Large Ramp Research Articles

Wheel wear of mountain metro vehicles with complex line conditions

Purpose Mountain metro vehicles have unique wheel wear characteristics due to the complex flat and longitudinal lines. With a combination of flat and longitudinal curved tracks, the traction and braking conditions are more frequent in mountain metro vehicles. This paper aims to analyze the wheel wear characteristics of mountain metro vehicles in complex flat and longitudinal lines. Design/methodology/approach A dynamic model of the mountain metro vehicle and a wear model are established to analyze the dynamic and wheel wear characteristics of mountain metro vehicles. The wheel wear law of mountain metro vehicles under complex track conditions is analyzed, and the suppression measure based on variable stiffness rotary arm nodes of mountain metro vehicles is proposed. Findings The results showed that the maximum wheel wear depth without considering the ramp track and considering the ramp track are 3.283 mm and 3.717 mm, respectively; the maximum wheel wear depth increases by 13.2%. Wheel wear can be effectively suppressed by the variable stiffness rotary arm model, and the maximum wear depth of the wheel profile is 3.316 mm, which is reduced by 10.79% compared with the constant stiffness model. Originality/value A dynamic model of a mountain metro vehicle is established, and the metro vehicle wheel wear under the large ramps under the traction and braking conditions is analyzed, and the metro vehicle wheel wear suppression measure based on variable stiffness rotary arm nodes is proposed. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0247

Numerical investigation of wheel-rail rolling contact characteristics and damage in a high-speed turnout switch panel under a large ramp

The damage pattern on a railway line under large ramp is more complicated than that of a standard railway line. In order to investigate the influence of the complex wheel-rail contact evolution in the turnout area on the service characteristics of the switch panel under a large ramp, this paper establishes an explicit FE model of the wheel-rail rolling contact on a 40‰ slope. The performance of a train crossing the turnout and the change in mesoscopic contact behavior is then analyzed under different operating conditions. The distribution rule for wear and fatigue damage to the switch rail under a large ramp is studied, with a regulation strategy proposed for improving the service performance of the switch rail based on the results. These show that there is an obvious cyclical incremental phenomenon on the mechanical behavior at the front end of the switch rail, with uneven abrasion distributed throughout the region. The increase in axle weight, speed and friction coefficient increases the stress concentration of the switch rail and exacerbates the damage. As the train passes through the switch panel, the service life of the switch rail can be significantly improved by reducing the traction.

Towards CSP technology modeling in power system expansion planning

Power systems with a high level of renewable energy penetration face challenges due to the inherent properties of some renewable energy sources, such as their variability and uncertainty. These systems require reliable technologies capable of handling large ramps and flexibility needs. Concentrating Solar Power (CSP) has been identified as one solution, which has been researched and implemented in several countries. This paper presents a novel analysis and evaluation of the impacts of choosing an inadequate representation of CSP technology in power system planning tools. The current state of CSP in power system expansion planning in the literature is examined, providing a classification for the modeling of investment and operation of CSP plants. Based on a proposed analysis framework, different models and configurations for CSP plants are evaluated and applied to a 5-bus test system. One of the key findings is that the selected model highly impacts the computational effort (150% more processing time), the quality of the planning decision (14% more overall costs), and the total emissions (up to 52% more emissions). A storage-based model proves to be the most suitable option, considering the operation and investment costs, as well as computational burden. The selected model achieves a 1% error compared to the results obtained with a reference model, while also requiring 40% less computation effort. The proposed framework can be applied to other power system structures by choosing the best suited CSP modeling.

An Improved Integral Sliding Mode Control for PMSM Drives Based on New Variable Rate Reaching Law With Adaptive Reduced-Order PI Observer

This paper focuses on speed control in a permanent-magnet synchronous motor (PMSM). To promote the speed tracking performance and anti-disturbance property of PMSM speed regulation system against various unknown disturbances, such as parameter mismatch, load torque variation, friction force, and so on, an improved integral sliding mode control (IISMC) method based on a new variable rate reaching law (NVRRL) and an adaptive reduced-order proportional integral observer (AROPIO) is proposed. The NVRRL method can reduce chattering, and convergence time of the system state at the same time compared to the existing sliding mode reaching law. An anti-windup sliding mode surface is proposed to overcome the overshoot problem of the integral sliding mode surface when the reference speed is large and rises in steps or large ramps. To further improve the system tracking accuracy and anti-disturbance ability, an AROPIO is used to estimate lumped disturbances and provides feedforward compensation for the IISMC. The simulation and experimental results show that the proposed IISMC+AROPIO method not only achieves high speed tracking accuracy and fast convergence speed but also achieves strong anti-interference ability.

