An assessment of stress and production rate of sucker rod heat pipes in oil well pumping system
Deep Underground Science and Engineering, EarlyView.The sucker rod pumping system is the preferred oil extraction technique. The concept about equipping the hollow vacuum space in solid sucker rods with heat pipe has been scrutinized in terms of stress and oil production evaluation. Abstract The implementation of the heat pipe concept in sucker rods for oil pumping systems negates the requirement for an
R. S. Anand +5 more
wiley +1 more source
The effects of the underground economy on economic competitiviness
A real, almost palpable, connection exists between the official and the underground economy. More than that, both sides of the economy (official and underground) are connected with the competitiveness of a country.
Donici, Gabriel-Andrei/GA
core
The size of the underground economy in Germany: A correction of the record and new evidence from the Modified-Cash-Deposit-Ratio approach [PDF]
Based on the Ahumada et al. (2007, Review of Income and Wealth) critique we revise existing estimates of the size of the German underground economy. Among other things, it turns out that most of these estimates are untenable and that the tax pressure ...
Pickhardt, Michael, Sarda, Jordi
core
An optimizing microseismic method for rock burst early warning based on mining production process
Deep Underground Science and Engineering, EarlyView.A classification early warning method of rock burst based on hourly microseismic data is proposed, which can be combined with the on‐site production process to provide more timely warning. Abstract Microseismic (MS) events have been reported in nearly every coal mining country, which could well lead to rock burst in underground coal mines.
Zepeng Han +6 more
wiley +1 more source
Currency Demand Modeling In Estimating The Underground Economy: A Critique on ‘Excess Sensitivity’ Method and Support for VAR Framework [PDF]
The ‘excess sensitivity’ as the method of estimating the underground economy by using currency modeling is found to be unreliable. In general, there are two major weaknesses in the method.
Jerry Marmen Simanjuntak
core
Deep Underground Science and Engineering, EarlyView.A novel cavity contraction solution and multilayer shaft wall model were developed to analyze deep shaft stability, considering rock viscosity, support structures, and water pressure, with successful validation through a Hulusu Coal Mine case study.
Bin Chen +5 more
wiley +1 more source
AN ANALYSIS OF THE SHADOW ECONOMY IN EU COUNTRIES [PDF]
CES Working Papers, 2016 The paper aims at analysing the dimension of the underground economy in the EU states between 2003 and 2015. In order to achieve this goal, we use qualitative and quantitative methods. In the first two sections of the study we resort to conceptualisation
Brindusa Mihaela Tudose +1 more
doaj
The dimension of the underground economy, in Romania, in the period after 1989 [PDF]
In the period after 1989, the underground economy in Romania had a constantly ascendant evolution. In this article we think about the distinguishness of the underground economy level and of the real possibilities of Romanian economy through the dimension
Stela Toader
core
Optimal taxation and monitoring in an economy with matching frictions and underground activities [PDF]
This short paper shows the interdependence of taxation and monitoring policy in a search and matching model of equilibrium unemployment with an underground sector.
Lisi, Gaetano
core +1 more source