scholarly journals HYPSOMETRY AND VOLUMETRY OF Eucalyptus urograndis IN A CROP-FOREST INTEGRATION SYSTEM

FLORESTA ◽  
2022 ◽  
Vol 52 (1) ◽  
pp. 159
Author(s):  
Stephany Diolino Cunha ◽  
Vagner Santiago Do Vale ◽  
Tatiana Vieira Ramos ◽  
Matheus Da Silva Araújo

Due to the positive impact that the eucalyptus species has on the Brazilian economy, it is currently the most used forest essence. The objective of this work was to evaluate different hypsometric and volumetric models for Eucalyptus urograndis clones (Eucalyptus urophylla S.T. Blak and Eucalyptus grandis W. Hill ex Maiden) in a Crop-Forest Integration (CFI) system. The trees were evaluated at 7 years of age and arranged in double rows, occupying 20.76% of the total system area. The individuals were subjected to rigorous volumetric cubing according to the Smalian method at intervals of one meter up to full height. The following models were evaluated for the collected height data: Linear, Trorey, Stofels, Curtis, Henriksen, Prodan, Chapman & Richards, Petterson and Bailey & Clutter. Furthermore, the Spurr, Hohenald-Krenn, Stoate, Schumacher Hall, Meyer, Husch, Ogaya and Takata models were used for volume data. The results were determined through the coefficient of determination (R2), standard error of the estimate in percentage (Syx%), significance of the regression coefficients (𝛽) and graphical distribution. The hypsometric model which best fit the database among tested models was the Prodan equation, with a coefficient of determination (R²) of 0.89, while the best result for volumetric models was found using the Meyer model, with a coefficient of determination (R²) of 0.99. All evaluated models were efficient in estimating the height and volume of the Crop-Forest Integration (CFI) system, thus demonstrating that GG100 eucalyptus is a good option in integrated systems.

Nativa ◽  
2018 ◽  
Vol 6 ◽  
pp. 795
Author(s):  
Valdir Carlos Lima de Andrade ◽  
Murilo Azevedo Glória Junior ◽  
David Lucas Camargo Vieira Terra

Este trabalho teve como objetivo avaliar um total de 26 modelos volumétricos para um clone do híbrido entre Eucalyptus urophylla e Eucalyptus grandis. Foram utilizados dados da cubagem rigorosa de 25 árvores, distribuídas em cinco classes diamétricas com amplitude de 2 cm cada. Para a avaliação dos modelos volumétricos, adotou-se os critérios: coeficiente de determinação ajustado, erro padrão residual, análise da distribuição de resíduos, soma dos quadrados dos resíduos relativos, erro médio e raiz do quadrado médio. O modelo logarítmo: , um dos mais utilizados no Brasil, teve o oitavo lugar como a melhor colocação dentre os 26 modelos volumétricos avaliados. O modelo que mais se destacou foi:  que, ajustado com a inclusão da variável binária Tx, permitiu o ajuste de uma única equação para quantificar, tanto o volume com casca como sem casca, para o clone estudado. A equação obtida foi: .Palavras-chave: inventário florestal, modelos volumétricos, eucalipto. VOLUMETRIC EQUATIONS FOR A YOUNG EUCALYPTUS CLONE IN THE SOUTH OF TOCANTINS ABSTRACT:This work aimed to evaluate a total of 26 volumetric models for clone of the hybrid between Eucalyptus urophylla and Eucalyptus grandis. We used data from the rigorous cubing of 25 trees distributed in five diameter classes with amplitude of 2 cm each. For the evaluation of the volumetric models, the following criteria were adopted: adjusted coefficient of determination, residual standard error, residue distribution analysis, sum of squares of relative residues, mean error and root mean square. The logarithm model: , one of the most used in Brazil, ranked eighth as the best placement among the 26 volumetric models evaluated. The best that most stood out was: which, adjusted with the inclusion of the binary variable Tx, allowed the adjustment of a single equation to quantify both the shell and shelled volume for the studied clone. The equation obtained was: .Keywords: forest inventory, volumetric models, eucalyptus.