Arthroscopic Meniscus Ramp Repair: The Shoelace Technique

Background: A “ramp lesion” is described as an injury involving the peripheral attachment of the posterior horn of the medial meniscus. Ramp lesions are associated with increased loads on anterior cruciate ligament and leads to rotatory instability of knee. During anterior cruciate ligament reconstruction, failure to identify and treat ramp lesion leads to increased forces on the reconstructed graft and residual instability which ultimately increases chances for graft failure. It is important to identify the ramp lesions by looking at the posterior compartment and repair ramp lesion. Ramp lesions are still a challenge to treat due to misdiagnosis and long learning curve of current techniques. In this technique, we are presenting margin convergence shoelace technique to repair a large ramp lesion. Indications: Isolated ramp lesions or ramp lesions associated with other ligamentous injuries. Technique Description: Through standard anteromedial and anterolateral portals, diagnostic arthroscopy is done. Using Gillquist maneuver, posteromedial compartment is visualized to look for ramp lesion. Probing is done with 18-gauge spinal needle from posteromedial aspect of knee to look for hidden lesions and extent of tear. We use 2 additional portals, low and high posteromedial portals for ramp repair. Visualizing from anterolateral portal entry is made in the posteromedial compartment; low posteromedial portal is created at the level of meniscus; 8-mm passport cannula is inserted and used as working portal; and then, high posteromedial portal is created and used as viewing portal. Visualizing through high posteromedial portal rasping of ramp lesion is done. Now with knee scorpion loaded with 2-0 fiber wire, bites are taken along posterior margin of meniscus and capsular portion of tear edges alternatively in shoelace manner from lateral to medial. Finally, compression and knot tying are done and secured with multiple half hitches. Results: Surgical repair of ramp lesions is associated with good healing, and it restores stability of knee. Follow-up of more than 2 years shows better functional outcome and reduced retear rates. Discussion/Conclusion: Currently, there are a lot of techniques described for ramp repair. We present arthroscopic ramp repair with dual posteromedial portals by shoelace technique, which is a safe, easy, and cost-effective method and gives excellent results and good healing especially in larger tears. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Performance Simulation of a Coal-Fired Power Plant Integrated with S-CO2 Brayton Cycle for Operational Flexibility Enhancement

In this study, a coal-fired power plant with an integrated S-CO2 cycle is proposed to improve the system operational flexibility. To optimize the performance, a control strategy of variable load regulation is proposed. First, a dynamic mathematical model of the system is established based on the conservation of mass and energy principles, and then, dynamic verification of the model is carried out. In order to evaluate the performance of the proposed system, an exergy analysis is performed on the S-CO2 cycle, indicating that the exergy loss rate of the heater in the cycle is the highest. Finally, the dynamic performance of the system is simulated, and the dynamic response of the power generation load is analyzed. In addition, the system is evaluated based on the performance indicator of the flexibility of the power generation. It was found that the proposed system in this paper has a large load ramp rate which can quickly follow the load response. Meanwhile, compared with load downregulation, the system has greater potential for load upregulation.

Understanding electricity prices beyond the merit order principle using explainable AI

Electricity prices in liberalized markets are determined by the supply and demand for electric power, which are in turn driven by various external influences that vary strongly in time. In perfect competition, the merit order principle describes that dispatchable power plants enter the market in the order of their marginal costs to meet the residual load, i.e. the difference of load and renewable generation. Various market models are based on this principle when attempting to predict electricity prices, yet the principle is fraught with assumptions and simplifications and thus is limited in accurately predicting prices. In this article, we present an explainable machine learning model for the electricity prices on the German day-ahead market which foregoes of the aforementioned assumptions of the merit order principle. Our model is designed for an ex-post analysis of prices and builds on various external features. Using SHapley Additive exPlanation (SHAP) values we disentangle the role of the different features and quantify their importance from empiric data, and therein circumvent the limitations inherent to the merit order principle. We show that load, wind and solar generation are the central external features driving prices, as expected, wherein wind generation affects prices more than solar generation. Similarly, fuel prices also highly affect prices, and do so in a nontrivial manner. Moreover, large generation ramps are correlated with high prices due to the limited flexibility of nuclear and lignite plants. Overall, we offer a model that describes the influence of the main drivers of electricity prices in Germany, taking us a step beyond the limited merit order principle in explaining the drivers of electricity prices and their relation to each other.

