scholarly journals Review of studies on motor-manual felling productivity in eucalypt stands

2021 ◽  
Vol 22 (1) ◽  
pp. 77-87
Author(s):  
Mohammad Reza Ghaffariyan
Keyword(s):  
International Studies ◽  
Land Area ◽  
Sustainable Harvesting ◽  
Operator Experience ◽  
Breast Height ◽  
Terrain Slope ◽  
Eucalypt Plantations ◽  
Main Factors ◽  
Manual Felling

AbstractGlobally, about 20 million ha of land area is occupied by plantations of Eucalyptus. Motor-manual tree harvest-ing techniques (using chainsaws) are still applied in eucalypt plantations, especially in difficult terrains or for large- sized trees where mechanised felling may not be an effective and safe possible option to apply. There is little information available on motor-manual felling in eucalypt stands. This article reviewed available literature on the productivity of motor-manual felling. The results were classified into four regions, including Africa, Asia/Oceania, America and Europe. Results of international studies indicate that the main factors impacting the productivity of motor-manual felling include diameter at the breast height (DBH), travelling distance to trees, understory density and terrain slope. Operator experience also plays a key role in felling operations. The range of reported productivity varied from 0.6 m3/PMH0 to 48.9 m3/PMH0 in different regions. This article provides key recommendations on improving motor-manual felling productivity, which can provide a guide for sustainable harvesting planning purposes. 

scholarly journals Productivity and cost of manual felling with a chainsaw in Caspian forests

2009 ◽  
Vol 55 (No. 2) ◽  
pp. 96-100 ◽  
Author(s):  
K. Behjou F ◽  
B. Majnounian ◽  
J. Dvořák ◽  
M. Namiranian ◽  
A. Saeed ◽  
...  
Keyword(s):  
Production Rate ◽  
Unit Cost ◽  
Regression Function ◽  
Forest Site ◽  
Net Production ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Production Study ◽  
Average Slope ◽  
Manual Felling

A field production study was conducted for a manual harvesting system using a chainsaw in a Caspian hardwood forest site. A selective cut was performed on a 42-hectare tract with an average slope of 30 percent. Felling time per tree was most affected by diameter at breast height and by the distance among harvested trees. The gross and net production rate was 20.6 m<sup>3</sup> and 26.1 m<sup>3</sup> per hour/one person, respectively. The unit cost considering the gross and net production rate was 1.05 USD/m<sup>3</sup> and 0.81 USD/m<sup>3</sup>, respectively. The significant variables included diameter at breast height (<I>D</I>) and distance among harvested trees (<I>L</I>) for the time expenditure model. This regression function is statistically significant at &alpha; = 0.01.

Review of Causes of Delay in Construction Projects

2020 ◽  
Vol 17 (2) ◽  
pp. 715-728
Author(s):  
Abdulhamid Al-Gheth ◽  
Md. Sayuti Bin Ishak
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
Research Study ◽  
Project Delivery ◽  
International Studies ◽  
Exploratory Research ◽  
Factors Affecting ◽  
Project Completion ◽  
Financial Factors ◽  
Main Factors

Globally, construction delay is the main factors which have a high impact on countries’ economy and development. The present paper reports an exploratory research study of previous international research into delay factors affecting project delivery. The objective of this study was to deliver an overview of construction delays in order to classify the main groups of delays and compare the UAE construction industry with international studies. In total, 14 groups were found to contribute to causing construction delays. Studies of the global and UAE construction industry are in agreement that the leading group of factors that affect project completion are management factors; then, the second group comprises financial factors.

scholarly journals ANALISIS REWORK PADA PROYEK KONSTRUKSI GEDUNG DI KABUPATEN BADUNG

1970 ◽  
Author(s):  
Nana Sutrisna ◽  
I N. Arya Thanaya ◽  
I Gst Ketut Sudipta
Keyword(s):  
Factor Analysis ◽  
Construction Materials ◽  
Operator Experience ◽  
Management Consultants ◽  
Lack Of Information ◽  
Lack Of Control ◽  
Systematic Planning ◽  
Main Factors ◽  
Flow Of Information

