scholarly journals Diffusion Mechanisms for the Occurrence of the Instability of Mechanical Equilibrium of a Ternary Gas Mixture Containing Carbon Dioxide

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 177
Author(s):  
Vladimir Kossov ◽  
Olga Fedorenko ◽  
Adilet Kalimov ◽  
Aiym Zhussanbayeva
Keyword(s):  
Carbon Dioxide ◽  
Gas Mixture ◽  
Mechanical Equilibrium ◽  
Significant Difference ◽  
Pressure Area ◽  
Multicomponent Gas ◽  
Diffusion Mechanisms ◽  
The Difference ◽  
Diffusion Convection ◽  
Kinetic Features

Mixing of carbon dioxide dissolved in a multicomponent gas mixture at different pressures was researched. It was found that the mechanical equilibrium of the ternary gas mixture 0.4163H2 (1) + 0.5837CO2 (2) − N2 (3) is violated at a pressure of p = 0.7 MPa and structured flows appear in the system. The pressure area (from 0.7 to 1.5 MPa) at which the conditions of priority transfer of components with the highest molecular weight in the mixture are realised in the system is fixed. To analyse the effect of pressure on the process of changing “diffusion–convection” modes, a mathematical model, which takes into account the kinetic features of multicomponent mixing, was applied. It was shown that the change in the modes of mass transfer is associated with a significant difference in the diffusion ability of the components. It is noted that the difference in the diffusion coefficients of components results in the nonlinearity of the concentration distribution, which leads to the inversion of the density gradient of the gas mixture, which is the cause of convective flows.

scholarly journals Molecular Simulations of CO2/CH4, CO2/N2 and N2/CH4 Binary Mixed Hydrates

2021 ◽  
Vol 83 (3) ◽  
pp. 372-378
Author(s):  
A. A. Sizova ◽  
S. A. Grintsevich ◽  
M. A. Kochurin ◽  
V. V. Sizov ◽  
E. N. Brodskaya
Keyword(s):  
Carbon Dioxide ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Gas Hydrates ◽  
Molecular Simulations ◽  
Gas Mixtures ◽  
Gas Mixture ◽  
Grand Canonical Monte Carlo ◽  
Multicomponent Gas ◽  
Grand Canonical

Abstract Grand canonical Monte Carlo simulations were performed to study the occupancy of structure I multicomponent gas hydrates by CO2/CH4, CO2/N2, and N2/CH4 binary gas mixtures with various compositions at a temperature of 270 K and pressures up to 70 atm. The presence of nitrogen in the gas mixture allows for an increase of both the hydrate framework selectivity to CO2 and the amount of carbon dioxide encapsulated in hydrate cages, as compared to the CO2/CH4 hydrate. Despite the selectivity to CH4 molecules demonstrated by N2/CH4 hydrate, nitrogen can compete with methane if the gas mixture contains at least 70% of N2.

scholarly journals Changes in arterial partial pressure and end-expired pressure of carbon dioxide in prepubescent and adult bitches undergoing ovariohysterectomy by videolaparoscopy or conventional laparotomy

2018 ◽  
Vol 48 (10) ◽  
Author(s):  
Luciana Branquinho Queiroga ◽  
Gabriela Marques Sessegolo ◽  
Fabiane Reginatto dos Santos ◽  
Letícia Mendes Fratini ◽  
Verônica Santos Mombach ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Partial Pressure ◽  
Postoperative Period ◽  
Base Excess ◽  
Mild Hypertension ◽  
Peak Inspiratory Pressure ◽  
Arterial Partial Pressure ◽  
Significant Difference ◽  
The Difference ◽  
Age Range

ABSTRACT: This paper aimed to determine arterial partial pressure of carbon dioxide (PaCO2), end-expired CO2 pressure (ETCO2), and the difference between arterial and end-expired CO2 pressure (Pa - ETCO2) in prepubescent and adult bitches undergoing videolaparoscopic or conventional ovariohyterectomy (OH). Forty bitches were randomly assigned to four groups: Conventional Adult (CA), Conventional Pediatric (CP), Videolaparoscopic Adult (VA) and Videolaparoscopic Pediatric (VP). Pulse rate (PR), respiratory rate (RR), systolic, mean, and diastolic arterial pressures (SAP, MAP, DAP), ETCO2, peak inspiratory pressure (PIP), pH, arterial partial pressure of oxygen (PaO2), PaCO2, base excess (BE) and HCO3 - were measured. Based on the PaCO2 and ETCO2 values, Pa-ETCO2 was determined. There was no significant difference in PaCO2 between the VA (42.5±5.2 to 53.7±5.2) and VP (48.4±5.4 to55.4±5.7) groups. During the postoperative period, all groups presented with hypertension. However, mild hypertension (SAP 150 to 159mmHg) was observed in the VP group as compared to severe hypertension (SAP>180mmHg) in the CA group, suggesting that both the age range and videolaparoscopic OH are associated with lower levels of hypertension during the postoperative period in dogs.

