The Energy-Sources in Ontogenesis

1926 ◽  
Vol 3 (3) ◽  
pp. 189-205
Author(s):  
JOSEPH NEEDHAM

1. Attention is drawn to the numerous facts in the literature of chemical embryology which point to a succession of energy-sources during ontogenesis, carbohydrate preceding protein and protein preceding fat. This question is discussed. 2. The urea content of the hen's egg has been investigated from the fourth to the nineteenth day of incubation. There is period of intensive urea production from the fifth to the ninth day. After that point the excretion of urea fails to keep pace with the growth and differentiation of the embryo. 3. It is pointed out that this period comes exactly between the stage at which carbohydrate is known to be utilised as an energy-source, and that at which the same may be said of fat.

1926 ◽  
Vol 4 (2) ◽  
pp. 145-154
Author(s):  
JOSEPH NEEDHAM

1. Investigation of the ammonia content of the developing hen's egg shows that though in absolute amount it steadily increases during incubation, in percentage of the embryonic weight it declines. 2. The intensity of production of ammonia reaches its highest point on the fourth day, i.e. five days before that of urea production, and seven days before that of the production of uric acid. 3. The absolute amounts of nitrogen excreted in the form of ammonia are so small, however, that the curve for protein combusted by 100 gm. of embryo each day is hardly affected, and rises to a peak between the eighth and ninth days. 4. These results are compared with others already in the literature of chemical embryology, which seem to bear on the theory of recapitulation. They afford further support to the conception of an ontogenetic succession of energy-sources.


2021 ◽  
Vol 4 (2) ◽  
pp. 22-26
Author(s):  
Hadi Santoso ◽  
Eris Santoso ◽  
Ruslim Ruslim

The supply of electrical energy in Tarakan City, North Kalimantan, still relies on diesel power which uses a limited number of petroleum energy sources. There is a need for research related to renewable energy sources that have the potential to become alternative energy for the people of Tarakan City. Water is an energy source that has great potential to generate electricity. The energy source that should be taken into account is micro-hydro which can be used as a Micro-hydro Power Plant (PLTMH). A survey of micro-hydro sources in Tarakan City, precisely in the Karungan area, East Mamburungan Village, has been carried out with the direct measurement method of water discharge and the relationship with the power generated. The result shows the water source has a discharge 0.00034 m3/ s, the water velocity of 0.035 m/s and generates power only up to 1.1 watts. Based on the power obtained, the water source in this place cannot be used as a source of micro-hydro energy, but has the potential as a source of pico-hydro energy.


1953 ◽  
Vol 30 (4) ◽  
pp. 492-501 ◽  
Author(s):  
HUGH CLARK

1. Post-deposition growth of the black snake embryo is characterized by k values as follows: days 1-11, 0.46; days 11-34, 0.057; days 34-67, 0.039. 2. Total excreted nitrogen is 12.55 mg. occurring successively in development as ammonia, urea and uric acid; k value of total nitrogen production is 0.062, days 11-67, which in comparison with those of growth during this period suggest that stored protein is an energy source during a large part of development. 3. Urea is excreted into the albumen which is the principal storage reservoir and into the yolk; that which is excreted into the yolk is reabsorbed after the 45th day and re-deposited in the albumen as urea, and is in part (22%) converted to uric acid. 4. Concentration of urea in the yolk and yolk-sac continues to increase at the same rate after the 11th day (k = 0.024), although the actual amount declines after the 45th day; concentration in the embryonic tissues increases to the 58th day, then decreases sharply to hatching time; concentration in the albumen increases throughout development, reaching a concentration of approximately 500 mg.%. 5. Uric acid synthesis is believed to be preceded by urea formation, and the presence of urease in the foetal liver and kidney suggest that the urea is hydrolysed to ammonia which is then incorporated into uric acid. Site of the transformation is uncertain, though the early and persistent localization of uric acid in the chorio-allantoic membrane points to this as the organ of synthesis. Decrease in total urea content is quantitatively identical with increase in uric acid. 6. The significance of these findings in relation to development of the vertebrate cleidoic egg is discussed.


2020 ◽  
Vol 25 (2) ◽  
pp. 68
Author(s):  
Nurul Afzan Hilda Zakiya ◽  
A H Yanti ◽  
T R Setyawati

The use of liquid semen for artificial insemination program of Etawah crossbreed goat (PE) is an alternative to replace frozen semen which is constrained by limited and expensive facilities. Production of liquid semen is faster than frozen semen, but the viability of liquid semen which preserved with a standard extender such as tris egg yolk is very short. The purpose of this study was to determine the viability of PE goat semen in egg yolk tris substituted with energy sources such as glucose, galactose, and mannose and to determine the most efficient energy source for semen preservation. This research was conducted from August to September 2018 at the Artificial Insemination Center in Lembang, West Java. This study was designed in a randomized block design (RBD) consist of three experimental groups divided into five groups. Fresh semen of PE goats were preserved using extender which energy source has been modified. Results showed that using glucose in PE goat semen extender produced the best motility among other groups (64.29 ± 9.2%). The highest viability was found in extender with fructose substitution (86.76 ± 2.3%). The longest viability of liquid semen was found in the extender with glucose substitution. It lasted for six days.


