scholarly journals Mechanical Properties of OSB Wood Composites with Resin Derived from a Renewable Natural Resource

2014 ◽  
Vol 4 (3) ◽  
pp. 157-161 ◽  
Author(s):  
Amós Magalhães de Souza ◽  
Luciano Donizeti Varanda ◽  
Laurenn Borges de Macedo ◽  
Diego Henrique de Almeida ◽  
Marília da Silva Bertolini ◽  
...  
Author(s):  
Tjokorda Gde Tirta Nindhia ◽  
Zdenek Knejzlík ◽  
Tomáš Ruml ◽  
I Wayan Surata ◽  
Tjokorda Sari Nindhia

Silk can be produced by spider or insect and have prospect as biomaterial for regenerative healing in medical treatment. Silk having physical and chemical properties that support biocompatibility in the living things..In this research, silk that was obtained from Indonesia natural resource of Attacus atlas silkmoth was explored and then will be  developed for biocompatible biomaterial. The treatment with NaOH was developed to separate the fiber from the cocoon. The obtained fiber is investigated its mechanical property by performing tensile test for single fiber. The biocompatibility testing was conducted with human cell (osteosarccoma) cultivation. The result identify that separation by using NaOH yield better better mechanical properties comparing konvenstional method with boiling in hot water. Biocompatibility testing indicate that the the fiber having good biocompatibility.


Author(s):  
Ivica Kisić

Soil is a thin (up to 50cm) loose top layer of the Earth's surface, located between the lithosphere and atmosphere. Total available land area on Earth is limited, and the soil is extremely important, and in one generation it is a non-renewable natural resource. Unfortunately, nowadays the soil is, next to water, one of the most endangered natural resources. Among the many processes of soil damage, which is not being addressed at this point, is the growing importance placed on soil contamination. Contaminated soil is the soil in which human or natural activity has increased the content of harmful substances whose concentrations may be harmful to human activity, that is, for the production of plants or animals.


Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 2053
Author(s):  
M’hamed Gaïgi ◽  
Idris Kharroubi ◽  
Thomas Lim

In this work, we study an optimization problem arising in the management of a natural resource over an infinite time horizon. The resource is assumed to evolve according to a logistic stochastic differential equation. The manager is allowed to harvest the resource and sell it at a stochastic market price modeled by a geometric Brownian process. We assume that there are delay constraints imposed on the decisions of the manager. More precisely, starting harvesting order and selling order are executed after a delay. By using the dynamic programming approach, we characterize the value function as the unique solution to an original partial differential equation. We complete our study with some numerical illustrations.


2015 ◽  
Vol 35 (6) ◽  
pp. 412-423 ◽  
Author(s):  
Ljerka Kratofil Krehula ◽  
Zvonimir Katančić ◽  
Gojko Marić ◽  
Zlata Hrnjak-Murgić

2019 ◽  
Vol 15 (4) ◽  
pp. 737-772 ◽  
Author(s):  
Alfonso Cruz ◽  
Tomas Reyes ◽  
Roberto Vassolo

ABSTRACTSize is an important antecedent of firm survival, and several studies theoretically sustain and empirically support a ‘liability of middleness’. Indeed, it is widely believed that companies should act strategically to either become large or remain small and occupy a niche position, because mid-sized firms face the strongest market selection pressures. This study challenges that logic in renewable natural resource industries. Measuring size as product-line scale and firm-level portfolio breadth, we argue that in industries characterized by cost competition, the lack of product differentiation, large capital investments, and sharp price oscillation, scale and breadth have a curvilinear effect on survival that favors mid-sized firms rather than penalizing them. An empirical analysis of the US pulp and paper (P&P) industry over the period 1970–2000 strongly supports our arguments. This study is particularly relevant for emerging economies, in which natural resource industries represent an important portion of the total economic activity.


Author(s):  
Clement Matthew Chan ◽  
Luigi-Jules Vandi ◽  
Steven Pratt ◽  
Peter Halley ◽  
Yiming Ma ◽  
...  

2008 ◽  
Vol 10 (01) ◽  
pp. 73-100 ◽  
Author(s):  
FRANCISCO CABO ◽  
GUIOMAR MARTÍN-HERRÁN ◽  
MARÍA PILAR MARTÍNEZ-GARCÍA

This paper develops a trade model for a technologically leading country and a developing country that exploits a renewable natural resource. Technology diffuses from the technological leader to the developing country through foreign direct investment (FDI). Alternatively, innovative activities can also be carried out in the developing economy. We prove the existence and uniqueness of an equilibrium path along which both countries grow at the same rate, maintaining the natural-resource stock at a constant level. The saddle-point property for this equilibrium is proved and a sensitivity analysis is carried out. The steady-state growth rate and consumption under both scenarios are compared and the effect of resource abundance analyzed.


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