Effects of Peracetic Acid(PAA) Combined with Calcium Treatments on Storage Quality of Loquat Fruit

[Objective] The paper was to evaluate effects of peracetic acid （PAA） combined with calcium treatments on storage quality of Ioquat fruits, so as to pro- vide practical techniques to solve the problems of postharvest rot and quality deteri- oration for Ioquat fruits. [Method] With Ioquat fruits of Qingzhong variety as materi- als, 0.2%, 0.4% and 0.8% PAA combined with 0.8% CaCI2 was used to soak Ioquat fruits for 4 min, 0.8% CaCl2 and water treatments were set as two controls; the fruits were dried and packaged by 0.02 mm PE bags, then stored under non-chilling low temperature of （7±1） ℃. The indicators related to storage quality of Ioquat fruits were randomly tested once every 3 d, and their variation situations were analyzed. [Result] Compared with two control treatments and 0.2% PAA, 0.8% PAA combined with calcium treatments, the treatment of 0.4% PAA combined with 0.8% CaCl2 could significantly inhibit rot index, weight loss rate, firmness and cell membrane permeability of Ioquat fruits during storage period, which could also effectively delay the reduction of titratable acid, vitamin C, soluble solid content and juice yield, and maintain respiration intensity of fruits at a low level; the appearance and flavor qual- ity of fruits were good after stored for 25 d. [Conclusion] 0.4% PAA combined with 0.8% CaCl2 treatment is an efficient, safe and economical practice technology in an- ti-corrosion and quality preservation for postharvest Ioquat fruits .

Inclusion variations and calcium treatment optimization in pipeline steel production

SiCa line and SiCaBaFe alloy were injected into liquid pipeline steel at the end of LF refining as calcium treatment,and samples were taken from the ladles,mould,and slabs.Analysis of Ca content and inclusions shows that Ca content in steel decreases obviously in the following process after calcium treatment;the compositions,morphology,and sizes of inclusions also vary much in the production;primary inclusions in the ladles prior to calcium treatment are mainly Al2O3 inclusions,but they turn to fine irregular CaS-CaO-Al2O3 compound inclusions after the treatment,then become fine globular CaO-Al2O3 inclusions in the mould,and finally change to a few larger irregular CaS-CaO-Al2O3 complex inclusions in the slabs.Thermodynamic study reveals that inclusion variations are related with the preferential reactions among Ca,Al2O3,and S and the precipitation of S in CaO-Al2O3 inclusions with high sulfur capacity.New evaluation standards for calcium treatment in high-grade pipeline steel were put forward according to the inclusion variations and requirements of pipeline steel on inclusion controlling,and the calcium process was studied and optimized.

Effect of calcium content on inclusions during the ladle furnace refining process of AISI 321 stainless steel

The effect of three heat processes with different calcium contents on the evolution of inclusions during the ladle furnace refining process of AISI 321 stainless steel was investigated.The size,morphology,and composition of the inclusions were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy.After the addition of aluminum and titanium,the primary oxide in the AISI 321 stainless steel was an AbOs—MgO—TiOx complex oxide,in which the mass ratio of AbOs/MgO was highly consistent with spinel(MgO・AbO3).After calcium treatment,the calcium content in the oxide increased significantly.Thermodynamic calculations show that when the Ti content was 0.2wt%,the Al and Ca contents were less than 0.10wt%and 0.0005wt%,respectively,which was beneficial for the formation of liquid inclusions in molten steel.Moreover,the modification mechanism of calcium on TiN-wrapped oxides in combination with temperature changes was discussed.

Influence of calcium content on solid ratio of inclusions in Ca-treated liquid steel

It has been found that Ca-treated liquid steel can be cast at a lower superheat. To ascertain the reason for the improved castability of Ca-treated liquid steel and to find the optimal range of calcium content, the behavior of calcium in liquid steel was studied in terms of the relationship between the calcium content and solid ratio of inclusions. The relationship between the calcium content and solid ratio of inclusions was obtained by means of the classification of nonmetallic inclusions in solid and liquid steels at casting temperature according to the Al2O3-CaO-SiO2 phase diagram. The optimum calcium content should be 17-23 ppm.