2021 ◽  
Author(s):  
Marija Živković ◽  
Dejan Ivezic

Abstract Transformation of the heating sector is recognized as being essential for ensuring reliable and affordable energy services provided with reduced consumption of energy sources, diminished impact on the environment and less import dependency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and treated as a big advantage of district heating systems. Despite many advantages, sewage wastewater heat is still a mostly unused resource at the global level and a totally unused energy source in Serbia, while data about the potential of this energy source are lacking. This research proposes a methodology for the determination of the technical potential of waste heat from wastewater treatment facilities for use in district heating systems by heat pump application. Data from existing wastewater treatment facilities are used for providing data for replication in cities without wastewater treatment plants but with district heating systems. An estimation of the recoverable heat energy potential of wastewater is used for evaluation of some effects that could be obtained through its full utilization for heat production in the existing district heating systems. Three groups of indicators are selected for analysis focusing on district heating systems' energy performance (primary energy factor, specific heat consumption per degree day and heating area), the security of energy supply (import dependency, Shannon Wiener diversification index, the share of renewables) and environmental impact (carbon dioxide emission coefficient). Values of the selected indicators are determined for the current state of district heating systems and for the possible future state that could be achieved after full utilization of sewage wastewater potential. The proposed methodology is applied to Serbia, as a case study. It has been shown that all analyzed indicators for the projected future would have more preferable values compared to the values that correspond to the current state of the district heating systems. The use of this renewable energy source should provide primary energy savings of 5% per year, reduction of carbon dioxide emission of 6.5% per year, reduction of import dependency of DH systems of 9.8% and improved diversification of energy sources of 21%.


2014 ◽  
Vol 1008-1009 ◽  
pp. 179-182
Author(s):  
Iveta Gressová

Our planet gives us many mineral sources, but they have a big disadvantage. They are finite. Non-renewable energy sources are enough only for decades, exceptionally for centuries. Current generation is aware of the importance of using other energy sources, such as sunlight, wind, rain, tides, waves and geothermal heat. These energy sources are renewable. It means that they come from sources, which are naturally replenished on a human timescale. One of these sources is wind energy. Use of this kind of energy source needs an initial investment, but it can reduce cost of running a household and other sectors. This article is about Savonius wind turbine and its use for the needs of public lighting.


Author(s):  
Alon Wolf ◽  
Ga´bor Ko´sa

Ask a mechanical designer, especially those dealing with robotics, what are the two main limitations when designing a new autonomous small mechanism. The answer will most likely be the need for better small-size actuation devices and better and smaller energy sources. Indeed, these two factors impose most of the constraints to designers, reflected in the size of the device, the forces it can apply, its achievable workspace, and the time duration it can work when not connected to a permanent energy source. Usually these parameters are in conflict with each other, that is, a small motor has somewhat low output torque and power, while a motor that can generate a large amount of torque is usually large in size and consumes a lot of power. Consequently, every mechanism designer is eager to design a small actuator that generates a large amount of torque while it simultaneously consumes a reasonable amount of energy. This report explains our efforts in developing an inflatable actuator having a small size yet can apply relatively large torque where at the same time can cover a large workspace. The inflatable actuator is shaped as a bellow which is composed of two materials with different shear modulus—one has high elasticity and the other low. By applying pressure inside the bellow, each of the materials tends to deform according to Hooke’s law, resulting in the bending effect due to the elongation differences between the two materials which are constrained to deform simultaneously. We describe the mechanical concept of the bellow actuator; we also provide an analytical model for the bellow deformation. Experimental results for verification of the model are also presented.


2014 ◽  
Vol 659 ◽  
pp. 463-468
Author(s):  
Adrian Alexandru Şerbănoiu ◽  
Gabriel Teodoriu ◽  
Bogdan Serbanoiu ◽  
Ion Serbanoiu ◽  
Marina Verdeș ◽  
...  

The major objective of this paper is to optimize the relationship insurance energy source - high thermal insulation of the building envelope analyzed in order to minimize the financial effort incurred by the beneficiary. In this respect, the paper proposes a methodology for analyzing the financial perspective of the relation envelope - equipment that capitalizes renewable energy sources, built on a newer concept - optimal cost.


