Energy recovery behavior of low-frequency electric heating assisted depressurization in Class 1 hydrate deposits

Fuel ◽  
2022 ◽  
Vol 309 ◽  
pp. 122185
Author(s):  
Ermeng Zhao ◽  
Jian Hou ◽  
Yunkai Ji ◽  
Yongge Liu ◽  
Yajie Bai
Keyword(s):  
Energy Recovery ◽  
Low Frequency ◽  
Electric Heating ◽  
Recovery Behavior ◽  
Class 1

The Key Factors of Low-Frequency Electric Heating Assisted Depressurization Method in the Exploiting of Methane Hydrate Sediments

2021 ◽  
Author(s):  
Ermeng Zhao ◽  
Jian Hou ◽  
Yunkai Ji ◽  
Lu Liu ◽  
Yongge Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Low Frequency ◽  
Electric Heating ◽  
Gas Production ◽  
Hydrate Decomposition ◽  
Hydrate Saturation ◽  
Production Behavior

Abstract Natural gas hydrate is widely distributed in the permafrost and marine deposits, and is regarded as an energy resource with great potential. The low-frequency electric heating assisted depressurization (LF-EHAD) has been proven to be an efficient method for exploiting hydrate sediments, which involves complex multi-physics processes, i.e. current conduction, multiphase flow, chemical reaction and heat transfer. The physical properties vary greatly in different hydrate sediments, which may profoundly affect the hydrate decomposition in the LF-EHAD process. In order to evaluate the influence of hydrate-bearing sediment properties on the gas production behavior and energy utilization efficiency of the LF-EHAD method, a geological model was first established based on the data of hydrate sediments in the Shenhu Area. Then, the influence of permeability, porosity, thermal conductivity, specific heat capacity, hydrate saturation and hydrate-bearing layer (HBL) thickness on gas production behavior is comprehensively analyzed by numerical simulation method. Finally, the energy efficiency ratio under different sediment properties is compared. Results indicate that higher gas production is obtained in the high-permeability hydrate sediments during depressurization. However, after the electric heating is implemented, the gas production first increases and then tends to be insensitive as the permeability decreases. With the increasing of porosity, the gas production during depressurization decreases due to the low effective permeability; while in the electric heating stage, this effect is reversed. High thermal conductivity is beneficial to enhance the heat conduction, thus promoting the hydrate decomposition. During depressurization, the gas production is enhanced with the increase of specific heat capacity. However, more heat is consumed to increase the reservoir temperature during electric heating, thereby reducing the gas production. High hydrate saturation is not conducive to depressurization because of the low effective permeability. After electric heating, the gas production increases significantly. High HBL thickness results in a higher gas production during depressurization, while in the electric heating stage, the gas production first increases and then remains unchanged with the increase of thickness, due to the limited heat supply. The comparison results of energy efficiency suggest that electric heating is more advantageous for hydrate sediments with low permeability, high porosity, high thermal conductivity, low specific heat capacity, high hydrate saturation and high HBL thickness. The findings in this work can provide a useful reference for evaluating the application of the LF-EHAD method in gas hydrate sediments.

The polymorphism linked to the human insulin gene: its lack of association with either IDDM or NIDDM in Japanese

1986 ◽  
Vol 113 (2) ◽  
pp. 268-271 ◽  
Author(s):  
Jun Takeda ◽  
Yutaka Seino ◽  
Hirofumi Fukumoto ◽  
Gyohan Koh ◽  
Akio Otsuka ◽  
...  
Keyword(s):  
Human Insulin ◽  
Low Frequency ◽  
Restriction Endonuclease Analysis ◽  
Insulin Gene ◽  
Genotypic Frequency ◽  
Very High Frequency ◽  
Base Pairs ◽  
Human Insulin Gene ◽  
Class 1 ◽  
Endonuclease Analysis

Abstract. Polymorphism of 5' portion of the human insulin gene was examined in 188 unrelated Japanese subjects (49 normal, 71 with IDDM, and 68 with NIDDM) using restriction endonuclease analysis. Restriction fragments were classified according to the insertion size: Class 1 (600 base pairs), Class 2 (1300 base pairs), and Class 3 (2000 base pairs). We found a very high frequency of Class 1 alleles (96.8%) and a low frequency of both Class 2 (0.8%) and Class 3 alleles (2.4%) and that approximately 94% of the genotypes were Class 1/Class 1 homozygote. In addition, there was no correlation of allelic or genotypic frequency with NIDDM or IDDM. We conclude that length polymorphism of the human insulin gene cannot be a useful marker for diabetes in Japanese.