Effects of calcium treatment on non-metallic inclusions and magnetic properties of non-oriented silicon steel sheets

Based on the industrial production of non-oriented silicon steel,calcium treatment by CaSi wire feeding during the RH refining process was studied. The thermodynamics of CaS inclusion formation was analyzed, and the morphology and the size distribution were observed. Furthermore, the change in inclusion characteristics after calcium treatment and the effect of calcium treatment on magnetic properties were discussed. The results show that the formation of MnS and A1N inclusions were restrained, and the aggregating, floating and removing of microinclusions after calcium treatment were effectively promoted. The cleanliness of liquid steel was obviously increased. The main type of inclusions was single phase of CaO, with some complex inclusions composed of CaO, SiO2 and MgO. No CaS inclusion was observed after an appropriate calcium treatment. The size of all inclusions was distributed in the range of 2 - 20 μm, and the number was about 1.8 × 10^5/mm3. In addition, as an increasing amount of calcium was added,the core loss gradually decreased to a stable level, and the magnetic induction decreased quickly after a slow increase. The optimal calcium treatment mode depends on the chemical composition of steel.

Vitamin D and calcium are required at the time of denosumab administration during osteoporosis treatment

To evaluate the differences in outcomes of treatment with denosumab alone or denosumab combined with vitamin D and calcium supplementation in patients with primary osteoporosis. Patients were split into a denosumab monotherapy group （18 cases） or a denosumab plus vitamin D supplementation group （combination group; 23 cases）. We measured serum bone alkaline phosphatase （BAP）, tartrate-resistant acid phosphatase （TRACP）-5b and urinary N-terminal telopeptide of type-I collagen （NTX） at baseline, 1 week, as well as at I month and 2, 4, 8 and 12 months. We also measured bone mineral density （BMD） of L1-4 lumbar vertebrae （L）-BMD and bilateral hips （H）-BMD at baseline and at 4, 8 and 12 months. There was no significant difference in patient background. TRACP-5b and urinary NTX were significantly suppressed in both groups from I week to 12 months （except at 12 months for NTX）. In the combination group, TRACP-5b was significantly decreased compared with the denosumab monotherapy group at 2 and 4 months （P 〈 0.05）. BAP was significantly suppressed in both groups at 2-12 months. L-BMD significantly increased at 8 and 12 months （8.9%） in the combination group and at 4, 8 and 12 months （6.0%） in the denosumab monotherapy group, compared with those before treatment. H-BMD was significantly increased in the combination group （3.6%） compared with the denosumab group （1.2%） at 12 months （P 〈 0.05）. Compared with denosumab monotherapy, combination therapy of denosumab with vitamin D and calcium stopped the decrease in calcium caused by denosumab, inhibited bone metabolism to a greater extent, and increased BMD （especially at the hips）.

Control of Al_2O_3 inclusions in austenite stainless steel

In the present study, samples were extensively collected throughout the stainless steel manufacturing process. The three-dimensional morphology of inclusions was revealed by non-aqueous solution electrolysis. The high concentration of aluminum in ferrosilicon caused the increment of [Al]s in steel and Al2 O3 in inclusions, which led to the higher melting temperature of inclusions. It was concluded that the application of low Al ferrosilicon and calcium treatment could prevent the formation of Al2 O3-rich inclusions.

Evolution of Nonmetallic Inclusion during Steelmaking Process of Cold Heading Steel SWRCH35K

In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS and the image processing software Image-Pro-Plus6.0 were employed to analyze the chemical composition, morphology, quantity and size of non-metal inclusions in the steel samples. The results show that from BOF tapping to continuous casting tundish, the composition of inclusions in SWRCH35K steel changes from Al2O3 →MgO·Al2O3 →CaO-MgO-Al2O3-CaS, and the typical morphology of the inclusions in the steel gradually changes from irregular blocks and clusters to spherical. The number of inclusions in the BOF argon blowing station is the largest, 213#/mm2, while the number of inclusions at the end of LF refining is the least, about 12#/mm2, and there are basically no inclusions above 5 μm. In addition, LF calcium treatment will adversely affect the size and quantity control of inclusions in steel. In order to effectively reduce the large-size calcium-containing spherical oxide inclusions in cold heading steel, it is necessary to find a technical method that can replace LF calcium treatment to solve the problem of molten steel continuous casting.

