Effect Of Equilibration Time Research Articles

The Effects of Equilibration Time and Post-Thawing Temperatures in Cryopreservation of Gaga Chicken Semen

The Effects of Equilibration Time and Post-Thawing Temperatures in Cryopreservation of Gaga Chicken Semen

Kinetics of Al uptake in synthetic calcium silicate hydrate (C-S-H)

The effect of equilibration time on the composition, structure and solubility of calcium aluminate silicate hydrate (C-A-S-H) was investigated in 0.5 M NaOH solutions at Al/Si = 0.1. Longer equilibration time led to longer silica chains, to less Na and, to more Ca in C-A-S-H, as well as to an increased fraction of tetrahedral Al(IV) charge-balanced by Ca2+. Aluminium, calcium and silicon concentrations in solution changed rapidly during the first day, while after 14 days only minor changes were observed. The long-term concentrations could be reproduced well by the thermodynamic CASH+ model. Over a longer time span of up to 10 years, a slow redistribution of Si and Al in C-A-S-H as well as the partial replacement of Na+ by Ca2+ in the interlayer space was observed. This study highlights the importance of considering the effect of time on C-A-S-H structure.

Sol-gel silica doped with 3-(2-naphthoyl)-1,1-dibutylselenourea, an efficient precursor for removal of Pb(II) and Zn(II) from water samples

ABSTRACT 3-(2-naphthoyl)-1,1-dibutylselenourea was prepared and Sol-gel silica was doped with it. The selenourea organic derivative was characterised in solid state by single-crystal X-ray diffraction, and doped sol-gel materials were characterised by FT-IR and SEM. The doping results were verified from their characteristic prominent bands v(cm−1) = 1753 and 1199 predominantly assigned to C = O and C = Se, respectively. The processed sol-gel was used as adsorbent to investigate its efficiency for removal of M(II) ions from aqueous solution using batch techniques (M = Pb and Zn). The porosity study reveals that the doped sol-gel contains pores which are responsible for the adsorption of metal ions, besides pores present in the material, the ligand possesses active sites (-NH, = O, = Se) readily available for coordination with metal ions, and the material thus acts as efficient chelating agent. Adsorption kinetics, isotherm, effect of equilibration time, initial concentration of adsorbate, and pH on the metal extraction were studied and conditions were optimised. Metal remediation capacity of the hybrid material i.e. sol-gel is pH dependent, and maximum removal was obtained at pH 5 (Pb) and pH 6 (Zn) with in 35 and 15 minutes, respectively. The prepared adsorbent shows rapid equilibrium and enough stability at elevated temperature in the given medium. Desorption of metal ions was carried out in 0.1 M HNO3 solution, and thereafter, sol-gel silica adsorbent was successfully regenerated and reused.

The effect of equilibration time on Al uptake in C-S-H

Calcium silicate hydrate (C-S-H) is the main hydration product of Portland cements. The partial replacement of Portland cements by supplementary cementitious materials can result in C-S-H with lower Ca/Si ratios and more aluminum and alkalis. The effect of equilibration time on Al uptake in C-S-H was investigated using equilibration times from 7 days up to 3 years. Lower Al concentrations were measured in the solution after longer equilibration times. In addition, a higher uptake of Al in C-S-H was observed based on the decrease in the content of secondary phases. Little further decrease in Al concentrations was observed after 2 years and longer at low Ca/Si. At high Ca/Si no significant change in solution concentrations was observed after more than 3 month, while the destabilization of secondary phases continued up to 1 year, indicating that a (meta)stable equilibrium was reached faster at higher Ca/Si ratios.

