scholarly journals The Impact of Weather and Slope Conditions on the Productivity, Cost, and GHG Emissions of a Ground-Based Harvesting Operation in Mountain Hardwoods

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1612
Author(s):  
Sättar Ezzati ◽  
Farzam Tavankar ◽  
Mohammad Reza Ghaffariyan ◽  
Rachele Venanzi ◽  
Francesco Latterini ◽  
...  
Keyword(s):  
Ghg Emissions ◽  
Timber Harvesting ◽  
Operating Conditions ◽  
Production Costs ◽  
Cost Models ◽  
Mixed Stands ◽  
Average Delay ◽  
Productivity Cost ◽  
Steep Slopes ◽  
The Impact

Mountainous hardwood mixed stands offer challenges to timber harvesting operations in practice, including a harsh climate, variable topography, steep terrain, and large-sized timbers. This paper aims to develop productivity and cost models for a mountain-ground-based harvesting operation across the terrain (e.g., slope conditions), stand (e.g., tree volume) environmental (e.g., weather), and yard (e.g., winching distance) variables and to assess GHG emissions related to the equipment in use. This development was implemented in a timber harvesting practice under single-tree selection in mountainous forests of Iran where a motor-manual chainsaw is used for felling and a rubber-tired cable skidder is used for log extraction. The average delay-free productivity was 4.55 m3 for felling and 14.73 m3 h−1for skidding. Lower production costs and higher productivity rates were observed over the gentle slopes and in sunny conditions. The average production costs ranged between USD 4.27m−3 for felling and USD 5.35m−3 for skidding. The average emissions ranged between 0.96 kg m−3 for felling and 7.06 kg m−3 for skidding in snowy conditions over steep slopes. The study’s results confirm avoiding harvesting operations on steep slopes (greater than 35%) and in extreme weather conditions to obtain higher work efficiency and to minimize adverse effects of machinery on forest ecosystems. The results should be of use to harvest managers and forest planners considering the application of ground-based harvesting operations using a semi-mechanized system on a range of operating conditions in mountain hardwood stands.

scholarly journals The cost disadvantage of steep slope viticulture and strategies for its preservation

OENO One ◽  
2021 ◽  
Vol 55 (1) ◽  
pp. 49-68
Author(s):  
Larissa Strub ◽  
Simone Mueller Loose
Keyword(s):  
Net Present Value ◽  
Univariate Analysis ◽  
Steep Slope ◽  
Production Costs ◽  
Pricing Policy ◽  
Fixed And Random Effects ◽  
Option Strategies ◽  
The Cost ◽  
Steep Slopes ◽  
The Impact

The falling fallow of steep slope vineyards is caused by cost disadvantages that have not been analysed so far. This study quantified the production costs of different types of steep slopes, identified cost drivers within viticultural processes and assessed the impact of grape yield on the production cost for vertical shoot positioning (VSP) systems. It also examined under what conditions the reshaping of steep slope vineyards into transversal terraces (TTs) is economically viable. Costs were derived from a dataset of 2321 working time records for labour and machine hours from five German wine estates over three years. The costs for standard viticultural processes were compared across five site types with different mechanisation intensities by univariate analysis of variance with fixed and random effects. The net present value (NPV) of reshaping slopes into horizontal terraces was also assessed. Manual management of steep slopes was determined to be 2.6 times more costly than standard flat terrain viticulture. The cost disadvantage of steep slopes mainly stems from viticultural processes with limited mechanisability that require specialised equipment and many repetitions. Current subsidies fall short of covering the economic disadvantage of manual and rope-assisted steep slopes. Climate change-related drought and yield losses further increase the economic unsustainability of steep slopes. Under certain conditions, the transformation of manual steep slope sites into TTs can be a viable economic option. Strategies to reduce the cost disadvantage are outlined. The estimated cost benchmarks provide critical input for steep slope wine growers’ cost-based pricing policy. These benchmarks also give agricultural policy reliable indicators of the subsidies required for preserving steep slope landscapes and of the support needed to transform manual steep slope sites into TTs.

scholarly journals Productivity and Costs of Two Beetle-Kill Salvage Harvesting Methods in Northern Colorado

Forests ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 572 ◽  
Author(s):  
Hee Han ◽  
Woodam Chung ◽  
Ji She ◽  
Nathaniel Anderson ◽  
Lucas Wells
Keyword(s):  
Timber Harvesting ◽  
Production Costs ◽  
Cost Models ◽  
Northern Colorado ◽  
Salvage Harvesting ◽  
Whole Tree Harvesting ◽  
Harvesting Costs ◽  
Tree Method ◽  
Whole Tree ◽  
Tree Harvesting

