Increasing Soaking Time Research Articles

Influence of KOCC Swelling by Soaking after Beating on Pulp and Paper Properties

KOCC is used as a very important raw material in industrial paper manufacturing in Korea. However, as KOCC is repeatedly used as a raw material, the aging and hornification of the pulp becomes more severe, making it difficult to produce industrial paper of excellent strength. In order to solve these problems, various methods such as addition of virgin pulp, enzyme treatment, mechanical treatment and polymer additive have been applied. This study was carried out to evaluate the applicability of swelling treatment by soaking after beating in order to improve the quality of KOCC by environmentally friendly method. As a result of this study, the WRV of KOCC and UKP increased with increasing soaking time, while the freeness tended to decrease. The air permeability of KOCC handsheet showed a tendency to decrease by swelling due to soaking, but the opacity and bulk did not show any significant changes. The tensile index was slightly improved by soaking, but no significant changes were observed in the tear index and Taber stiffness. Considering the above results, although swelling due to soaking helps somewhat to improve some physical properties, it is difficult to expect the significant improvement of physical properties of paper only by a single swelling treatment.

Influent of soaking time in liquid nitrogen on microstructure and mechanical properties of AISI 1018 low carbon steel processed by cryorolling

Cryorolling was identified as a new potential route to fabricate ultrafine grained of AISI 1018 low carbon steel plate with less plastic deformation. This work aims to study the influence of soaking time in liquid nitrogen on microstructure and mechanical properties of AISI 1018 carbon steel. AISI 1018 low carbon steel was processed by soaking in liquid nitrogen at various soaking times (5, 10, 20, 30 minutes) and then followed by rolling up to 50% thickness reduction. Microstructure and mechanical properties were investigated using an optical microscope, Vickers microhardness, and tensile test. The hardness and strength were increased up to 10 mins of soaking time and then gradually dropped as the soaking time increases. The highest tensile strength and hardness were 501.75 MPa and 176.04 HV achieved at 10 minutes soaking time.

Synergistic reinforcement of surface modification on improving the bonding of veneering ceramics to zirconia

Veneering ceramics should be strongly bonded to zirconia core in order to achieve successfully long-term clinical practice. Indeed, to pursue the high zirconia core–veneering ceramic bonding is still a concerned issue. In this regard, this study was to treat zirconia surface using a 3 wt% Si3N4 solution in 4 M NaOH and to investigate the effect of soaking time (5, 10, and 20 days) on the surface properties of zirconia and shear bond strength between zirconia and veneering ceramics. The residual veneering ceramics on zirconia surfaces and failure modes were also examined after fracture. The results showed that the phase composition of zirconia before and after surface modification was not changed. The elemental mapping and depth profiling consistently revealed the soaking-time-dependent Si content on the zirconia surface. The surface roughness of zirconia was significantly (P < 0.05) increased with the increasing soaking time. When zirconia was treated for 10 days, the shear bond strength value of 27.4 MPa was significantly (P < 0.05) higher than the control (18.6 MPa), associated with greater remaining amounts of veneering ceramics on the zirconia surface. The failure mode of the treated zirconia was almost the mixed failure. On the basis of the data, surface modification using Si3N4 in NaOH solution for zirconia core could be a simple and effective method for enhancing the veneering ceramic–zirconia bonding.

Recovery and formation mechanism of high brightness calcite powders from marble waste by the alkaline hydrothermal treatment

Abstract Large amounts of marble wastes have been generated annually from the marble processing industry, which pose serious hazards to the environment and healthcare. In this work, high brightness calcite powders were recycled from marble powder by the alkaline hydrothermal treatment. The ball milling pretreatment had a prominent effect on the brightness of calcite powders, resulting in an optimum milling time of 22 h. In the alkaline hydrothermal treatment, the brightness of calcite powders increased to constant values with increasing hydrothermal temperature and solid content, whereas it firstly increased and then decreased with the increase of soaking time and alkaline concentration. The maximum brightness of calcite powders was 95% when the milled marble powder was hydrothermally treated at 220 °C for 4 h in an alkaline solution of 0.1 mol/l. The sheet-like calcite crystallites (