Pre-freezing equilibration for 22 h improves post-thaw sperm functions in cryopreserved ram semen by reducing cholesterol efflux

Failure of cervical insemination with cryopreserved semen is hindering implementation of AI in sheep in field condition. Here the effect of equilibration time and catalase on post-thaw qualities of ram semen was investigated. Pooled semen was diluted (800 × 106 sperm mL−1) with a TES-Tris-fructose extender with 6% glycerol, 15% egg yolk and supplemented with 0, 50, 100 and 200 U mL−1 catalase and packaged into 0.25 mL straws. In experiment 1, straws were equilibrated at 5 °C either for 3 h in a cold cabinet (E3) or for 10 (E10) and 22 h (E22) inside a refrigerator. In experiment 2, all straws were equilibrated for 22 h inside refrigerator. Straws were frozen at −25 °C min−1 up to −125 °C using a cell freezer and finally plunged into liquid nitrogen. The post-thaw total and rapid motility were higher (P < 0.05) in E22 compared to E3 and E10. Sperm kinetics was comparable between E3 and E22, but lower in E10. Similarly, acrosome integrity, functional membrane integrity, percent high cholesterol (mCHO) and live-high mitochondrial membrane potential (MMP) were higher (P < 0.05) while live-high intracellular calcium and acrosome-reacted sperm were lower in E22 compared to E3 and E10. The percent rapid motile, high mCHO and live-high MMP were significantly (P < 0.05) lower in catalase-treated samples compared to the control, while the membrane integrity was comparable within the groups. In conclusion, pre-freezing equilibration for 22 h compared to 3 or 10 h resulted in higher post-thaw sperm functions while catalase had negative impact on cryopreservation of ram semen.

Effect of equilibration time on clinical and neonatal outcomes in human blastocysts vitrification.

PurposeProlonged exposure to equilibration solutions may be detrimental to an embryo's developmental potential, whereas a shorter exposure may affect the penetration of cryoprotectants into blastomeres. The purpose of this study was to evaluate the effects of different equilibration times on the clinical and neonatal outcomes of human blastocyst vitrification.MethodsThis is a retrospective study based on data collected between November 2008 and November 2015. A total of 192 blastocysts (80 non‐expanded and 112 expanded) obtained from 167 patients were analyzed. The blastocysts were divided into two groups according to their equilibration time: 8‐11 minutes or 12‐15 minutes. The clinical and neonatal outcomes of warmed blastocysts were evaluated.ResultsThe survival, implantation, and live birth rates of non‐expanded blastocysts were not different between the two groups, but they significantly improved for the expanded blastocysts in the 12‐15 minutes group compared to the 8‐11 minutes group. The results were similar for the neonatal outcomes after vitrified embryo transfer, when partitioned by equilibration time and blastocyst stage at vitrification.ConclusionsFor the non‐expanded blastocysts, a shortened equilibration time (8‐11 minutes) is sufficient for effective vitrification.

Effect of Equilibration Time and Temperature on Murine Spermatogonial Stem Cell Cryopreservation.

Cryopreservation of spermatogonial stem cells (SSCs) is essential for preservation of valuable livestock and clinical applications. Although optimal equilibration of cryoprotectants has emerged as a promising approach to improve the cryopreservation efficiency, standard equilibration protocols have not yet been considered in cryopreservation of SSCs. This study aimed to establish a standard equilibration protocol to improve the cryopreservation efficiency of murine germ cells enriched for SSCs. After time- and temperature-dependent equilibration, the germ cells were cryopreserved with 10% dimethyl sulfoxide (DMSO) and 200 mM trehalose. To investigate cryopreservation efficiency at different equilibration conditions, the survival and proliferation rates were assessed after thawing, and then, cytotoxicity and intracellular trehalose quantification were analyzed. Protein (PLZF, GFRα1, VASA, and c-Kit) and gene (Bcl6b, Erm, Dazl, and Sycp1) expression was determined using immunofluorescence and real-time quantitative polymerase chain reaction (RT-qPCR), respectively. The proliferation rate increased significantly following equilibration for 20 minutes at room temperature (RT; 163.7% ± 24.6%) or 4°C (269.0% ± 18.2%). Cytotoxicity was reduced in 10% DMSO with 200 mM trehalose compared with that of 10% DMSO alone. Also, intracellular trehalose was observed after equilibration. The immunofluorescence and RT-qPCR data revealed that the murine germ cells enriched for SSCs retained their self-renewal ability after cryopreservation following equilibration. The most effective protocol was equilibration with 10% DMSO and 200 mM trehalose for 20 minutes at RT or 4°C, which is due to synergistic effects of intracellular and extracellular trehalose. This improved methodology will contribute toward the development of a standardized freezing protocol for murine germ cells enriched for SSCs and thereby expand their application in various fields.