Day‐ahead wind power ramp forecasting using an image‐based similarity search strategy

With the increase in penetration of wind generation on interconnected power systems, the importance of wind power ramp forecasting has continuously grown. Large power ramps caused by sudden weather changes raise more concerns due to their significant impact on the power system economics and stability. Correct wind power ramp forecasts can help the system operators and utility companies to tradeoff the risks when scheduling wind energy in the electricity market. In this paper, a day-ahead wind power ramp forecasting algorithm is developed to provide probabilistic ramp forecasts for look-ahead times up to 48 h using hourly wind speed forecasts from Environment Canada High Resolution Deterministic Prediction System (HRDPS). An image-based similarity search strategy has been designed to build a direct link between the wind speed forecasts and the wind power ramp prediction, thus reducing the impact of the uncertainty from both the power production forecast model and the ramp identification process on the forecasting accuracy. A performance assessment and validation of the proposed ramp event forecasting method is conducted by using the forecast and operation data from six investigated wind farms across Canada.

Research on Automatic Driving Path Tracking Control of Open-Pit Mine Transportation Vehicles with Delay Compensation

The transportation environment of the open-pit mine is complex, the steering actuator of the mine vehicle has a large delay and poor response accuracy, and there are a lot of bumpy roads, large undulating ramps, and narrow-area curves in the mining area. These road sections seriously reduce the tracking accuracy of the mine vehicle path. Tracking control presents great challenges. Therefore, this study first conducts a simulation comparison study on commonly used path tracking methods such as pure pursuit control, Stanley control, and model predictive control (MPC), and then designs a path tracking control strategy for automatic driving of open-pit mine transportation vehicles based on the MPC algorithm. Finally, the proposed control strategy was verified through actual mining vehicle tests. The results showed that the maximum lateral deviation obtained by the MPC-based path tracking control strategy was reduced from 0.55 m to 0.08 m under the C-shaped reference path compared with the traditional method. Under the S-shaped reference path, the lateral deviation is reduced from 0.4 m to 0.16 m.

A Practical Metric to Evaluate the Ramp Events of Wind Generating Resources to Enhance the Security of Smart Energy Systems

The energy industry, primarily based on the use of fossil fuels (e.g., coal and oil) is rapidly shifting toward renewable energy for securing sustainable resources. Thus, preparing for large wind power ramp events is essential to retain reliable and secure power systems. This study proposed a new statistical approach to predict wind power ramp events, and evaluated the performance of prediction. The empirical data, which is the observed wind power output data and wind speed data from Taebaek (South Korea) were used for analyzing ramp events and for evaluation. Based on the data analysis, a practical metric for evaluating the performance of wind power ramp events forecasting was developed and presented in detail. Notably, the accuracy of forecasting was evaluated through various metrics, whereas the normalized mean absolute error (NMAE) analysis demonstrated ≤ 10% values for all the analyzed months. In addition, a system review was conducted to check if the methodology suggested in this study has helped enhance the security of power systems. The results show that evaluating and considering the ramp events can improve the accuracy of wind power output forecasting which can secure the smart energy systems.

Data-driven energy management of isolated power systems under rapidly varying operating conditions

We propose an energy management algorithm for isolated industrial power systems that integrate uncertain renewable generation and energy storage. The proposed strategy is designed to ensure sustainable and cost-effective operations by managing the energy flows in the grid, and is structured so to cope with: (1) high levels of renewable power penetration, and (2) load profiles characterized by non-smooth patterns and irregular events (i.e., events such as those occurring from connections/disconnections of large scale equipment, or from large wind speed ramps). The proposed algorithm leverages a stochastic economic model predictive control (MPC) scheme capable of dealing simultaneously with the dispatch and scheduling of the local generation units. More precisely, the scheme embeds a mixed-integer linear programming (MILP) optimal control policy formulation together with a stochastic programming approach. Moreover, the optimization problem accounts for multiple techno-economical objectives, such as minimization of operational costs, battery degradation, and non-utilized energy. We test the algorithm on a case study of an isolated offshore Oil & Gas platform producing energy onsite with conventional gas turbines and a local wind farm, while integrating a battery energy storage system. The results show that the proposed approach can issue ensemble predictions that successfully capture the potential irregular variations just by using recent past information of the associated random variable, even when no particular sudden events are anticipated in the near-future (i.e., step changes/trend reversals). In this way, the approach provides useful future information for the optimal management of the grid. This effect is numerically quantified via simulations that compare the performance of the proposed stochastic optimization approach against its deterministic MPC version in several realistic operating conditions. The empirical results suggest that the stochastic version leads to better scheduling of the conventional generators, with up to 12.86% reductions of the operating cost, 2.56% reduction in fuel consumption and emissions, and 35.29% reduction in status transitions (on/off) of the gas turbines, while keeping dumped energy and battery degradation as low as possible.