Rework is unavoidable from the world of construction, Rework can be a devastating effect on the performance and productivity of both the consultant and the contractor. This study aims to determine the main factors causing rework, efforts to reduce rework. The analysis used the analysis Multivariant factor analysis with the help of Statistical Package for Social Science (SPSS) for Windows version 17.0. From the results obtained by factor analysis the main factors causing the occurrence of rework are: aspects of the owner (poor communication, poor coordination, poor information flow), aspects of planning consultants (lack of information in the field, lack of communication, the situation in the picture on the ground is not suitable). aspects of construction management consultants (lack of information in the field, lack of communication, lack of control), aspects of mechanical electrical plumbing contractors (Materials misdirected, MEP staff inexperience, lack of knowledge about the character of the material, the amount of overtime), aspects of the contractor (lack of competence foreman, foreman lack of experience, lack of experience, the quality of labor is bad, the error in interpreting the specification), aspects of operator (poor flow of information, lack of communication, lack of coordination, lack of operator experience). Efforts to systematically reduce rework most effective according to the respondent's answer is: Systematic planning, detailing and describing the project at every stage of the steps to be taken to achieve quality objectives, set standards of communication, coordination and construction project sinkronasi work with all parties involved in the implementation of the project, Constructing specification limits and criteria and quality standards to be used in engineering design, procurement and construction materials.

Sapwood and heartwood width relationship to tree age in Pinusbanksiana

1991 ◽  
Vol 21 (4) ◽  
pp. 521-525 ◽  
Author(s):  
K. C. Yang ◽  
G. Hazenberg
Keyword(s):  
Linear Relationship ◽  
Average Rate ◽  
Basal Area ◽  
Tree Age ◽  
Curvilinear Relationship ◽  
Breast Height ◽  
Thunder Bay ◽  
Main Factors ◽  
The Difference ◽  
Natural Stands

The relationships of sapwood and heartwood width with tree age were studied in 101 trees of Pinusbanksiana Lamb. The sample trees were selected from natural stands growing at various stand densities at the Lakehead University woodlot, Thunder Bay, Ontario, and ranged in age from 6 to 97 years at breast height. The number of rings in both sapwood and heartwood and their respective widths were recorded. The sapwood basal area was expressed as the difference between the stem basal area and the heartwood basal area. A linear relationship was found between tree age and sapwood width, sapwood basal area, and heartwood width. A curvilinear relationship was observed between the number of rings in the sapwood or heartwood and tree age. The number of rings in sapwood increased at an average rate of 0.43 ring per year until the tree reached the age of about 70 years. The number of rings in sapwood was, more or less, constant after 70 years. Heartwood began to form at about the age of 6 years. Heartwood was produced at the average rate of 0.57 ring per year until the tree reached approximately 70 years. After 70 years, the average rate of heartwood expansion was 1 ring per year. It is concluded that tree age is one of the main factors that controls sapwood and heartwood width.

scholarly journals Analisis Produktivitas dan Efisiensi Hutan Tanaman Industri dalam Produksi Kayu Bulat di Indonesia

2020 ◽  
Vol 4 (2) ◽  
pp. 81-89
Author(s):  
Ahmad Yani
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Cultivated Land ◽  
Land Area ◽  
Forestry Industry ◽  
Main Factors ◽  
Production Labor