Experimental investigation of the effects of supercritical carbon dioxide on fracture toughness of bituminous coals

Effects of supercritical carbon dioxide (scCO2) on fracture toughness of bituminous coals are studied. The semi-circular specimens under three-point bending (SCB) were adopted for conducting experiments on the coal samples after being immersed in scCO2 for different soaking periods. To investigate the fracture toughness in different loading conditions, including pure mode I, pure mode II, and mixed mode I/II, the inclination angles of the prefabricated cracks in the coal SCB samples were set as 0°, 5°, 15°, 30°, 45° and 54°, respectively. The experimental results show that after being soaked in scCO2 for 7 days, 14 days and 21 days, the pure mode I fracture toughness of the coals reduced by up to 30.8%, 69.2% and 82.1%, respectively, and the mode II fracture toughness 29.1%, 66.7% and 79.9%, respectively. The fracture toughness in pure mode I loading is more sensitive to the effect of scCO2 than that in pure mode II loading. The values of the effective fracture toughness Keff in mixed mode I/II loading also declined due to the effect of scCO2, and the samples with different crack inclination angles exhibited no obvious differences in the degradation degrees of Keff. With increasing soaking time, the compaction stage extended, and the slope of the load–displacement curve in the elastic stage decreased significantly. The microcracks on the surface of the coal SCB specimens gradually increased with the soaking time increasing. In addition to causing the reduction of surface energy and swelling of coals, scCO2 mobilizes organic molecules from coals, leading to the modification of the physical structure of the coal matrix and the degradation of fracture toughness in various loading modes. Based on the modified maximum tangential stress (MMTS) criterion, which takes into account the effects of T-stress, the theoretical values are in better agreement with experimental results compared with the traditional maximum tangential stress (MTS) criterion.

Pyrolysis-controlled synthesis and magnetic properties of sol–gel electrospun nickel cobaltite nanostructures

Nickel cobaltite (NCO) is a binary transition-metal oxide, which is extensively used as an electrocatalyst and magnetic material. NCO nanofibers and NCO/graphene composite exhibit high electrochemical reactivity due to the directional bridging of NCO particles. This makes NCO a promising candidate electrode material for use in supercapacitors and batteries. Besides, NCO is also a promising magnetic material due to its unique structural composition, where the cations are seated in octahedral sites surrounded by oxygen vacancies. In the present work, a simple and reliable method was discovered for tuning the morphological and structural changes of nickel cobaltite (NCO) nanoparticles, which were reshaped along the NCO nanofibers, by controlling the pyrolysis soaking time. As the pyrolysis soaking time increases, NCO transforms from inverse spinel to normal spinel; and the morphology of NCO nanoparticles changes from spherical to rod-like. These changes were validated by the hypsochromic peak shifts in Raman, and FTIR spectroscopies. The magnetic measurements reveal changes in the shape of the hysteresis loop, which are explained on the basis of structural and morphological changes in the nanostructure. The net magnetisation increases and coercivity decreases, with an increase in pyrolysis soaking time. These changes in magnetic parameters are attributed to structural changes caused by the formation of oxygen vacancies, and surface effects due to switching in morphology of the NCO nanoparticle.

Effect of salt concentration on the rehydration capacity of sundried ribbon fish (Trichiurus haumela) stored at ambient (28-330c) and refrigeration (40c) temperature

A study was done to investigate the changes in water rehydration capacity of laboratory prepared control dried (dried fish treated without salt), 15% salt dried and 25% salt dried ribbon fish (Trichiurus haumela) stored in polyethene bag at ambient (28-330C) and refrigeration temperature (40C). The main objective of this study was to observe the effect of salt on the rehydration capacity of the dried ribbon fish during 2 months storage period. On the 1st day of storage the reconstitution level of control dried, 15% salt and 25% salt dried fish at 280, 400 and 600C was in the range of 30.05 to 70.98% having maximum value for control dried fish after 60 minute of soaking at 600C and minimum value for 25% salt dried fish after 15 minute of soaking at 280C. The reconstitution capacity of the dried fish products gradually increased with increasing soaking time and temperature. After 60 days of storage the rehydration capacity of dried products at same temperatures of 280, 400 and 600C ranged between 27.16 to 61.43% with highest value for control dried products stored at refrigeration temperature (40C) after soaking for 60 minutes at 600C and lowest value for 25% salt dried fish stored at ambient temperature (28-330C) after soaking for 15 minutes at 280C. Rehydration capacity of the dried products decreased very slowly during storage period due to the slow increment of moisture in the products stored both at ambient and refrigeration temperature. Salt-dried fish absorbed less moisture than that of unsalted dried fish and increased salt concentration resulted in the lower moisture absorption in the dried fish and thus reduced rehydration capacity.Res. Agric., Livest. Fish.5(1): 107-115, April 2018