Two ground-based timber harvesting methods have been commonly used for beetle-kill salvage treatments after a bark beetle epidemic in northern Colorado. A “lop and scatter” method uses a mobilized stroke delimber to delimb and buck trees at the stump, leaving tree tops and limbs on the forest floor, while a whole-tree harvesting method brings the entire tree to the landing where it is delimbed and bucked, and thus produces logging residue piles at the landing as a byproduct. We conducted a detailed comparative time study of the two harvesting methods to develop productivity and cost models and compared the performance of the two methods under various site conditions. We applied the productivity and cost models to lodgepole pine forest stands totaling 3400 hectares of the Colorado State Forest State Park to estimate salvage harvesting costs for each forest stand and identify the least costly harvesting options. The results show that the estimated stump-to-truck timber production costs were $30.00 per oven dry ton (odt) for lop and scatter and $23.88 odt−1 for the whole-tree method in our study harvest unit. At the forest level, the estimated average stump-to-truck costs were $54.67 odt−1 and $56.95 odt−1 for lop and scatter and whole-tree harvesting, respectively. Skidding distance and downed trees affect the harvesting costs of both methods, but their influence appears to be more significant on the whole-tree method.

scholarly journals Productivity and costs modeling for tree harvesting operations using chainsaws in plantation forests, Tanzania

2014 ◽  
Vol 3 (4) ◽  
pp. 464 ◽  
Author(s):  
Dos Santos Silayo ◽  
George Migunga
Keyword(s):  
Cutting Tools ◽  
Timber Harvesting ◽  
Production Costs ◽  
Private Forests ◽  
Productivity Cost ◽  
Plantation Forests ◽  
Unit Costs ◽  
Delay Times ◽  
Unit Of Measurement ◽  
Tree Cutting

With exemption of a few private forests, timber harvesting in most plantation forests in Tanzania is carried out by less skilled and less equipped crews. Newly recruited crews often learn from experienced ones which may not be doing it in the perfect way. Therefore estimation and projecting production and costs becomes a big problem to logging managers. This study was carried out to develop productivity and costs models for chainsaw operators in a learning experiment. The experiments were designed in clear felling operations. Three experiments were set where each crew category was studied using time study and work sampling techniques that involved studying crews before training, after training and after the break at an interval of three months. Descriptive statistics and modelling was performed for each crews performance. Specific crews productivity and costs models have been developed reflecting necessary and unnecessary delay times. Assessment of the production costs show that unit costs decreases with increasing productivity in each unit of measurement of the production rate. It is recommended that productivity and costs for two-man crosscut saw operators be studied and modelled since they are also the main cutting tools used in tree cutting in Tanzania. Keywords: Productivity, Cost, Timber Harvesting, Modelling, Chainsaw, Tanzania.

scholarly journals Nitrous oxide, ammonia and methane from Australian meat chicken houses measured under commercial operating conditions and with mitigation strategies applied

2016 ◽  
Vol 56 (9) ◽  
pp. 1404 ◽  
Author(s):  
S. G. Wiedemann ◽  
F. A. Phillips ◽  
T. A. Naylor ◽  
E. J. McGahan ◽  
O. B. Keane ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Ghg Emissions ◽  
Operating Conditions ◽  
Mitigation Strategies ◽  
N2o Emissions ◽  
Standard Diet ◽  
Litter Depth ◽  
Carbon Dioxide Equivalents ◽  
The Impact

Greenhouse gas (GHG) and ammonia emissions are important environmental impacts from meat chicken houses. This study measured ammonia (NH3), nitrous oxide (N2O) and methane (CH4) in two trials from paired, commercial meat chicken houses using standard (control) and mitigation strategies. In Trial 1, emissions from houses with standard litter depth of 47 mm (LD47) or increased litter depth of 67 mm (LD67) were compared. When standardised to a 42-day-old bird, emissions were 11.9 g NH3/bird, 0.30 g N2O/bird and 0.16 g CH4/bird from the LD47 and 11.7 g NH3/bird, 0.69 g N2O/bird and 0.12 g CH4/bird from the LD67. Emissions per kilogram of manure N were 0.14 and 0.11 for NH3-N, 0.003 and 0.005 N2O-N and CH4 conversion factors were 0.08% and 0.05%. Total direct and indirect GHG emissions reported in carbon dioxide equivalents were found to be higher in LD67 in response to the elevated direct N2O emissions. Trial 2 compared the impact of reduced crude protein (CP19.8) and a standard diet (CP21.3) developed using least-cost ration formulation, on emissions. Emissions per bird for the CP19.8 diet were 7.7 g NH3/bird, 0.39 g N2O/bird and 0.14 g CH4/bird, while emissions from birds fed the CP21.3 diet were 10.6 g NH3/bird, 0.42 g N2O/bird and 0.19 g CH4/bird. Significant differences were observed only in the NH3 results, where emissions were reduced by 27% for the low-CP diet. Because of the low emission levels, total mitigation potential from indirect GHG emissions was relatively small in Trial 2, corresponding to 11 t carbon dioxide equivalents/year per million birds.

