still were examined. It was found that the increase in vacuum pressure enhanced performance, whereas the increase in wind speed had a detrimental effect on the yield of the solar still. A higher ambient temperature increased the yield of the solar still. Finally, the design of the heat exchanger for condensing the distilled water using geothermal cooling water was also investigated in terms of the increase in UA (the product of overall heat transfer coefficient and the area of heat exchanger) with inlet cooling geothermal water temperature.

scholarly journals Pengaruh Volume Air Pada Media Terhadap Pertumbuhan Panjang Dan Berat Ikan Sidat (Anguilla bicolor bicolor)

2017 ◽  
Vol 6 (2) ◽  
pp. 117
Author(s):  
Nur Taufiq-Spj ◽  
Virda Maya Definta ◽  
Raden Ario
Keyword(s):  
Growth Rate ◽  
Water Temperature ◽  
Water Volume ◽  
Eastern Asia ◽  
Weight Growth ◽  
Economic Prospect ◽  
Absolute Growth ◽  
Water Volumes ◽  
Tight Correlation ◽  
Optimum Water

Budidaya ikan sidat (Anguilla sp.) di Indonesia baru mulai berkembang beberapa tahun belakangan meskipun ikan ini memiliki banyak prospek di berbagai negara Asia maupun Eropa. Kegiatan budidaya yang dilakukan di beberapa daerah baru pada taraf pembesaran pada kolam persawahan (earthen pond) dan hanya sebagian kecil yang menggunakan sistim resirkulasi. Penelitian ini bertujuan untuk mengetahui pengaruh volume air terhadap pertumbuhan panjang dan berat ikan sidat (Anguilla bicolor bicolor) stadia awal dari elver dengan sistim budidaya resirkulasi. Metode eksperimental digunakan dalam penelitian ini dengan Rancangan Acak Lengkap (RAL) menggunakan 3 perlakuan volume air yang berbeda (E: 942 l, F: 1413 l, dan G: 750 l). Sampling panjang dan berat dilakukan setiap 2 minggu selama 8 minggu budidaya. Hasil penelitian pertumbuhan panjang dan berat tiap Kolam menunjukkan nilai yang tidak berbeda nyata (α > 0.05). Pertumbuhan Mutlak (berat) pada kolam E: 33,33 g, F: 23,33 g, dan kolam G: 40,00 g, sementara pertumbuhan mutlak (panjang) pada kolam E: 8,67 cm, F: 7,67 cm, serta kolam G: 9,50 cm selama 8 minggu budidaya. Hasil dari perhitungan Spesific Growth Rate (SGR) pada kolam E: 0,48; F:0,33 dan G: 0,57 %/hari selama 70 hari budidaya. Pertumbuhan panjang dan berat ikan sidat pada percobaan ini mempunyai hubungan yang sangat kuat dengan korelasi antara 83,5 – 94,5%. Hasil percobaan ini dapat disimpulkan bahwa pertumbuhan sidat stadia awal elver akan meningkat dengan menurunnya volume air pada kondisi suhu optimum 28±2 ºC. The eel (Anguilla sp.) cultivation in Indonesia recently has just begun to develop, eventhough this species has so many economic prospect especially in eastern Asia and European countries. Aquaculture activities in some province (of Indoesia) still using earthen pond and only certain places which used Resirculating Aquaculure System (RAS) for racing the local eels. The aims of this study were to determine the effect of water volume on early elver of Anguilla bicolor bicolor length and weight growth and it’s corelations. Experimental method was used, complitely random design with 3 treatments of different water volumes i.e. E: 942 liter, F: 1413 liter, and G: 750 l. Sampling were taken every fortnight during 8 weeks culture. The results shows that length and weght growth have no significantly different (α > 0.05). Absolute growth (of weight) in each tank i.e. E: 33.33 g, F: 23.33 g, and G: 40.00 g, meanwhile the length absolute growth i.e. E: 8.67 cm, F: 7.67 cm, and G: 9.50 cm. Spesific growth rate of early elver were: E = 0.48, F=0.33 and G= 0.57 ini % d-1 during 70 d culture. Length and weght growth have a tight correlation i.e. 83.5 to 94.5%. The results of this study indicate that the growth of early eel (Anguilla bicolor bicolor) increased by decreasing water volume in the optimum water temperature of 28±2 ºC.

