scholarly journals Evaluación de la sostenibilidad de las empresas forestales del Valle del Mantaro -2008

2022 ◽  
Vol 6 (1) ◽  
pp. 99-103
Author(s):  
Hugo Miguel Miguel ◽  
Jesús Antonio Hurtado Rivera
Keyword(s):  

Se estudió la sostenibilidad de las empresas forestales más representativas del Valle del Mantaro que transforman primariamente la madera de Eucalyptus globulus Labill. Se evaluaron mediante encuestas, indicadores de gestión de las dimensiones: ambiental, social y económico de dos aserraderos, un aserradero de sierra circular y un aserradero de sierra banda. Los objetivos del estudio fueron: determinar cuantitativamente los grados o niveles de sostenibilidad de las empresas forestales del Valle del Mantaro, y analizar comparativamente la sostenibilidad ambiental, económica y social de las empresas forestales. Se concluye que las industrias forestales del Valle del Mantaro son insostenibles; asimismo, la dimensión ambiental es la más insostenible, seguidas por las dimensiones social y económica.

TAPPI Journal ◽  
2012 ◽  
Vol 11 (6) ◽  
pp. 31-38
Author(s):  
TATIANA M. PÓVOAS ◽  
DINA A.G. ANGÉLICO ◽  
ANA P.V. EGAS ◽  
PEDRO E.G. LOUREIRO ◽  
LICÍNIO M. GANDO-FERREIRA ◽  
...  

We conducted a comparative evaluation of different treatments for the bleaching of eucalypt kraft pulps beginning with OP stages. The treatments tested were (1) an acid chelation stage with DTPA (OQP sequence); (2) a hot acid stage (AOP sequence); and (3) a chelant addition into the alkaline oxygen stage ((OQ)P and A(OQ)P sequences). The latter strategy was also studied for environmental reasons, as it contributes to the closure of the filtrate cycle. The OQP sequence leads to the highest brightness gain and pulp viscosity and the lowest peroxide consumption caused by an efficient metals control. Considering that the low biodegradability of the chelant is a problem, the A(OQ)P sequence is an interesting option because it leads to reduced peroxide consumption (excluding OQP) while still reaching high brightness values and similar brightness reversion to OQP prebleaching, with only a viscosity loss of 160 dm3/kg. Therefore, a hot acid stage could be considered when a separate acid Q stage is absent in a prebleaching sequence of Eucalyptus globulus kraft pulps involving OP stages.


2020 ◽  
Vol 14 (3) ◽  
pp. 187-195
Author(s):  
Berhan Mengiste ◽  
Tizazu Zenebe ◽  
Kassahun Dires ◽  
Ermias Lulekal ◽  
Awol Mekonnen ◽  
...  

Background: The Eucalyptus globulus extractions have been used by the traditional healers to treat diseases in the study area. Our previous study revealed that the essential oil has antimicrobial and antifungal activity. This study determined phytochemical analysis, skin irritation, acute and subacute toxicity of Eucalyptus globulus essential oil in mice and rats. Methods: The phytochemicals were analyzed using GC-MS mass spectrometry. The acute toxicity study was determined at three dose levels of 1500 mg/kg, 1750mg/kg, and 2000 mg/kg. The essential oil limit test at a dose of 1000 mg/kg was administered to mice for 28 consecutive days for sub-acute toxicity study. The mice mortality, behavioral change, injury and other signs of illness were recorded once daily. Biochemical parameters were evaluated. Liver and kidney were analyzed for histopathological analyses. The 5% ointment formulation was applied to the rat skin to determine skin irritation effects. Results: The Eucalyptus globulus essential oil showed no effect on the mice at a dose of 1500mg/kg and below, but caused signs of toxicity and death at a dose of 1750mg/kg and above compared to the controls (p<0.05). The LD50 value was 1650 mg/kg. There was no significant difference (p > 0.05) in the body weights, gross abnormalities of the organs and biochemical parameters compared to the control at 1000 mg/kg subacute toxicity study. No histopathological changes were detected in the organs tested. The 5% ointment formulation did not show any abnormal skin reaction. Discussion: In the present study, the Eucalyptus globulus essential oil was comparable with other studies in terms of both chemical composition and its effects on sub-acute and topical application. Conclusion: This toxicity study demonstrated that Eucalyptus globulus essential oil is nontoxic at a relatively lower concentration.


1994 ◽  
Vol 91 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Catherine Albrecht ◽  
Alain Asselin ◽  
Yves Piche ◽  
Frederic Lapeyrie

1982 ◽  
Vol 30 (6) ◽  
pp. 1964-1973 ◽  
Author(s):  
MUTSUO KOZUKA ◽  
TOKUNOSUKE SAWADA ◽  
EIJI MIZUTA ◽  
FUMIKO KASAHARA ◽  
TOSHIO AMANO ◽  
...  
Keyword(s):  

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 507
Author(s):  
Eduardo Troncoso-Ortega ◽  
Rosario del P. Castillo ◽  
Pablo Reyes-Contreras ◽  
Patricia Castaño-Rivera ◽  
Regis Teixeira Mendonça ◽  
...  

The objective of this study was to investigate structural changes and lignin redistribution in Eucalyptus globulus pre-treated by steam explosion under different degrees of severity (S0), in order to evaluate their effect on cellulose accessibility by enzymatic hydrolysis. Approximately 87.7% to 98.5% of original glucans were retained in the pre-treated material. Glucose yields after the enzymatic hydrolysis of pre-treated material improved from 19.4% to 85.1% when S0 was increased from 8.53 to 10.42. One of the main reasons for the increase in glucose yield was the redistribution of lignin as micro-particles were deposited on the surface and interior of the fibre cell wall. This information was confirmed by laser scanning confocal fluorescence and FT-IR imaging; these microscopic techniques show changes in the physical and chemical characteristics of pre-treated fibres. In addition, the results allowed the construction of an explanatory model for microscale understanding of the enzymatic accessibility mechanism in the pre-treated lignocellulose.


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