Logjam fluctuations during the decade after a major blowdown along a mountain stream in the US Southern Rockies

AbstractA blowdown in 2011 along a 1200‐m length of Glacier Creek in the Southern Rockies of Colorado, USA substantially increased the number of channel‐spanning logjams and initiated formation of a 100‐m‐long multithread channel segment. Annual logjam surveys during 2012–2020 indicate that these effects have persisted for a decade, with the number of logjams remaining high despite inter‐annual variations in the location of individual jams. No single logjam has remained in place continuously since the blowdown, but logjams tend to persist longest and to re‐form at sites with large ramp pieces from one or both sides of the channel and a lateral constriction created by bedrock or large boulders that can buttress the ramped piece(s) downstream. The most persistent logjams also form in secondary channels in the multithread section and logjams in the multithread reach tend to have larger backwater storage than logjams in the single‐thread reaches. The results presented here are unique in detailing changes in logjams during the decade following abrupt recruitment of a substantial volume of large wood to a mountain stream.

Joint‐Rupture Pattern and Newly Generated Structure of Fault Intersections on the Northern Margin of the Linhe Basin, Northwestern Ordos Block, China

AbstractThe activity of major active faults around the Ordos Block is of great interest to seismologists, as at least fourM ≥ 8 earthquakes have been recorded. However, the Linhe Basin, which has the thickest Cenozoic sediments, has no record of large earthquakes. Does this basin have the structural conditions required for large earthquakes? The northern boundary fault of the Linhe Basin is composed of the NE‐striking Langshan piedmont fault (LPF), E‐W‐striking western section of the Seertengshan piedmont fault (WSPF), and NW‐striking eastern section of the Seertengshan piedmont fault (ESPF). Based on large‐scale active fault mapping, this article analyzes data from 23 trenches, using an unmanned aerial vehicle to measure the faulted landform, and combines these data with Quaternary dating methods to acquire the paleoearthquake sequences of the LPF, WSPF, and ESPF. Furthermore, this article explores their rupture modes and discusses the structural evolution of two intersection points. Through paleoseismic comparison, seven trenches revealed historical earthquakes from 7 BC, with a common magnitude ofM8.1. The trenches also revealed seven paleoseismic events since the Holocene, which conformed to the periodic model with a period of 1.37 ± 0.11 ka. The elapsed time since the latest event (2.0 ka) has exceeded the earthquake recurrence period; thus, the area is currently at risk of anM7.4–8.0 earthquake. The NE‐striking LPF and E‐W‐striking WSPF are connected by two left‐stepping small fault segments. The E‐W‐striking WSPF and NW‐striking ESPF are connected by a large triangular relay ramp.

Representations of everyday life in İnci Eviner’s We, Elsewhere: comedy, use and free will

ABSTRACT İnci Eviner's installation We, Elsewhere for the Turkey Pavilion at the 58th Venice Art Biennial offers a spectacle of the incomplete, in which the objects, videos and their characters, and sounds in the piece, along with the exhibition space itself, consist all of halves, missing something. It is designed as a non-place in the midst of nowhere, which appears as a liminal space of exception, in which the inside and outside become indistinct. In this respect, the role of the large ramp, which transgresses the public-private divide, is particularly remarkable for it both connects and disconnects the place in relation to the outside, incarnating a paradoxical form of inclusionary exclusion. One cannot avoid noticing the ramp on entering the pavilion: cut horizontally and vertically, the spaces between left void, it is a cross-sectional space experienced through its corridors, area closed off by metal bars, a semi-closed room and viewing area arranged on stairs. However, its interior is rendered visible through the cross-sections of buildings and the subterranean. We bear witness to the events inside it, and, ceasing to be spectators, participate in the installation. Through this displacement, we also move from a representational space to a lived space.