COMPARISON OF PHOTOSYNTHESIS IN NORMAL AND TRIAZINE-RESISTANT Brassica

1987 ◽  
Vol 67 (2) ◽  
pp. 457-466 ◽  
Author(s):  
S. L. A. HOBBS
Keyword(s):  
Carbon Dioxide ◽  
Exchange Rate ◽  
Chlorophyll A ◽  
Dry Weight ◽  
Stomatal Resistance ◽  
Carbon Dioxide Exchange ◽  
Shoot Dry Weight ◽  
Significant Difference ◽  
The Difference ◽  
Net Assimilation

In spaced field plantings, triazine-resistant types of Brassica campestris L. and B. napus L. had a carbon dioxide exchange rate (CER) 28% lower in 1983 and 25% lower in 1984 than normal (triazine-susceptible) types. In plots simulating agronomic spacings in 1984, the difference between CER in normal and resistant types was 17% for B. campestris, 14% for B. napus and 13% for B. juncea L. Differences were apparent throughout the season and were not associated with any particular stage of growth. Resistant progeny from reciprocal crosses between resistant and susceptible plants of B. napus exhibited reduced CER at all levels of photosynthetically active radiation and at all temperatures. There was no significant difference between plant types for chlorophyll a + b content or chlorophyll a/b ratio. Shoot dry weight, stomatal resistance and specific leaf weight were higher in the normal types, but there was no difference between types in either relative growth rate or net assimilation rate. The reduced biomass was not therefore linked to reduced CER.Key words: Carbon dioxide exchange rate, herbicide, oilseed, rapeseed

scholarly journals Use of 9.3μm CO2 Laser for Removal of Zirconia Restorations

2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Grace Call
Keyword(s):  
Carbon Dioxide ◽  
Bond Strength ◽  
Co2 Laser ◽  
Shear Force ◽  
Shear Bond Strength ◽  
Stabilized Zirconia ◽  
Comparison Results ◽  
Significant Difference ◽  
The Difference ◽  
Carbon Dioxide Co2

Objective: The primary aim of this study was to test if a 9.3µm Carbon Dioxide (CO2 ) laser could be used to effectively separate a cemented zirconia restoration from dentin. The secondary aim was to compare shear bond strength (SBS) between RelyXTM Unicem 2 Automix Cement (3M ESPE) (RelyXTM Unicem 2) and RelyXTM Luting Plus Automix Cement (3M ESPE) (RelyX™ Luting Plus). Methods: 40 teeth were prepared to expose dentin and then randomized into four groups of 10 samples. Zirconia slices (non-glazed Yttrium stabilized zirconia samples (2.5 x 3 x 1.5 mm)) were sandblasted with 50 micron aluminum oxide at 30 psi and then cemented onto the dentin samples with RelyX™ Unicem 2 or RelyX™ Luting Plus, dependent on the group. The cements were applied to both the zirconia and dentin with a force of 20 g/mm2 for 30 seconds following manufacturer’s recommendations. After 48 hours, the 9.3µm CO2 laser was used on half the samples for 5 seconds. All 40 zirconia samples were removed with the Instron 5566A in a traditional SBS test. The groups were: 1A - RelyX™ Unicem 2 and Laser, 1B - RelyX™ Unicem 2 and Shear Bond, 2A - RelyX™ Luting Plus and Laser, and 2B - RelyX™ Luting Plus and Shear Bond. The Mann–Whitney U test was used for comparison. Results: Mean SBS of four groups ranged from 0.5 to 4.4 MPa. There was a significant difference in the SBS between 9.3µm CO2 laser and Shear Force methods for RelyX™ Luting Plus. However, the difference between the two methods was not significant for RelyX Unicem 2. RelyX™ Unicem 2 provided significantly higher SBS than RelyX™ Luting Plus for both the CO2 laser and shear force methods (Table 2). Conclusion: The 9.3µm CO2 laser effectively separated the zirconia restoration cemented with RelyX™ Luting Plus from dentin. RelyX™ Unicem 2 provided significantly stronger SBS than RelyX™ Luting Plus.