Soil Phosphate Sorption Characteristics of Selected Calcareous Soil Series of Southern Punjab, Pakistan

To estimate the sorption and desorption capacity of some selected calcareous soils Jhatpat, Miani Pacca and Hadhwar from southern Punjab in Pakistan were analyzed. The sorption isotherms of the three soils yielded different curves. The maximum sorption was recorded in the Miani pacca soil series with value of sorption 201. 23 mg kg-1 which was followed by the Hadhwar series with peak sorption value of 190.04 mg kg-1. The lowest value for sorption was determined in the Jhatpat soil series. Comparing the different models (Langmuir, Freundlich and Temkin), Freundlich model showed good fit to the sorption isotherms with regression coefficient (R2) having value of 0.99, 0.99 and 0. 98 for Jhatpat, Miani pacca and Hadhwar soil series respectively, which was higher than the other two models used. The study on the effect of equilibration time (1, 10, 30 and 60 days) of applied inorganic Phosphatic fertilizers i.e. Single super phosphate (SSP) and diammonium phosphate (DAP) @ 60 and 120 kg ha-1 on two soil series with highest P sorption. The P sorption increased with increase in the time of equilibration, with higher value of extractable P was found 22.246 mg P kg-1 after 1 day of incubation, and it gradually decreased with the lowest value of 8.271 mg kg-1after 60 days of incubation.

Impact of modified chitosan on pore water bioavailability of zinc in contaminated soils

The present work examines the utilisation potential of the bio-waste, chitosan for the remediation of soils contaminated with zinc (Zn). The mechanism involved was elucidated via a study of Zn sorption kinetics on pure and modified chitosan beads, the latter containing molybdate and phosphate compounds. The effect of equilibration time on adsorption was explained with reference to chemical sorption and intra-particle diffusion mechanisms. The findings showed that chitosan acts upon freely dissolved zinc in soil pore water. The use of modified chitosan beads resulted in a significant decrease in Zn bioavailability, which may be attributed to a combination of Zn complexation, the sorbent's high surface area and cation exchange capacity (CEC). This study provides an insight into issues associated with zinc contaminated soils and the amelioration of nutrient-deficient soil through modified chitosan amendments.Capsule abstractModified chitosan has potential to remediate Zn-contaminated soil. The bioavailability of zinc in the pore water of contaminated soils decreased upon the application of chitosan beads.

The effect of equilibration time on semen freezing of local swamp buffalo (Bubalus bubalis) with combination extender of lactose and glycerol

Eriani K, Sari N, Ihdina M, Rosnizar. 2017. The effect of equilibration time on semen freezing of local swamp buffalo (Bubalus bubalis) with combination extender of lactose and glycerol. Nusantara Bioscience 9: 77-82. This study was to determine the different time of equilibration on semen of swamp buffalo (Bubalus bubalis) which was diluted by adding Tris-Egg Yolk extender of lactose and glycerol cryoprotectant combination. Fresh sperm of the swamp buffalo (B. bubalis) was diluted by using Tris-Egg Yolk extender of lactose cryoprotectants combination 0 mM (L0), 60 mM (L60), 120 mM (L120) and glycerol 3% (G3), 5% (G5), 7% (G7) with the equilibration of 2,5, 3, and 4 hours. The parameter used in this study was the percentage of sperm motility and live treatment. The results of the 2.5-hour equilibration with a combination of cryoprotectants L60G7 showed the best quality in all parameters. The results of the 3-hour equilibration with combination of cryoprotectants L60G7 showed the best quality in all parameters whereas the best quality in all parameters in 4-hour equilibration was the combination of cryoprotectants L120G7.