Denaturation behavior of inclusions in industrial pure iron by calcium treatment

Only a few Chinese enterprises can produce high-quality industrial pure iron,and studies on the smelting process of industrial pure iron were limited.The inclusions in a melting process were characterized by means of electron microscopy and an automatic inclusion analysis system,and the evolution mechanism of inclusion was studied using thermodynamic calculation to optimize the calcium alloy addition in liquid window.The results show that during the smelting process,inclusions mainly composed of Al_(2)O_(3)and spinel are formed before calcium treatment.After calcium treatment,they continuously react with[Ca],[S]and[Ti],grow up,and are removed during refining and tundish pouring.In the end,there are more small-sized inclusions containing CaS,and the contents of Al_(2)O_(3)and spinel are less.According to thermodynamic calculations,the appropriate calcium treatment liquid window for the molten steel composition is(10-38)×10^(-6).Calcium treatment has changed the main types of inclusions in industrial pure iron from Al_(2)O_(3)to small-sized inclusions containing CaS and effectively reduces the influence of Al_(2)O_(3)inclusions on the quality of industrial pure iron.

Effect of Calcium Treatment on Non-Metallic Inclusions in Ultra-Low Oxygen Steel Refined by High Basicity High Al_2O_3 Slag

The influence of calcium treatment on non-metallic inclusions had been studied when control technology of refining top slag in ladle furnace was used in ultra-low oxygen steelmaking. A sufficient amount aluminium was added to experimental heats for final deoxidizing during BOF tapping, and the refining top slag with strong reducibility, high basicity and high Al2O3 in ladle furnace was used to produce ultra-low oxygen steel and the transformation of nonmetallic inclusions in molten steel was compared by calcium treatment and no calcium treatment. The results show that the transformation of Al2O3--MgO - Al2O3 spinel-CaO-MgO-Al2O3 complex inclusions has been completed for aluminum deoxidation products and calcium treatment to molten steel is unnecessary when using the control technology of ladle furnace refining top slag to produce ultra-low oxygen steel, and the complex inclusions are liquid at the temperature of steelmaking and easily removable to obtain very high cleanliness steel by flotation. Further- more, the problems of nozzle clogging in casting operations do not happen and the remaining oxide inclusions in steel are the relatively lower melting point complex inclusions.

Inclusion engineering and metallurgy of calcium treatment

Although a great deal of research has been done in the area of inclusion control during steelmaking, a complete description of the process of inclusion modification and shape control cannot be found in literatures. As a result, the terms ＂inclusion modification＂ and ＂shape control＂ are often used loosely in the technical community. To utilize the full potential offered by a calcium treatment, it is important to understand why an inclusion whose composition has been modified may not necessarily have its shape modified. With the purpose of decoupling the process of inclusion phase change from inclusion shape control, and to provide a complete description of the metallurgy of calcium treatment, a detailed literature survey has been performed on the subject. By coupling the survey with a new concept developed to tailor the cleanliness of steels to the intended applications, the hope is to provide the reader with valuable information on calcium treatment for inclusion modification and shape control.

Optimization of Calcium Addition to High-strength Low-alloy Steels

Nozzle blockage is a common problem during continuous casting of Al-killed steel, and calcium treatment is widely used to resolve it. In consideration of the production costs, the technology of nonmetallic inclusion control was studied to optimize the Ca consumption. The proposed process of slag washing was employed, and the refining slag composition, deoxidation conditions and alloying systems were optimized. Using these measures, the steel cleanliness before Ca addition was improved significantly, and the corresponding Ca consumption was reduced. More- over, the continuous casting could be conducted smoothly.

