scholarly journals Influence of Sea Sand on Sintering of V–Ti–Fe Concentrate—A Case Study from Indonesia

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 793
Author(s):  
Yuelin Qin ◽  
Qingfeng Ling ◽  
Ke Zhang ◽  
Hao Liu
Keyword(s):  
Low Temperatures ◽  
Degradation Index ◽  
Sea Sand ◽  
Utility Factor

This study explores the feasibility of Indonesian sea sand in replacing V–Ti–Fe concentrate for sintering. The influence of different additive proportions of Indonesian sea sand on sintering index and sinter properties is examined in a laboratory by adjusting the substitution proportion from 5% to 40%. Results imply that vertical sintering speed and utility factor show an apparent decreasing trend, but drum strength, finished product rate and returned fine rate are not significantly affected with the increase in the proportion of Indonesian sea sand and with the decrease in the proportion of V–Ti–Fe concentrate. With the increase in the proportion of sea sand, the reduction degradation index of sinter at low temperatures declines sharply from 65% to 31%, the grade of sinter and content of TiO2 changes slightly, and the reduction degradation and degree decline. Unlike V–Ti–Fe concentrate, Indonesian sea sand does not perform well in sintering, and the substitution proportion should not exceed 35%.

Low Temperature Fault Isolation Using Soft Defect Localization

2012 ◽  
Author(s):  
Kristopher D. Staller
Keyword(s):  
Low Temperatures ◽  
Laser Scanning ◽  
Low Cost ◽  
Fault Isolation ◽  
Laser Scanning Microscopy ◽  
Cold Temperature ◽  
Multiple Point ◽  
Defect Localization ◽  
Low Levels

Abstract Cold temperature failures are often difficult to resolve, especially those at extreme low levels (< -40°C). Momentary application of chill spray can confirm the failure mode, but is impractical during photoemission microscopy (PEM), laser scanning microscopy (LSM), and multiple point microprobing. This paper will examine relatively low-cost cold temperature systems that can hold samples at steady state extreme low temperatures and describe a case study where a cold temperature stage was combined with LSM soft defect localization (SDL) to rapidly identify the cause of a complex cold temperature failure mechanism.

scholarly journals Legal regulation on protecting marine environment from sea sand mining impact: a case study of spermonde archipelago

2021 ◽  
Vol 860 (1) ◽  
pp. 012092
Author(s):  
Maskun ◽  
Sri Susyanti Nur ◽  
Achmad ◽  
Nurul Habaib Al Mukarramah ◽  
Muhammad Arfan Arif
Keyword(s):  
Marine Environment ◽  
Legal Regulation ◽  
Sand Mining ◽  
Sea Sand ◽  
Mining Impact ◽  
Spermonde Archipelago

Non-Equilibrium Properties of Au-Pd Nanoparticles

2011 ◽  
Vol 172-174 ◽  
pp. 670-675 ◽  
Author(s):  
Ivailo S. Atanasov ◽  
Marc Hou
Keyword(s):  
Molecular Dynamics ◽  
Low Temperatures ◽  
Pd Nanoparticles ◽  
Core Shell ◽  
Embedded Atom ◽  
Cluster Morphology ◽  
Pd Clusters ◽  
Atom Potential ◽  
The Way

We address the question of the evolution of a nanostructured system in a metastable state to equilibrium. To this purpose, we use the case study of the transition of an AucorePdshell nanoalloy cluster containing up to about 600 atoms toward the equilibrium Au segregated configuration. We start from a molecular dynamics approach with an embedded atom potential. The way the transition develops at low temperatures is found to be very sensitive to the cluster morphology and the way energy is exchanged with the environment. The transition of icosahedral inverse core-shell Au-Pd clusters is predicted to nucleate locally at the surface contrary to clusters with other morphologies, and starting at lower temperatures compared to them.

Magnetostratigraphy from the Hominin Sites Paleolakes Drilling Project (HSPDP) drill cores, low latitudes reorientation

2021 ◽  
Author(s):  
Mark Jan Sier ◽  
Guillaume Dupont-Nivet ◽  
Cor Langereis ◽  
Andy Cohen ◽  
Keyword(s):  
Low Temperatures ◽  
Low Latitude ◽  
The Core ◽  
The North ◽  
Low Latitudes ◽  
Age Model ◽  
Important Building Block ◽  
Paleomagnetic Direction ◽  
Drilling Project