Effects of equilibration time on post thaw motility and fertility of bull semen

Effects of equilibration time on post thaw motility and fertility of bull semen

Effect of equilibration times, freezing, and thawing rates on post-thaw quality of buffalo (Bubalus bubalis) bull spermatozoa.

The effects of equilibration times (E1, 2h; E2, 4h; E3, 6h), freezing rates (FR1, manual, 5cm above liquid nitrogen (LN2 ) for 10min, plunging in LN2 ; FR2, programmable ultra-fast, holding at +4°C for 2min, from 4 to -10°C at -10°C/min, from -10 to -20°C at -15°C/min, from -20 to -120°C at -60°C/min, holding at -120°C for 30sec, plunging in LN2 ), and thawing rates (T1, 37°C for 30sec; T2, 50°C for 15sec; T3, 70°C for 7sec) were evaluated on quality of buffalo bull spermatozoa. Progressive motility (%), rapid velocity (%), average path velocity (VAP, μm/s), straight line velocity (VSL, μm/s), and mitochondrial transmembrane potential (%) were higher (p<0.05) with E2, FR2, and T3 compared to other groups. Sperm curved line velocity (VCL, μm/s) was higher (p<0.05) with E2 and FR2 compared to other groups. Sperm straightness (%) and linearity (LIN, %) were higher (p<0.05) with E2 compared to other groups. Sperm LIN was affected (p<0.05) with T3 compared to other groups. Supravital-plasma membrane integrity (%), viability and acrosome integrity (%) of spermatozoa were higher (p<0.05) with E2 and FR2 compared to other groups. Sperm DNA integrity (%) was higher (p<0.05) with FR2 and T1 compared to other groups. We concluded that inclusion of 4h-equilibration time, programmable ultra-fast freezing rate, and rapid thawing at 70°C for 7sec in cryopreservation protocol improves the post-thaw quality of buffalo bull spermatozoa.

The Effect of Equilibration Time and Tubing Material on Soil Gas Measurements

ABSTRACTThe collection of soil vapor samples representative of in-situ conditions presents challenges associated with the unavoidable disturbance of the subsurface and potential losses to the atmosphere. This article evaluates the effects of two variables that influence the concentration of volatile organic compounds in soil vapor samples: equilibration time and tubing material. The time for three types of soil vapor probes (i.e., macro-purge, mini-purge, and post-run tubing probes [PRT]) to equilibrate with subsurface conditions was assessed by installing probes and collecting multiple samples over a 72-hour period. The effect of tubing material was evaluated by collocating soil vapor probes constructed with different tubing material and collecting samples over several months. We recommend that soil vapor probes constructed with a sand filter-pack and bentonite seal (i.e., macro-purge probe) equilibrate for 24 to 48 hours prior to sample collection. Post-run tubing (PRT) probes equilibrated within one to two hours while a new probe design, (i.e., mini-purge probe) equilibrated and could be sampled after only 30 minutes for screening assessments. Nylaflow, Teflon®, polyetheretherketone (PEEK), and stainless-steel tubing had comparable trichloroethene (TCE) concentrations over all sampling time frames. We recommend that copper tubing be avoided and polyethylene only be used for screening assessments.

Effect of equilibration time on Pu desorption from goethite

Abstract It has been suggested that strongly sorbing ions such as plutonium may become irreversibly bound to mineral surfaces over time which has implications for near- and far-field transport of Pu. Batch adsorption–desorption data were collected as a function of time and pH to study the surface stability of Pu on goethite. Pu(IV) was adsorbed to goethite over the pH range 4.2 to 6.6 for different periods of time (1, 6, 15, 34 and 116 d). Following adsorption, Pu was leached from the mineral surface with desferrioxamine B (DFOB), a complexant capable of effectively competing with the goethite surface for Pu. The amount of Pu desorbed from the goethite was found to vary as a function of the adsorption equilibration time, with less Pu removed from the goethite following longer adsorption periods. This effect was most pronounced at low pH. Logarithmic desorption distribution ratios for each adsorption equilibration time were fit to a pH-dependent model. Model slopes decreased between 1 and 116 d adsorption time, indicating that overall Pu(IV) surface stability on goethite surfaces becomes less dependent on pH with greater adsorption equilibration time. The combination of adsorption and desorption kinetic data suggest that non-redox aging processes affect Pu sorption behavior on goethite.

