scholarly journals Permeability of Parkia gigantocarpa as affected by wood anatomy

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 4924-4933
Author(s):  
Edy Eime Pereira Baraúna ◽  
José Tarcísio Lima ◽  
Thiago Campos Monteiro ◽  
Vaniele Bento dos Santos ◽  
Jean Henrique dos Santos
Keyword(s):  
Fiber Length ◽  
Inverse Relationship ◽  
Wood Anatomy ◽  
Positive Relationship ◽  
Flow Model ◽  
Longitudinal Direction ◽  
Air Permeability ◽  
Amazon Rainforest ◽  
Longitudinal Flow ◽  
High Permeability

This study evaluated Parkia gigantocarpa wood from the Amazon rainforest for its permeability to air and liquid in the longitudinal direction. The influence of anatomical characteristics on the permeability of wood was characterized. Three trees were collected in the State of Pará, Brazil. Samples were converted into specimens and subjected to permeability tests and anatomical characterization. Permeability was obtained in the laboratory, and the results were compared with the permeability data estimated by a longitudinal flow model for hardwoods. The air permeability of wood was 140.2 x 10-9 m3.[m.(N.m-2).s]-1 liquid permeability was 3.28 x 10-9 m3.[m.(N.m-2).s]-1. The fiber length and thickness of the cell wall had a direct and positive relationship with the permeability, whereas fiber width presented an inverse relationship with permeability. The vessel frequency and diameter did not influence the permeability of wood from the heartwood of P. gigantocarpa that presented high permeability and potential for easy wood drying and treatment.

Transient Analysis of In-Plane and Through Thickness Flow During VARTM in the Presence of HPM

2014 ◽  
Author(s):  
Debabrata Adhikari ◽  
Suhasini Gururaja
Keyword(s):  
Transient Analysis ◽  
Flow Model ◽  
Resin Flow ◽  
Constant Flow ◽  
High Permeability ◽  
Coupled Flow ◽  
Resin Infusion ◽  
Plane Flow ◽  
Constant Flow Rate ◽  
Vartm Process

Modeling resin flow for a Vacuum Assisted Resin Transfer Molding (VARTM) process involves developing an approach for coupled flow-compaction, porosity-permeability, resin-cure and stress-development phenomena. In the present work, a modified transient incompressible resin flow model has been developed for VARTM without considering the constant flow rate assumption. The use of High Permeability Medium (HPM) during VARTM results in a through-thickness flow in addition to in-plane flow developing due to the pressure gradient. Results have been validated with existing literature. Fill time comparisons for with and without HPM cases have been presented. Some preliminary results of 2D plane flow have also been obtained which show promise in replicating the physics of vacuum assisted resin infusion composite manufacturing process.

scholarly journals Role of Social Capital on Prospering Informal sector Enterprise (Case of Street Vendors in street market Dewi Sartika, Bogor)

2018 ◽  
Vol 2 (2) ◽  
pp. 207 ◽  
Author(s):  
Dedy Yahya Harahap ◽  
Ivanovich Agusta
Keyword(s):  
Social Capital ◽  
Informal Sector ◽  
Inverse Relationship ◽  
Qualitative Data ◽  
Positive Relationship ◽  
Survey Methods ◽  
Rank Test ◽  
Street Vendors ◽  
Spearman Rank

PERAN MODAL SOSIAL TERHADAP KESEJAHTERAAN PENGUSAHA SEKTOR INFORMAL (Kasus Pengusaha Sektor Informal di Pasar Jl. Dewi Sartika, Bogor)Goal of the study was to test contribution social capital on migration, of the informal sector, social capital education entrepreneurs to improve informal sector entrepreneurs. The research conducts quantitative approach by survey methods and supported by qualitative data. The results showed assosiation between social capital and informal entrepreneur’s welfare. Spearman rank test between social anf welfare showed -0.480. That indicated inverse relationship among them. Spearman rank test between social capital on imigration and welfare showed 0.723. That indicate positive relationship between them. Spearman rank test between social capital an education and welfare showed 1.000. That indicated fully positive relationship between them.Keywords : Welfare, Social Capital, Informal Sector.---------------------ABSTRAK Tujuan dalam penelitian ini adalah menguji kontribusi modal sosial pekerja pengusaha sektor informal, modal sosial migrasi sektor informal, modal sosial pendidikan pengusaha sektor informal dalam meningkatkan kesejahteraan pengusaha sektor informal. Penelitian ini menggunakan pendekatan kuantitatif dengan metode survey didukung dengan data kualitatif berupa wawancara mendalam, observasi. Hasil penelitian menunjukkan bahwa, peran modal sosial terhadap kesejahteraan berhubungan nyata. Uji kolerasi rank spearman menunjukkan bahwa hubungan pengusaha sektor informal dan kesejahteraan sebesar -0.480 dan nilai probabilitas sebesar 0.004. Hasil tersebut menunjukkan hubungan kuat namun berdifat negatif. Hubungan modal sosial migrasi pengusaha sektor informal dan kesejahteraan sebesar 0.723 dan nilai probabilitas sebesar 0.000. Hasil tersebut menunjukkan hubungan yang kuat dan bersifat positif antara kedua variabel. Hubungan modal sosial pendidikan pengusaha sektor informal dan kesejahteraan sebesar 1.000 dan nilai probabiliti sebesar 1.000. Hasil tersebut menunjukkan hubungan yang kuat, bersifat positif antara kedua variabel.Kata Kunci : Kesejahteraan, modal sosial, sektor informal.