Effects of soaking and grinding conditions on anti-nutrient and nutrient contents of soy milk

Although soy milk is a very good source of nutrient with high biological value, the presence of anti-nutritional factors affects its nutrition quality and limits bioavailability of the nutrients. The effects of soaking duration and combination of soaking and grinding (hot or cold) on phytate, lipoxygenase, urease, trypsin inhibitor activity, protein solubility and other nutrient contents were investigated. Soaking alone at 55 and 60oC for different durations was found effective for the reduction of lipoxygense activity. Combination of soaking, blanching (80oC for 10 min) and hot grinding (100oC) significantly (P&gt;0.05) reduced urease activity, more than 80% phytate activity and deactivated trypsin inhibitor, but did not affect protein solubility. Meanwhile, protein solubility (10–15%) was increased due to hot grinding. Soy milk extracted from soaking at 55 and 60oC for 2, 4 and 6 h with hot grinding provided higher protein content compared to cold grinding. Increase in soaking temperature from 55 to 60oC increased the extracted solid content having a potential fraction of lipid. Increasing soaking time from 4 to 6 h did not show any significant difference in terms of phytate inhibition, urease activity reduction, trypsin inhibition and protein solubility except lipoxygenase activity. The results suggested that soaking of soybean at 60oC for 6 h and hot grinding (100oC) with blanching at 80oC for 10 min is the best for reducing anti-nutrient and retaining nutrient activity for soy milk and other soy-based products.J. Bangladesh Agril. Univ. 16(1): 158-163, April 2018

A Mechanistic Study on the Structure Formation of NiCo2O4 Nanofibers Decorated with In Situ Formed Graphene-Like Structures

Nickel cobaltite (NCO) nanofibers were synthesized using poly(styrene-co-acrylonitrile) (SAN) as the polymeric binder through sol–gel assisted electrospinning. Defect-free precursor nanofiber mats were pyrolyzed at 773 K at three different pyrolysis soaking times t = 2, 4, and 6 h. The SAN present in the precursor nanofibers caused morphological changes in the NCO nanofibers during their thermochemical degradation. Consequently, fractal aggregates of NCO nanoparticles were formed along the length of the nanofibers. X-ray photoelectron spectroscopy (XPS) revealed both + 2 and + 3 oxidation states for Ni and Co, with spinel crystal defects due to oxygen rich atmosphere. XPS, high-resolution transmission microscopy, and optical analysis showed graphene-like structures embedded within the NCO nanofibers. With increase in pyrolysis soaking time, the morphology of the NCO particles markedly changed from spherical to rod-like. We propose a mechanism for the morphological change of NCO nanoparticles on the basis of crystallite splitting accompanied by particle splitting and reordering.

Biomimetically Co-Deposition of Bovine Serum Albumin and Calcium Phosphate on 3D Printed Hydroxyapatite: Influence of Time, Temperature and Concentration

Influence of bovine serum albumin (BSA) concentration, soaking times and soaking temperatures during biomimetic co-deposition process of three dimensionally printed hydroxyapatite (3D printed HA) on weight change, phase composition and microstructure were studied. At 23°C, weight change of all samples monotonically increased with increasing soaking time regardless of BSA concentration used while the weight change initially increased, but leveled off later with increasing soaking time when using solution temperature of 37°C. At 50°C, weight change initially increased for up to 4 h and remained constant for up to 16 h where the weight decreased afterward. This decrease could be related to the competition between the dissolution of 3D printed HA, the deposition of new calcium phosphate crystals and the incorporation of BSA during biomimetic process at high temperatures. From X-ray diffraction, no influence in BSA concentration, time and temperature on the phase composition was observed. Scanning electron microscopy revealed the deposition of new plate-like calcium phosphate crystals on all 3D printed HA. Hydroxyapatite and octacalcium phosphate were found to be the main phases of all biomimetically BSA.

