scholarly journals Integrity Analysis of the Sheath Considering Temperature Effect under Deep and Large-Scale Multi-Section Hydraulic Fracturing

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7162
Author(s):  
Xiaoyu Zhang ◽  
Lei Wang ◽  
Chunhe Yang ◽  
Xin Chang ◽  
Yintong Guo ◽  
...  
Keyword(s):  
Temperature Stress ◽  
Large Scale ◽  
Friction Angle ◽  
Negative Influence ◽  
Effect Of Temperature ◽  
Shakedown Theory ◽  
Different Temperatures ◽  
Negative Effect ◽  
Integrity Analysis ◽  
Well Cement

Different operations make the borehole temperature change and cause periodic stresses, which often cause variations in the stress state of the sheath or damage. In this paper, the effect of temperature on sheath integrity is investigated. First, the mechanical model of sheath is established and analyzed by shakedown theory. Then, compression experiments of well cement at different temperatures are carried out, and the law of mechanical properties with temperature is obtained. Finally, combining the theoretical analysis and mechanical experiments, the results show that (1) when only the temperature inside the sheath cyclically varies, the negative influence of temperature caused by the practical operations can be negligible. (2) When the internal pressure and temperature act together, the effect of temperature on the sheath is reflected in temperature stress and the change of the cement properties. (3) With the increase of temperature difference (∆T), the cohesion of cement decreases while the internal friction angle increases, and the plasticity characteristics of the cement are enhanced, and the negative effect on the Pmax ascends slowly. (4) The temperature stress is in a positive relationship with the ∆T, and its weakening on the Pmax is about 6% to 7%. (5) Combining the temperature stress and the change of the cement properties, total negative effect of temperature on the sheath accounts for 10% to 12%, when ∆T ranges from 60 to 110 °C.

scholarly journals Climate, nitrogen and grass. 7. Comparison of production and chemical composition of Brachiaria ruziziensis and Setaria sphacelata grown at different temperatures.

1976 ◽  
Vol 24 (1) ◽  
pp. 67-78 ◽  
Author(s):  
B. Deinum ◽  
J.G.P. Dirven
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Protein Content ◽  
Plant Development ◽  
Effect Of Temperature ◽  
Brachiaria Ruziziensis ◽  
Setaria Sphacelata ◽  
Lower Protein ◽  
Different Temperatures ◽  
Negative Effect

7. In order to test the validity of previous results, a trial was performed in greenhouses on the effect of temperature, age and N level on production, morphological and chemical composition of Brachiaria ruziziensis Germain & Evrard and Setaria sphacelata (Schum) Stapf & Hubbard. The 2 grasses were equally productive, but Setaria had a lower optimum temperature. Brachiaria was leafier than Setaria and had higher contents of nitrate and protein; it was also more digestible. It had higher contents of cations, inorganic anions and organic acids, but its oxalate content was lower both in leaves and in stems. Leaves of Brachiaria were much richer in nitrate than those of Setaria at the same protein content. At a greater age, both grasses had higher yields that originated from a greater number of heavier tillers. Plants were less leafy; nitrate and protein contents, and digestibility of organic matter were lower, but percentage of cell-wall constituents was higher. Increase of temperature stimulated plant development in both grasses, causing lower protein content and lower digestibility of organic matter in leaves and stems. Temperature also had a direct negative effect on stem digestibility apart from its effect on stem development. N application increased production, nitrate and protein content in both grasses, but had hardly any effect on plant development and digestibility. Consequently, Setaria reacted to environmental conditions like the other tropical grasses studied in this and previous trials, so confirming the conclusions. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Comparative Study on the Thermal Performance of Three Aedes aegypti (Diptera: Culicidae) Populations From Argentina

2021 ◽  
Author(s):  
María Sol De Majo ◽  
Gabriela Zanotti ◽  
Javier O Gimenez ◽  
Raúl E Campos ◽  
Sylvia Fischer
Keyword(s):  
Aedes Aegypti ◽  
Development Time ◽  
Buenos Aires ◽  
Wing Length ◽  
Thermal Conditions ◽  
Effect Of Temperature ◽  
Survival And Development ◽  
Different Temperatures ◽  
Negative Effect ◽  
Stage Development

Abstract The distribution of Aedes aegypti (L.) (Diptera: Culicidae) is expanding towards colder regions, which could be aided by an adaptation of the immature stages to the local thermal conditions. This study aimed to assess the developmental success at different temperatures in three populations of Ae. aegypti located across a climate gradient in Argentina. Survival to the adult stage, development time, and wing length at 14, 18.5 and 24°C were compared among three populations of Argentina: Resistencia in the subtropical region, and Buenos Aires and San Bernardo in the temperate region. Survival was similar between populations and equal to or higher than 69%, and increased at higher temperatures within the studied range. Development times were similar between populations. A negative effect of temperature was observed and the reduction of development time at increasing temperatures was stronger for males than for females. Wing lengths were negatively affected by increasing temperatures, and the reduction of wing length was stronger for females than for males. Also, the reduction of wing lengths with temperature was stronger for San Bernardo and Resistencia than for Buenos Aires, and differences between sexes were larger for Resistencia than for Buenos Aires or San Bernardo. Although the results do not evidence differences in survival and development time between temperate and tropical populations, the three populations have a higher tolerance to low temperatures than the populations from other regions.

