THE CRITICAL OPALESCENCE OF ETHYLENE

1948 ◽  
Vol 26b (8) ◽  
pp. 592-603
Author(s):  
O. Maass ◽  
S. G. Mason
Keyword(s):  
Oleic Acid ◽  
Critical Temperature ◽  
Time Lag ◽  
The Other ◽  
Statistical Fluctuations ◽  
Maximum Value ◽  
Critical Opalescence ◽  
Phase Discontinuity ◽  
Two Phases ◽  
Smoluchowski Theory

The opalescence of ethylene has been investigated under various conditions in the region of the critical temperature. The opalescence of critical fillings increases as the temperature is lowered and passes through a maximum at the critical dispersion temperature Ts. When the system is heated the value depends upon the thermal history, both below and above Ts. Two types of time lag curve are observed in the irreversible region, one in which the opalescence passes through a minimum and then a maximum value, and the other through a minimum only. It is believed on the basis of previous qualitative studies that violent shaking would result in reversibility with respect to changes in temperature. Once the apparent phase discontinuity has disappeared the opalescence becomes reversible as long as condensation is prevented. The opalescence of critical fillings depends upon the density and appears to be a maximum when the two phases are present in equal volumes at Ts. Air and oleic acid present in small quantities depress Ts but do not appear to change the variation of opalescence with (T − Ts) when T > Ts. These observations appear to disagree with the classical Einstein–Smoluchowski theory based on light scattering resulting from statistical fluctuations in density. This theory predicts a maximum opalescence at the classical critical temperature, which in the case of ethylene is 0.7 °C. higher than Ts. If, however, the more recent views of the nature of the P − V isotherms near the critical point are taken into account, some of the conflict disappears.

Avrupa’ya Türk göçü: Almanya örneği

2014 ◽  
Vol 1 (1) ◽  
pp. 47-56
Author(s):  
Milan Palat
Keyword(s):  
Network Theory ◽  
Quantitative Methods ◽  
Positive Relationship ◽  
Time Lag ◽  
Theoretical Concept ◽  
Living Standards ◽  
The Other ◽  
The European Union ◽  
Effective Mechanism ◽  
The Eu

Bu çalışmanın amacı, Türkiye’den göç ve Almanya’nın ekonomik göstergeleri arasındaki ilişkiyi, nicel metot yöntemleri kullanarak değerlendirmektir. Türkiye’nin belirsiz Avrupa ile bütünleşme beklentilerine rağmen  Avrupa Birliğinin köklü üyelerine olan Türk göçü devam edecektir. Çok sayıda Türk azınlığın yaşadığı ve hayat standartlarının yüksek olduğu Almanya, Hollanda ve Fransa’ya  büyük bir göç dalgası gerçekleşebilir. Çalışmanın istatistiksel bölümünün sonuçları, toplam göç ile gayri safi yurtiçi hasıladaki büyüme arasında pozitif, toplam göç ile işsizlik arasındaki negatif ve tahmin edilen bağımlılık yönüyle uygunluk içerisinde olan toplam göç ile aylık gelir arasında pozitif ilişki olduğunu göstermektedir. Türkiye’den göçle işsizlik arasındaki ilişki, toplam göçle olan ilişkiden daha düşüktür. Ancak, Almanya’daki yabancı mevcudiyeti ile Türkiye’den göç arasında bir ilişki bulunmaktadır. Bu durum, var olan göçmen topluluğunun olduğu yerin, yeni göçmenleri, köken bağlarına dayanarak cezbetmesi ve maliyet- riskler sebebiyle göçün düşük seviye de olduğuna dayanan kuramsal Ağ teorisi görüşü ile uygunluk göstermektedir. Göç ve işsizlik arasında gözlenen ilişki, Almanya’ya göçün  işgücü piyasasında talepte meydana gelen değişime karşılık geldiği gerçeğini göstermektedir. İşsizlik ve göç olgularının meydana geliş zamanlarında bir aralık  olsa bile  göç, Alman emek pazarında var olan dengesizliklerin azaltılmasında nispeten etkili bir mekanizma gibi görünmektedir. ENGLISH TITLE & ABSTRACTTurkish Immigration to the European Union: The Case of GermanyThe objective of the paper was to evaluate the relationships between immigration from Turkey and economic indicators in Germany using  quantitative methods. Despite Turkey’s unclear European integration prospects, it is predicted that Turkish immigration to  established member countries of the EU will continue. The strongest waves may flow to Germany, Netherlands or France, where numerous Turkish minorities are already present and where the living standards are high. Results from the statistical analysis of the paper showed a positive correlation between immigration total and the growth of gross domestic product. On the other hand, a negative correlation of immigration total and unemployment was found and a positive relationship between immigration total and income total which is in agreement with the expected dependency direction. With regards to  immigration from Turkey it is less correlated to unemployment than immigration total. But there is a correlation between immigration from Turkey and the stock of foreigners in Germany This is in accordance with the theoretical concept of network theory where an existing community of migrants keeps attracting new migrants because the costs and risks associated with migration are lower, thanks to established linkages to the country of origin. The observed correlation of migration and unemployment points to the fact that immigration to Germany responds to changes in demand in the labour market. Even though a time lag may occur in the case of unemployment and immigration, migration appears to be a relatively effective mechanism to offset existing imbalances in German labour markets. 

