scholarly journals Evaluation of productivity and costs of Malwa forest machine in sanitary fellings in Latvia

2020 ◽  
Author(s):  
Agris Zimelis ◽  
◽  
Santa Kaleja ◽  
Sergey Ariko ◽  
Keyword(s):  
Middle Class ◽  
Soil Compaction ◽  
Mechanical Damage ◽  
Field Trials ◽  
Manual Work ◽  
Spruce Stands ◽  
Compact Class ◽  
Pine Stands ◽  
Increasing Demand ◽  
The Cost

The topicality of the study is determined by the increasing demand for sanitary felling services currently mainly provided by manual work. Harvesting using hand-held motor instruments is a physically hard work whose costs are increasing rapidly, but labor availability is declining. In sanitary cuttings, additional complications are caused by the use of conventional machinery in harvesting, which necessitates the creation of wide (4 m) technological corridors and significantly increases the proportion of damaged remaining trees in a stand (according to past studies, a set of middle-class forest machines in thinning of spruce stands results in 4–5% of damaged trees, but in pine stands – in approximately twice less damaged trees than in spruce stands). The compact class forest machines in thinnings result in mechanical damage to not more than 1% of remaining trees. During field trials in sanitary felling 9329 trees were felled. The average productivity working in one shift is 5.35 m3 h-1 with average stands 10 cm. The cost of harvester’s productive hour is 92 € but of a forwarder it is 78. The compact class forwarder creates significantly smaller impact on the soil by reducing ruts depth and soil compaction, which is especially important in sanitary fillings and extraction of seed trees in regenerated areas.

Qualitative Descriptions of Middle-Class, African American Mothers’ Child-Rearing Practices and Values

2016 ◽  
Vol 39 (4) ◽  
pp. 868-895 ◽  
Author(s):  
Stephanie M. Curenton ◽  
Jocelyn Elise Crowley ◽  
Dawne M. Mouzon
Keyword(s):  
African American ◽  
Middle Class ◽  
Romantic Partners ◽  
Child Rearing ◽  
African American Mothers ◽  
Family Friendly ◽  
Strength Based ◽  
American Children ◽  
Decision To Stay ◽  
The Cost

During qualitative phone interviews, middle-class, mostly married African American mothers ( N = 25) describe their child-rearing responsibilities, practices, and values. They explain (a) why they decided to stay home or take work leave to attend to child rearing, (b) how they divided child-rearing responsibilities with their husbands/romantic partners, (c) whether they faced unique parenting challenges raising African American children, and (d) whether they identified as feminists. Responses revealed the decision to stay home or take work leave comprised values about gender roles, concerns about the cost and/or quality of child care, and the availability of family-friendly workplace policies. Most couples shared child-rearing responsibilities, although mothers admit to doing more. Their unique parenting challenge was protecting their children from racism, stereotyping, and discrimination. Only one third of the mothers identified as being feminists. These results have implications for furthering our knowledge about African American coparenting from a positive, strength-based perspective.

The Technology Innovation of Green Soft Ground Handling Based on Squeezing and Consolidation Composited

2014 ◽  
Vol 580-583 ◽  
pp. 2244-2248
Author(s):  
Jun Yi Shao ◽  
Xiao Zhang
Keyword(s):  
Life Cycle ◽  
Carrying Capacity ◽  
Soil Compaction ◽  
Environmental Load ◽  
Treatment Technology ◽  
Foundation Treatment ◽  
Soft Foundation ◽  
Ground Handling ◽  
Pump Pressure ◽  
The Cost

In this paper, we sorted soft foundation treatment technology by quantifying based on evaluation technique of life cycle environmental load and choose cement mixing pile which life-cycle environmental load is small and spiral pump pressure CFG pile which carrying capacity is high to integrate. It not only improved soil compaction effects, but also solved the problems of other technologies in the foundation process, such as low carrying capacity, reduced diameter, broken pile, virtual pile and so on. Besides, it has reduced the cost of the project and the application prospects are broad.