2019 ◽  
Author(s):  
Chem Int

Mathematical model was developed and evaluated to monitor and predict the groundwater characteristics of Trans-amadi region in Port Harcourt City. In this research three major components were considered such as chloride, total iron and nitrate concentration as well as the polynomial expression on the behavious on the concentration of each component was determined in terms of the equation of the best fit as well as the square root of the curve. The relationship between nitrate and distance traveled by Nitrate concentration by the model is given as Pc = 0.003x2 - 0.451x + 14.91with coefficient of determination, R² = 0.947, Chloride given as Pc = 0.000x2 - 0.071x + 2.343, R² = 0.951while that of Total Iron is given as Pc = 2E-05x2 - 0.003x + 0.110, R² = 0.930. All these show a strong relationship as established by Polynomial Regression Model. The finite element techniques are found useful in monitoring, predicting and simulating groundwater characteristics of Trans-amadi as well as the prediction on the variation on the parameters of groundwater with variation in time.


Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 123-128
Author(s):  
Andréia S. Magaton ◽  
Teresa Cristina F. Silva ◽  
Jorge Luiz Colodette ◽  
Dorila Piló-Veloso ◽  
Flaviana Reis Milagres ◽  
...  

Abstract 4-O-methylglucuronoxylans isolated from Eucalyptus grandis and Eucalyptus urophylla kraft black liquors (KBLs) were chemically characterized by Fourier transform infrared spectroscopy (FT-IR), size exclusion chromatography (SEC), and nuclear magnetic resonance (NMR) spectroscopy. Doses of alkali charge, expressed as active alkali (AA), were 16, 17, and 18% while the sulfidity was kept at 25%. Kappa numbers of 19.1, 17.5, and 16.1 for E. grandis and 20.4, 16.8, and 15.4 for E. urophylla were obtained. At higher alkali charges, the recovery of xylans from the KBLs was lower and the degree of substitution of xylans with uronic acids decreased. The average molecular weight (Mw) of the recovered xylans was greater under conditions of mild pulping, i.e., in the case of pulps with higher kappa numbers. Mw of xylans ranged from 16.1 to 19.1 kDa for E. grandis and from 15.4 to 20.4 kDa for E. urophylla. The xylans from KBL may be useful as pulp modifying agents or as a raw material for advanced applications.


Author(s):  
Jhonatas C. Rosa ◽  
Andreza P. Mendonça ◽  
Angélica dos S. Oliveira ◽  
Sylviane B. Ribeiro ◽  
Andréia do R. Batista ◽  
...  

ABSTRACT ‘Babassu’ mesocarp flour has been used by the pharmaceutical, human food and animal feed industries. However, there is lack of standardization in the production, as well as absence of information on the management of the product’s quality. Thus, the objective of this study was to dry the ‘babassu’ mesocarp in forced-air oven and solar dryer, adjust different mathematical models to the experimental data, as well as to quantify the levels of proteins and crude fiber of the produced flour. The criteria for the adjustment were the coefficient of determination, magnitude of the mean relative error, standard deviation of estimate and the residual distribution trend. Drying in the shortest time occurred in oven at 60 °C (370 min), leading to water content of 4.62%, while in the solar dryer the final water content was 8.07% in 6 days. The mathematical model Two Terms showed the best fit to the experimental data for oven drying and the Midilli model showed the best fit in solar dryer. There was an increase in protein content with the drying in solar dryer and oven at 40, 50 and 60 °C (1.36, 1.33, 1.15 and 1.37%, respectively) in relation to fresh mesocarp (0.88%). Drying in both oven and solar dryer promoted increase of protein in the flour.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Bala Gambo Jahun ◽  
Desa Bin Ahmad ◽  
Muhammad Razif Mahadi ◽  
Shamsuddin Sulaiman ◽  
Shehu Adamu Iya