Magnetocrystalline Anisotropy and Twinning Stress of 10M and 2M Martensites in Ni-Mn-Ga System

2006 ◽  
Vol 512 ◽  
pp. 195-200 ◽  
Author(s):  
Nariaki Okamoto ◽  
Takashi Fukuda ◽  
Tomoyuki Kakeshita ◽  
Tetsuya Takeuchi
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Magnetocrystalline Anisotropy ◽  
Anisotropy Constant ◽  
The Other ◽  
Magnetic Shear ◽  
Maximum Value ◽  
Twinning Plane ◽  
Twinning Shear ◽  
The Difference

Ni2MnGa alloy with 10M martensite exhibits rearrangement of martensite variants (RMV) by magnetic field, but Ni2.14Mn0.92Ga0.94 with 2M martensite does not. In order to explain the difference, we measured uniaxial magnetocrystalline anisotropy constant Ku and the stress required for twinning plane movement τreq in these alloys. Concerning the former alloy, the maximum value of magnetic shear stress acting across twinning plane τmag, which is evaluated as |Ku| divided by twinning shear, becomes larger than τr eq. On the other hand, concerning the latter alloy, the maximum of τmag is only one-tenth of τreq at any temperature examined. Obviously, the relation, τmag> τr eq, is satisfied when RMV occurs by magnetic field and vice versa. In this martensite, the large twinning shear of 2M martensite is responsible for small τmag and large τreq.

CHANGES IN THE COMPOSITION AND YIELD OF THE MAMMARY SECRETION OF COWS DURING THE INITIATION OF LACTATION

1973 ◽  
Vol 59 (2) ◽  
pp. 231-247 ◽  
Author(s):  
P. E. HARTMANN
Keyword(s):  
Mammary Gland ◽  
Late Pregnancy ◽  
The Other ◽  
Small Samples ◽  
Dry Period ◽  
Abrupt Increase ◽  
Milk Samples ◽  
Casein Protein ◽  
Two Phases

SUMMARY Mammary secretion (1·2–2·0 ml) was collected from the milk sinus of each mammary gland (quarter) of two pregnant heifers and eight pregnant cows (dry period 49–229 days), first at weekly intervals from 40 days before parturition, then with increasing frequency as parturition approached. The progressive changes in the concentration of lactose, glucose, casein, non-casein protein and fat in the mammary secretion were determined. Calves were separated from the cows immediately after birth and the yield and composition of milk from individual quarters were determined for 5 days after parturition. Two quarters (milked quarters) of each of a further five cows were milked throughout pregnancy, while the other two quarters (unmilked quarters) of each cow were allowed to involute (dry off) 63– 104 days before parturition. Small samples (5–10 ml) of secretion were collected from the unmilked quarters, first at weekly intervals after drying off and then every second day from 10 to 15 days before parturition. On the days that the unmilked quarters were sampled, corresponding composite milk samples were collected from the milked quarters and the progressive changes in the yield of milk, lactose and fat were determined. The changes in the concentration of lactose and glucose in the mammary secretion, during drying off in late lactation, were determined in an additional five cows. In most cows allowed a usual dry period, and in the unmilked quarters of cows in which two quarters were milked throughout pregnancy, the concentration of lactose gradually increased from about 8 to 12 days before parturition to reach levels of about half those found in normal milk just before parturition. However, in some cows the concentration of lactose was low until 1–2 days before parturition and then increased abruptly, whereas in others the concentration of lactose increased slowly from as early as 32 days before parturition. A further rapid increase in the concentration of lactose in the mammary secretion occurred between 0 and 4 days before parturition in all cows. This latter increase was accompanied by an abrupt increase in the yield of milk, lactose and fat in the milked quarters of the cows in which two quarters were milked throughout pregnancy. These observations suggest that the initiation of lactation in the cow develops in two phases, a limited secretion of milk constituents occurs in late pregnancy and then 0–4 days before parturition copious secretion (lactogenesis) occurs.

