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How elevation and soil properties affect plant distribution patterns and species diversity in the Mediterranean mountain ecosystem of Al-Jabal Al- Akhdar, Libya

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Journal of Mountain Science 2024年第11期21卷 3683-3701页

作者： ABD EL-GHANI Monier AL BORKI Abd El-Nasser Department of Botany and Microbiology Faculty of ScienceCairo UniversityGiza 12613Egypt Department of Biology Faculty of EducationUniversity of BenghaziBenghaziLibya

The objectives of this study were to assess distribution patterns of plant species richness,plant diversity and vegetation structure in relation to environmental factors along elevation gradient in Al-Jabal Al-Akhdar,*** each species,its growth form,chorological affinities,degree of occurrence,endemism status and originality were provided.A total of 534 taxa were generated from 70 families of the flowering plants,and 3 of the non-flowering plants were *** native flora of the study area was counted for 80.2%of the total indigenous taxa(465).The hump-shaped pattern of plant species richness was obtained,with the highest species richness at the mid-elevations,and both ends of the gradient have the *** annuals(300 species,56.2%)and non-succulent perennial herbs(165 species,30.9%)were the most dominant growth forms of the total species *** the elevation gradient,Asteraceae,Fabaceae,Poaceae,Lamiaceae and Apiaceae were the dominant families with the highest numbers of *** investigation recorded 31 endemic taxa,comprising 25 dicots and 6 monocots,primarily of Mediterranean origin,with most belonging to the Asteraceae and Lamiaceae *** chorotype was the dominant,whether pure(mono-),or combined with one(bi-and pluri-regional)or more(pluri-regional).Application of cluster analysis on the vegetation data yielded four cluster groups;each was linked to an elevation *** emphasized the importance of establishing conservation strategies to minimize human disturbance and safeguard relic habitats of Juniperus phoenicea *** its southern distribution limits in Africa,underlining the proactive management required for species *** application of Redundancy Analysis revealed that Shannon diversity index(H'),pH and Fe were the determinant soil factor in the mid-elevation levels(L2 and L3)whereas altitude,fine sand,HCO3,OM,and soil contents of Na,SO4 and Cl for the extreme levels(L1 and L4).

关键词： Altitudinal gradient Distribution patterns Floristic diversity Growth forms Libya Soil structure Vegetation analysis

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Robust Stabilization of Load Frequency Control System Under Networked Environment

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International Journal of Automation and computing 2017年第1期14卷 93-105页

作者： Ashraf Khalil Ji-Hong Wang Omar Mohamed Electrical and Electronics Engineering Department University of Benghazi Benghazi Libya School of Engineering University of Warwick Coventry UK King Abdullah Ⅱ Faculty of Engineering Princess Sumaya University of Technology Amman Jordan

The deregulation of the electricity market made the open communication infrastructure an exigent need for future power system. In this scenario dedicated communication links are replaced by shared networks. These shared networks are characterized by random time delay and data loss. The random time delay and data loss may lead to system instability if they are not considered during the controller design stage. Load frequency control systems used to rely on dedicated communication links. To meet future power system challenges these dedicated networks are replaced by open communication links which makes the system stochastic. In this paper, the stochastic stabilization of load frequency control system under networked environment is investigated. The shared network is represented by three states which are governed by Markov chains. A controller synthesis method based on the stochastic stability criteria is presented in the paper. A one-area load frequency control system is chosen as case study. The effectiveness of the proposed method for the controller synthesis is tested through simulation. The derived proportion integration （PI） controller proves to be optimum where it is a compromise between compensating the random time delay effects and degrading the system dynamic performance. The range of the PI controller gains that guarantee the stochastic stability is determined. Also the range of the PI controller gains that achieve the robust stochastic stability is determined where the decay rate is used to measure the robustness of the system.

关键词： Load frequency control load frequency control (LFC) Markov chains networked control system robust stabilization.

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Cancers in Eastern Libya: First results from benghazi Medical Center

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World Journal of Gastroenterology 2014年第20期20卷 6293-6301页

作者： Zuhir Bodalal Raouf Azzuz Riyad Bendardaf Department of Surgery Faculty of Medicine Libyan International Medical University Benghazi 15016 Libya Department of Oncology and Hematology Benghazi Medical Center Benghazi 24508 Libya Oncology Unit Department of Medicine University Hospital Sharjah Sharjah 72772 United Arab Emirates

AIM: To study the pattern of cancer incidence and determine the incidence rates in Eastern Libya (for the first time in a decade).

