scholarly journals Chemical characteristics of snow in the region along the Sea of Japan

1993 ◽  
Vol 18 ◽  
pp. 227-233 ◽  
Author(s):  
Kazuhide Satow

The amount of acidity in precipitation has been measured in heavy-snowfall regions facing the Sea of Japan. The average pH value of precipitation measured throughout the year at Nagaoka was 4.80 during 4.5 years, 1987–92. During winter the pH value is lower and electric conductivity higher. The spatial distribution of chemical components in new-fallen snow was studied along a 55 km-long sampling route. Results from four surveys showed that acidic snows have average pH values of 4.63–4.90. From the distribution of anion and cation concentration in new-fallen snow, it is concluded that strong northwest monsoons during winter bring an abundance of snow with salt components and many non-salt components from the Sea of Japan and also, possibly, from the Asian continent.

1993 ◽  
Vol 18 ◽  
pp. 227-233 ◽  
Author(s):  
Kazuhide Satow

The amount of acidity in precipitation has been measured in heavy-snowfall regions facing the Sea of Japan. The average pH value of precipitation measured throughout the year at Nagaoka was 4.80 during 4.5 years, 1987–92. During winter the pH value is lower and electric conductivity higher. The spatial distribution of chemical components in new-fallen snow was studied along a 55 km-long sampling route. Results from four surveys showed that acidic snows have average pH values of 4.63–4.90. From the distribution of anion and cation concentration in new-fallen snow, it is concluded that strong northwest monsoons during winter bring an abundance of snow with salt components and many non-salt components from the Sea of Japan and also, possibly, from the Asian continent.


1988 ◽  
Vol 24 (1-4) ◽  
pp. 93-95 ◽  
Author(s):  
T. Nishikawa ◽  
S. Okabe ◽  
M. Aoki

Abstract The atmospheric radon daughters concentration at Fukui in the Japanese coastal region of the Sea of Japan shows a seasonal variation whose high values appear in summer and low values in winter. On the other hand, the radon daughters concentration in precipitation at Fukui and that in the maritime atmosphere over the Sea of Japan are high in winter and low in summer. It is concluded from these phenomena that the greater part of the continental radon and its daughters are transported by seasonal winds from Siberia and China to Japan across the Sea of Japan in winter. However, when the air masses approach the shore, the cumulonimbus grows and the heavy snowfall scavenges out the radon daughters from the air masses in large quantities at the Japanese coastal region of the Sea of Japan.


1988 ◽  
Vol 55 (3) ◽  
pp. 457-464 ◽  
Author(s):  
Buensuceso Fernandez Del Pozo ◽  
Pilar Gaya ◽  
Margarita Medina ◽  
M. Asunción Rodríguez-Marín ◽  
Manuel Nuñez

SummaryCasein breakdown and free fatty acids formation were studied in ten batches of La Serena cheese throughout a 60 d ripening period. A rapid degradation of αs1-casein occurred, with only 18·6% residual αs1-casein being detected in 60 d-old cheese, whereas 49·5% β-casein remained unattacked. High pH values, low NaCl-in-moisture concentrations and high moisture contents enhanced proteolysis. Lac-tobacilli and yeasts were the only microbial groups which significantly influenced αs1-casein breakdown, and only yeasts affected β-casein hydrolysis. No significant effect of chemical characteristics or microbial groups on FFA levels was detected, an average level of 12·7 mequiv./100 g fat being recorded for 60 d cheese. Rheological characteristics of the cheese reached their minimum values after 15–30 d of ripening and were dependent on αs1- and β-casein breakdown, pH value, NaCl-in-moisture concentration and moisture content.