Resistive transition broadening in two-phase polycrystalline YBaCuO

1993 ◽  
Vol 8 (5) ◽  
pp. 957-961 ◽  
Author(s):  
J.C. Abele ◽  
R.L. Bristol ◽  
T.C. Nguyen ◽  
M.W. Ohmer ◽  
L.S. Wood
Keyword(s):  
Magnetic Fields ◽  
Computer Models ◽  
Structured Data ◽  
The Other ◽  
Critical Ratio ◽  
Resistive Transition ◽  
Two Phase ◽  
Two Phases

A model proposed by Tinkham1to explain the resistance versus temperature broadening found in highTcsuperconductors in applied magnetic fields is extended to “foot and knee”-structured data taken on polycrystalline YBa2Cu3O6+δ. The proposed extension involves a series combination of two types of superconductors. For this series combination to result, a critical ratio of the two types of superconductors must be met—a result common to both percolation and randomized cellular autonoma theory. This critical ratio is investigated via statistical computer models of a polycrystalline superconductor having two phases of crystallites—one with substantially lowerJcthan the other.

scholarly journals Logros de niños y niñas de educación inicial mediante el juego con bloques de Lego (Achievements of Early Childhood Education children through play with Lego blocks)

Retos ◽  
2020 ◽  
pp. 241-249
Author(s):  
Alix María Casadiego ◽  
Karina Avendaño Casadiego ◽  
Leidy Carolina Cuervo ◽  
Gabriel Avendaño Casadiego ◽  
Alvaro Avendaño Rodríguez
Keyword(s):  
Early Childhood ◽  
Early Childhood Education ◽  
Temporal Relationship ◽  
Free Play ◽  
The Other ◽  
Pedagogical Practices ◽  
Childhood Education ◽  
Didactic Engineering ◽  
Two Phases ◽  
Observation Code

 El juego, además de ser una de las experiencias que más disfrutan niños y niñas durante su etapa en educación inicial, les permite aprender y desarrollarse en forma integral. De acuerdo con ello, el presente estudio tiene como objetivo indagar en cuáles logros en relaciones espaciales, temporales y socioafectivas son más exitosos los niños y las niñas de educación inicial e identificar su evolución durante 10 semanas de observación. La metodología tuvo dos fases: inicialmente, mediante la ingeniería didáctica, se construyó un código de observación y una vez construido se realizaron las observaciones durante 10 semanas de trabajo. Las actividades fueron realizadas, durante las horas de juego libre, en las escuelas donde la Facultad de Educación de la Universidad Surcolombiana realiza sus prácticas pedagógicas. Los resultados mostraron que es en la actividad socio afectiva donde se obtienen mayores logros desde el comienzo de la experiencia; por otro lado, el principal logro se obtiene en la característica relación temporal, relacionada con la capacidad para anticiparse a los acontecimientos o predecir resultados, específicamente en la capacidad de organizar un plan para llevar a cabo una idea, que se logra en un 87%. Abstract. Playing, in addition to being one of the experiences that children enjoy the most during their stage of early childhood education, allows them to learn and develop in an integral way. In accordance with this, the present study aims to investigate which achievements in spatial, temporal and socio-affective relationships are more successful in early childhood education children and to identify their evolution during 10 weeks of observation. The methodology had two phases: initially, through didactic engineering, an observation code was constructed and once it was ready, observations were made during 10 weeks of work. The activities were carried out, during free play hours, in the schools where the Education Faculty of the Surcolombiana University carries out its pedagogical practices. The results showed that it is in the socio-affective activity where the greatest achievements are obtained from the beginning of the experience; on the other hand, the main achievement is obtained in the characteristic temporal relationship, related to the ability to anticipate events or predict results, specifically in the ability to organize a plan to carry out an idea, is achieved 87%.