Mechanical Properties and Interfacial Interaction of Modified Calcium Sulfate Whisker]Poly(Vinyl Chloride)Composites

Calcium sulfate whiskers（CSWs） modified with glutaraldehyde-crosslinked poly（vinyl alcohol）（PVA） or traditional surface modifiers,including silane coupling agent,titanate coupling agent and stearic acid,were used to strengthen poly（vinyl chloride）（PVC）,and the morphologies,mechanical and heat resistant properties of the resulting composites were compared.The results clearly show that glutaraldehyde cross-linked PVA modified CSW/PVC composite（c PVA@CSW/PVC） has the strongest interfacial interaction,good and stable mechanical and heat resistant properties.Nielsen＇s modified Kerner＇s equation for Young＇s modulus is better than other models examined for the CSW/PVC composites.The half debonding angle θ of c PVA@CSW/PVC composite is lower than that of other composites except silane coupling agent modified CSW/PVC composites,indicating a very strong interfacial adhesion between c PVA@CSW and PVC.In general,cross-linked PVA is effective and environmentally friendly in modifying inorganic fillers.

Effect of Ca and Ti contents on characteristics of inclusions in Fe-Si-Cr-Mn-Al-Ti-Ca-O melts

The inclusion characteristics in 55SiCr spring steel with different contents of titanium and calcium were investigated.The chemical compositions of steel samples were detected by inductively coupled plasma optical emission spectrometer,and the inclusion characteristics was determined by field emission scanning electron microscopy(FE-SEM)and energy-dispersive spectroscopy.The results show that the Ti/Al ratio should be kept at less than 1,and the content of calcium should be controlled between 0.0015 and 0.0025 wt.%in Si-Mn-Al deoxidized steel,so that more solid inclusions can be converted to liquid inclusions.Moreover,the high Ti content in melts is the direct cause of the high proportion of Ti_(3)O_(5) in the inclusions,which involves[Ti]to reduce SiO_(2) and A1_(2)O_(3) in inclusions.In addition,calcium treatment can reduce the content of Ti_(3)O_(5) in inclusions,and the degree of reduction is closely related to the content of[O].The thermodynamic calculation of Fe-Si-Mn-Cr-Al-Ti-Ca-O molten steel system during solidification process was performed by FactSage software,taking all types of inclusions into account,such as titanium oxide,calcium oxide,aluminum oxide,silicon oxide,manganese oxide,calcium titanate,mullite,calcium aluminate,and liquid inclusion.The inclusion type of calculation results was in accordance with the experimental results at 1550℃,and TiO_(x) aggregation behavior was consistent with the Ti_(2)O_(3)-containing precipitation phase.

Effect of Sulfur Content and Sulfide Shape on Fracture Ductility in Case Hardening Steel

The effects of sulfur content and calcium addition on smooth axisymmetric tensile fracture ductility of case hardening steel DIN 18CrNiMo7-6 have been investigated. The quantitative metallographic analysis of sulfide inclusions and the correlations between sulfide inclusions and fracture ductility were examined. Sulfide inclusions were found to have deleterious effect on fracture ductility, whereas the effect can be offset to some extent by calcium-treat- ment due to less easily deforming of sulfides during hot-working. The product （AA·λAW） of sulfide inclusion area fraction （An） and its area-weighted aspect ratio （λAW） can be used as a parameter to describe the effect of sulfide inclusions on fracture true strain.

Clinical Study of Acute Vasoreactivity Testing in Patients with Chronic Thromboembolic Pulmonary Hypertension

