Chemical Properties and Microbial Analysis of Waterlogged Archaeological Wood from the Nanhai No. 1 Shipwreck

The Nanhai No. 1 was a wooden merchant ship of the Southern Song Dynasty, which wrecked and sank in the South China Sea, Yangjiang City, Guangdong Province, China. The Nanhai No. 1 shipwreck was salvaged as a whole in 2007 and began to be excavated in 2013. During the archaeology excavation, some of the hull wood fell off the hull. These waterlogged archaeological woods (WAW) were immersed in the buffer containing EDTA-2Na and isothiazolinone K100 for moisture stabilization, preliminary desalination, and microbial inhibition. We evaluated the properties of these WAW through testing the chemical components (including lignin, holocellulose, and ash content) of the wood, and monitoring the iron element content, anion and cation content in the buffer. At the same time, the microbial composition in the desalination buffer was also detected. The results showed that the holocellulose content in these WAW were much lower than in fresh wood. The ash content in these WAW decreased after desalination treatment. The iron element content, anion and cation content in the buffer were high and kept at a certain level after desalination treatment. At the same time, the problem of biodegradation in the buffer should be paid attention to. The comprehensive protection of WAW requires to combine wood properties and microbial problems. This study provides a reference for the protection of WAW from the Nanhai No. 1 shipwreck and other similar historical wood.

MO188RECONSIDERING THE EDELMAN EQUATION: IMPACT OF INDIVIDUAL TOTAL BODY CATION CONTENT AND BODY WEIGHT

Background and Aims Treatment of dysnatremias is guided by formulas that are based on the Edelman equation, including Adrogue-Madias’ and others. Edelman’s equation is the result of a unique study in which serum sodium concentration ([Na+]), total body exchangeable sodium (Nae+) and potassium (Ke+) and total body water (TBW) were measured in a highly heterogeneous population. Because these observations resulted from steady state observations, the equation might not account for the recently uncovered highly dynamic Na+ body compartment where Na+ is temporarily stored and released without affecting TBW. Various factors that influence this Na+ body compartment have been identified and we questioned as to what extent these factors affect associations between serum [Na+] and [Nae+Ke]/TBW. Method We performed a post-hoc analysis of original data published by Edelman. In the linear regression model, effects of sex, edema (y/n), age and body weight (>/< median split) were examined. Serum [Na+] was calculated by multiplying serum water [Na+] of the original data set by 0.93. Using piecewise regression, we analyzed differences in slope and y-intercept for the regression between serum [Na+] and increasing values of (Nae+Ke)/TBW, in which the clinical characteristics from the subgroups were included as interaction factors . Results Data was available for 85 measurements in 82 patients; 57 males and 25 females. The median age (range) age was 58 (27-90) years and median weight (range) was 59.6 (36.4 – 168.2) kilograms. Median serum [Na+] (range) was 131.4 (103.4 – 150.2) mmol/L. The association between serum [Na+] and (Nae+Ke)/TBW was different for high and low weight categories (figure 1A). Sex, age or presence of edema did not alter the relationship. Piecewise regression showed a significant decrease in slope in the regression between serum [Na+] and (Nae+Ke)/TBW above 149 mmol/L (Nae+Ke)/TBW (figure 1B). Conclusion Edelman equation’s coefficients are significantly affected by weight and total body cation content. In subjects with a low weight and low total body cation content, the Edelman equation seems to adequately predict the course of serum [Na+]. However, the clinical use of the Edelman-based formulas may be hampered in subjects with higher weight and higher total body cation content, which may reflect increased tissue Na+ storage. Our analysis underlines the importance of further research into the role of osmotically inactive Na+ storage in osmoregulation.

Impact Of Defensive Covering Of Anti-Inflamatory Medicine Tablets With Acrylatemethacrylate Copolymers On Tablet Crumbling Times And Disintegration Rates

Tablets of headache medicine (a dampness degradable medication) have been film covered with two undifferentiated from Eudragit RL and RS copolymers assigned here as An and B which vary just in their cation content in the proportion 2:1 (A:B). An, is in this manner more hydrophilic than B. The tablets were film covered with ethanol arrangements of these two polymers. Film covering with either An or B fundamentally decreased the dampness take-up possibilities of the tablets however caused an expansion in the breaking down occasions of the tablets and hindered disintegration rates. The mean deterioration times were 0.5±0.1 min (uncoated tablets), 16±2.5 min (tablets covered with An) and 115±3.6 min (tablets covered with B). The relating disintegration rates % h - 1 were 28.3 for uncoated, 16.6, covered with An and 14.8, covered with B, separately. Subsequently, covering with polymer B impressively impeded the crumbling and disintegration properties of the tablets.