scholarly journals Power Generation on a Bare Electrodynamic Tether during Debris Mitigation in Space

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Kan Xie ◽  
Fuwen Liang ◽  
Qimeng Xia ◽  
Ningfei Wang ◽  
Zun Zhang ◽  
...  
Keyword(s):  
Power Generation ◽  
Energy Conversion ◽  
Energy Conversion Efficiency ◽  
Stable Phase ◽  
Electrodynamic Tether ◽  
Maximum Value ◽  
Battery Design ◽  
Li Ion ◽  
Two Phases ◽  
Debris Mitigation

Power generation can be realized in space when current is induced on a bare electrodynamic tether system. The performance of power generation is discussed based on a debris mitigation mission by numerical simulation in the paper. A Li-ion battery subsystem is used to complete the energy conversion—harvest and supply the energy. The battery can provide 10–300 W average electric power continuously during several hundred hour mission time. The energy conversion efficiency ranges from 1% to a maximum value 30%. With constant power consumption on board, the battery operation generally experiences a discharging phase, a charging phase, and a stable phase. The first two phases determine the mission risk coefficient. The heating problem in the stable phase cannot be ignored. The optimization of battery design and tether design should be considered for each debris mitigation mission. An extra control circuit or small battery voltage with large capacity for battery design is suggested to eliminate the stable phase. Wide or long tether designs are more appropriate for mission with high or low power demands on board, respectively. The power generation is affected by the system mass and the mission orbit parameters.

scholarly journals Synthesis of 1,4-Dioxaspiro[4.4] and 1,4-Dioxaspiro[4.5] Novel Compounds from Oleic Acid as Potential Biolubricant

2017 ◽  
Vol 17 (2) ◽  
pp. 301
Author(s):  
Yehezkiel Steven Kurniawan ◽  
Yudha Ramanda ◽  
Kevin Thomas ◽  
Hendra Hendra ◽  
Tutik Dwi Wahyuningsih
Keyword(s):  
Oleic Acid ◽  
Viscous Liquid ◽  
Acid Number ◽  
The Other ◽  
Esterification Reaction ◽  
Base Number ◽  
Sonochemical Method ◽  
Total Acid ◽  
Hydroxylation Reaction ◽  
Total Base

Two 1,4-dioxaspiro novel compounds which derivated from methyl 9,10-dihydroxyoctadecanoate (MDHO) with cyclopentanone and cyclohexanone had been synthesized by a sonochemical method in the presence of montmorillonite KSF catalyst. The MDHO compound had been prepared from 9,10-dihydroxyoctadecanoic acid (DHOA) and methanol. Meanwhile, DHOA was synthesized by hydroxylation of oleic acid with the solution of 1% KMnO4 under basic condition. The structures of the products were confirmed by FTIR, GC-MS, 1H-NMR, and 13C-NMR spectrometers. Hydroxylation reaction of oleic acid gave DHOA as a white solid powder in 46.52% yield (m.p. 131-132 °C). On the other side, esterification reaction via sonochemical method between DHOA and methanol gave MDHO as a white powder in 93.80% yield (m.p. 80-81 °C). The use of cyclopentanone in 45 min sonochemical method gave methyl 8-(3-octyl-1,4-dioxaspiro[4.4]nonan-2-yl)octanoate as a yellow viscous liquid in 50.51% yield. The other compound, methyl 8-(3-octyl-1,4-dioxaspiro[4.5]decan-2-yl)octanoate as yellow viscous liquid had been synthesized by similar method with cyclohexanone via the sonochemical method in 45.12% yield. From physicochemical properties, i.e. density, total acid number, total base number, and iodine value, gave the conclusion that these novel compounds are potential biolubricant candidates to be developed.

scholarly journals A.C conductivity and dielectric properties of (PVA/ PEO) blends doped with MWCNTs