2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Abdul Ghofur ◽  
Aqli Mursadin

Berdasarkan ketersediaan sumber daya gambut yang besar di Provinsi Kalimantan Selatan, maka peluang untuk memanfaatkan potensi tanah gambut sebagai sumber energi alternatif sangat besar. Sumber energi yang didapat dari minyak, gas bumi, dan batubara sedikit demi sedikit berkurang, sehingga perlu dicarikan sumber energi alternatif. Peneliti Lahan Gambut dari Balai Penelitian Tanaman Rawa Pertanian (Balittra) Banjarbaru, Dr Muhammad Noor dalam berita Banjarmasin post tanggal 24 Nopember 2005 tentang “PLN Melirik Lahan Gambut”  menjelaskan, dalam gambut memang terdapat energi yang dapat membangkitkan tenaga listrik, energi yang terdapat dalam gambut cukup tinggi yakni sekitar 5.000 kilo kalori per kilogram. Di Kalsel, keberadaannya setara dengan 65 miliar barel minyak bumi atau sebesar 10 juta barel per tahun energi yang dihasilkan.  Berdasarkan latar belakang tersebut beberapa perumusan masalah  dalam penelitian ini adalah bagaimana usaha untuk melakukan tanah gambut untuk menjadi sumber energi alternatif  yang berkualitas dan  mudah digunakan,  bagimana karateristik tanah gambut sebagai sumber energi alternatif. Salah  satu  cara  untuk mengoptimalkan potensi gambut adalah memanfaatkannya sebagai bahan baku dalam pembuatan briket yang dapat dijadikan sebagai bahan bakar altematif  .  Tujuan dari penelitian ini adalah a) memanfaatkan ketersediaan sumber daya alam dengan menggunakan tanah gambut sebagai energi alternatif  dan b ) mengetahui Nilai kalori, berat jenis, kadar air dan kadar abu di wilayah studi. Tanah gambut yang digunakan sebagai  bahan baku untuk energi alternatif  berasal  dari Desa Gambut Kabupaten Banjar.  Prosedur pelaksanaan penelitian dilakukan terhadap karateristik tanah  gambut diwilayah studi  sebagai sumber energi. Dari hasil penelitian ini menunjukan bahwa untuk tanah gambut di Desa Gambut Kec. Gambut bisa   untuk digunakan sebagai bahan bakar alternatif dengan  teknologi pembriketan. Dengan nilai Kadar Air  0,10%, Kadar Abu 72,65%, berat jenis 2,11 Gs dengan nilai kalori 579,2 cal/g bisa digunakan sebagai bahan  bakar alternatif. Key word : energi alternatif, nilai kalori, tanah gambut. Based on the availability of large peat resources in the province of South Kalimantan, the opportunity to utilize the potential of peat soil as an alternative energy source is very large. Energy sources derived from oil, natural gas, and coal gradually diminish, so alternative energy sources are needed. Peatland Researchers from the Agricultural Swamp Research Institute (Balittra) Banjarbaru, Dr. Muhammad Noor in the Banjarmasin post on November 24, 2005 on "PLN Looking at Peatlands" explained that in peat there is indeed energy that can generate electricity, energy contained in peat quite high at around 5,000 kilos of calories per kilogram. In South Kalimantan, its existence is equivalent to 65 billion barrels of oil or 10 million barrels per year of energy produced. Based on this background, several formulations of the problem in this study are how to make peat soils to be a quality alternative energy source that is easy to use, how the characteristics of peat soil as an alternative energy source. One way to optimize the potential of peat is to use it as a raw material in making briquettes that can be used as alternative fuels. The purpose of this study is a) utilizing the availability of natural resources by using peat soil as alternative energy and b) knowing the calorific value, specific gravity, moisture content and ash content in the study area. Peat soil used as raw material for alternative energy comes from the Gambut Village of Banjar Regency. The procedure for conducting research was carried out on the characteristics of peat soil in the study area as an energy source. From the results of this study indicate that for peat soil in the village of Gambut Kec. Peat can be used as an alternative fuel with briquette technology. With a value of 0.10% moisture content, ash content 72.65%, specific gravity of 2.11 Gs with a calorific value of 579.2 cal / g can be used as an alternative fuel. Key word: alternative energy, calorific value, peat soil.


2021 ◽  
pp. 131-136
Author(s):  
A. S. Prozorov ◽  
E. O. Kalmykova

At the beginning of the XXI century environmental problems began to have an integrated impact on various regions of our planet. The agenda of major international forums addresses issues related to their solution with the active use of renewable energy sources, including the expansion of the use of hydrogen in various sectors of the world economy. The article provides a brief overview on the prerequisites for the resumption of interest in the use of hydrogen as an energy source, a review of foreign experience in terms of regulatory regulation and incentives, as well as a retrospective analysis of domestic experience in the use of hydrogen and the prospects for the development of hydrogen energy in modern Russian realities. 


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