Industrial Policy as an Environmental Policy: Forest Preservation and the Industrialization of Manaus

2021 ◽  
Author(s):  
Alexandre A.F. Rivas ◽  
James R. Kahn
Keyword(s):  
Economic Development ◽  
Global Warming ◽  
Free Trade ◽  
Economic Activity ◽  
Forest Conservation ◽  
Positive Relationship ◽  
Tropical Rainforest ◽  
Free Trade Zone ◽  
Amazon Rainforest ◽  
The World

The world is experiencing a major dilemma between the need to reduce global warming and to promote economic development. Brazil has the largest tropical rainforest on the planet, which plays an important role in this scenario. In the heart of this forest there is a special economic zone (SEZ), the Manaus Free Trade Zone. Studies indicate that there is a positive relationship between this economic activity and the level of forest conservation in the state of Amazonas, where the Manaus Free Trade Zone is located. There is important literature on SEZs, examining their economic and environmental impact in general, and specifically examining the Manaus Free Trade Zone. There is also a proposal to turn this SEZ into a major Brazilian economic initiative to protect the Amazon rainforest.

A Case Study in Smartphone Usage and Gratification in the Age of Narcissism

2019 ◽  
pp. 17-34
Author(s):  
Alan J. Reid ◽  
Chelsea N. Thomas
Keyword(s):  
Undergraduate Students ◽  
Empirical Data ◽  
Inverse Relationship ◽  
Positive Relationship

This research tracked the daily smartphone usage and checking habits of 43 undergraduate students at a mid-sized university for a minimum of thirty days to examine the primary uses of smartphones as well as the gratifications received from their usage. Empirical data was correlated with narcissism levels to better understand what drives a person to access media, often involuntarily. Results indicated significant differences between genders for device usage (how smartphones are used), the resulting gratifications (why smartphones are used), and narcissism. Findings showed an inverse relationship between smartphone usage and narcissism, and between usage and GPA. There also was a positive relationship between a user's smartphone checking habits and exhibitionism. These results are explained further through the lens of modern society's dependence on personal technologies and the gratifications that are satisfied.

scholarly journals Farm Size, Tenancy, and Productivity: An Overview

2021 ◽  
pp. 165-171
Keyword(s):  
Inverse Relationship ◽  
Positive Relationship ◽  
New Technology ◽  
Secondary Data ◽  
Policy Implications ◽  
Farm Size ◽  
Output Level ◽  
Policy Measures ◽  
Enhancing Production ◽  
The Relationship

The present study intends to investigate the relationship between farm size and productivity. The objectives of the study are: to investigate the relationship between farm size and productivity, to suggest some policy implications. The study is based on secondary data. Data were collected from different published and unpublished documents. The main findings of the study are: the small farms have the higher productivity of land than the larger ones, there exists the inverse farm size productivity relationship, few studies showed that although there exists an inverse relationship between these two this inverse relationship got weakened or even disappeared in the regions adopting new technology, some cases there also exists the positive relationship between farm size and productivity, the output level of owner cultivator is likely to be higher than the share-cropper. Few researchers pointed out the higher productivity of sharecroppers than the owner cultivators. In view of the above findings, the following policy measures are suggested: emphasis should be given to farm-related research, the assistance of small farmers in order to form associations for enhancing production, absorbing credit, and adopting farm technologies.

scholarly journals Formal and Informal Savings Habits and Income Levels: A Case Study in Mexico

2021 ◽  
Vol 12 (5) ◽  
pp. 1
Author(s):  
Georgina Manrique Morteo ◽  
Milka Elena Escalera-Chavez ◽  
Elena Moreno-Garcia
Keyword(s):  
Logit Model ◽  
Inverse Relationship ◽  
Positive Relationship ◽  
Developing Economies ◽  
Income Levels ◽  
Future Studies ◽  
Convenience Sampling ◽  
Personal Success ◽  
Larger Sample

Saving represents one of the most important determinants of personal success and economic development. However, in developing economies, opportunities for structured and institutionalized savings are rare. The intention of the study is to generate evidence on the type of relationship existing between income levels and formal and informal saving habits of a group of people from three different cities in Mexico. From a non-probabilistic convenience sampling, the data of 260 participants were obtained. A logit model was estimated. The results show that there is a positive relationship between higher income levels and formal saving habits and an inverse relationship between higher income levels and informal saving practices. Although the size of the sample does not allow conclusions to be drawn to the level of generalization, it has allowed the generation of evidence that in future studies can be contrasted with a larger sample.