Effect of temperature on behaviour of red clay–structure interface

2019 ◽  
Vol 56 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Chunhong Li ◽  
Gangqiang Kong ◽  
Hanlong Liu ◽  
Hossam Abuel-Naga
Keyword(s):  
Temperature Effect ◽  
Conceptual Understanding ◽  
Friction Angle ◽  
Effect Of Temperature ◽  
Experimental Program ◽  
Test Results ◽  
Shear Strength Parameters ◽  
Red Clay ◽  
Strain Behaviour ◽  
Different Temperatures

This study presents the results of an experimental investigation conducted to assess the temperature effects on shear stress–strain behaviour and shear strength parameters of red clay and its interface with the geostructure under different normal stresses (50, 100, 200, and 400 kPa). A modified direct shear test apparatus, capable of handling temperatures up to 50 °C, was used in this study. The experimental program includes shearing the red clay and red clay–structure interface at different temperatures (2, 15, 38 °C) and after subjecting it to different heating–cooling cycles. The test results in this study and the previous studies in the literature indicated that the temperature has insignificant effects on the friction angle of clay and clay–structure interface. However, the temperature effect on the cohesion of clay and the adhesion between the clay and structure depends on the normal stress level and history. A new conceptual understanding for the possible temperature effect on the clay–structure interface was introduced in this study and it was used to interpret the different interface test results in the literature.

scholarly journals Children’s Internet Use, Self-Reported Life Satisfaction, and Parental Mediation in Europe: An Analysis of the EU Kids Online Dataset

2022 ◽  
Vol 12 ◽  
Author(s):  
Tijana Milosevic ◽  
Seffetullah Kuldas ◽  
Aikaterini Sargioti ◽  
Derek A. Laffan ◽  
James O’Higgins Norman
Keyword(s):  
Life Satisfaction ◽  
Family Environment ◽  
Large Scale ◽  
Economic Status ◽  
Emotional Problems ◽  
Negative Influence ◽  
Parental Mediation ◽  
Cross Sectional ◽  
Positive Effects ◽  
Negative Effect

The present research examines how children’s time spent online is associated with their perceived life satisfaction accounting for their age, gender, socio-economic status (SES), emotional problems, country, and family environmental factors. This article is based on the data of the large scale cross-sectional EU Kids Online survey from 16 European countries with nationally representative samples of children aged 9–17 (N = 11,200, Mage = 13.3, SD = 2.36; 50.6% boys, 49.4% girls). The results indicated that the time children spent online appeared to have no considerable negative effect on their self-reported life satisfaction (SRLS). Comparatively, the positive effects of children’s SES and family environment accounted for 43% of the overall 50% of the variance in children’s SRLS scores. Considering that children’s SES alone accounted for 42% of the variance, children’s emotional problems, country of residence, and enabling parental mediation accounted for the remaining 3, 4, and 1% of the variance, respectively. In line with previous studies that urge caution when discussing the negative influence of time spent online on children’s mental health and overall wellbeing, the current findings suggest that social-ecological characteristics and how children use the Internet, need to be examined further.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

scholarly journals Effect of temperature, CO2 and O2 on motility and mobility of Anisakidae larvae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aiyan Guan ◽  
Inge Van Damme ◽  
Frank Devlieghere ◽  
Sarah Gabriël
Keyword(s):  
Enzymatic Digestion ◽  
Infected Fish ◽  
Effect Of Temperature ◽  
Video Recordings ◽  
Different Temperatures ◽  
Semi Solid ◽  
Zoonotic Parasites ◽  
The Impact ◽  
Phosphate Buffered Saline

AbstractAnisakidae, marine nematodes, are underrecognized fish-borne zoonotic parasites. Studies on factors that could trigger parasites to actively migrate out of the fish are very limited. The objective of this study was to assess the impact of different environmental conditions (temperature, CO2 and O2) on larval motility (in situ movement) and mobility (migration) in vitro. Larvae were collected by candling or enzymatic digestion from infected fish, identified morphologically and confirmed molecularly. Individual larvae were transferred to a semi-solid Phosphate Buffered Saline agar, and subjected to different temperatures (6 ℃, 12 ℃, 22 ℃, 37 ℃) at air conditions. Moreover, different combinations of CO2 and O2 with N2 as filler were tested, at both 6 °C and 12 °C. Video recordings of larvae were translated into scores for larval motility and mobility. Results showed that temperature had significant influence on larval movements, with the highest motility and mobility observed at 22 ℃ for Anisakis spp. larvae and 37 ℃ for Pseudoterranova spp. larvae. During the first 10 min, the median migration of Anisakis spp. larvae was 10 cm at 22 ℃, and the median migration of Pseudoterranova spp. larvae was 3 cm at 37 ℃. Larval mobility was not significantly different under the different CO2 or O2 conditions at 6 °C and 12 ℃. It was concluded that temperature significantly facilitated larval movement with the optimum temperature being different for Anisakis spp. and Pseudoterranova spp., while CO2 and O2 did not on the short term. This should be further validated in parasite-infected/spiked fish fillets.

