scholarly journals The simplistic nitrogen input and output balance in Lake Łebsko – case study

Author(s):  
Roman Cieśliński

AbstractThe paper is based on the hypothesis that coastal lakes significantly affect changes in the quality of freshwater coming from catchments, which is best reflected in the reduction of biogenic loads. Some of the main reasons for this phenomenon include unique geographic locations of coastal lakes and physical and chemical properties of their waters as well as other hydrographic determinants that affect water circulation in catchments. The study area covered the direct drainage basin of Lake Lebsko, which is located in Słowiński National Park in northern Poland, on the coast of the southern Baltic Sea. The study was conducted from June 2008 to October 2010. Fieldwork was the main part of the research project and included hydrographic mapping, water sampling for laboratory analysis, and measurement of the discharge in all tributaries and outflows of the studied lake. Water chemistry data for Lake Lebsko indicate a significant accumulation of biogenic materials in the lake, which proves a strong effect exerted by the lake on the incoming water. This is true for both total chemical loads per year as well as concentrations of selected ions over short time intervals. This standard pattern may be interrupted by seawater intrusions that alter water chemistry in the whole lake.


2021 ◽  
pp. 10-24
Author(s):  
C. R. Abah ◽  
C. N. Ishiwu ◽  
J. E. Obiegbuna ◽  
E. F. Okpalanma ◽  
C. S. Anarado

Quality cassava(Manihotesculentus, Crantz) flour is often influenced by process variables such as slice weight and soaking time which may affect its nutritional quality. In this study, the effect of process variables (slice weight and soaking time) on quality of cassava flour was carried out. Cassava root was peeled, washed and cut into varied sizes (25.86 - 54.14 g) and soaked at varied time (7.03 - 40.97 h). The proximate composition, physical and chemical properties of the flour were carried out using standard methods. The result in our findings showed that slice weight and soaking time had significant increase (p<0.05) on the proximate and physico-chemical properties of the flour.The amylose and amylopectin content of the flour increased with increasing soaking time while the hydrogen cyanide content decreased with increase in soaking time. Overall, the quality cassava flour displayed desirable properties for its incorporation into baked goods.



2020 ◽  
Vol 1 (2) ◽  
pp. 7-16
Author(s):  
Winda Amilia ◽  
Andrew Setiawan Rusdianto ◽  
Arma Dwi Novemi

The amount of mango production in Indonesia is quite high, but the quality of postharvest mangoes is still quite low. The quality of the fruit will decline due to contamination; one of the contaminants is fungi. The way to reduce the damage of postharvest products is by coating applications. The purpose of this study was to study the physical, chemical and antifungal activities of harumanis mangoes’s quality which had been given coating during storage that could cause postharvest losses of harumanis mangoes. There are 3 treatments, each of them are respectively the provision of corn based coating  6% tobacco extract, 8% tobacco extract and 10% tobacco extract. The physical and chemical properties of the antifungal coating of tobacco extract made from corn coating for post-harvest damage on harumanis mangoes were obtained by weight loss, texture, colour, respiration rate, vitamin C and total dissolved solid. Preventing coating can prevent damage after harvest and protect the harumanis mango; therefore the quality of the mangoes can be maintained. The best results from the priority with the largest diameter inhibition zone were given corn starch 10% tobacco extract. Then the higher the concentration of extract used, the greater the diameter of the inhibition zone obtained. Based on all the tests performed (physical, chemical, and antifungal) the best treatment from the treatment was obtained that consisted of mangoes with antifungal layers of corn starch 10% tobacco extract. Because the P3 obtained the best results in maintaining physical, chemical content and fungi for 15 days.



2004 ◽  
pp. 79-90
Author(s):  
Vesna Vratusa

Efficient nursery production of woody plants, as well as the level of their successful application in urban green spaces, greatly depends upon properties of substrates in which these individuals grow, develop and endure. Furthermore, quality of substrate does not only affect the quality of future product (plant individual or green space), but distinctly determines its price. This element, extremely significant for all countries in transition, thus Serbia as well, commands finding ways of making qualitative, but least expensive substrate. The most logical solution is to use mixtures/substrates of precisely defined properties, composed of domestic components. Results presented in this paper imply that it is possible to create precisely such standard mixtures from domestic resources at relatively low cost, adjusted to needs of particular species, which would ultimately lead to successful, non-expensive nursery production and application of produced stock, both on domestic and foreign markets.