scholarly journals Cluster Analysis of Residential Personal Exposure to ELF Magnetic Field in Children: Effect of Environmental Variables

2019 ◽  
Vol 16 (22) ◽  
pp. 4363 ◽  
Author(s):  
Gabriella Tognola ◽  
Emma Chiaramello ◽  
Marta Bonato ◽  
Isabelle Magne ◽  
Martine Souques ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cluster Analysis ◽  
Harmonic Component ◽  
Low Frequency ◽  
Electric Heating ◽  
Personal Exposure ◽  
Electric Networks ◽  
Field Exposure ◽  
Indoor Exposure ◽  
Exposure Patterns

Personal exposure to Extremely Low Frequency Magnetic Fields (ELF MF) in children is a very timely topic. We applied cluster analysis to 24 h indoor personal exposures of 884 children in France to identify possible common patterns of exposures. We investigated how electric networks near child home and other variables potentially affecting residential exposure, such as indoor sources of ELF MF, the age and type of the residence and family size, characterized the magnetic field exposure patterns. We identified three indoor personal exposure patterns: children living near overhead lines of high (63–150 kV), extra-high (225 kV) and ultra-high voltage (400 kV) were characterized by the highest exposures; children living near underground networks of low (400 V) and mid voltage (20 kV) and substations (20 kV/400 V) were characterized by mid exposures; children living far from electric networks had the lowest level of exposure. The harmonic component was not relevant in discriminating the exposure patterns, unlike the 50 Hz or broadband (40–800 Hz) component. Children using electric heating appliances, or living in big buildings or in larger families had generally a higher level of personal indoor exposure. Instead, the age of the residence was not relevant in differentiating the exposure patterns.

scholarly journals Model involving gene inactivation in the generation of autosomal recessive mutants in mammalian cells in culture.

1982 ◽  
Vol 2 (9) ◽  
pp. 1126-1133 ◽  
Author(s):  
A E Simon ◽  
M W Taylor ◽  
W E Bradley ◽  
L H Thompson
Keyword(s):  
Chinese Hamster Ovary ◽  
High Frequency ◽  
Mammalian Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Low Frequency ◽  
Two Dimensional ◽  
Wild Type ◽  
Proposed Model ◽  
Class 1

We present evidence for a two-step model for expression of the recessive phenotype at the diploid adenine phosphoribosyl transferase (aprt) locus in Chinese hamster ovary cells. This model proposes a high-frequency event leading to allelic inactivation and a low-frequency event leading to a structural alteration of the APRT protein. Either event can occur first, resulting in two types of heterozygous cells. The proposed model is based on analysis of Chinese hamster ovary presumptive aprt heterozygotes and APRT- mutants, derived by two different laboratories. The major class of heterozygotes (class 1) had approximately 50% parental APRT activity, 50% immunologically precipitable APRT protein, and only wild-type enzyme as based on two-dimensional gel electrophoresis and thermal inactivation studies. We propose that one allele at the aprt locus has been inactivated in these heterozygotes. APRT- mutants derived from any single class 1 heterozygote arose at a low frequency and contained either no immunologically detectable APRT protein or an APRT enzyme which was, in most cases, demonstrably altered. The second class of heterozygotes, consisting of two independent isolates, gave rise to APRT- cells at a high frequency (10(-3) to 10(-5). These heterozygous cell lines had 50% of parental APRT activity and only wild-type spot, or wild-type and an electrophoretic variant spot, on two-dimensional gels. These aprt heterozygotes appear to have arisen by mutation at one allele. APRT- mutants derived from either heterozygote of this class had all lost the wild-type activity, consistent with the proposed model.

scholarly journals Quinolone resistant Salmonella species isolated from pediatric patients with diarrhea in central Iran

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elnaz Abbasi ◽  
Ehsanollah Ghaznavi-Rad
Keyword(s):  
Antibiotic Resistance ◽  
Pediatric Patients ◽  
Low Frequency ◽  
Central Iran ◽  
Empiric Antibiotic Therapy ◽  
Infectious Diarrhea ◽  
Culture Methods ◽  
Class 1 ◽  
Empiric Antibiotic ◽  
Resistance Patterns