scholarly journals Effect of Temperature during Drying and Storage of Dried Figs on Growth, Gene Expression and Aflatoxin Production

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 134
Author(s):  
Ana Isabel Galván ◽  
Alicia Rodríguez ◽  
Alberto Martín ◽  
Manuel Joaquín Serradilla ◽  
Ana Martínez-Dorado ◽  
...  
Keyword(s):  
Gene Expression ◽  
Aflatoxin Production ◽  
Effect Of Temperature ◽  
Mycotoxin Production ◽  
Industrial Processing ◽  
Factors Associated ◽  
Different Temperatures ◽  
Major Producer ◽  
Main Factors ◽  
And Storage

Dried fig is susceptible to infection by Aspergillus flavus, the major producer of the carcinogenic mycotoxins. This fruit may be contaminated by the fungus throughout the entire chain production, especially during natural sun-drying, post-harvest, industrial processing, storage, and fruit retailing. Correct management of such critical stages is necessary to prevent mould growth and mycotoxin accumulation, with temperature being one of the main factors associated with these problems. The effect of different temperatures (5, 16, 25, 30, and 37 °C) related to dried-fig processing on growth, one of the regulatory genes of aflatoxin pathway (aflR) and mycotoxin production by A. flavus, was assessed. Firstly, growth and aflatoxin production of 11 A. flavus strains were checked before selecting two strains (M30 and M144) for in-depth studies. Findings showed that there were enormous differences in aflatoxin amounts and related-gene expression between the two selected strains. Based on the results, mild temperatures, and changes in temperature during drying and storage of dried figs should be avoided. Drying should be conducted at temperatures >30 °C and close to 37 °C, while industry processing, storage, and retailing of dried figs are advisable to perform at refrigeration temperatures (<10 °C) to avoid mycotoxin production.

scholarly journals Influence of the Upstream Terrain on the Formation of a Cold Frontal Snowband in Northeast China

2021 ◽  
Author(s):  
Na Li ◽  
Baofeng Jiao ◽  
Lingkun Ran ◽  
Zongting Gao ◽  
Shouting Gao
Keyword(s):  
Gravity Waves ◽  
Northeast China ◽  
Large Scale ◽  
Control Experiment ◽  
Vertical Motion ◽  
Near Surface ◽  
Inertial Instability ◽  
Two Factors ◽  
Negative Effect ◽  
Conditional Instability

AbstractWe investigated the influence of upstream terrain on the formation of a cold frontal snowband in Northeast China. We conducted numerical sensitivity experiments that gradually removed the upstream terrain and compared the results with a control experiment. Our results indicate a clear negative effect of upstream terrain on the formation of snowbands, especially over large-scale terrain. By thoroughly examining the ingredients necessary for snowfall (instability, lifting and moisture), we found that the release of mid-level conditional instability, followed by the release of low-level or near surface instabilities (inertial instability, conditional instability or conditional symmetrical instability), contributed to formation of the snowband in both experiments. The lifting required for the release of these instabilities was mainly a result of frontogenetic forcing and upper gravity waves. However, the snowband in the control experiment developed later and was weaker than that in the experiment without upstream terrain. Two factors contributed to this negative topographic effect: (1) the mountain gravity waves over the upstream terrain, which perturbed the frontogenetic circulation by rapidly changing the vertical motion and therefore did not favor the release of instabilities in the absence of persistent ascending motion; and (2) the decrease in the supply of moisture as a result of blocking of the upstream terrain, which changed both the moisture and instability structures leeward of the mountains. A conceptual model is presented that shows the effects of the instabilities and lifting on the development of cold frontal snowbands in downstream mountains.

The Effect of Deformation on Mechanical Properties and Shakedown on Railroad Wheels

2014 ◽  
Author(s):  
Steven L. Dedmon ◽  
Takashi Fujimura ◽  
Daniel Stone
Keyword(s):  
Mechanical Properties ◽  
Rolling Contact ◽  
Effect Of Temperature ◽  
Plastic Deformations ◽  
Rail Head ◽  
Class D ◽  
Shakedown Theory ◽  
Freight Car ◽  
Class C ◽  
Railroad Wheels

Plastic deformations alter the mechanical properties of many metals and alloys. Class C and Class D wheel steels such as are used in North American freight car service are particularly affected by plastic deformations occurring during rolling contact between the wheel tread and rail head. This investigation determines the effect plastic deformations have on the mechanical properties of Class C and D wheel steels and how those changes could relate to shakedown theory. The effect of temperature is also discussed.

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