549 research outputs found
A complex networks based analysis of jump risk in equity returns:An evidence using intraday movements from Pakistan stock market
International audienceWe employ a multi-stage methodology combining complex network analytics and financial risk modelling to unveil the correlation structures amongst the price jump risks of companies forming the KSE-100 index in Pakistan. We identify the most influential companies in terms of jump risk, and identify communities — clusters of companies with similar price movement characteristics or with highly correlated price jumps. We find that equities in Pakistan stock market experience jumps in different time periods that are correlated to varying degrees within and across industries resulting in 19 different communities, four of which are strongly connected. While Oil & Gas, Cement and Banking sectors exhibit a significant representation of firms in communities, the automobile industry, however, seems to play an important role in risk propagation. These results provide an interesting insight to investors and other stakeholders from an emerging market viewpoint identifying the major sectors driving the volatility of KSE-100 index
Cultivation of tropical red seaweeds in the BIMP-EAGA region
The Brunei–Indonesia–Malaysia–Philippines East Asia Growth Area (BIMP-EAGA) is located within the Coral Triangle, known to have the world’s richest biodiversity in marine flora and fauna. This region lies within the 10° N and 10° S of the Equator where natural populations of both Kappaphycus and Eucheuma grow luxuriantly and abundantly. It is in this same region where commercial cultivation of Kappaphycus and Eucheuma began in the Philippines around the mid-1960s. Commercial farming of Kappaphycus (which was originally called Eucheuma) was successful in the Philippines from the early 1970s, after which the technology was transferred to Indonesia and Malaysia in the late 1970s. No seaweed cultivation has been reported in Brunei. At present, carrageenophytes are cultivated in sub-tropical to tropical countries circumferentially around the globe within the 10° N and S of the Equator. However, their combined production is still low as compared to Indonesia, the Philippines, and Malaysia. Notably, few improvements in farming techniques have been made since its first introduction. Some of the major improvements were the introduction of deep-water farming using hanging long lines, multiple rafts, and spider webs in the Philippines; the use of short and long ‘loops’, instead of plastic ‘tie-tie’ in Indonesia; and mechanization in harvesting and use of solar “greenhouse” drying in Malaysia. Commercial cultivation of tropical red seaweeds in the BIMP-EAGA region is dominated by Kappaphycus and Eucheuma (carrageenophytes) and Gracilaria (agarophytes) and the area became the major region for the production of carageenophytes and agarophytes globally. In particular, Indonesia is a major center for the production of Gracilaria. There is an increasing demand for other agarophytes / carrageenophytes in the international market such as Gelidium spp., Pterocladia spp., Porphyroglossum sp., and Ptilophora sp. for paper and ethanol production in Indonesia and Malaysia, and Halymenia for phycoerythrin pigments in the Philippines currently pursued in an experimental stage. A summary of the present status, problems, sustainability, and challenges for the cultivation of tropical red seaweeds in the BIMP-EAGA region are discussed in this paper
Utilizing Steel Slag in the Removal of Suspended Solids from Dewatered Construction Water
Construction dewatering is an operation used to remove shallow groundwater that
infiltrates construction sites. After recovering this water from the construction sites, the
water is either discharged to the sea, injected in deep groundwater aquifers, or treated
and reused in some other applications. However, municipal and industrial application of
this water is unfeasible due to its poor quality. Thus, in this study, dewatered construction
water is being treated utilizing waste steel slag in order to improve the quality of the
water. The pH of the dewatered construction water used for this study was 7.59 and the
average diameter of steel slag used was 425 nm. For coagulation, the impact of the mass
of steel slag and the contact time on the quality of dewatered construction water were
studied. By using 5gm/L of steel slag, more than 85% of the total suspended solids and
turbidity were removed within 30 minutes.The authors would like to thank Qatar University for the financial support. In addition,
the authors would like to thank Qatar Steel for the supply of the steel slag sample
Estrategia de precaución de la práctica de riesgos morales en los seguros agrícolas en Indonesia: un enfoque de la metodología de los sistemas blandos
[EN] This paper uses Soft Systems Methodology (SSM) to formulate strategies to prevent moral hazard acts in agricultural insurance in Indonesia. Agricultural insurance takes place, mainly, through Rice Crop Insurance and Cattle Insurance. Generally, the strategies that can be performed to minimize moral hazard practice in agricultural insurance programs are: developing the capacity of human resources, improving field communication, enforcing penalties, institutional strengthening, and adding new products through Islamic agricultural insurance. Specifically, this paper proposes that the prevention of moral hazard practices can be done by implementing Islamic agricultural insurance systems with the concept of risk-sharing instead of risk transfer.[ES] Este trabajo utiliza Soft Systems Methodology (SSM) para formular estrategias para prevenir el riesgo moral en los seguros agrícolas en Indonesia. El Seguro de Cosecha de Arroz y el Seguro de Ganado son los más utilizados. Las estrategias son: desarrollo de la capacidad de los recursos humanos, mejora de la comunicación sobre el terreno, aplicación de sanciones, fortalecimiento institucional e incorporación de nuevos productos a través del seguro agrícola islámico. En concreto, se propone que la prevención del riesgo moral puede realizarse mediante sistemas de seguros agrícolas islámicos basados en el concepto de compartir el riesgo en lugar de transferirlo.The authors thank Lembaga Pengelola Dana Pendidikan (LPDP), Riset Inovatif Produktif (RISPRO) Tata Kelola/Kebijakan No. PRJ-120/LPDP/2019, the Ministry of Finance of the Republic of Indonesia, the Regional Development Planning Board (BAPPEDA) Aceh, Agriculture and Plantation Department (DISTANBUN) Aceh, Animal Husbandry Department (DISNAK) Aceh.Fadhil, R.; Yusuf, MY.; Bahri, TS.; Maulana, H.; Fakhrurrazi, F. (2021). Precaution Strategy of Moral Hazard Practice in Agricultural Insurance in Indonesia: An Approach of Soft Systems Methodology. Economía Agraria y Recursos Naturales - Agricultural and Resource Economics. 21(2):79-99. https://doi.org/10.7201/earn.2021.02.04OJS799921
