Chemical composition changes of post-harvest coconut inflorescence sap during natural fermentation

2011 ◽  
Vol 10 (66) ◽  
Author(s):  
Xia
2019 ◽  
Author(s):  
Ye Tao ◽  
Jennifer G. Murphy

Abstract. Aerosol pH is difficult to measure directly but can be calculated if the chemical composition is known with sufficient accuracy and precision to calculate the aerosol water content and the H+ concentration through ion balance. In practical terms, simultaneous measurements of at least one semi-volatile constitute, e.g. NH3 or HNO3, are required to provide a constraint on the calculation of pH. Long-term records of aerosol pH are scarce due to the limited monitoring of NH3 in conjunction with PM2.5. In this study, 10-year (2007–2016) records of pH of PM2.5 at six eastern Canadian sites were calculated using the E-AIM II model with the input of gaseous NH3, gaseous HNO3 and major water-soluble inorganic ions in PM2.5 provided by Canada's National Air Pollution Surveillance (NAPS) Program. Clear seasonal cycles of aerosol pH were found with lower pH (~2) in summer and higher pH (~3) in winter consistently across all six sites, while the day-to-day variations of aerosol pH were higher in winter compared to summer. Tests of the sensitivity of aerosol pH to meteorological parameters demonstrate that the changes in ambient temperature largely drive the seasonal cycle of aerosol pH. The sensitivity of pH to chemical composition shows that pH has different responses to the changes in chemical composition in different seasons. During summertime, aerosol pH was mainly determined by temperature with limited impact from changes in NHx or sulfate concentrations. However, in wintertime, both meteorological parameters and chemical composition contribute to the variations in aerosol pH, resulting in the larger variation during wintertime. This study reveals that the sensitivity of aerosol pH to chemical composition is distinctly different under different meteorological conditions and needs to be carefully examined for any particular region.


1996 ◽  
Vol 34 (3-4) ◽  
pp. 525-531 ◽  
Author(s):  
W. T. Huang ◽  
I. L. Chang ◽  
D. J. Lee ◽  
S. G. Hong

The chemical compositions changes for waste activated sludge at different freezing speeds were analyzed via FTIR spectra. With a high speed of freezing, the chemical compositions are little influenced by the action of ice formation, which with a low speed of freezing, the chemical compositions are largely affected. The prerequisite for sufficient dewaterability improvement is found as the global floc migration owing to the ice front formation, which releases some ECPs (basically cellulose) from the sludge and after the resulting cake structure ultimately.


Author(s):  
T. Manso ◽  
A.R. Mantecó ◽  
T. Castro ◽  
P. Lavin

Body composition changes in animals undergoing compensatory growth and these response vary with the age or stage of maturity at which the restriction is applied and with the undegradable protein in the diet during post-restriction period (O'Donovan, 1984; Ryan, 1990).This experiment was conducted to determine the effect of level of intake during milk-fed period and the energy/protein relationship during post-weaning period on changes in carcass, non-carcass and empty body weigth (EBW) components in lambs slaughtered at 20 Kg live weigth (LW).A total of 16 lambs of Churra breed were used in a comparative slaughter experiment to determinate the effect of level of intake during milk-fed period (4 weeks) and the protein supplement in the diet during post-weaning period on chemical body composition at 20 Kg LWThe lambs were assigned to a 2×2×4 factorial design, defined by 2 levels of milk intake (High: 1.5 MJ GE/Kg LW°75/day and Low: 0.9 MJ GE/kg LW°75/day) during milk-fed period, 2 post-weaning concentrate supplements (HP: barley grain plus 200g/kg fish meal and LP: barley) and 4 lambs per treatment.All lambs were individually penned. During post-weaning period low quality hay and concentrate were independently offered ad libitum. Intake and LW were recorded daily and three times a week respectively. At slaughter (20Kg LW), EBW was estimated and carcass and non-carcass chemical composition (water, fat, ash and protein) and energy content was measured.


Author(s):  

Analysis of the hydro/chemical regime and spatial regularities of the water composition changes in the Vasyugan Bog North-Eastern part between the Bakchar and Iksa rivers is presented. It has been noted that the chemical composition transformation with water class, group and type during the year is a special feature of the high bog hydro/chemical regime. Within the bog limits three clusters have been identified by bog waters chemical composition characteristics on the basis of the cluster analysis. Reliable differences between the tree clusters have been determined by the mineralization amount, Са2+, Mg2+, Feобщ, NH4 +, NO3 - ions, humic and fulvene acids, Сорг and СО2 content. Analysis of the seasonal indices has demonstrated that during the vegetation period two significant maximal peaks of the bog water seasonal wave of chemical composition occur, namely in March and September. It has been noted that that the near-ground air temperature sum increase more than 10 ºС is accompanied by the pH increase in the high bog water, increase of СО2, ammonia, sulphate, iron ions, and organic matter (humic and fulvene acids, Сорг).


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