This study investigates the influence of blade lifting angles, tractor forward speed, and tractor power take off (PTO) speed on the degree of mulching. Four blades with different lifting angles, two tractor PTO speeds, and three tractor forward speeds were assessed using the parametric test at the Universiti Putra Malaysia oil palm plantation. The result shows that the best-fit regression equation was a quadratic regression with a high coefficient of determination. It indicates that any change in this three-factor interaction has a significant effect using Tukey’s Studentized mean comparison and can predict the degree of mulching. Seventy-four percent of the degree of mulching variance is explained by blade lifting angles, tractor forward speed, and tractor PTO speed. Since the blade lifting angle was a major predictor of the degree of mulching, this result implies that any change in the blade lifting angle can provide a significant prediction of the degree of mulching in an oil palm plantation. Additionally, the predicted model can further be used to predict the degree of mulching during field operations, replanting, and access for mulching of oil palm fronds. A detailed field evaluation of the performance of a tractor-mounted mulcher with different blade lifting angles in other parts of Malaysia is highly recommended to cater for the differences in soil moisture content and bulk density.


FLORESTA ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 240
Author(s):  
Gabriel Paes Marangon ◽  
Emanuel Arnoni Costa ◽  
César Augusto Guimarães Finger ◽  
Paulo Renato Schneider ◽  
Matheus Teixeira Martins

Density management diagram for eucalyptus stands controlled by dominant height. The present study aimed to elaborate Density Management Diagrams (DMD) for Eucalyptus grandis W. Hill. ex Maiden stands including the dominant height. Data were obtained from permanent plots installed in the Centro Oriental Riograndense region and the Porto Alegre Metropolitan area, both located in the state of Rio Grande do Sul. The models to describe the relationships between average volume, number of trees per hectare, mean diameter, and dominant height were assessed by the statistical criteria of coefficient of determination (R²), standard error of the estimate in percentage (Syx%), and graphical analysis of residuals. The developed DMD allows for a better control of stocks in the management of stands due to the strong relationship of dominant height with stand development site and forest yield.Keywords: Growth, Site index, Forest regulation, Yield.


2020 ◽  
Author(s):  
Nana Yaw Sarpong ◽  
Frank Ofori Agyemang ◽  
Daniel E.K.A Siaw ◽  
Essakku Menason

Abstract BackgroundIncreasing global wood demands have necessitated an overall push for cost-effective methods of vegetative propagation using cuttings. Vegetative plant propagation through cuttings although a breakthrough is mostly hampered with the inability of cuttings to root effectively to achieve maximum yield. Ten clones each of Eucalyptus grandis x Eucalyptus urophylla (E. grandis x E. urophylla) and Eucalyptus pellita (E. pellita) were treated with Indole-3-butyric acid (IBA) concentrations of 0 ppm (control), 2000 ppm, 3000 ppm and 4000 ppm respectively.ResultsOverall mean survival of cuttings was low (< 50%) for all concentrations of IBA used in this research. Survival rates of individual clones however varied from clone to clone. E. grandis x E. urophylla cuttings had the highest mean survival (43.39%) when treated with 2000 ppm of IBA and lowest mean survival (37.86%) when treated with 0 ppm. Results from the survival rates of E. grandis × E. Urophylla and Eucalyptus pellita cuttings were subjected to an Analysis of Variance test to identify any significant differences between hormone concentration and cutting survival. ANOVA results indicated that differences between cutting–IBA concentrations for E. grandis × E. Urophylla were significant (p=1.85x10-08) which is lower than standard p value (p=0.05) used in the test.For E. pellita (P) cuttings the highest mean survival (27.14%) was achieved when treated with 2000 ppm of Indole-3-butyric acid (IBA). Individual clones however showed significant differences in survival. E. pellita clone P2 achieved the highest survival (52.68%) in the control experiment (0 ppm). Some clones i.e P51 and P82 achieved survivals of less than 10% in all four levels of IBAConclusionThe best surviving Eucalyptus grandis x Eucalyptus urophylla clone (GH11) achieved a mean survival rate of 75% when the GH11 basal cutting was treated with 2000 ppm IBA. The results indicated that the production of clones with survival rates of less than 20% should be discarded since it makes no economic sense clones with survival rates of more than 40% should be planted out in the field to compare field performance with greenhouse survival.