FLORESTA ◽  
2020 ◽  
Vol 50 (4) ◽  
pp. 1844
Author(s):  
Guilherme Giesel ◽  
Martha Andreia Brand ◽  
Flaviana Reis Milagres ◽  
Renato Augusto Pereira Damasio

In pulp production, wood in logs is stored for periods that can range from a few weeks to several months. During storage, changes in the wood properties that affect the pulping process and the quality of the pulp may occur. The objective of this study was to determine the ideal timing of wood storage in logs by evaluating the variations (a) in the chemical properties of wood (b) in the parameters of the pulping process and (c) the quality of the Pinus taeda pulp. Logs were stored in an industrial courtyard for 30, 60, 90, 120 and 150 days. In each storage period, the physical and chemical properties of the wood, the cooking parameters, and the properties of the pulp were analyzed. The chemical properties of wood varied throughout storage, but only the solubility in sodium hydroxide showed a positive and significant correlation with storage time. In pulping, the yield and tailings had an inversely proportional correlation with the storage time, while the organic and total solids content had a positive correlation. As for cellulose quality, arabinan and soluble lignin contents did not vary during storage. The mannan content had a positive and significant correlation with the storage time. Taking into account all the variables analyzed, the storage time of P. taeda logs should be up to 30 days.



2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Hao Liu ◽  
Bing Xie ◽  
Yue-lin Qin

The physical and chemical properties such as particle size, montmorillonite content, swelling degree, water absorption, and blue absorption of A, B, and C bentonites were studied under laboratory conditions. The effects of adding different quality and different proportion of bentonite on falling strength, compression strength, and shock temperature of green pellet were investigated. The experimental results show that the montmorillonite content, water absorption, and methylene blue absorption of bentonite-B are the highest. And the quality of bentonite-B is the best, followed by bentonite-C and bentonite-A poor quality. When the amount of bentonite-B reduced from 1.5% to 1.0%, the strength of green pellets and the shock temperature both decrease. As the same proportion of A, B, and C bentonites, the green-ball strength and shock temperature are as follows: bentonite-A > bentonite-B > bentonite-C.



1999 ◽  
Vol 5 (4) ◽  
pp. 285-297 ◽  
Author(s):  
A. Mulet ◽  
J. Benedito ◽  
J. Bon ◽  
N. Sanjuan

Ultrasonic applications can be classified into low intensity or high intensity applications. The latter are used to modify a process or product with ultrasonics, while in low intensity applications the process or product modifies the ultrasonic signal, thus providing information about the product. Low inten sity ultrasonics in food technology can be used to monitor a process (liquid level, flowmeters) or to determine the quality of food products. Since ultrasonic techniques are rapid, non-destructive, easy to automate and relatively inexpensive, the number of applications is rapidly growing in this field. Ultrasonics can also be considered for use in laboratory testing devices to determine physical and chemical properties of foods. Ultrasonics has been used to determine texture, composition and physical state in liquid and solid foods. The commonly measured ultrasonic parameters are velocity, attenua tion and frequency spectrum composition. Velocity is the parameter used most since it is the simplest and most reliable measurement. This paper reviews the basic principles of ultrasonics, the most suit able techniques for each type of application, the testing devices needed to make measurements and the most interesting applications.



2014 ◽  
Vol 979 ◽  
pp. 440-443
Author(s):  
W. Siriprom ◽  
K. Teanchai ◽  
S. Kongsriprapan ◽  
J. Kaewkhao ◽  
N. Sangwaranatee

The chemical and physical properties of topsoil and subsoil which collected from the cassava cropping area in Chonburi Province have been investigated. The characterization of both soil sample were used X-Ray Diffraction (XRD), Energy Dispersive X-Ray Fluorescence (EDXRF) while FTIR used to confirmed the formation of intermolecular bonding and Thermo-Gravimetric Analysis (TGA) used for investigated the crystalline. It was found that, the XRD pattern indicated quartz phase. The chemical composition by XRF reported that the soils samples consist of Si, Al, Ca, Fe, K, Mn, Ti, Cr, Zn, Ag and Cu. and TGA results, noticed that the removal of moisture and organics material.



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