Abstract Background This study aimed to investigate the frequency and the antibiotic resistance patterns of Salmonella species that were isolated from infectious diarrhea samples taken from pediatric patients in central Iran. Methods The study analyzed 230 stool specimens that were cultured on XLD, MacConkey agar and GN broth. Polymerase chain reaction (PCR) assay was used to identify the Salmonella genus. The antibiotic resistance profiles and the frequency of quinolone and integron genes were obtained. Results Out of 230 samples of infectious diarrhea, 21 (9.1%) cases of Salmonella spp. were identified using culture methods. Another 28 (12.1%) samples had positive PCR results, with S. serovar Paratyphi B and C (9/21; 42.8%) and S. Typhi (3/21; 14.3%) being the most recognized. The highest antibiotic resistance rates were found for nalidixic acid (15/21; 71.4%), tetracycline (9/21; 42.8%). However, six (28.5%) of isolates were found resistant to cotrimoxazole, ampicillin and chloramphenicol. Among the plasmid-mediated quinolone resistance (PMQR) determinants, qnrS, qnrA, and qnrB were positive in (9/15; 60%), (6/15; 40%) and (3/15; 20%) of the isolates, respectively. Class 1 and 2 integrons were identified in 15 (71.4%) and 3 (14.3%) isolates, respectively. Conclusion High rates of quinolone resistant and low frequency of MDR Salmonella spp. isolates were identified in central Iran, similar to findings in other parts of Asia. To prevent the spread of these resistant strains, the antimicrobial resistance of Salmonella spp. isolates should be under constant surveillance, and empiric antibiotic therapy should be adapted appropriately.

scholarly journals The effect of nitroglycerin on cardiac extrasystoles and heart rate variability in patients with ­stable angina pectoris class 1 and 2

2020 ◽  
Vol 101 (5) ◽  
pp. 645-651
Author(s):  
E A Safronova ◽  
A I Kuzin ◽  
U V Kharlamova ◽  
T N Shamaeva ◽  
L V Ryabova
Keyword(s):  
Heart Rate ◽  
Angina Pectoris ◽  
Stable Angina ◽  
Low Frequency ◽  
Exercise Stress ◽  
Stress Tests ◽  
Stable Angina Pectoris ◽  
Ventricular Extrasystoles ◽  
Class 1 ◽  
Low Frequency Waves

Aim. To study the effect of nitroglycerin on the heart rate and its variability in patients with stable angina pectoris class 1 and 2. Methods. 85 men with stable angina pectoris class 1 and 2 pathologies were examined between 2007 and 2012 in the City Clinical Hospital No. 8 of Chelyabinsk (mean age 53.15.66 years). In addition to common methods, a rhythmocardiographic study was performed, which allows you to calculate heart rate variability. An electrocardiogram was recorded simultaneously with the rhythmocardiogram. Results. After sublingual nitroglycerin, the number of ventricular extrasystoles decreased in the background test and during Valsalva maneuver, increased in the Ashner's test and an exercise stress tests and did not change in the orthostatic test. An increase in supraventricular extrasystoles after nitroglycerin administration occurred in 10.6% of patients. Nitroglycerin administration resulted in a decrease in the inter-systolic intervals, an increased in the proportion of slow low-frequency waves statistically significant in the background and an exercise stress test. Spectral indicators of cardiac sympathetic modulation significantly increased in the Ashners test and decreased in the background test, while spectral indicators of cardiac parasympathetic modulation decreased in all samples except in exercise stress tests. Conclusion. Under the influence of nitroglycerin, supraventricular arrhythmias increased in all vegetative tests except for orthostatic, the number/severity of ventricular extrasystoles ambiguously changed: decreased in Valsalva manoeuvre the background test, did not change in orthostatic and increased in Aschner's and an exercise stress tests; after nitroglycerin, the proportions of sympathetic influence (in Ashner's test) and slow low-frequency waves in the spectrum of the vegetative modulation increased with a decrease in parasympathetic.