关键词： Colorectal cancer Cancer incidence Age-standardized rates Libya Mediterranean Epidemiology

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Daily, monthly and annual thermal performance of a linear Fresnel reflector to drive an organic Rankine-cycle system

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Clean Energy 2021年第4期5卷 673-689页

作者： Hassan Mahmood Khaled Hossin Mechanical and Construction Engineering University of NorthumbriaNewcastle upon TyneUK Mechanical and Industrial Engineering Department American University of Ras Al KhaimahRas Al KhaimahUnited Arab Emirates Mechanical Engineering Department University of BenghaziBenghaziLibya

The organic Rankine cycle(ORC)coupled with a linear Fresnel reflector(LFR)utilizes a low-grade heat *** article presents the study of a small-scale LFR-ORC power-generation plant under the climatic conditions of Almatret,*** mathematical modelling is performed using thermodynamic equations and simulations are conducted to evaluate the optical performance of the LFR system and thermal performance of the ORC ***-62 is used as a heat-transfer fluid(HTF)in the solar field,whereas NOVEC^(TM) 649 is used as the working fluid in the ORC power *** LFR is integrated with a thermal-storage unit based on a two-tank system and stores the solar thermal energy via a heat *** thermal-energy output of the receiver tube of the LFR system is 108 kW and thermal losses are 7.872 kW during the peak time operation of a day at 1:00 *** mechanical power output of the ORC turbine is 7.296 kW using the specific design conditions and the two-tank thermal-storage system adds 4 operation hours to the power plant after sunset.

关键词： solar energy linear Fresnel reflector energy storage organic Rankine cycle

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Demography of the threatened endemic shrub, Arbutus pavarii,in the Al-Akhdar mountainous landscape of Libya

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Journal of Forestry Research 2016年第6期27卷 1295-1303页

作者： Hanan F.Kabiel Ahmad K.Hegazy Lesley Lovett-Doust Saud L.Al-Rowaily Abd EI-Nasser El Borki Department of Botany and Microbiology Faculty of ScienceCairo University Giza 12613 Egypt Department of Biology and Chemistry Nipissing UniversityNorth Bay ON Canada Department of Plant Production College of Food and Agricultural Sciences King Saud University Riyadh SaudiArabia Department of Botany Faculty of Science University of Benghazi Benghazi Libya

We sampled twenty populations of the vulnera- ble endemic shrub or tree, Arbutus pavarii Pampan., at different elevations and aspects within the A1-Akhdar mountainous region of Libya. Our sampling sites were at elevations ranging from 285 to 738 m above sea level, and several different habitats： vallies （locally known as wadis）, north- and south-facing slopes, and mountaintops. All individuals within each quadrat were studied. Population size and structure, and plant functional traits were assessed. None of the populations had a stable distribution of size classes. Some consisted mostly of small plants, with little or no fruit production; others consisted only of mid-sized and large plants, with high fruit production, but no juvenile recruitment. There was a significant increase in percent cover with increasing elevation; reproductive output （the number of fruits per branch and total number of fruits per individual） also generally increased with elevation. In some of these populations the lack of recruitment, and in others the failure to produce fruit, together constituted serious demographic threats. In light of these results, recommen- dations are made for conservation of this vulnerable endemic species.

关键词： Al-Akhdar mountains Conservation Demography Elevation Functional traits Vulnerable species

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Market Orientation and Libyan Tourism Business＇ Performances： A Comparative Study Between Public and Private Sector

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Economics World 2014年第2期2卷 124-136页

作者： Sabri G. M. Elkrghli university of benghazi Benghazi Libya

This paper aims to achieve these key objectives：（1） to measure the extent to which Libyan tourism businesses embrace the market orientation concept; （2） to evaluate the private and public tourism businesses＇ performance; （3） to identify the link between market orientation and tourism businesses＇ performances; and （4） to test the influence of ownership and organisational positions on market orientation-business performance relationship. A number of 582 questionnaires were distributed to high-level executives and clerks in tourism businesses in Libya. The key finding is that there is a growth in market orientation adoption. The performance of the private businesses is judged to be much better than the public one. There is a positive correlation between market orientation and tourism businesses＇ performance. This link is much stronger in the private sector. The market orientation in tourism sector is a critical element to drive business performance even in the less competitive environment such as Libya. The value of the paper is that it is the first paper to focus on market orientation in tourism sector in Libya. Therefore, the paper enriches the marketing literature with findings from the Arabic and North African region. Practically, the paper demonstrates the importance of market orientation to improve the Libyan tourism sector performance. Hence, international businesses, Libyan Government, tourism sector managers and employees should benefit from the results of the study. The paper concludes with limitations and future researches.