scholarly journals Does Board Size Really Matter? Evidence from Australia

2008 ◽  
Vol 10 (3) ◽  
pp. 331 ◽  
Author(s):  
Lukas Y. Setia-Atmaja
Keyword(s):  
Panel Data ◽  
Agency Theory ◽  
Random Effects ◽  
Inverse Relationship ◽  
Positive Relationship ◽  
Resource Dependence ◽  
Tobin’S Q ◽  
Board Size ◽  
Tobin's Q ◽  
The Impact

This study examines the impact of board size of Australian firms on Tobin’s Q. Agency theory suggests that there is an inverse relationship between board size and Tobin’s Q (Yermack 1996; Eisenberg et al. 1998). The resource dependence argument, however, hypothesizes that larger boards can lead to higher performance as the CEO’s need for advice is a function of the complexity of the organization (Pfeffer 1972; Klein 1998). Analyzing a panel data of 1,530 firm-year observations using random effects technique, this study finds a positive relationship between board size and Tobin’s Q. The random effects regression results also reveal that the positive relationship between board size and Tobin’s Q is driven by firm size as this positive relationship is only found in larger firm sample but not in the smaller firm sample. The overall results support the resource dependence argument.

Ethnic Density is Unrelated to Incidence of Schizophrenia

1988 ◽  
Vol 153 (3) ◽  
pp. 363-366 ◽  
Author(s):  
Raymond Cochrane ◽  
Sukhwant S. Bal
Keyword(s):  
Mental Health ◽  
Mental Illness ◽  
Ethnic Groups ◽  
Inverse Relationship ◽  
Positive Relationship ◽  
Foreign Born ◽  
Ethnic Density ◽  
Significant Positive Relationship ◽  
Admission Rates ◽  
Department Of Health

Data deriving from the Mental Health Enquiry were obtained from the Department of Health and Social Security (DHSS) for all 186 000 admissions in England in 1981 to test the ‘ethnic density hypothesis'. This hypothesis has been used to explain variations in rates of mental illness between ethnic groups in other countries, and suggests that there is an inverse relationship between the size of ethnic groups and their admission rates. The data analysed in the present paper for the main foreign-born immigrant groups to England not only failed to support the ethnic-density hypothesis, but in some cases, showed a significant positive relationship between group size and admission rates. Some possible reasons for these findings are explored.

scholarly journals EFFECTS OF SULFATE SALINITY AND SELENIUM TOLERANCE OF PLANTS ON SELENIUM ASSIMILATION IN WHITE CLOVER AND TALL FESCUE.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 657a-657
Author(s):  
Lin Wu ◽  
Zhang Z. Huang
Keyword(s):  
Growth Inhibition ◽  
White Clover ◽  
Tall Fescue ◽  
Protein Level ◽  
Festuca Arundinacea ◽  
Inverse Relationship ◽  
Positive Relationship ◽  
Exclusion Mechanism ◽  
Se Uptake

Substantial difference of selenium tolerance was found between the tall fescue (Festuca arundinacea Schreb.) and white clover (Trifolium rapens L.) An inverse relationship between Se accumulation and Se tolerance suggests an exclusion mechanism that restricts Se uptake by the plant with greater Se tolerance. A positive relationship between the increase of protein Se concentration and growth inhibition in the plants suggests that assimilation of Se into protein is responsible for the reducing Se toxicity at the protein level. No evidence of a Se exclusion mechanism which exclude Se from incorporating into protein plays any major role of Se tolerance in this two species.

scholarly journals Effect of provenances on wood properties of Balfourodendron riedelianum

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Amanda Aparecida Vianna Assad ◽  
Adriano Wagner Ballarin ◽  
Miguel Luiz Menezes Freitas ◽  
Eduardo Luiz Longui
Keyword(s):  
Fiber Length ◽  
Wood Anatomy ◽  
Wood Properties ◽  
Wood Formation ◽  
Annual Increment ◽  
Lower Growth ◽  
Paulo State ◽  
Experimental Station ◽  
Volume Properties ◽  
Seed Origin

Wood is comparatively more conservative than other parts of trees, such as leaves, which present greater phenotypic plasticity. We studied the effect of seed origin on annual increment, physical-mechanical properties and anatomical characteristics of Balfourodendron riedelianum wood in a homogeneous plantation (Luiz Antônio Experimental Station (LAES)) from three natural provenances (Gália and Bauru in São Paulo State and Alvorada do Sul in Paraná State, Brazil). Because genotypic information is a determinant of wood formation, trees were expected to develop wood structure based on their provenances. Our results demostrate that variations in volume, properties and wood anatomy were influenced by provenance. Alvorada do Sul trees showed lower growth in volume and higher strength and homogeneity, compared to Gália and Bauru. Typical radial pattern was not observed for most characteristics, except modulus of elasticity and fiber length in Gália and compression parallel to the grain in Bauru that increased towards the bark. Based on the latter characteristc, B. riedelianum wood in a homogeneous planting has class C40 mechanical strength, as indicated for use in medium-sized structures, light civil construction and the manufacture of furniture.

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