scholarly journals The Effects of Soil Moisture on Harvesting Operations in Populus spp. Plantations: Specific Focus on Costs, Energy Balance and GHG Emissions

2021 ◽  
Vol 13 (9) ◽  
pp. 4863
Author(s):  
Farzam Tavankar ◽  
Mehrdad Nikooy ◽  
Francesco Latterini ◽  
Rachele Venanzi ◽  
Leonardo Bianchini ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Ghg Emissions ◽  
Production Costs ◽  
Tree Plantations ◽  
Productivity Cost ◽  
High Soil Moisture ◽  
Harvesting Systems ◽  
Poplar Plantations

Background: Poplar tree plantations for wood production are part of a worldwide growing trend, especially in moist soil sites. Harvesting operations in moist sites such as poplar plantations require more study for detailed and increased knowledge on environmental and economic aspects and issues. Methods: In this study, the effects of soil moisture content (dry vs. moist) on productivity, cost, and emissions of greenhouse gases (GHG) caused by operations of different harvesting systems (chainsaw-skidder and harvester-forwarder) were evaluated in three poplar plantations (two in Italy and one in Iran). Results: The productivity (m3 h−1) of both systems in the dry sites were significantly higher (20% to 30%) than those in the moist sites. Production costs (€ m−3) and GHG emissions (g m−3) of both systems in the dry sites were also significantly lower than those in the moist sites. The productivity of the harvester-forwarder system was about four times higher, and its production cost was 25% to 30% lower than that of the chainsaw-skidder system, but the calculated GHG emissions by harvester-forwarder system was 50–60% higher than by the chainsaw-skidder system. Conclusions: Logging operations are to be avoided where there are conditions of high soil moisture content (>20%). The result will be higher cost-effectiveness and a reduction in the emission of pollutants.

scholarly journals Carbon Footprint and Related Production Costs of Pot-in-Pot System Components for Red Maple Using Life Cycle Assessment

2015 ◽  
Vol 33 (3) ◽  
pp. 103-109 ◽  
Author(s):  
Dewayne L. Ingram ◽  
Charles R. Hall
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Carbon Footprint ◽  
Production Systems ◽  
Ghg Emissions ◽  
Acer Rubrum ◽  
Production Costs ◽  
Red Maple ◽  
Bare Root ◽  
The Impact

Component input materials and activities of a model pot-in-pot (PIP) production system were analyzed using life cycle assessment methods. The impact of each component on global warming potential (GWP; kilograms of CO2-equivalent), or carbon footprint, and variable production costs was determined for a 5 cm caliper Acer rubrum L. ‘October Glory’ in a #25 container. Total greenhouse gas emissions (GHG) of inputs and processes at the nursery gate for a defined model system were 15.317 kg CO2e. Carbon sequestration weighted over a 100-year assessment period was estimated to be 4.575 kg CO2, yielding a nursery gate GWP of 10.742 kg CO2e. The major contridbutors to the GWP at the nursery gate were the substrate, production container, the 1.8 m (6 ft), branched, bare root liner, PIP system installation, and fertilization while the liner and production container also contributed significantly to the variable costs. Input materials and labor constituted about 76 and 21% of variable costs, respectively. Unlike field production systems, equipment use in PIP production accounted for only 13% of GHG emissions and 2% of variable costs.

scholarly journals Optimasi siklus termodinamika integrasi boiler AQC dan PH pada desain WHRPG di industri semen

2019 ◽  
Vol 9 (1) ◽  
pp. 51-57
Author(s):  
Teguh Sasono, Tjatur Udjianto
Keyword(s):  
Steam Turbine ◽  
Ghg Emissions ◽  
Electricity Consumption ◽  
Electrical Energy ◽  
Cement Industry ◽  
Operating Conditions ◽  
Production Costs ◽  
Pinch Point ◽  
Electric Generator ◽  
Exhaust Heat