Author(s):  
Hakan Benli

The aim of this study was to investigate some chemical characteristics and residual nitrite and nitrate levels of sucuk and salami samples collected from retail outlets of major supermarkets in Adana province. A total of 36 sucuk samples (12 brands; 7 national and 5 local producers) and 30 salami samples (10 brands; Macar salamis) were purchased from local markets. Sucuk and salami samples were analyzed for pH value, moisture content, water activity and nitrite and nitrate contents. The average pH values of sucuk samples ranged between 4.69 and 6.56 indicating a higher variation while the average pH values of salami samples ranged between 6.05 and 6.43. Likewise, the average moisture contents of sucuk samples were between 33.56% and 46.78% whereas the average moisture contents of salami samples ranged between 62.09% and 67.91% indicating a relatively lower variation. Water activity values of the sucuk samples were between 0.932 and 0.861 while the average aw values of the salami samples ranged between 0.916 and 0.940. Among the sucuk samples analyzed in the present study mean nitrite and nitrate contents ranged from 58.65 mg/kg to 216.63 mg/kg and 34.86 mg/kg to 161.08 mg/kg, respectively. While relatively lower nitrite (14.30 mg/kg - 35.96 mg/kg) and no nitrate contents were observed in salami samples, the data indicated that a higher variation of both nitrite and nitrate contents were still present in sucuk samples in the local markets requiring more studies and inspections to lower the variation related to dietary exposure to nitrite and nitrite from these types of products.


2014 ◽  
Vol 54 (1) ◽  
pp. 30-40 ◽  
Author(s):  
P. A. Saveliev ◽  
A. A. Balanov ◽  
P. V. Kalchugin ◽  
D. V. Antonenko ◽  
S. F. Solomatov ◽  
...  

2020 ◽  
Vol 20 (5) ◽  
pp. 2719-2734 ◽  
Author(s):  
Shenbo Wang ◽  
Lingling Wang ◽  
Yuqing Li ◽  
Chen Wang ◽  
Weisi Wang ◽  
...  

Abstract. Particle acidity is a fundamental property that affects atmospheric particulate chemistry. Synchronous online monitoring was performed at two urban sites, Zhengzhou (U-ZZ) and Anyang (U-AY), and three rural sites, Anyang (R-AY), Xinxiang (R-XX), and Puyang (R-PY) in Henan Province, during a haze episode to investigate the pH value and its driving factors in the agricultural regions of China. The pH values of particles calculated by ISORROPIA-II model at rural sites were slightly higher than those at urban sites, with the median (min–max) values of 5.2 (4.8–6.9, R-PY), 5.1 (4.7–6.5, R-AY), 4.9 (4.1–6.8, R-XX), 4.8 (3.9–5.9, U-AY), and 4.5 (3.8–5.2, U-ZZ). Sensitivity tests show that TNHx (total ammonium, gas + aerosol) followed by total sulfate were the most important factors that influenced the predicted pH. Generally, particle pH increased with a cation increase and decreases in anions, temperature, and relative humidity. Similar pH values (∼3.0) at the required NHx concentrations for the five sites indicated that the presence of excess NHx was likely important for the lower acidity of PM2.5 during the severe haze episodes in this region. Moreover, the concentrations of excess NHx may drive the higher pH values at rural sites, because of the higher excess NHx concentrations at rural sites than those at urban sites. The underlying influence of regional transport on local particle pH cannot be neglected, as it differs the chemical components of PM2.5 and meteorological conditions. Air masses transported from rural and agricultural regions may enhance the particle pH value in urban aerosols given the high pH of particles and high ammonia levels. These results suggest that ammonia is urgently needed to be involved in the regional strategy for the improvement of air quality in China.


2014 ◽  
Vol 11 (9) ◽  
pp. 10903-10930
Author(s):  
M. Katsuyama ◽  
T. Yoshioka ◽  
E. Konohira

Abstract. The spatial distribution of oxygen and hydrogen isotopic composition (δ18O and δ2H) of stream waters across Japan was clarified with a data set compiling sample data obtained from 1278 forest catchments during the summer of 2003. Both δ18O and δ2H values showed positive correlations with the mean annual air temperature and annual evapotranspiration, and negative correlations with latitude and elevation. Deuterium excess (d excess) values in stream waters were higher on the Sea of Japan side, and lower on the Pacific Ocean side, of the Japanese archipelago. The d excess in precipitation was generally higher in winter and lower in summer in Japan. The Sea of Japan side experiences a great deal of snowfall, and seasonal changes in monthly precipitation are rather small. In contrast, the Pacific Ocean side experiences a large amount of rainfall during summer with low levels of precipitation during the winter. Therefore, the lower d excess in stream waters on the Pacific Ocean side reflects summer precipitation, and the higher values on the Sea of Japan side are affected by delayed recharge from snowmelt. The isoscapes of stream water connote not only spatially integrated but also temporally integrated isotope signals of precipitation, and provide a framework for addressing applied hydrological, ecological, or meteorological research questions at regional scales, such as the effects of climate change.


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