2019 ◽  
Vol 8 (2) ◽  
pp. 111-120
Author(s):  
Moh. Deni Andri Saputra ◽  
Widiartanto Widiartanto

The aims of this study is to measure the effects of structural assurance and perceived reputation to purchase intention through trust. The population of this research is consumers of Tokopedia in Faculty of Social and Political Science of Diponegoro University, while the sample is 100 consumers of Tokopedia with some certain prerequirements.The data was analyzed using two-step analysis with SPSS 17.0 for windows where previously tested the validity test, reliability test, coefficient of correlation, coefficient of determination, and test of significance (t-test and f-test). The result of this study is showing that structural assurance and perceived reputation has positive impact toward trust, the biggest impact is own by perceived reputation. Based on the result of two step analysis, trust is an intervening variable toward purchase intention in this study. Some recommendations are added based on those results. It is recommended that Tokopedia should improve the ability to solve hacking, provide guaranteed data information so that visitors' responses to structural assurance are safe, besides that it needs to focus on customer satisfaction, provide high service and increase credibility so consumers arise trust and increase purchase intention to Tokopedia. Tujuan dilakukanya penelitian ini adalah untuk mengetahui pengaruh antara structural assurance dan perceived reputation terhadap purchase intention melalui trust. Populasinya adalah seluruh konsumen Tokopedia di Fakultas Ilmu Sosial dan Ilmu Politik di Universitas Diponegoro, sedangkan sampelnya adalah 100 konsumen Tokopedia dengan kriteria tertentu. Analisis yang digunakan dalam penelitian ini adalah analisis dua tahap menggunakan software SPSS for Windows, di mana sebelumnya dilakukan uji validitas, uji reliabilitas, uji koefisien korelasi, koefisien determinasi, analisis regresi sederhana dan berganda, dan uji signifikansi (uji t dan uji F). Hasil penelitian ini menunjukan bahwa structural assurance dan perceived reputation berpengaruh secara parsial dan simultan terhadap trust, dimana ketika bersama-sama perceived reputation memiliki pengaruh yang paling besar terhadap trust. Berdasarkan hasil analisis dua tahap trust merupakan variabel intervening terhadap purchase intention dalam penelitian ini. Berdasarkan hasil tersebut maka disarankan supaya Tokopedia dapat meningkatkan kemampuan dalam memecahkan masalah hackers, menyediakan jaminan informasi data sehingga tanggapan pengunjung mengenai structural assurance aman, selain itu perlu memfokuskan terhadap kepuasan konsumen, memberikan pelayanan yang tinggi dan meningkatkan kredibilitas yang dimiliki sehingga konsumen timbul trust dan berminat untuk membeli di Tokopedia.


Author(s):  
Ufuk Karadavut ◽  
Adil Bakoglu ◽  
Halit Tutar ◽  
Kagan Kokten ◽  
Hava Seyma Yilmaz

This study was carried out in Bingol province on eastern Anatolian Region between 2013 and 2015. In this study, we obtained 14 bitter vetch genotypes from different sources. The experiment was carried our in three replications in randomized block design. Each plant was weekly measured for 6 weeks starting from germination. For each plant, plant height, fresh and dry stem weight, fresh and dry leaf weights were determined. Logistic, Richards and Weibull growth models were fitted to describe the growth pattern of the genotypes. The best fitting model criteria used were coefficient of determination and mean squared. Richards’s growth model was found to best fit the data for most of the genotypes. Logistic model was the worst fit. In Turkey, climate and soil properties have very large variations. For this, local genotypes showed large variation according to plating areas. YEREL LICE genotype showed more stable and it is the height identified all growth models than other local genotypes. However, IFVE 2923 SEL and IFVE 2977 SEL 2802 these genotypes gave positive results in different environmental conditions.


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