关键词： market orientation tourism businesses' performance public and private sector Libya

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Colorectal Cancer Implantation Metastasis in Haemorrhiodectomy Wound, Case Report

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Open Journal of Gastroenterology 2019年第9期9卷 185-191页

作者： Manal Algallai Mohamed Moftah Muftah A. Manita Soad I. Eldruki Department of General Surgery Benghazi Medical Centre Benghazi State of Libya Department of General Surgery Benghazi Medical Center Benghazi University Benghazi State of Libya Department of Radiology Benghazi Medical Center Benghazi University Benghazi State of Libya Department of Pathology Benghazi Medical Centre Benghazi State of Libya

Implantation metastasis from colorectal cancer into haemorroidectomy wound is very rare. The management of this condition remains controversial. We report a case of 68-year-old man with perianal soft tissue lesion biopsied and histopathology revealed an adenocarcinoma. Further investigation by colonoscopy and computed tomography scan revealed rectal adenocarcinoma. Pathological examination confirmed that this lesion was a distant metastasis from rectal cancer. The case was discussed at the multidisplinary meeting and the patient was advised to undergo long course neoadjuvant chemoradiotherapy followed by anterior resection and local excision of perianal metastasis. This case will be treated with long course neoadjuvannt chemoradiotherapy and after six weeks from treatment completion the plan is to perform sphincter sparing anterior resection and local excision of perianal implanted tumor.

关键词： Colorectal Cancer Haemorrhiodectomy Wound

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Assessments of Antibacterial and Antioxidant Properties in the Methanolic and Aqueous Leaf Extracts of Pistacia lentiscus against Different Antibiotic Resistance Pathogenic Bacteria

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Advances in Bioscience and Biotechnology 2022年第3期13卷 113-133页

作者： Aml O. Alhadad Galal S. Salem Maraia F. Elmhdwi Suliman M. Hussein Sarah M. Elshareef Department of Botany Faculty of Science University of Benghazi Benghazi Libya Department of Chemistry (Biochemistry) Faculty of Science University of Benghazi Benghazi Libya

The current study was carried out to determine the bioactivity of P. lentiscus leaf extracts as potential antibacterial and antioxidant properties. The plant extracts were examined for antibacterial activity against antibiotic-resistant Staphylococcus aureus, Staphylococcus haemolyticus, Pseudomonas aeruginosa, and Proteus mirabilis using the agar well method (according to the guidelines of Clinical and Laboratory Standard Institute). The antioxidant potential of 3 plant leaf extracts was determined by their ability to convert Fe3+ to Fe2+ and scavenge the DPPH free radical. At all concentrations studied, the methanolic leaf extract had higher total phenolic and flavonoid content, as well as stronger antioxidant and antibacterial inhibitory activity compared to aqueous extract. Our findings with P. aeruginosa were especially interesting, because this bacterium was inhibited by methanol extract than that of the reference antibiotics. The results also demonstrated a link between DPPH radical scavenging ability, reducing power, and total phenolic and flavonoid content of plant extracts (r > 0.97, R2 > 0.95, P = 0.01). As a result, the methanolic leaf extract of the chosen plant might be employed as an effective antioxidant and antibacterial agent for the treatment of a variety of morbidities.

关键词： Antioxidant Activity Polyphenols Methanolic Leaf Extracts DPPH Reducing Power Pistacia lentiscus

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Metal-Semiconductor Interfaces Investigated by Positron Annihilation Spectroscopy

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World Journal of Condensed Matter Physics 2016年第2期6卷 68-74页

作者： Abdulnasser S. Saleh Department of Physics University of Benghazi Benghazi Libya

Variable-energy positron annihilation spectroscopy has been applied to study interfaces in Al/Si, Au/Si and Au/GaAs structures. Computational fittings of ROYPROF program were used to analyze Doppler broadening results in order to determine kinds of regions that positrons were likely to sample. The interfaces were found acting as a capturing thin layer with negligible positrons stopped in them and their characteristics came only from positrons diffusing to these interfaces, the positron work function of these materials were taken into consideration. In all fittings, the interfaces are found to have 1 nm thickness and act as an absorbing sink for all thermal positrons diffusing towards them, and this indicates either the existence of open volume defects or a weakness of known theoretical models for positron affinities. The result is supported by measurements obtained by applying external electric fields on Al/Si sample. Theoretical fittings have clearly demonstrated the sensitivity of interfaces in these attempts and their importance in data analyzing and in developing of fitting cods.

关键词： Positron Annihilation Interface Metal-Semiconductor Defects

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The Early Warning Signs of a Stroke: An Approach Using Machine Learning Predictions

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Journal of Computer and Communications 2024年第6期12卷 59-71页

作者： Esraa H. Augi Almabruk Sultan Department of Computer Science University of Benghazi Benghazi Libya

Early stroke prediction is vital to prevent damage. A stroke happens when the blood flow to the brain is disrupted by a clot or bleeding, resulting in brain death or injury. However, early diagnosis and treatment reduce long-term needs and lower health costs. We aim for this research to be a machine-learning method for forecasting early warning signs of stroke. The methodology we employed feature selection techniques and multiple algorithms. Utilizing the XGboost Algorithm, the research findings indicate that their proposed model achieved an accuracy rate of 96.45%. This research shows that machine learning can effectively predict early warning signs of stroke, which can help reduce long-term treatment and rehabilitation needs and lower health costs.

关键词： Machine Learning Stroke k-Nearest Neighbors Decision Tree Random Forest GXboost

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