Mechanism of mutation at the aprt locus in Chinese hamster ovary cells: analysis of heterozygotes and hemizygotes

1983 ◽  
Vol 3 (10) ◽  
pp. 1703-1710
Author(s):  
A E Simon ◽  
M W Taylor ◽  
W E Bradley
Keyword(s):  
Point Mutation ◽  
High Frequency ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Low Frequency ◽  
Gene Products ◽  
Wild Type ◽  
Gene Copies ◽  
Aprt Gene ◽  
Class 1

A two-step model to explain the high frequency of mutation at the diploid adenine phosphoribosyltransferase (aprt) locus in CHO cells has been proposed previously (Simon et al., Mol. Cell. Biol. 2:1126-1133, 1982). This model indicates that two distinct classes of aprt heterozygotes can be isolated. Class 1 heterozygotes, the most abundant class, were defined as those which arose spontaneously and were capable of undergoing mutation to the APRT- phenotype only at a low frequency (putative point mutation). Class 2 heterozygotes arose from a mutation and gave rise at a high frequency to APRT- cells. This high-frequency event has been identified as a deletion of the wild-type allele (A. E. Simon and M. W. Taylor, Proc. Natl. Acad. Sci. U.S.A. 80:810-814, 1983). In this paper we report further analysis of class 1 heterozygotes with respect to genetic structure, gene products, and karyotype. Our study indicated that class 1 heterozygotes contain two different types of mutants. About half have only one copy of the aprt gene and an unaltered karyotype, indicating that a deletion (similar to the high-frequency second-step event observed for class 2 heterozygotes) rather than a loss of the chromosome was responsible for the generation of the aprt+/- genotype. The remainder of the previously designated class 1 heterozygotes still contained two copies of the aprt gene (within the limits of the quantitation technique used) and arose presumably by a point mutation. One of this group, D423, was characterized with respect to aprt gene products and found to produce an electrophoretic variant in addition to the wild-type protein. APRT- mutants derived from D423 retained the same number of aprt gene copies as D423 and still synthesized a protein that comigrated with wild type, unlike APRT- mutants derived from class 2 heterozygotes. D423 and the other heterozygotes with two aprt genes therefore did not fit into either class 1 or 2 and are now designated class 3. The model we present suggests that only one of the two aprt alleles present in wild-type cells can undergo the deletion.

scholarly journals Different Characteristics and Heritabilities of Alcohol Use Disorder Classes: A Population-Based Swedish Study

2019 ◽  
Vol 54 (6) ◽  
pp. 647-655
Author(s):  
E C Long ◽  
H Ohlsson ◽  
J Sundquist ◽  
K Sundquist ◽  
K S Kendler
Keyword(s):  
Alcohol Use ◽  
Criminal Behavior ◽  
Alcohol Use Disorder ◽  
Latent Class ◽  
Environmental Influence ◽  
Low Frequency ◽  
Population Based ◽  
Outpatient Prescription ◽  
Class 1 ◽  
Swedish Sample

Abstract Aims The aims of the present study are to identify alcohol use disorder (AUD) classes among a population-based Swedish sample, determine if these classes differ by variables known to be associated with AUD and determine whether some AUD classes have stronger genetic influences than others. Methods A latent class analysis (LCA), based on types of registrations, was conducted on Swedish individuals with an AUD registration born between 1960 and 1990 (N = 184,770). These classes were then validated using demographics; patterns of comorbidity with drug abuse, psychiatric disorders and criminal behavior; and neighborhood-level factors, i.e. peer AUD and neighborhood deprivation. The degree of genetic and environmental influence was also investigated. Results The best-fit LCA had four classes: (a) outpatient/prescription, characterized by a mix of outpatient medical and prescription registrations, (b) low-frequency inpatient, characterized entirely by inpatient medical registrations, with the majority of individuals having one AUD registration, (c) high-frequency mixed, characterized by a mix of all four registration types, with the majority having four or more registrations and (d) crime, characterized almost entirely by criminal registrations. The highest heritability for both males and females was found for Class 3 (61% and 65%, respectively) and the lowest for Class 1 (20% for both), with shared environmental influences accounting for 10% or less of the variance in all Classes. Conclusions Using comprehensive, nationwide registry data, we showed evidence for four distinct, meaningful classes of AUD with varying degrees of heritability.

Sign in / Sign up

Export Citation Format

Share Document