The steric influence of extra-framework cations on framework flexibility: an LTA case study

The theoretical extent of framework flexibility of Zeolite A (LTA) in response to the steric and geometric effects of different Si/Al compositions and extra-framework cation content has been explored using GASP software. Flexibility windows and compression mechanisms for siliceous LTA and aluminosilicate Na-LTA, Ca-LTA and K-LTA have been modelled. As expected, relatively small cations in the zeolite pores have little effect on the range of flexibility observed. Aluminosilicate LTA, Na-LTA and Ca-LTA frameworks exhibit identical flexibility windows and these frameworks also follow the same compression mechanisms. The introduction of larger K+ ions, however, results in greater steric hindrance. This restricts the flexibility of the framework and alters the compression mechanism to accommodate these larger cations. It is shown that the limits of the flexibility window of Zeolite A are dependent on framework aluminium content and extra-framework cation size.

A Further Investigation of NH4+ Removal Mechanisms by Using Natural and Synthetic Zeolites in Different Concentrations and Temperatures

We investigated the ammonium removal abilities of natural and synthetic zeolites with distinct Si/Al ratios and various surface areas to study how adsorption and ion exchange processes in zeolites perform under different ammonium concentrations and different temperatures. Five zeolites—natural mordenite, chabazite, erionite, clinoptilolite, and synthetic merlinoite—were immersed in 20, 50, and 100 mg/kg ammonium solutions. The results demonstrate that zeolites under high ammonium concentrations (100 mg/kg) possess higher physical adsorption capacity (0.398–0.468 meq/g), whereas those under lower ammonium concentrations (20 mg/kg) possess greater ion exchange properties (64–99%). The ion exchange ability of zeolites is extremely dependent on the cation content of the zeolites, and the cation content is affected by the Si/Al ratio. The surface area of zeolites also has a partial influence on its physical adsorption ability. When the surface area is less than 100 m2/g, the adsorption ability of zeolite increases obviously with surface area; however, adsorption ability is saturated as the surface area becomes larger than this critical value of 100 m2/g. When we placed the zeolites in 50 mg/kg ammonium concentration at different temperatures (5–50 °C), we found that the zeolites exhibited the highest ammonium removal ability at 30 °C and the potassium release was enhanced at 30–40 °C.

A Further Investigation of NH4+ Removal Mechanisms by Using Natural and Synthetic Zeolites in Different Concentrations and Temperatures

We investigate the ammonium removal abilities of natural and synthetic zeolites, which have distinct Si/Al ratios and various surface areas, to study how adsorption and ion-exchange processes in zeolites perform under different ammonium concentrations and different temperatures. Five zeolites including natural mordenite, chabazite, erionite, clinoptilolite and synthetic merlinoite were immersed in 20 mg/kg, 50 mg/kg and 100 mg/kg ammonium solutions. The results demonstrate that zeolites under high ammonium concentrations (100 mg/kg) possess higher physical adsorption capacity (0.398–0.468 meq/g), whereas those under lower ammonium concentrations (20 mg/kg) possess greater ion-exchange property (64–99%). The ion-exchange ability of zeolites are extremely dependent on the cation content of the zeolites, and the cation content is affected by the Si/Al ratio. The surface area of zeolites also has a partial influence on its physical adsorption ability. When the surface area is less than 100 m2/g, the adsorption ability of zeolite increases obviously with surface area; however, adsorption ability is saturated as the surface area becomes larger than this critical value of 100 m2/g. When we carried out the zeolites in 50 mg/kg ammonium concentration at different temperatures (5~50 ℃), we found that zeolites exhibit the highest ammonium removal ability at 30°C and the potassium release was enhanced at 30~40 ℃.