Microwave Synthesis of Nanocrystalline Hydroxyapatite and the Application in Bio-Composite

This research synthesized nanocrystalline hydroxyapatite (HA) via microwave assisted heating method. The morphology and crystallinity of nanocrystalline hydroxyapatite were affected by heating power and pH of the mixed solution. Nanocrystalline HA was best obtained when synthesized at pH = 11. Crystal size increased and crystal shape changed from spherical to rod and plate-like when the microwave power was increased from 320 to 800 watts. The synthesized nano-HA could be fabricated into bio-composite films using poly lactic acid (PLA) as the matrix and solvent casting method was utilized. In-vitro study for bioactivity was carried out in the SBF solution which formed hydroxyl-carbonate apatite (HCA) layer on the PLA/nano HA composite surface. The layer thickness increased in the background with increasing soaking time in the SBF.

Enhanced corrosion resistance and in vitro bioactivity of NiTi alloys modified with hydroxyapatite-containing Al2O3 coatings

Hydroxyapatite (HA)-containing Al2O3 coatings were prepared on NiTi alloys through a cathodic plasma electrolytic deposition (CPED) process, followed by hydrothermal treatment (HT). The surface morphology, elemental distribution and phase composition of each coating were studied by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD). SEM observations revealed that the coatings exhibited a “crater-like” porous structure, and that the thickness of the coating could be up to 100 μm. The results of EDS demonstrated that the Ca and P concentrations in the Al2O3 coatings could be increased to 8.2% and 4.7%, respectively, and that the Ca/P ratio could reach 1.72, which was close to that of natural HA. The results of XRD analysis showed that the CPED coating mainly comprised α-Al2O3 and γ-Al2O3, and that HA crystallization was induced by the subsequent HT. The corrosion resistance of the samples was investigated by potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS). The results showed that the corrosion resistance of the sample with the CPED-HT coating was enhanced by more than two orders of magnitude compared to that of the uncoated NiTi alloy. Ni ion release in simulated body fluid (SBF) was characterized by inductively coupled plasma-atomic emission spectroscopy, and the results showed a significant drop in the concentration of released Ni ions from 18.0 μg/mL for the uncoated NiTi alloy to 0.7 μg/mL for the CPED-HT coating. In addition, the SBF soaking test showed that HA precipitated on the CPED-HT coating and that the HA layer became thicker and larger with increasing soaking time, indicating that the CPED-HT coating exhibited excellent apatite-inducing ability. Thus, the introduced CPED-HT treatment provides a new and effective route for the surface modification of NiTi alloys for use as biomedical materials.

Experimental study on the influence of slickwater on shale permeability

There are two diametrically opposite views of the influence of slickwater on shale permeability among scholars at home and abroad. We used the shale outcrops rock samples from the Lower Silurian Longmaxi Formation in Sichuan Basin. The permeability of these dry samples before and after immersion in different solution systems were tested by pulse attenuation method. The experimental results show that the impregnation of different slickwater components and standard salt solution can promote the increase of the permeability of shale samples. The stress sensitivity of shale samples after liquid immersion is medium weak to weak. The sample stress sensitivity is weak after soaked by the synergist solution and Drag reducing agent solution, and the sensitivity of the sample stress is medium weak after immersed by the standard saline solution, defoamer solution and antiswelling solution; The Ki/K0 of the shale sample after liquid immersion on σi/σ0 is consistent with the exponential stress sensitive evaluation model. With the increase of soaking time, the increase of sample permeability increases first and then decreases.