The cement industry is a chemical industry that requires large amounts of energy and releases CO2 emissions, one of which is produced from limestone calcination. Electricity consumption index for 2017 at PT Holcim Indonesia Tbk. Cilacap Plant averaged 92.20 kWh / ton cement and 3,352MJ / ton clinker in thermal form. This shows that the use of thermal energy is very dominant in the production process. The opportunity to reduce the index of electricity consumption is a very appropriate step in order to reduce greenhouse gas (GHG) emissions and production costs, thereby increasing its competitiveness. Installation of WHRPG system in the preheater (PH) process output unit and the water quenching cooler (AQC) output to utilize exhaust heat that can produce pressurized steam and when combined with the steam turbine starter drive and electric generator coupled, the system is able to generate electricity to supply the needs electrical energy industry. From the data of potential exhaust gases in PH and AQC and the design determination of the choice of operating conditions of the selected three-level steam turbine pressure, the optimization results are obtained by applying a graded nonlinear GRG model, the thermal efficiency of the WHRPG water system is optimal at 24.38% with work output the optimum thermal value is 6,420.29 kW and the estimated gross electric power yield is 6.089,51kW. The optimal conditions achieved are indicated by the pinch point value on the AQC boiler that occurs in the economizer at 10K while the PH boiler occurs at the superheater of 10K according to the specified pinch minimum constraints. If the estimated power of the balance of plant and auxiliaries in the WHRPG system is 12% and the cement production capacity is 7,800 tons / day assuming a WHRPG capacity factor of 73%, then the magnitude of the reduction in electrical energy intensity is at least 12.04 kWh / ton cement. Keyword : Preheater, Air Quenching Cooler, WHRPG, HRSG, Cement, GRG nonlinear, Optimamization, Kawasaki

scholarly journals Performance Analysis of Log Extraction by a Small Shovel Operation in Steep Forests of South Korea

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 585 ◽  
Author(s):  
Eunjai Lee ◽  
Sang-Kyun Han ◽  
Sangjun Im
Keyword(s):  
South Korea ◽  
Predictive Ability ◽  
Stand Density ◽  
Production Costs ◽  
Mixed Stands ◽  
Forest Road ◽  
Stem Size ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
The Impact

In South Korea, logs for low-value products, such as pulpwood and fuelwood, are primarily extracted from harvest sites and transported to roadside or landing areas using small shovels. Previous studies on log extraction, however, have focused on cable yarding operations with the goal of improving productivity on steep slopes and inaccessible sites, leaving small-shovel operations relatively unexamined. Therefore, the main objectives were to determine small-shovel extraction productivity and costs and to evaluate the impact of related variables on productivity. In addition, we developed a model to estimate productivity under various site conditions. The study took place in 30 case study areas; each area has trees with stems at a diameter at breast height ranging from 18 to 32 cm and a steep slope (greater than 15%). The areas ranged from 241 to 1129 trees per hectare, with conifer, deciduous, and mixed stands. Small-shovel drives ranged from 36 to 72 m per extraction cycle from stump to landing. The results indicated that the mean extraction productivity of small-shovel operations ranged between 2.44 to 9.85 m3 per scheduled machine hour (including all delays). At the forest level, the estimated average stump-to-forest road log production costs were US $4.37 to 17.66/m3. Small-shovel productivity was significantly correlated with stem size (diameter at breast height and tree volume) and total travelled distance (TTD). However, a Pearson’s correlation analysis indicated that stand density and slope did not have a significant effect on productivity. Our findings provide insights into how stem size and TTD influence small shovel performance and the predictive ability of productivity. Further, this information may be a valuable asset to forest planners and managers.

Truck Tire Operating Temperatures on Flat and Curved Test Surfaces

2005 ◽  
Vol 33 (3) ◽  
pp. 156-178 ◽  
Author(s):  
T. J. LaClair ◽  
C. Zarak
Keyword(s):  
Flat Surface ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Load Pressure ◽  
Truck Tire ◽  
Endurance Testing ◽  
Operating Temperatures ◽  
The Impact ◽  
Tread Rubber ◽  
Cylindrical Test

Abstract Operating temperature is critical to the endurance life of a tire. Fundamental differences between operations of a tire on a flat surface, as experienced in normal highway use, and on a cylindrical test drum may result in a substantially higher tire temperature in the latter case. Nonetheless, cylindrical road wheels are widely used in the industry for tire endurance testing. This paper discusses the important effects of surface curvature on truck tire endurance testing and highlights the impact that curvature has on tire operating temperature. Temperature measurements made during testing on flat and curved surfaces under a range of load, pressure and speed conditions are presented. New tires and re-treaded tires of the same casing construction were evaluated to determine the effect that the tread rubber and pattern have on operating temperatures on the flat and curved test surfaces. The results of this study are used to suggest conditions on a road wheel that provide highway-equivalent operating conditions for truck tire endurance testing.

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