Background： The clinical significance of acute vasoreactivity testing （AVT） in patients with chronic thromboembolic pulmonary hypertension （CTEPH） remains unclear. We analyzed changes in hemodynamics and oxygenation dynamics indices after AVT in patients with CTEPH using patients with pulmonary arterial hypertension （PAH） as controls. Methods： We analyzed retrospectively the results of AVT in 80 patients with PAH and 175 patients with CTEPH registered in the research database of Beijing Chao-Yang Hospital between October 2005 and August 2014. Demographic variables, cardiopulmonary indicators, and laboratory findings were compared in these two subgroups. A long-term follow-up was conducted in patients with CTEPH. Between-group comparisons were performed using the independent-sample t-test or the rank sum test, within-group comparisons were conducted using the paired t-test or the Wilcoxon signed-rank test, and count data were analyzed using the Chi-squared test. Survival was estimated using the Kaplan-Meier method and log-rank test. Results： The rates of positive response to AVT were similar in the CTEPH （25/175, 14.3%） and PAH （9/80, 11.3%） groups （P 〉 0.05）. Factors significantly associated a positive response to AVT in the CTEPH group were level of N-terminal pro-brain natriuretic peptide （〈1131.000 ng/L）, mean pulmonary arterial pressure （mPAE ≤44.500 mmHg）, pulmonary vascular resistance （PVR, 〈846.500 dyn＇s-1·m-5）, cardiac output （CO,≥3.475 L/rain）, and mixed venous oxygen partial pressure （PvO2, ≥35.150 mmHg）. Inhalation of iloprost resulted in similar changes in mean blood pressure, mPAE PVR, systemic vascular resistance, CO, arterial oxygen saturation （SaO2）, mixed venous oxygen saturation, partial pressure of oxygen in arterial blood （PaO2）, PvO2, and intrapulmonary shunt （Qs/Qt） in the PAH and CTEPH groups （all P 〉 0.05）. The survival time in patients with CTEPH with a negative response to AVT was somewhat shorter than that in AVT-responders although the difference was not statistically significant （X2= 3,613, P = 0.057）. The survival time of patients with CTEPH who received calcium channel blockers （CCBs） was longer than that in the group with only basic treatment and not shorter than that of patients who receiving targeted drugs or underwent pulmonary endarterectomy （PEA） although there was no significant difference between the four different treatment regimens （X2 = 3.069, P = 0.381 ）. Conclusions： The rates of positive response to AVT were similar in the CTEPH and PAH groups, and iloprost inhalation induced similar changes in hemodynamics and oxygenation dynamics indices. A positive response to AVT in the CTEPH group was significantly correlated with milder disease and better survival. Patients with CTEPH who cannot undergo PEA or receive targeted therapy but have a positive response to AVT might benefit from CCB treatment.

Nonmetallic Inclusion Control of 350 km/h High Speed Rail Steel

Inclusion has an important effect on quality of high speed rail steel. In consideration of the lower acceptance percentage of the inclusion and its constraint against the requirement for large scale production of 350 km/h high speed rail steel in Panzhihua Iron and Steel （Group） Co,the technology of nonmetallic inclusion control for 350 km/h high speed rail steel was studied. An optimized model of the argon-blowing in ladle furnace （LF）,the control of the components of the ladle slag,and the technique of calcium treatment for the molten steel was brought forward. Using the researched technology,the removal ratio of the inclusion was increased and the components,distribution,and shape of the inclusion in the rail steel were changed,which resulted in a reduction in the average total oxygen content to 10.17×10^-6 and an increase in the comprehensive acceptance percentage of the nonmetallic inclusion from 48.21% to 98.1%. Test has shown that this metallurgical technology can meet the requirement for large scale production of 350 km/h high speed steel in Panzhihua Iron and Steel （Group） Co.

Investigations of Inclusion Modification in High Grade Pipeline Steel

SiCa line was injected into liquid pipeline steel at the end of LF refining as calcium treatment, and samples were taken from liquid steel in ladles before and after calcium treatment, liquid steel in mould, and slabs. Results show that Ca content in steel decreased obviously after calcium treatment with production, and the compositions, morphologies and sizes of inclusions in steel also varied with time; Al2O3 inclusions turned to be fine irregular CaS-CaO-Al2O3 compound inclusions after calcium treatment, and then to be fine globular CaO-Al2O3 inclusions in mould, and finally changed to be a few larger irregular CaS-CaO-Al2O3 complex inclusions in slabs; reoxidation of molten steel treated by Ca deteriorates effect of calcium treatment. Thermodynamic study revealed that inclusion variations were related with preferential reactions among Ca, Al2O3 and S and precipitation of S in high sulfur capacity CaO-Al2O3 inclusions. New calcium treatment controlling rules were put forward according to the inclusion variations and requirements of pipeline on inclusion controlling.