Laboratory and Field Investigations of the Performance of HPCC Coatings

2004 ◽  
Author(s):  
Fraser King ◽  
Jenny Been ◽  
Robert Worthingham ◽  
Grant Rubie
Keyword(s):  
Laboratory Testing ◽  
High Performance ◽  
Impact Damage ◽  
Mechanical Damage ◽  
Degradation Process ◽  
Field Trials ◽  
Hot Water ◽  
Corrosion Properties ◽  
Field Exposure

Three-layer FBE-polyolefin coatings offer the promise of good adhesive and corrosion properties from the FBE layer coupled with resistance to mechanical damage from the outer polyolefin layer. TransCanada Pipelines have been investigating the long-term behaviour of High Performance Composite Coating (HPCC) using a combination of laboratory testing and field trials. In the laboratory, panels of HPCC were subjected to standard CD disbondment testing following a two-stage degradation process. The degradation process, designed to simulate field exposure, involved impact damage followed by exposure to either a hot-water soak (60°C), or to microbiologically active soil with and without the application of CP. Following exposure, the duplicate panels were subject to 28-day CD disbondment tests to determine the extent of damage caused by the combination of impact and soil/hot water exposure. In the field, a section of HPCC coating was excavated and examined after 11 years service. In addition to visual inspection, the coating was examined in situ using a newly developed impedance technique EISPlus. This technique is a development of earlier EIS techniques and allows the dielectric properties of the coating to be determined in addition to the impedance of the solution-filled pores. EISPlus provides an improved sensitivity for high-impedance coatings, such as FBE, HPCC, and polyolefin tape. Furthermore, since it is a dry technique, rapid measurements can be made on coatings exposed to field conditions allowing the in-service performance to be determined. Results of both the laboratory testing and field EISPlus measurements are presented and the long-term performance of the coating discussed.

Challenges of Integrating Information and Communication Technology in Teaching among National Teachers' Colleges in Uganda

2021 ◽  
Vol 2 (Issue 3) ◽  
Author(s):  
Charles Nyakito ◽  
Catherine Amimo ◽  
Vencie B. Allida
Keyword(s):  
Sampling Strategy ◽  
Teachers Colleges ◽  
Internet Connectivity ◽  
Teachers College ◽  
Attitudinal Barriers ◽  
Information And Communication ◽  
Increasing Demand ◽  
High Level ◽  
Teaching Programs ◽  
The Cost

In this 21st century, educational institutions the world over are faced with increasing demand from society to transform from analogue practices to digital systems using technology. This study investigated the challenges experienced by teacher education college lecturers in their quest to integrate ICT in teacher training practices. The study was qualitative, using focus group discussions, interview and observation with 10 college lecturers from each of the 4 colleges and 4 Principals, one from each college. Snowball purposive sampling strategy was used to draw the participants. The findings revealed a host of challenges, despite a high level of appreciation among college lecturers on the importance of ICT integration into classroom instructional practices. Several debilitating factors evolved including, lack of experience and skills in using ICT, lack of ICT curriculum for the teachers' colleges, lack of clear government policy on the teaching of ICT in the teachers' college curriculum, inadequate ICT resources, obsolete ICT hardware and soft wares, intensive teaching programs due to examination pressures, overcrowded classrooms, lack of time, heavy workload, slow internet connectivity, intermittent electricity supply and, attitudinal barriers from the relatively older lecturers with technophobia. The researchers therefore, recommended government intervention with a clear policy on ICT inclusion in the curriculum, equipping the colleges with adequate and up-to-date equipment, regular training opportunities for the lecturers, provision of alternative and affordable source of power, recruiting more human resource in the colleges to reduce the workload for the lecturers and government subsidizing on the cost of internet connectivity.

Inter-basin water transfer

2021 ◽  
pp. 15-32
Author(s):  
Shima Kheirinejad ◽  
Omid Bozorg-Haddad ◽  
David Quanrud
Keyword(s):  
Water Resource Management ◽  
Economic Value ◽  
Water Transfer ◽  
Management Tool ◽  
Social Challenges ◽  
Basin Water ◽  
Increasing Demand ◽  
Water Transmission ◽  
Water Scarce ◽  
The Cost