Complex Basement‐Involved Contractional Structures in the Pre‐Andean Basins of Northern Chile: A Review From Seismic Data

AbstractFor many years, the geometry, kinematic, and the age of the basement‐involved structures of the Pre‐Andean basins of northern Chile have been debated. Even, many tectonic models supported by surface geological data have ignored how is the continuity of these structures in the subsurface, and also their possible relation with ancient preorogenic structures, thus difficulting the understanding of the main tectonic mechanisms that acted during the Andean uplift. To solve this problem, we discussed in this study the geometry and timing of the basement‐involved contractional structures present in the Pre‐Andean basins of northern Chile. We present field and seismic evidences of different basement‐involved structural styles, including reverse faults, inverted normal faults, basement thrust ramps, and rotated and reworked basin margins, and use it them to produce three large structural cross‐sections showing the geometries and distribution of structures along the inner forearc region. The structures are interpreted to have resulted from basin inversion, which was followed by large reverse faulting accumulating 43 km in the Salar de Atacama, 10 km in the Salar de Punta Negra, and 27 km in the Salar de Pedernales. Major reverse faults are predominantly located along the western and eastern edges of the basins, whereas inverted normal faults, basement thrust ramps, and other structures are confined to the central sections. In this context, large basement thrust ramps and reverse faults are the most effective structures for generating crustal thickening. Previous analyses (U‐Pb dating) of synorogenic deposits over inverted structures and apatite fission track data from Paleozoic basement prerift rocks suggest that contraction in the region began in the Late Cretaceous‐Paleocene and continued throughout the Cenozoic; however, basement rocks experienced rapid cooling due to tectonic uplift during the Eocene. Further, the results indicate that basement‐involved contractional structures are not only generated by flat‐slab subduction processes, but also observed in other regions of northern Chile (e.g., Frontal Cordillera). Finally, we conclude that the observed structural complexity predominantly results from the initial distribution of preorogenic extensional structures.

Working zone for a least-squares support vector machine for modeling polymer electrolyte fuel cell voltage

The least squares support vector machine method has been successfully applied to modeling the transient behavior of polymer electrolyte fuel cells; this paper analyzes the credibility and definition of its reliable working zone when dealing with multiple load changes. The transient model based on the least squares support vector machine is initially established. Then, the effects of the fuel cell system’s setup and exterior load behavior on the transient model are investigated. Artificial data from experimentally-validated Simulink simulations are used, by which extreme working conditions could be taken into account. We found that the fuel cell system’s setup with intensive sampling brings about better model performance than that with a sparse sampling interval, as sharp peaks are well characterized when intensive sampling is applied and more information on the fuel cell system is provided to the transient model. Furthermore, the performance of the transient model is better when smoother load changes are imposed on the system, and so a large ramp time and small ramp value are preferable. A working zone for a least squares support vector machine to model polymer electrolyte fuel cell is defined, for which an absolute error is used. Based on the acceptable level of error in the fuel cell system, a set of feasible combinations of its setup and exterior load changes is regulated. Accuracy in the transient model is achieved when the fuel cell runs within the working domain.

Maximum expected ramp rates using cloud speed sensor measurements

Large ramps and ramp rates in photovoltaic (PV) power output are of concern and sometimes even explicitly restricted by grid operators. Battery energy storage systems can smooth the power output and maintain ramp rates within permissible limits. To enable PV plant and energy storage system design and planning, a method to estimate the largest expected ramps for a given location is proposed. Because clouds are the dominant source of PV power output variability, an analytical relationship between the worst expected ramp rate, cloud motion vector, and the geometrical layout of the PV plant is developed. The ability of the proposed method to bracket actual ramp rates is assessed over 10 months under different meteorological conditions, demonstrating an average compliance rate of 98.9% for a 2 min evaluation time window. The largest observed ramp of 29.7% s−1 is contained with the worst case estimate of 34.3% s−1. This method provides a convenient yet economical approach to worst-case PV ramp rate modeling and is compatible with solar irradiance measured at coarse temporal resolution.

A rotating fluidized bed reactor for rapid temperature ramping in two-step thermochemical water splitting

Two-step thermochemical water splitting (TWS) is a promising carbon-free/low-carbon technology for producing hydrogen in a mass production scale, in which water is dissociated in the presence of metal oxide-based catalysts via redox cycles driven by thermal energy. While active research is underway to develop high-performance metal oxide catalysts, less attention has been paid to reactor design and relevant system analysis, which are essential for constructing an actual system. The gas and solid flow configuration is one of the key design parameters in reactor design that determines thermodynamic and kinetic characteristics of the entire two-step TWS system. In this study, we propose a rotating fluidized bed reactor design wherein the rotating current flow configuration allows a much larger relative velocity between sweep gas and redox particles compared to conventional flow configurations. The rotating current flow configuration significantly improves the temperature ramp rate of redox particles via enhanced heat transfer between particles and sweep gas. Through thermodynamic and kinetics analysis of the reactor system, we show that the large temperature ramp rate of the proposed reactor results in a considerable improvement in the hydrogen yield per hour. This work adds a new dimension to the reactor design for two-step TWS.