Removal of Carbon Dioxide from a Multicomponent Gas Mixture by Absorption Using a Y-Type Microreactor

2021 ◽  
Author(s):  
Sarah Natacha de Oliveira Almeida Morais ◽  
Ciro Evandro da Silva Lobo ◽  
Carlos Eduardo de Araújo Padilha ◽  
Domingos Fabiano de Santana Souza ◽  
José Roberto de Souza ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Gas Mixture ◽  
Multicomponent Gas ◽  
Multicomponent Gas Mixture

An Efficient Method for Modeling Radiative Transfer in Multicomponent Gas Mixtures With Soot

2000 ◽  
Vol 123 (3) ◽  
pp. 450-457 ◽  
Author(s):  
Vladimir P. Solovjov ◽  
Brent W. Webb
Keyword(s):  
Carbon Dioxide ◽  
Radiative Transfer ◽  
Narrow Band ◽  
Gas Mixtures ◽  
Distribution Functions ◽  
Individual Species ◽  
Gas Mixture ◽  
Weighted Sum ◽  
Multicomponent Gas ◽  
The Individual

An efficient approach for predicting radiative transfer in high temperature multicomponent gas mixtures with soot particles is presented. The method draws on the previously published multiplication approach for handling gas mixtures in the spectral line weighted-sum-of-gray-gases (SLW) model. In this method, the gas mixture is treated as a single gas whose absorption blackbody distribution function is calculated through the distribution functions of the individual species in the mixture. The soot is, in effect, treated as another gas in the mixture. Validation of the method is performed by comparison with line-by-line solutions for radiative transfer with mixtures of water vapor, carbon dioxide, and carbon monoxide with a range of soot loadings (volume fractions). Comparison is performed also with previously published statistical narrow band and classical weighted-sum-of-gray-gases solutions.

Cranial crassicaudiasis in two coastal dolphin species from South Africa is predominantly a disease of immature individuals

2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  
Keyword(s):  
South Africa ◽  
Bone Development ◽  
Bottlenose Dolphins ◽  
Fatal Outcome ◽  
Population Level ◽  
Cape Coast ◽  
Osteolytic Lesions ◽  
Immune Mediated ◽  
Significant Difference ◽  
The Difference

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.

Perbedaan Penggunaan Antikoagulan K2EDTA DAN K3EDTA Terhadap Hasil Pemeriksaan Indeks Eritrosit

2018 ◽  
Vol 1 (2) ◽  
pp. 114
Author(s):  
Wahdaniah Wahdaniah ◽  
Sri Tumpuk
Keyword(s):  
Screening Test ◽  
Venous Blood ◽  
The Body ◽  
Ethylene Diamine ◽  
P Value ◽  
Cross Sectional ◽  
Significant Difference ◽  
Ethylene Diamine Tetra Acetate ◽  
The Difference ◽  
Index Value

Abstract: Routine blood examination is the earliest blood test or screening test to determine the diagnosis of an abnormality. Blood easily froze if it is outside the body and can be prevented by the addition of anticoagulants, one of which Ethylene Diamine Tetra Acetate (EDTA). Currently available vacuum tubes containing EDTA anticoagulants in the form of K2EDTA and K3EDTA. K3EDTA is usually a salt that has better stability than other EDTA salts because it shows a pH approaching a blood pH of about 6.4. The purpose of this research is to know the difference of erythrocyte index results include MCH, MCV and MCHC using K3EDTA anticoagulant with K2EDTA. This research is a cross sectional design. This study used venous blood samples mixed with K2EDTA anticoagulant and venous blood mixed with K3EDTA anticoagulants, each of 30 samples. Data were collected and analyzed using paired different test. Based on data analysis that has been done on MCH examination, p value <0,05 then there is a significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value. Then on the examination of MCV and MCHC obtained p value <0.05 then there is no significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value.Abstrak: Pemeriksaan darah rutin merupakan pemeriksaan darah yang paling awal atau screening test untuk mengetahui diagnosis suatu kelainan. Darah mudah membeku jika berada diluar tubuh dan bisa dicegah dengan penambahan antikoagulan, salah satunya Ethylene Diamine Tetra Acetate (EDTA). Dewasa ini telah tersedia tabung vakum yang sudah berisi antikoagulan EDTA dalam bentuk  K2EDTA dan  K3EDTA. K3EDTA  biasanya berupa garam yang mempunyai stabilitas yang lebih baik dari garam EDTA yang lain karena menunjukkan pH yang mendekati pH darah yaitu sekitar 6,4. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil indeks eritrosit meliputi MCH, MCV dan MCHC menggunakan antikoagulan K3EDTA dengan K2EDTA. Penelitian ini merupakan penelitian dengan desain cross sectional. Penelitian ini menggunakan sampel darah vena yang dicampur dengan antikoagulan K2EDTA dan darah vena yang dicampur dengan antikoagulan K3EDTA, masing-masing sebanyak 30 sampel. Data dikumpulkan dan dianalisis menggunakan uji beda berpasangan. Berdasarkan analisis data yang telah dilakukan pada pemeriksaan MCH didapatkan nilai p < 0,05 maka ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit. Kemudian pada pemeriksaan MCV dan MCHC didapatkan nilai p < 0,05 maka tidak ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit.