Removal of boron from aqueous solution using magnesite and bentonite clay composite

The removal of boron from industrial effluents using the composite was studied in batch equilibration technique. The effects of equilibration time, adsorbent dosage, concentration and pH on removal of boron were investigated. The experiments demonstrated that boron removal is optimum at 30 min of agitation, 1 g of dosage and 20 mg L−1 of ion concentration. Adsorption of boron by the composite was independent of pH. The adsorption data fitted well into both Langmuir adsorption isotherm and Freundlich adsorption isotherm hence proving monolayer and multilayer adsorption. The kinetic studies reported that the data favours pseudo-second-order reaction than first order hence proving chemisorption. Under optimized conditions, the composite was able to remove boron to below World Health Organization (WHO) water quality guidelines. Henceforth, it was concluded that this comparative study will be helpful for further application in the treatment of boron-contaminated water.

Application of magnesite–bentonite clay composite as an alternative technology for removal of arsenic from industrial effluents

This study evaluated the feasibility of integrating amorphous magnesite and bentonite clay (composite) as an alternative technology for removing arsenic from industrial effluents. The removal of arsenic from industrial effluents by using magnesite–bentonite clay composite was carried out in batch mode. The effects of equilibration time, adsorbent dosage, adsorbate concentration, and pH on removal of arsenic were investigated. The experiments demonstrated that ≈100% arsenic removal is optimum at 30 minutes of agitation, 2 g of adsorbent dosage (2 g: 100 mL, S/L ratio), and 20 mg L−1 of arsenic concentration. The adsorption data fitted well to both Langmuir and Freundlich adsorption models, hence proving monolayer and multilayer adsorption. The kinetic studies revealed that the data fitted better to a pseudo-second-order reaction than to a pseudo-first-order reaction, hence proving chemisorption. At optimized conditions, the composite was able to remove arsenic to below World Health Organization water quality guidelines, hence depicting that the composite is effective and efficient in removing arsenic from contaminated water. Based on that, this comparative study proves that the composite is a promising adsorbent with high adsorption capacity for arsenic and can be a suitable substitute for the conventional treatment methods.

Effect of equilibration time on estimates of the maximum phosphorus sorption capacity of industrial by-products using the Langmuir model

Using reactive industrial by-products (IBPs) to reduce phosphorus (P) losses associated with diffuse water pollution is a potentially cost-effective mitigation strategy. However, IBPs must be screened to assess their effectiveness and optimum application rates. This requires accurate estimates of parameters such as the maximum P sorption capacity. Traditionally, these parameters have been derived from the Langmuir model applied to data from batch sorption experiments following a 24-h equilibration period. In this paper, we examined (i) how equilibration time can influence estimates of the maximum P sorption capacity for IBPs and (ii) the relative P sorption characteristics of a range of IBPs available in the UK. Four IBPs containing different reactive components including ochre, aluminium (Al)-based water treatment residual (WTR), iron (Fe)-based WTR and Fe-lime (CaO)-based WTR were selected for this study. The maximum P sorption capacities of these IBPs were determined using a linearized Langmuir model applied to batch sorption data collected at different equilibration times of 24 h, 5 days and 10 days. The maximum P sorption capacity of ochre, Al-based WTR, Fe-based WTR and Fe-CaO-based WTR estimated from the linearized Langmuir model following a 24-h equilibration period was 10.1, 13.7, 2.4 and 9.3 mg P g−1, respectively. However, extending the equilibration time from 24 h to 5 days increased the estimated maximum P sorption capacity for these IBPs by factors of 2.2, 2.1, 6.8 and 2.3, respectively. No significant increase was found in estimates of the maximum P sorption capacity when further extending the equilibration time to 10 days. A minimum equilibration period of 5 days is recommended to avoid underestimating the maximum P sorption capacity of the IBPs examined in this paper. Each of the IBPs we evaluated was able to sorb P from solution, although with variable capacity (maximum sorption capacity after 5 days of equilibration ranged from 16.3–28.5 mg P g−1). These findings emphasise the importance of accurate quantification of the P sorption capacity of IBPs before application.