Abstrak: Produktivitas dan efisiensi merupakan masalah penting dalam sebuah kegiatan usaha, begitu juga dalam kegiatan industri kehutanan. Penelitian ini bertujuan untuk menganalisis tingkat produktivitas kegiatan hutan tanaman industri dalam memproduksi kayu bulat di Indonesia dalam kaitannya dengan dua faktor utama yaitu luas lahan budidaya dan tenaga kerja lapangan. Kajian ini dilakukan dengan pendekatan kuantitatif dengan metode analisis regresi linear berganda. Hasil analisis regresi linier berganda memperlihatkan adanya hubungan linier antara variabel luas lahan budidaya, variabel tenaga kerja lapangan dengan variable produksi. Temuan lain produktivitas hutan tanaman industri dalam menghasilkan kayu bulat semakin meningkat dan efisien. Variabel luas lahan budidaya merupakan faktor yang berpengaruh positif dan signifikan pada produksi kayu bulat, naiknya luas lahan akan menaikkan produksi kayu bulat. Tenaga kerja juga berpengaruh positif tetapi tidak signifikan pada produksi kayu bulat. Rasio produksi kayu bulat terhadap tenaga kerja menunjukkan efisiensi pemakaian tenaga kerja. Dengan tenaga kerja yang sedikit menghasilkan produksi yang lebih banyak.   Kata kunci: industri kehutanan, luas lahan budidaya kehutanan.   Abstract: Productivity and efficiency are important issues in a business activity, as well as in the activities of the forestry industry. This study aims to analyze the level of productivity of industrial plantations in producing logs in Indonesia in relation to two main factors, namely the area of ​​cultivated land and field labor. This study was conducted with a quantitative approach with multiple linear regression analysis methods. The results of multiple linear regression analysis showed a linear relationship between the variable area of ​​cultivated land, the variable of field labor with the variable of production. Another finding is the productivity of industrial plantations in producing logs and increasing and efficient. The variable area of ​​cultivated land is a factor that has a positive and significant effect on log production, increasing the area of ​​land will increase log production. Labor also has a positive but not significant effect on log production. The ratio of log production to labor shows the efficient use of labor. With less labor, more production  Keywords: field labor, forestry cultivation land area.

The Symptom Check-List 90R (SCL-90R) in a French general psychiatric 708 outpatient sample: is there a factor structure?

1989 ◽  
Vol 4 (3) ◽  
pp. 151-157 ◽  
Author(s):  
P. Pariente ◽  
J. P. Lepine ◽  
J.P. Boulenger ◽  
E. Zarifian ◽  
T. Lemperiere ◽  
...  
Keyword(s):  
Principal Component ◽  
Self Report ◽  
International Studies ◽  
Check List ◽  
Varimax Rotation ◽  
Factor Solution ◽  
French Study ◽  
Symptom Check List ◽  
Main Factors ◽  
Clinically Significant

SummaryDuring a French study on anxiety disorders, 708 outpatients seen in general psychiatric settings answered the French version of the SCL-90 R (Symptom Check-List 90-Revised) as a self-report check-list of complaints. A principal component analysis followed by screenplot examination and Varimax rotation yielded an 11-factor solution explaining 47.5% of total variance. These orthogonal factors each have at least 3 items whose loadings are above 0.4 and are all clinically significant. After replication on split-half samples, the 3 main factors (Depression, Somatization, Panic-Agoraphobia) proved to be stable. These results are compared to those from other international studies.

scholarly journals Payments for ecosystem services in Indonesia

Oryx ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Helen Suich ◽  
Mega Lugina ◽  
Muhammad Zahrul Muttaqin ◽  
Iis Alviya ◽  
Galih Kartika Sari
Keyword(s):  
Ecosystem Services ◽  
Payments For Ecosystem Services ◽  
Service Users ◽  
Land Area ◽  
Service Outcomes ◽  
The Status ◽  
Main Factors ◽  
Further Development ◽  
Limited Scope