2019 ◽  
Vol 14 (30) ◽  
pp. 64-72
Author(s):  
Ahmad A. Hasan
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Properties ◽  
The Other ◽  
Poly Vinyl Alcohol ◽  
Conductivity Measurements ◽  
Frequency Range ◽  
Maximum Value ◽  
Multi Walled Carbon Nanotube ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

A.C electrical conductivity and dielectric properties for poly(vinyl alcohol) (PVA) /poly (ethylene oxide) (PEO) blends undopedand doped with multi-walled carbon nanotube (MWCNTs) withdifferent concentrations (1, and 3 wt %) in the frequency range(25x103 - 5x106 Hz) were investigated. Samples of (PVA/PEO)blends undoped and doped with MWCNTs were prepared usingcasting technique. The electrical conductivity measurements showedthat σA.C is frequency dependent and obey the relation σA.C =Aωs forundoped and doped blends with 1% MWCNTs, while it is frequencyindependent with increases of MWCNTs content to 3%. Theexponent s showed proceeding increase with the increase of PEOratio (≥50%) for undoped blends samples, while s value for dopedblends exhibits to change in different manner, i.e. s increases andreach maximum value at 50/50 PVA/PEO, then decreases forresidual doped blends samples with 1% MWCNTs on the other handthe exponent s decrease and reach minimum value at 50/50PVA/PEO for samples doped with 3% MWCNTs, then return toincrease. The results explained in different terms.

Effect of Cooling on Neuromuscular Transmission in the Frog

1958 ◽  
Vol 192 (3) ◽  
pp. 464-470 ◽  
Author(s):  
Choh-Luh Li ◽  
Peter Gouras
Keyword(s):  
Critical Temperature ◽  
Neuromuscular Junction ◽  
Nerve Stimulation ◽  
Neuromuscular Transmission ◽  
The Other ◽  
Sartorius Muscle ◽  
Single Muscle ◽  
Miniature Endplate Potentials ◽  
Endplate Potentials ◽  
Muscle Responses

Recording with intracellular electrodes from endplate regions of frogs sartorius muscle showed that at –1°C miniature endplate potentials still occurred and that the resting membrane potentials differed very little from those recorded at room temperatures. The miniature potentials, however, were decreased in frequency and increased in amplitude by cooling; and at about 5°C, the amplitude began to fall while the frequency continued to be low. It was also at about 5°C that the muscle responses to nerve stimulation frequently consisted of endplate potentials only. Upon rewarming spike potentials again appeared. These observations suggest that there is a critical temperature for neuromuscular transmission, below which impediment of impulse transmission began; and in the frog it is 5°C. The experiments also demonstrated that during the process of cooling a blockage of impulses at one neuromuscular junction and transmission across the other in a single muscle fiber could occur.

Response Time of Forested Mountainous Watersheds in Humid Regions

2000 ◽  
Vol 31 (3) ◽  
pp. 149-168 ◽  
Author(s):  
A. Loukas ◽  
N. R. Dalezios
Keyword(s):  
Field Experiments ◽  
Time Lag ◽  
Wave Theory ◽  
Roughness Coefficient ◽  
Stream Channel ◽  
Stream Channels ◽  
Mountainous Watersheds ◽  
Two Phases ◽  
Comparison Of The Results ◽  
Estimation Of Time

This study proposes an analytical method for the estimation of time lag for forested mountainous watersheds. The water flow in a watershed is separated and analyzed in two phases, the land or hillslope phase and the stream channel phase. In many areas around the globe the flow in a forested high gradient watershed is generated through subsurface pathways as several field experiments have shown. The kinematic wave theory is used to describe the generation of flow from steep forested hillslopes. This hillslope runoff is, then, used as input to the stream channels. The equations were developed by assuming kinematic conditions in the stream channel and that the stream slope and the roughness coefficient i) vary according to a second order polynomial with the distance from the mouth of the watershed, ii) vary linearly with the distance from the outlet of the watershed, and iii) are constant throughout the watershed. Comparison of the results of the proposed equation with data from two experimental watersheds in Coastal British Columbia indicates that the three expressions of the proposed equation, even the simplest one assuming constant stream slope and roughness coefficient, are reliable and give good approximation of the observed time lag.

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