Effects of equilibration time on clinical outcomes in embryo vitrification procedure

Vitrification is an efficient way to store human embryos. During this procedure, the duration that embryo suspends in vitrification solution is commonly considered to be critical, which should be strictly controlled within 1 min. However, the duration that embryo suspends in equilibration solution is flexible, ranged from 5 min to 15 min. The purpose of this study is to examine the effects of different equilibration time on the outcomes of frozen-thawed embryo transfer cycles.

Kinetic and thermodynamic studies of adsorption of Cd2+ by superparamagnetic nano iron oxide-loaded poly(acrylonitrile-co-acrylic acid) hydrogel

The efficiency of adsorption of cadmium ions from aqueous solutions by superparamagnetic nano iron oxide-loaded poly(acrylonitrile-co-acrylic acid) hydrogel has been investigated. The effect of equilibration time, amount of adsorbent, temperature, adsorbate concentration, and pH was studied by use of a batch system. The copolymer was magnetized in situ and the size, phase identification, morphology, and coating of magnetic nanoparticles were characterized by TEM, AFM, XRD, and FTIR analysis respectively. The sorption data were analyzed and fitted to linearized equations of the Langmuir, Freundlich, and Temkin isotherms. The kinetics of sorption were analyzed by use of pseudo-first-order and pseudo-second-order kinetic models. Kinetic data, rate constants, equilibrium sorption capacities, and related correlation coefficients for each kinetic model were calculated and are discussed. Thermodynamic data ΔG°, ΔH°, and ΔS° were evaluated. It was found the sorption process was feasible, spontaneous, and exothermic in nature. This hydrogel was an efficient adsorbent for removal of Cd2+ ions from water (>98 % removal) and could be regenerated efficiently (>99 %).

Developmental competence of ovine oocyte following vitrification: effect of oocyte developmental stage, cumulus cells, cytoskeleton stabiliser, FBS concentration, and equilibration time

The aim of the present study was to examine the effects of fetal bovine serum (FBS) concentration, equilibration time, and oocyte pre-treatment with cytochalasin B (CCB) on subsequent development of vitrified-warmed ovine immature (GVCOCs) and matured (MII) oocytes with (MIICOCs) or without cumulus cells (MIIDOs). In Experiment 1, the effects of FBS concentrations (10 and 20%) during the vitrification-warming procedure were examined. Survival rates after warming were not different between GVCOCs, MIICOCs and MIIDOs oocytes. After in vitro fertilization, rate of cleaved embryos in MIICOCs group at the presence of 20%FBS was higher than MIIDOs and GVCOCs groups. In Experiment 2, the effects of equilibration times (5, 7, and 10 min) were examined. There was no difference in survival rate of vitrified-warmed oocytes equilibrated at different times. Although, the rate of cleavage in MIICOCs and MIIDOs oocytes equilibrated for 10 and 7 min, respectively, was higher than 5 min equilibrated MIIDOs and 7 and 10 min equilibrated GVCOCs oocytes. In Experiment 3, the effects of oocyte pre-treatment with CCB were examined. Despite the insignificant difference in survival rate of vitrified-warmed ovine immature and matured oocytes, the rates of cleavage in CCB pretreated groups were significantly lower than untreated groups. Moreover, the blastocysts were only derived from those cumulus enclosed vitrified-warmed germinal vesicle (GV) and MII oocytes that had been exposed to 10% FBS in the absence of CCB. In conclusion, the presence of cumulus cells, 10% FBS, and the omission of CCB were beneficial for post-warming development of vitrified ovine oocytes.