Abstract Providing water to satisfy human demands is one of the greatest challenges of the present century and has been the source of many changes in the world. Since the amount of renewable water the Earth receives is only equal to, or even less than, that received many years ago, renewable water per capita decreases as human population increases. Inter-basin water transfer is a method to augment supply in water-scarce regions. Increasing demand for water in some areas sometimes justifies the transfer of water from one basin to another. Water consumption in densely populated cities and in large industrial and agricultural operations produces an economic value that justifies the cost of expensive water transport equipment and infrastructure such as transmission channels, pipelines, pumping stations and dams. Under these conditions, water that is not in high demand in one basin is transferred to another basin for use. These projects are supply-driven engineering solutions to major social challenges. Inter-basin water transmission is carried out across local, regional, national, and international boundaries to overcome water scarcity, to meet demand in the agricultural, industrial and domestic sectors as well as to achieve economic and social development. Inter-basin transfer (IBT) is an important water resource management tool that can have significant impacts on the donor and recipient basins. This chapter aims to provide insights into the concepts, logics, methods and tools used to evaluate inter-basin transfer projects. Challenges that may arise with implementation of such projects and management methods to overcome these challenges are reviewed. Several case study examples of existing projects are presented to provide insight into how to better manage such projects in the future.

scholarly journals Optimizing Sowing Depth of Tef for Irrigated Mediterranean Conditions: From Laboratory to Field Studies

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1983
Author(s):  
Shiran Ben-Zeev ◽  
Shane Kerzner ◽  
Onn Rabinovitz ◽  
Yehoshua Saranga
Keyword(s):  
Field Experiments ◽  
Field Studies ◽  
Field Trials ◽  
Eragrostis Tef ◽  
Sowing Depth ◽  
New Crops ◽  
Different Depths ◽  
Plant Emergence ◽  
Increasing Demand ◽  
Mediterranean Conditions

Developing new crops adapted to arid conditions is a promising approach to meet the increasing demand for food production under expanding aridity. Tef [Eragrostis tef (Zucc.) Trotter] is a C4 cereal crop cultivated mainly in Ethiopia and the Horn of Africa, and known for its high resilience to stressful environments. Due to their tiny size, tef seeds are traditionally sown by broadcasting and lightly covering with soil. Under semiarid Mediterranean conditions, a deeper sowing may guarantee seedling establishment while saving on irrigation water. The objective of this study was, therefore, to determine the effects of sowing depth on tef emergence, development, lodging, and productivity. Tef seeds were sown at different depths in test tubes and pots, and in two field experiments. In tubes and pots, time from sowing to emergence increased about twofold and emergence rate decreased in the deepest sowing (3 cm) treatment compared to controls (0 cm). In the pot and field trials, deep sowing (3 cm) significantly reduced plant height, shoot and root biomass, and lodging. Sowing depths of 1–2 cm allowed successful plant establishment while not exacting penalties on plant emergence or development; hence this range appears to be optimal for sowing irrigated tef.

scholarly journals Tax or Subsidy? Optimal Carbon Emission Policy: A Supply Chain Perspective

2020 ◽  
Vol 12 (4) ◽  
pp. 1548 ◽  
Author(s):  
Xing Yin ◽  
Xiaolin Chen ◽  
Xiaolin Xu ◽  
Lianmin Zhang
Keyword(s):  
Supply Chain ◽  
Carbon Emission ◽  
Negative Impact ◽  
Green Technology ◽  
Manufacturing Firm ◽  
Numerical Studies ◽  
The Social ◽  
The Government ◽  
Increasing Demand ◽  
The Cost

With a rigid requirement for environment protection, governments need to make appropriate policies to induce firms to adopt green technology in consideration of the rapidly increasing demand for environmentally friendly products. We investigated the government policy from the perspective of a supply chain, which consisted of the upstream government (she) and the downstream manufacturing firm (he). The government decided on the policy (tax or subsidy) to maximize the social welfare, while the firm decided on the greenness level of the product, which affects the consumers’ choice behavior and hence his own demand. Assuming else being equal, the government should adopt the tax policy if consumers are very sensitive to the greenness, the cost of greening is high, or the negative impact due to carbon emission is large, and subsidize the firm otherwise. We also conduct some numerical studies when price is endogenous. The main insights can be carried over.

scholarly journals The effect of ecological growing on the potatoes yield and quality

2011 ◽  
Vol 51 (No. 9) ◽  
pp. 397-402 ◽  
Author(s):  
K. Hamouz ◽  
J. Lachman ◽  
P. Dvořák ◽  
V. Pivec
Keyword(s):  
Mechanical Damage ◽  
Field Trials ◽  
Matter Content ◽  
Point Of View ◽  
Nitrate Content ◽  
Dry Matter Content ◽  
Yield And Quality ◽  
Negative Effect ◽  
Cultivated Potatoes