Geometry and development of a hybrid thrust belt in an inner forearc setting: Insights from the Potrerillos Belt in the Central Andes, northern Chile

Thick- and thin-skinned “hybrid” thrust belts are typically developed in areas where crustal shortening was preceded by extension and normal faulting. They have been recognized in many places within the Central Andean backarc regions of Perú, Argentina, and Bolivia. In contrast, these structures have not been broadly studied in forearc regions. To understand the geometry and kinematics of this style of tectonism in a forearc setting related to Andean-type subduction zones, we used field and industrial 2D seismic data to study the Potrerillos thrust and fold belt and the Salar de Pedernales Basin in northern Chile (26°S). Our results indicate that the structure in this region consists of a dominantly east-verging contracting system composed of large basement thrusts, Mesozoic inverted normal faults, and shallow thrust-related folds. Large basement thrust ramps and imbricated wedges represent the most prominent basement structures, which accommodated major crustal shortening. Reactivated and tectonically inverted Mesozoic extensional structures also constitute an important structural component, especially beneath the Salar de Pedernales Basin. These exhibit asymmetrical inverted anticlines with arrowhead shapes on the hanging walls of the inverted normal faults. The subsidiary shallow thrust-related folds commonly display fault bend and propagation folds that primarily accommodated the shortening of the Mesozoic and Cenozoic stratified deposits overlying the basement thrusts and cored anticlines. The age of the contraction in this region is poorly constrained; however, many of the oldest sequences accumulated in the top of the syn-rift sequences and related to synorogenic deposits, can be correlated with those identified in neighboring regions (e.g., Salar de Atacama, Salar de Punta Negra basins and Frontal Cordillera, among others), which have reported Upper Cretaceous ages. Based on this stratigraphic correlation we suggest that orogenesis may have begun in the Late Cretaceous with basin inversion, and then continued during the Cenozoic with basement thrusting.

Analysis of the origin, formation and development of sand ramps on the Eastern slopes of Shirkouh, Yazd, Central Iran

The purpose of this study is to examine the sand ramps in the margin of Ernan playa located in Yazd Province, central Iran. The region is marked with several sand ramps, many of which are not observable as they are buried under colluvial and alluvial sediments or dense vegetation. Field studies indicated at least 18 fairly large sand ramps in the region in the form of both climbing and falling dunes. These sand ramps were formed mostly in the past and are stable and inactive now. However, in some parts of the region in question, these landforms are still forming and developing. The results indicated that the sediment, especially those of the sand ramps on windward slopes, have large grains. Also, over 50 percent of the sediments generally have grains with a diameter of more than 1mm. The presence of such minerals as Alkali Feldspar, Plagioclase, Quartz, Biotite, Muscovite, Amphibole, and Apatite, respectively in terms of quantity and frequency, in the sand ramp sediments indicates that the origin of sand ramp sediments is the monzogranites of the eastern slope of Shirkouh Mountain with the same texture and frequency. The very fact that the above-mentioned minerals are intact, i.e. they have not been rounded or eroded, suggests that these sediments have not been displaced a lot. The study of the developing sand ramps proved that such structures form at the height of more than 2400m with two months of frost annually, over 100mm of precipitation (periglacier conditions), and granite outcrops. The reconstruction of the past climate conditions indicated that the temperature in the cold Quaternary glacial age was 13 degrees lower than present, with glacier and periglacier conditions dominating. Under such conditions, the region’s granites were extremely weathered, hence producing a large quantity of grain sediments. The surface run-offs or ice tongues drifted these sediments toward Lake Ernan (i.e. the present Ernan playa) and deposited them at its shoreline. After the lake and the main river dried up, southwest winds led the sediments of the lakeshore and the Tang-e-Chenar River upward to the top of the mountains, where sand ramps were, thus, formed. Due to the short formation duration and steady climate, no colluvial, alluvial material, or even soil (despite the large quantity of feldspars in the sand ramps) was traced amid the sediment layers of the sand ramps in the studied region. The only features traced there were slopes, alluvial debris and vegetation, indicating the dominance of warmer and moister climate as compared to the conditions at the time of formation. The directions of the past and developing sand ramps are similar but opposed to the prevailing and secondary wind of the region, indicating that it is the local winds which have formed those ramps.