Enhanced properties of novel zirconia-based osteo-implant systems

Zirconia (ZrO2) ceramic has attracted much attention because of its superior mechanical properties and chemical stability in vivo for medical applications. However, this material has a poor affinity to cells and tissues, which needs to be overcome for bone implant applications. Thus, further research is required to develop a high efficacy ZrO2-based material candidate. Calcium silicate (CaSi)-based materials have gained increasing interest for use as bone graft substitutes because of their high osteogenesis. Efforts have been oriented toward the design of novel ZrO2-based systems where CaSi was added to enhance the osteogenesis of the structural implant ceramics. The effect of CaSi on the phase composition, long-term in vitro degradation, and osteogenesis of the ZrO2-based osteo-implants was evaluated. The experimental results revealed that the CaSi additive did not affect the tetragonal-monoclinic phase transformation of ZrO2. The 5 and 10wt% CaSi-containing composites had three-point bending strength and biaxial strength values comparable to those of the ZrO2 control, whereas excessive CaSi resulted in the decreased strength. However, the three-point bending strength of 15 and 20wt% CaSi-containing composites was within the reported bending strength for cortical bone. Interestingly, the bending modulus of the composite implants decreased with the increasing CaSi content. For the in vitro degradation, there were no obvious changes for all osteo-implants with the increasing soaking time, except the slight weight loss (less than 1%) of the 20wt% CaSi implant. As expected, the higher CaSi implants appreciably enhanced the biological functions of the ZrO2 implant. It is concluded that the CaSi-ZrO2 composite osteo-implants offered a promising alternative to ZrO2 for load-bearing bone implant application.

Structure, dissolution behavior, cytocompatibility, and antibacterial activity of silver‐containing calcium phosphate invert glasses

Novel CaO‐P2O5‐Nb2O5‐Ag2O invert glasses with substitution Ag2O for Nb2O5 were successfully prepared using a melt‐quenching method. Ag2O in the glasses act as a network modifier oxide, playing the same role as Na2O, which breaks the phosphate chains. Analysis of the ultraviolet‐visible absorption spectra of the glasses showed that the glass matrix contained ionic silver species and silver nanoparticles. Approximately 0.05 mM of Nb5+ ions released from the glasses, which would be expected to stimulate osteoblast differentiation. A glass containing 1 mol % Ag2O showed a linear increase in the releasing amount of Ag+ ions with increasing soaking time, whereas glasses containing 3–5 mol % Ag2O showed Ag+ ion concentrations of around 13 μM at day 3, and then maintained similar values until day 7. When the solution was replaced with fresh solution every 2 days, the Ag+ ion dissolution amounts indicated almost constantly 13 μM due to AgCl formation. There were no differences in the numbers of primary osteoblast cells on silver‐free and silver‐containing glasses after cultivation for 1–7 days. The silver‐containing calcium phosphate invert glasses showed cytocompatibility with simultaneous antibacterial activity to Escherichia coli and Staphylococcus aureus. © 2017 The Authors. Journal of Biomedical Materials Research Part A published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3127–3135, 2017.

Effect of Process Parameters on Biomimetic Deposition of Calcium Phosphate on 3D Printed Hydroxyapatite

Factors influencing calcium phosphate deposition on three dimensional printed hydroxyapatite (3D printed HA) by biomimetic process including soaking times (2, 4 and 6 hrs), solution temperatures (23, 37 and 50 °C) and solution refreshment (refreshed and non-refreshed) were studied. It was found that the weight change of the samples increased with increasing soaking times at all temperatures regardless of solution refreshment. Using refreshed solution resulted in greater increase in weight change than using non-refreshed solution. In the case of solution temperature, two opposite trends were observed depending on the solution refreshment. Increasing solution temperatures in non-refreshed solution exhibited a decrease in the weight change whereas the increase in the weight change was observed when using refreshed solution. This could be related to the competition between the dissolution of 3D printed HA and the deposition of new calcium phosphate crystals during biomimetic process. Octacalcium phosphate and HA were found to be the main phases of biomimetically deposited 3D printed HA.