In the years 1995–1997 the effect of ecological growing on the yield and selected parameters of quality of consumer potatoes (in comparison with conventional way) were investigated. The ecological way of growing differed in the lack of chemical protection against diseases and pests and industrial fertilizers. Field trials were realised with seven varieties (Impala, Karin, Agria, Korela, Rosella, Santé and Ornella) on two sites (Uhříněves and Valečov). The ecological way of growing had markedly negative effect on the yield (decrease by 36%). In qualitative parameters the ecological way increased inconclusively polyphenol content (by 10.2%), decreased inconclusively nitrate content (by 11.0%) and reducing sugars (by 22%). It did not affect dry matter content, resistance of tubers to mechanical damage, table value and glycoalkaloid content. Variety Santé achieved the best results from the point of view of the yield and majority of qualitative parameters among varieties. Qualitative parameters of ecologically cultivated potatoes were significantly affected by the year of cultivation.

scholarly journals The Relationship Between Bulb Yield and Allicin Concentration in Garlic Varieties

Proceedings ◽  
2019 ◽  
Vol 36 (1) ◽  
pp. 28
Author(s):  
Nguyen ◽  
Wehr ◽  
O’Hare ◽  
Hong ◽  
Menzies ◽  
...  
Keyword(s):  
Block Design ◽  
Health Benefits ◽  
Field Trials ◽  
Organosulfur Compounds ◽  
Potential Health ◽  
Agronomic Practices ◽  
Negative Effect ◽  
Increasing Demand ◽  
Tropical Varieties ◽  
The Relationship

Garlic (Allium sativum L.) is used as a vegetable and medicinal plant. It is a rich source of organosulfur compounds, in particular allicin, which contributes to the flavour and health benefits. Although worldwide garlic production is increasing, demand continues to outstrip supply. Improving the yield of garlic will address the increasing demand, while increasing allicin concentration will improve its potential health benefits and flavour. It is unknown if increasing garlic bulb size (yield) has a negative effect on allicin concentration of garlic. Therefore, a fundamental understanding of the relationship between yield and allicin concentration is required. A field experiment was conducted at Gatton (QLD, Australia) with 32 varieties, of which 29 varieties were sourced from World Vegetable Centre and 3 varieties from existing Queensland sub-tropical varieties. The garlic cloves were planted in March 2018 with 4 replicates in a randomised complete block design and harvested when garlic had 70% senescence. Varieties showed large variation in bulb size, ranging from about 35 to 120 g, with fresh yield ranging from about 5.5 to 16 t/ha. The allicin concentration ranged from 3.5 to 6.6 mg g−1 fresh weight (FW) between varieties and more than 50% of varieties were under the minimum pharmaceutical standard for allicin concentration (>4.5 mg g−1 in FW). Across varieties there was an inverse relationship between yield and allicin concentration. However, there were some varieties which had both high allicin concentration and yield. Current field trials investigate the effect of agronomic practices on yield and allicin concentration in garlic varieties.

Opportunities and costs of intensification and clustering of forest management activities

2008 ◽  
Vol 38 (4) ◽  
pp. 711-720 ◽  
Author(s):  
Anne-Hélène Mathey ◽  
Emina Krcmar ◽  
John Innes ◽  
Ilan Vertinsky
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Timber Harvesting ◽  
Conservation Areas ◽  
Intensive Forest Management ◽  
Trade Offs ◽  
Planning Approach ◽  
Increasing Demand ◽  
Canadian Boreal Forest ◽  
The Cost

The intensification of forest management in Canada has been advocated as a possible solution to the conundrum that increasing demand for conservation areas and increasing pressure for timber production have created. The benefits and disadvantages of intensive forest management in the context of the Canadian boreal forest are unclear and reaching conclusions about its general value from stand analyses may be difficult. In this study, a boreal forest in Ontario has been used to investigate the potential of intensive management to generate financial revenues and meet management constraints on volume flow and old-growth retention. Two aspects of intensive forest management are considered: intensive silviculture and concentrated harvest activities. The plans are generated with a decentralized planning approach based on cellular automata. The results for the case study show that increasing silviculture intensity can help fulfill high timber flow requirements under strict conservation requirements. This comes at the cost of reduced net revenues but from a smaller timber harvesting landbase. The main trade-offs found were those between harvest flow and financial benefits. Clustering both protected areas and harvest operations could help achieve the conservation and timber-related objectives simultaneously by improving the habitat value of conserved areas and decreasing the operational costs in harvested areas.

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