The Prospects of Thermal Water Exploration in Ukraine

2017 ◽  
Vol 25 ◽  
pp. 28-34
Author(s):  
Ivan Sadovenko ◽  
Dmytro Rudakov ◽  
Oleksandr Inkin
Keyword(s):  
Water Temperature ◽  
Geothermal Energy ◽  
Thermal Water ◽  
Feasibility Studies ◽  
Heat Extraction ◽  
Circulation System ◽  
Geothermal Heat ◽  
Black Sea Coast ◽  
Environmentally Safe ◽  
Depth Ranges

The total resources of geothermal energy in Ukraine up to the depth of 10 km are estimated at 1022 J, which significantly exceeds the reserves of fossil fuel sources. Nevertheless, geothermal exploration in each specific case requires comprehensive thermodynamic and feasibility studies taking into account local geological, hydrogeological conditions, and depth ranges. To facilitate such kind of studies an analysis has been made for Ukraine’s territory with the identification of aquifers that can be potentially used including the Transcarpathian trough, the Volyn-Podil’ska plate, the Dnipro-Donets depression, and Black Sea coast area. Regarding high thermal water mineralization a geo-technological scheme has been justified for environmentally safe exploration that suggests a closed cycle including (i) pumping out water to the surface, (ii) heat extraction, and (iii) re-injection of water into the aquifer. A mathematical model developed to evaluate the geo-circulation system effectiveness for various conditions allows predicting the changes in water temperature during circulation, power consumption, and heat capacity. Besides, the model enables optimizing the system performance depending on pumped water temperature. We assessed the effectiveness of geothermal heat extraction with the geo-circulation system in terms of profitability and net the present value (NPV). According to the estimations made for aquifers in Ukraine the geo-circulation system can be operated with the positive NPV in many regions of the country depending on the aquifer depth, heat flux, and groundwater flow. The obtained results correlate to the world standards of rational exploitation of geothermal energy.

Experimental Investigation and Numerical Simulation for High Temperature Air Source Heat Pump with New Mixed-Refrigerant

2014 ◽  
Vol 541-542 ◽  
pp. 752-755
Author(s):  
Jun Yang ◽  
Guo Zhong Ding ◽  
Xiao Yan Zhang ◽  
Shui Ming Shu ◽  
Jun Yi Tan
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
High Temperature ◽  
Ambient Temperature ◽  
Water Temperature ◽  
Heat Pump ◽  
Air Source Heat Pump ◽  
Discharge Temperature ◽  
Heating Capacity ◽  
Theory And Experiments

Studies on air source heat pump (ASHP) transfer to high temperature, the performance of air source heat pump greatly depends on the ambient temperature. Aimed at the prototype aeroplane of high temperature air source heat pump, New mixed-refrigerant M-R was adopted, and a simulation was made under a standard conditions with Aspen Plus software. And the results was validated by the experiments. The results showed that a well trend between theory and experiments. In addition, experimental investigation of high temperature air source heat pump were carried out at different conditions. The COP was 1.15, the discharge temperature of compressor was 108.6°Cwhen the outlet water temperature was 85.1°C. The heating capacity is superior. This achieved a leading level at home and abroad.

Breeding of Panulirus longipes cygnus George under natural and controlled conditions

1976 ◽  
Vol 27 (3) ◽  
pp. 499 ◽  
Author(s):  
RG Chittleborough
Keyword(s):  
Ambient Temperature ◽  
Water Temperature ◽  
Population Size ◽  
Natural Population ◽  
Commercial Fishing ◽  
Breeding Stock ◽  
The Past ◽  
Adult Females ◽  
Abundant Food ◽  
Mean Size

Fertilization of eggs is external: the female does not need to be newly moulted to be mated. The incubation period of eggs (19-68 days) varied inversely with water temperature, being longest at 19� C and shortening towards an asymptote at 25� C. Most adult females breed every year. When given abundant food, 77% of those breeding in aquaria at ambient temperature had two successive spawnings in a breeding season, whereas in a relatively crowded part of the natural population less than 12% of the breeding females spawned twice in a season. When held at a constant temperature of 25� C and given abundant food, adult females bred continuously, averaging six spawnings and three moults each year. In the natural population, size at first breeding and mean size of breeding females did not vary with depth but differed from one locality to another. At the Abrolhos Islands where the present density of breeding stock is highest, adults appear to be stunted and fecundity is relatively low. This situation may have existed to some extent in other parts of the population before heavy commercial fishing of the past 20 years or more reduced the density of the breeding stock to present levels. The operation of density-dependent regulation of fecundity in this population is discussed.

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