An investigation into tapping of Al6061/SiC metal matrix composite with straight flute HSS machine tap
The present study deals with tapping of Al6061/SiC metal matrix composite. Stir casting technique was used for the fabrication of composite. Castings were produced by varying weight percentages of SiC (5%, 7.5% and 10%) of 23μm size in Al6061. The tapping experiments were conducted for the machinability study of Al6061/SiC metal matrix composite using M8 x 1.25 HSS machine taps. The tapping operation was performed under dry condition with different cutting speeds. Torque required for tapping was measured using piezoelectric based 4-component drill tool dynamometer. Surface morphology and profile of thread surfaces were analysed using Scanning Electron Microscope (SEM) and metallurgical microscope. Estimation of progressive flank wear of machine taps was undertaken using profile projector. The performance of HSS machine tap was evaluated in terms of tapping torque, tool flank wear, and surface characteristics of thread surfaces. The flank wear of uncoated HSS machine tap increased with the increase in weight percentage of SiC in Al/SiC composite for a particular cutting speed. Further, when the matrix materials were reinforced by the same kind and the same weight percentage of SiC particles, the flank wear of the tool was found to increase with cutting speed. In addition, the damage caused to thread profiles increased with the increase in cutting speed and weight percentage of SiC
The optimisation of a turbulent swirl nozzle using CFD
Swirl is imparted into free and impinging nozzle flows as well as jet flames to affect convective heat transfer, fluid mixing or flame stability. At the nozzle exit plane, the emerging flow strongly influences downstream flow development and so factors which impact upon the emitted flow are worthy of study. This paper presents preliminary CFD analyses into the effect of design parameters and operational settings on the emerging flow at the exit plane for a swirl nozzle (Remax~30,500). The research was conducted in the premanufacture stage to optimise the nozzle. Swirl is aerodynamically generated using multiple tangential ports located upstream of the exit plane and the streamwise flow is augmented with flow from two axial ports located at the nozzle base. Before reaching the exitplane, all flows pass through a contraction en route to a straight section of length (L). Factors studied in this paper include the angle of (inlet) tangential ports, the total length of the straight section (L), the ratio of axial-to-tangential inflows and the Reynolds number. Results show that larger tangential port angles and a shorter straight section help develop a modestly greate
Molecular identification and genetic diversity study of the Iraqi truffles
The aim of this study is to investigate the molecular identification of the Iraqi truffles species and a better understanding of genetic diversity in the center of the truffles habitat. Thirty-two samples were collected from the Iraqi desert and local markets. Samples were chosen depending on the morphological diversity of the fruit body and sample collection area. Results of ITS region sequencing for the 32 samples showed two genuses Tirmania and Terfezia are the main dominant, 4 species of Tirmania pinoyi and 28 species of Terfezia claveryi. All species sequences were deposited in NCBI GenBank and all had accessions number. The neighbor-Joining method was used to generate a phylogenic tree to study the genetic diversity of the ITS sequences for the 32 Iraqi truffle samples. Results showed a high genetic diversity for the Iraqi truffles samples. The phylogenic study showed Iraqi truffles clustered with different groups as a clade with the reference sequences from other countries represent three continents Asia, Africa, and Europe. Also, we found in this study a unique cluster group for the Iraqi sequences for T. pinoyi and T. claveryi truffles cluster in one group and do not match with any reference sequences used in this study. This is a piece of strong evidence proofed the Iraqi habitat could be the origin of center diversity for the T. pinoyi and T. claveryi truffles
Lipid Profile Parameters and Coronary Artery Disease in Young Patients Undergoing Diagnostic Angiography
Introduction: It is vital to understand the association between lipid profile and the severity of coronary artery disease (CAD) in young patients with suspected CAD. The clinical presentation, lipid profile and severity of CAD may differ in patients who develop CAD at young age and those at older age. Friesinger (FR) index is an important tool to assess the extent and severity of coronary artery lesions.Methods: This study was a single center retrospective study involving patients below 40 years who underwent diagnostic coronary angiography. Demographic variables, lipid profile and FR index were estimated. Patients were divided into four groups based on the FR index scores of 0, 1–4, 5–10 and 11-15, respectively.Results: A total of 158 patients (Mean ± SD of age; 35.65 ± 3.81 years) were included in the study. Among demographic variables, gender (P = 0.03) and body mass index (BMI) (P < 0.001) were found to be associated with FR index. In addition, total cholesterol (P < 0.001), low density cholesterol (LDL) cholesterol (P < 0.001), non-high density cholesterol (non-HDL) (P < 0.001) and ratio of triglycerides (TG) /non-HDL cholesterol (P = 0.004) showed significant differences between the FR groups. Logistic regression analysis showed that only diabetes (P = 0.02) and BMI (P = 0.004) were significant predictors of the extent and severity of coronary artery lesions in terms of FR index.Conclusions: A strong direct relationship was observed between total cholesterol, LDL and non HDL cholesterol while a negative correlation with the TG/non HDL ratio. Diabetes and BMI also play a very significant role
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