<p>The Hominin Sites Paleolakes Drilling project (HSPDP) has collected around 2000 meters of drilled cores in lake sediment in Kenya and Ethiopia. All cores were drilled near important sites in human evolution with as main goal to help us better understand the influence of climate change on our evolutionary past.</p><p>An important first step in this research is building an age-model for these cores with magnetostratigraphy being important building block. However, building a magnetostratigraphy for the HSPDP cores is not straightforward. Due to the rotational movement of the coring process the azimuthal orientations of the cores is lost. This hinders the construction of magnetostratigraphy based of correctly orientated paleomagnetic samples. For high latitudes a high quality magnetostratigraphy can be reconstructed on the basis of the inclination of the paleomagnetic direction.</p><p>However, at low latitudes near the equator the inclination of the (paleo) magnetic field are near zero. As a result a magnetostratigraphy on the basis of inclination alone cannot be made.</p><p>In this presentation we discuss two methods that can be used to build a core based magnetostratigraphy at low latitudes. First, the anisotropy of the magnetic susceptibility (AMS) can be used in certain cases to reorientate the paleomagnetic samples by identifying the bedding of the sediments throughout the core.</p><p>Second, the present/recent low temperatures –low coercivity (LT/LC) overprint can be used to reorientate the paleomagnetic directions by orientating these LT/LC components towards the north and recalculate the paleomagnetic directions.</p><p>Both methods have been used on the ICDP Hominin Sites Paleolakes Drilling Project (HSPDP) cores taken in Ethiopia and Kenia with varied success. Here we will present data of four HSPDP cores as case study to help illustrate the effectiveness of these two methods for building a magnetostratigraphy for low latitude cores.</p>

The Effect of Some Climatic Variables and Frosts Waves on Citrus Crops

2021 ◽  
Vol 1 (138) ◽  
pp. 51-66
Author(s):  
Moshabab M Alhader ◽  
Mohammed S Hafez
Keyword(s):  
Saudi Arabia ◽  
Relative Humidity ◽  
Low Temperatures ◽  
High Relative Humidity ◽  
Climatic Variables ◽  
Climatic Data ◽  
Citrus Fruits ◽  
Air Masses

This study examined the effect of some climatic variables and their role in growing citrus fruits in northern Saudi Arabia, which showed that low temperatures accompanied by calm winds and high relative humidity as well as creeping air masses are among the most important factors that contribute to the worsening of frost. This study also dealt with hourly frost waves - a case study - based on the study of climatic data of the study area stations for one day of frost waves that occurred in the study area for the year 2008.

Substantiation of a Technique of Determining Stress in Thin Films at Very Low Temperatures

2015 ◽  
Vol 14 ◽  
pp. 28-36
Author(s):  
C.C. Chama
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Low Temperatures ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
High Temperature Stress ◽  
Hysteresis Curves ◽  
Stress Hysteresis

Substantiation of a technique earlier employed in determining stress in Copper-Silver thin films at very low temperatures is presented. It is shown that the stress measured at elevated temperatures using Stoney’s equation can be utilized in the determination of stress at very low temperatures. To demonstrate the application of this technique, a case study has been conducted by utilizing stress hysteresis curves obtained from the Cu-6at%Ag thin film heated from room temperature to 400°C and cooled back to room temperature in two cycles. The stresses in the Cu-6at%Ag thin film at various low temperatures up to-197°C have been determined by utilizing data from high temperature stress hysteresis curves.

scholarly journals Reclamation of Jakarta Bay, Impoverishment and Marginalization of Fisherwomen: Case Study at Akuarium and Kamal Muara Village, Penjaringan

2017 ◽  
Vol 22 (4) ◽  
pp. 333 ◽  
Author(s):  
Endah Wardhani
Keyword(s):  
Data Collection ◽  
Qualitative Study ◽  
Direct Impact ◽  
Sea Sand ◽  
Depth Interview ◽  
Reclamation Project ◽  
Observation Selection ◽  
Selection Of ◽  
Do So

It has been more than ten years since The Jakarta Bay reclamation project displaced fishermen from the sea where they were normally fishing. The direct impact of reclamation on fisherwomen was income decrease, because it has damaged the marine ecosystems due to the effects of sucking and backfilling of the sea sand. In addition, there will be at least 16,998 of fishermen households will be evicted from the coastal areas of Jakarta, Banten and Bekasi due to this reclamation. The findings of this study are: the reclamation made the<br />fisherwomen become poorer, their burden is higher and they have experienced double marginalization. The research methodology is a qualitative study with feminist perspective. Data collection are by in-depth interview with ten fisherwomen, document study, and fields<br />observation. Selection of research sites is purposive, namely Kampung Akuarium and Kampung Kamal Muara, District of Penjaringan, North Jakarta Municipality. In particular, this study wants to bring up the voices of poor fisherwomen as marginalized group of people, who have not been heard. It is hoped they will be brave and voiced their rights and aspirations openly which they have not dared to do so.

Optimized Particles Size Distribution Lightweight Cement at Low Temperatures: Case Study from Eastern Siberia, Russia (Russian)

2013 ◽  
Author(s):  
Alexander Malyshev ◽  
Tatiana Doronina ◽  
Mikhail Popov ◽  
Alexander Ryabchikov ◽  
Vladimir Shulga
Keyword(s):  
Size Distribution ◽  
Low Temperatures ◽  
Eastern Siberia ◽  
Particles Size Distribution
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