Effect of Soaking Time on Paste Carburizing of Carburized Low Carbon Steel

Increase of soaking time contributed to the effectiveness of case depth formation, hardness properties and carbon content of carburized steel. This paper investigates the effect of different soaking time (7-9 hours) using powder and paste compound to the carburized steel. Low carbon steels were carburized using powder and paste compound for 7, 8 and 9 hours at temperature 1000°C. The transformation of microstructure and formation carbon rich layer was observed under microscope. The microhardness profiles were analyzed to investigate the length of case depth produced after the carburizing process. The increment of carbon content was considered to find the correlation between types of carburizing compound with time. Results shows that the longer carburized steel was soaked, the higher potential in formation of carbon rich layer, case depth and carbon content, which led to better hardness properties for carburized low carbon steel. Longer soaking time, 9 hours has a higher dispersion of carbon up to 41%-51% compare to 8 hours and 7 hours. By using paste carburizing, it has more potential of carbon atom to merge the microstructure to transform into cementite (1.53 wt% C) compare to powder (0.97 wt% C), which increases the hardness of carburized steel (13% higher).

Electrochemical study of the effect of oxidation and amorphization of Cr nanoparticles on the co-deposition of Ni-Cr nanocomposite film

The oxidation and amorphous transformation of Cr nanoparticles in a Ni sulfate electrolyte and its subsequent effect on the co-deposition of Ni-Cr was investigated. Transmission electron microscopy (TEM) results revealed the oxidation process of the Cr nanoparticles with increasing soaking time. In addition, the polarization of Ni reduction showed that the amorphous transformation of the Cr nanoparticles shifted the nickel reduction to more negative potentials. Electrochemical impedance spectroscopy with fresh and amorphous Cr nanoparticles verified that the kinetics of nickel electrodeposition changed to a diffusion-controlled process. Amorphous Cr nanoparticles restricted the diffusion of Ni+ads on the cathode, which made nickel reduction more difficult, thereby impairing the incorporation of Cr nanoparticles into the Ni matrix.

Effect of Heating and Thermal Deformation on Austenite Grain Size of B1500HS Boron Steel

Abstract To investigate the effect of temperature and soaking time on the austenite grain size of B1500HS boron steel, samples of B1500HS steel were, respectively, heated at 900, 925, 950, 975, and 1000°C for 10, 20, 40, and 60 min, and the grain sizes of austenite for the heated samples were measured. Besides that, samples of B1500HS steel were heated at 1000°C for 10, 20, and 40 min by the thermo-mechanical simulator Gleeble-1500D, and then deformed with the deformation of 10, 20, and 30 % at the strain rate of 0.1 and 0.5 s−1, respectively, the effect of deformation degree and strain rate on the grain size of austenite was also studied. The experimental results showed that the average grain size of austenite rises with the increase of austenitization temperature and soaking time, but the average grain size reduced with the increase of deformation degree and strain rate. Finally, a grain growth model of B1500HS steel was given according to the experimental results.

Investigation on snow-melting performance of asphalt mixtures incorporating with salt-storage aggregates

Chloride salts are the most commonly used chemicals that serve as snow-melting agents for winter highway maintenance due to their abundance and low cost. However, the heavy use of chloride-based deicers has caused a series of environmental problems, because the deicers are directly spread on the pavement surface before snowing. Therefore, how to decrease the damage of chloride salts on pavement and environment is very important. Thus, introduction of the deicer into the asphalt mixtures and making the deicer slow release has brought a recent scientific and industrial interest. In this work, salt-storage aggregates (SSA) were innovatively prepared. Asphalt mixtures incorporating 0%, 5%, 10%, 15% and 20% SSA by volume as limestone aggregates (LSA) were prepared and their engineering properties were tested, such as high temperature stability, crack resistance at low temperature and water stability. In addition, salt-release performance of asphalt mixtures with SSA was investigated. Finally, field snow-melting test was conducted by outdoor experiments of the asphalt mixtures. The results show The SSA possesses excellent water stability, high mechanical strength and salt-storage function. The properties of asphalt mixtures with SSA can meet the requirements of specification, but the influence of SSA on water stability of asphalt mixtures should be noticed. The electrical conductivity of asphalt mixtures increases with the increase of SSA content. Salt precipitation amount per unit area increases and then gradually becomes stable with the increase of soaking time. Salt precipitation amounts from asphalt mixtures increase with the standing time and the SSA content. The asphalt pavement with SSA can possess satisfied snow-melting performance in reference to the simulated field tests.