Pengaruh Jumlah Pencucian Beras dengan Kadar Klorin

2017 ◽  
Vol 1 (1) ◽  
pp. 89
Author(s):  
Indah Purwaningsih ◽  
Supriyanto Supriyanto
Keyword(s):  
Mucous Membrane ◽  
Confidence Level ◽  
Iodometric Titration ◽  
Titration Method ◽  
Anova Test ◽  
Average Value ◽  
Significant Difference ◽  
The Difference

Abstract: Chlorine is a green halogen-shaped halogen gas at normal temperature and serves as bleach, stain remover and disinfectant. Chlorine is now widely used for bleaching rice so that less quality rice looks like quality rice. Chlorine is very toxic and causes mucous membrane irritation, highly reactive and very powerful oxidizer. The purpose of this research was to determine the difference of chlorine level in chlorinated rice washed once, twice and 3 times. The sample in this study amounted to 11 samples calculated by replication formula. Each sample was treated 3 times, ie 1 washed once, 2 washed twice and washed 3 times. The samples then examined by iodometric titration method. Based on the results of the study using ANOVA test, 11 samples obtained the average value of chlorine after washed once amount of 0.0176%, after washed twice amount of 0.0111%, and after washed 3 times amount of 0.0052% with the value significance p = 0.03 (p <0.05) at 95% confidence level which means there was a significant difference between chlorine levels in chlorinated rice washed once, twice and 3 times.Abstrak: Klorin merupakan unsur halogen berbentuk gas berwarna kuning kehijauan pada suhu normal danberfungsi sebagai pemutih, penghilang noda maupun desinfektan. Klorin sekarang banyak digunakan untuk bahan pemutih beras agar beras yang kurang berkualitas tampak seperti beras berkualitas. Klorin sangat toksik dan menyebabkan iritasi membran mukosa, sangat reaktif dan merupakan oksidator yang sangat kuat. Tujuan dari penelitian ini ialah untuk mengetahui perbedaan kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali. Sampel dalam penelitian ini berjumlah 11 sampel yang dihitung dengan rumus replikasi. Setiap sampel diberi perlakuan sebanyak 3 kali, yaitu 1 kali pencucian, 2 kali pencucian dan 3 kali pencucian. Sampel penelitian kemudian diperiksa dengan metode titrasi iodometri. Berdasarkan hasil penelitian menggunakan uji Anova secara komputerisasi terhadap 11 sampel diperoleh nilai rata-rata kadar klorin setelah 1 kali pencucian sebesar 0,0176 %, setelah 2 kali pencucian sebesar 0,0111 %, dan setelah 3 kali pencucian sebesar 0,0052 % dengan nilai signifkansi p = 0,03 (p<0,05) pada tingkat kepercayaan 95% yang artinya ada perbedaan yang bermakna antara kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali.

P-Removal in Completely Mixed Systems

1985 ◽  
Vol 17 (11-12) ◽  
pp. 325-326 ◽  
Author(s):  
H J. G. W. Donker ◽  
P. Opic ◽  
H. P. de Vries
Keyword(s):  
Mixed System ◽  
Domestic Waste ◽  
Recirculation Flow ◽  
Start Up ◽  
Significant Difference ◽  
Aerobic Reactor ◽  
The Difference ◽  
Positive Effect ◽  
Mixed Systems ◽  
P Removal

Ca. 60 % of the Dutch activated sludge plants consist of completely mixed systems, experiments have been carried out in completely mixed pilot plants to study the biological P-removal. The research was carried out in two pilot plants. The pilot plants consisted of: anaerobic reactor, anoxic reactor, aerobic reactor and a clarifier. All the reactors were completely mixed. Both plants were fed with settled domestic waste water at a sludge loading of 400 and 250 g COD/kg sludge.day respectively. The results are given below:sludge loading (g COD/kg sludge.day)400400250ratio Anaerobic : Anoxic : Aerobic1: 1:2,71:1:4,11:1:2,7P-removal (%)802875N-removal (%)505065COD-removal (%)858585 It has been shown that there is no significant difference between the results at the two different sludge loadings. Remarkable is the difference between the ratio 1:1:2,7 in combination with the internal recirculation flow anoxic-anaerobic of 160 % and the ratio 1:1:4,1 with a recirculation flow of 30 %. During the start-up at a sludge loading of 250 g COD/kg sludge.day and an internal recirculation flow of 30 %, bulking sludge developed almost immediately. The Premoval was completely disturbed. Increasing the internal recirculation flow to 160% had a positive effect on settling properties and P-removal. This investigation has pointed out that a completely mixed system is suitable for biological P-removal, without negatively affecting the nitrification. Important factors in the process are the ratio anaerobic:anoxic:aerobic and the recirculation flows.

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