AbstractPayments for ecosystem services schemes are viewed as having the potential to achieve positive biodiversity and ecosystem service outcomes and social outcomes, and they have been widely studied since their development in the 1990s. We describe the state of payments for ecosystem services in Indonesia, where nine schemes were identified, four involving water and five involving carbon. We also assess the perceptions of stakeholders (donors, government, and non-government agencies) regarding the status of such schemes in Indonesia, and their views on what factors support or constrain their development. The main factors perceived to support payments for ecosystem services schemes were easily identifiable ecosystem services and service users, and the long-term support provided by individuals or institutions that facilitate the schemes, building on existing relationships between communities and these facilitating agencies. Stakeholders identified problems relating to regulation: the lack of regulation specifically in relation to payments for ecosystem services, but also overlap and uncertainties regarding regulations. Other constraining factors identified were the lack of recognition of environmental problems amongst potential buyers, and issues of rights and tenure for local communities. With so few operational programmes to date, covering a relatively small land area, and such constraints to further development, payments for ecosystem services schemes appear to have limited scope to supply ecosystem services successfully and sustainably at scale.

scholarly journals Transnational families in the light of the practice-based approach

2020 ◽  
pp. 113-129
Author(s):  
Małgorzata Szyszka
Keyword(s):  
International Migration ◽  
Family Life ◽  
Transnational Families ◽  
International Studies ◽  
Everyday Practices ◽  
Use Of Technology ◽  
Transnational Family ◽  
Family Practices ◽  
Main Factors ◽  
Transnational Parenting

Today, international migration is one of the main factors that determine functioning of families. Transnational families and transnational parenting are becoming increasingly more common and have been gaining considerable interest of researchers and social practitioners. One perspective that may be useful for examining transnational families is the practice-based approach. The concepts put forward by Morgan and Finch (‘doing’ and ‘displaying’ family) help to analyse families not as structures, but as everyday practices which constitute them (Morgan) and which must be associated with a system of meanings to be displayed (Finch). In the article, the analysis of transnational family practices will focus on the ‘tools’ for displaying (Finch) that are characteristic of transnational family life, and it will be based on the results of Polish and international studies. The article will discuss the tools proposed by Finch, such as physical objects or the use of narratives, as well as the use of technology in communication and taking care of children, as these practices are specific to transnational families. Those ‘tools’ for displaying show that transnational families are flexible, they are constantly happening, and by being embedded in broader systems of meanings, they become acceptable.

Epidemiological Trends in Attempted Suicide in Adolescents and Young Adults Between 1996 and 2004

Crisis ◽  
2009 ◽  
Vol 30 (3) ◽  
pp. 115-119 ◽  
Author(s):  
Stephanie De Munck ◽  
Gwendolyn Portzky ◽  
Kees Van Heeringen
Keyword(s):  
Young Adults ◽  
Attempted Suicide ◽  
Suicide Attempts ◽  
Epidemiological Studies ◽  
Adolescents And Young Adults ◽  
University Hospital ◽  
International Studies ◽  
Suicide Attempters ◽  
Increased Risk ◽  
Epidemiological Trends

Background: Notwithstanding the epidemiological studies indicating an increased risk of attempted suicide among adolescents and young adults, there is a scarcity of international studies that examine long-term epidemiological trends in rates and characteristics of this vulnerable group. Aims: This article describes the results of a 9-year monitoring study of suicide attempts in adolescents and young adults referred to the Accident and Emergency Department of the Gent University Hospital (Belgium). Methods: Between January 1996 and December 2004, trends, sociodemographic, and methodrelated characteristics of suicide attempts were assessed by a psychiatrist on data sheets. Results: Attempted suicide rates declined from 1996 to 2001 and then rose until 2004, but did not exceed previous rates. During the 9 years of monitoring, there was a preponderance of female suicide attempters, except for 1997. Rates of attempts and of fatal suicide were negatively correlated. Significantly more males than females deliberately injured themselves. Younger attempters, especially females, significantly more often poisoned themselves with analgesics. In nearly one in five attempts, alcohol was used in combination with other methods, and alcohol intake was more commonly observed in older suicide attempters. Nearly half of the adolescents were identified as repeaters. Conclusions: The results of this study warrant further monitoring of trends and characteristics of young suicide attempters.

Sign in / Sign up

Export Citation Format

Share Document