scholarly journals Protecting River Environment through Proper Management of Material Mining by Matrix Method (Case Study of A'la River in Iran)

2018 ◽  
Vol 3 (12) ◽  
pp. 1301
Author(s):  
Farhang Azarang ◽  
Ghazal Jafari ◽  
Maryam Karami Karami ◽  
Mahmood Shafaie Bejestan

Regarding the importance of rivers, appropriate management of aggregate mining is of great significance. Mining of river materials has a direct impact on environmental conditions of the river. Today, aggregate mining management represents a crucial topic in river engineering. Often selected based on the pattern of the considered river, matrix method provides a suitable approach to improve the river aggregate mining management. The present research aims at presenting the application of the matrix method in river material mining location evaluation. Given the capabilities of the matrix method for determining potential of mine area and aggregate mining method, this method can be seen as a suitable solution for reducing negative environmental impacts of river material mining. A'la River is one of the most important rivers streaming in Khouzestan Province (Iran), with its sediment load and mining potential being of critical importance. In this research, the reach of A'la River at the intersection of Rood-Zard River and Rahmhormoz diversion dam was studied for aggregate mining and application of matrix method. The main purpose of this work is to study the application of matrix method to A'la River. The results indicate braided pattern of the river and appropriateness of the matrix method. Available volume of aggregate for mining within the mentioned reach of A'la River was estimated as 50,000 m3, and scraping method at a maximum depth of 1 m was proposed for mining of the aggregates.

2018 ◽  
Vol 13 (2) ◽  
pp. 369-382 ◽  
Author(s):  
Radislav TOŠIĆ ◽  
◽  
Novica LOVRIĆ ◽  
Slavoljub DRAGIĆEVIĆ ◽  
Sanja MANOJLOVIĆ

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
A. de Giorgi ◽  
S. Vogl

Abstract The Kaluza-Klein (KK) decomposition of higher-dimensional gravity gives rise to a tower of KK-gravitons in the effective four-dimensional (4D) theory. Such massive spin-2 fields are known to be connected with unitarity issues and easily lead to a breakdown of the effective theory well below the naive scale of the interaction. However, the breakdown of the effective 4D theory is expected to be controlled by the parameters of the 5D theory. Working in a simplified Randall-Sundrum model we study the matrix elements for matter annihilations into massive gravitons. We find that truncating the KK-tower leads to an early breakdown of perturbative unitarity. However, by considering the full tower we obtain a set of sum rules for the couplings between the different KK-fields that restore unitarity up to the scale of the 5D theory. We prove analytically that these are fulfilled in the model under consideration and present numerical tests of their convergence. This work complements earlier studies that focused on graviton self-interactions and yields additional sum rules that are required if matter fields are incorporated into warped extra-dimensions.


2021 ◽  
Vol 18 (6) ◽  
pp. 1591-1608
Author(s):  
Maryam Tajbakhshian ◽  
Abolfazl Mosaedi ◽  
Mohamad Hosein Mahmudy Gharaie ◽  
Sayyed Reza Moussavi Harami

Palaios ◽  
2021 ◽  
Vol 36 (3) ◽  
pp. 115-121
Author(s):  
EDUARDO MAYORAL ◽  
JORGE F. GENISE ◽  
FRANCISCO J. RODRÍGUEZ-TOVAR ◽  
ANA SANTOS

ABSTRACT Plio?-Pleistocene outcrops located at the southwestern edge of the Guadalquivir Basin in the area of Lepe (Huelva, Spain) provide an interesting example for studying the contemporaneity of traces with the rocks that contain them. Two different types of cells compatible with the ichnogenera Celliforma (Type 1) and Palmiraichnus (Type 2) were found in these outcrops. Their walls were constructed with the same material as the matrix and our first research in the area showed no extant bees producing them suggesting that they were coeval with the trace-bearing rocks. The case of the “Palmiraichnus-like” Type 2 cells was misleading because of its similarity with Palmiraichnus described from the region in the Canary Islands and Balearic Archipelago (Spain). Two determining features were vital in clarifying this first appearance. In the Palmiraichnus-like cells we found remains of a larval cocoon in one cell that could be dated by C14, giving a modern age. In the Celliforma-like cells more field research in the area allow us to observe extant bees nesting in these rocks in autumn. Ichnological literature show a few cases of asynchronies involving extant traces found mostly in Paleozoic and Mesozoic rocks. In contrast, the case presented herein indicates the time gap between the bearing rocks and the Lepe traces was shorter (ca. 12 ky–2.6 My), enhancing the similarity of traces and rocks and thus their potential coevalness. This case may serve as a warning about other potential examples in the fossil record in which relatively short asynchronies between traces and paleosols exist.


Sign in / Sign up

Export Citation Format

Share Document