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Application of the N + 2 Transversal Network Method to the Study of a Coupled Resonator Filter

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Open Journal of Applied Sciences 2024年第6期14卷 1412-1424页

作者： Charmolavy Goslavy Lionel Nkouka Moukengue Conrad Onésime Oboulhas Tsahat Haroun abba Labane Barol Mafouna Kiminou Achille Makouka Electrical and Electronic Engineering Laboratory ENSP Marien Ngouabi University Brazzaville Congo Electrical Engineering Research Laboratory Polytechnic University of Mongo Mongo Tchad

This paper presents a new approach to synthesize admittance function polynomials and coupling matrices for coupled resonator filters. The N + 2 transversal network method is applied to study a coupled resonator filter. This method allowed us to determine the polynomials of the reflection and transmission coefficients. A study is made for a 4 poles filter with 2 transmission zeros between the N + 2 transversal network method and the one found in the literature. A MATLAB code was designed for the numerical simulation of these coefficients for the 6, 8, and 10 pole filter with 4 transmission zeros.

关键词： Resonator Filter Coupling Matrix Transmission Zero Transversal Network Method

The seasonal role of field characteristics on seed-eating bird abundances in agricultural landscapes

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Current Zoology 2017年第3期63卷 279-286页

作者： emmanuel ZUFIAURRE Mariano CODESIDO Agustin M. abba David BILENCA Grupo de Estudios sobre Biodiversidad en Agroecosistemas (6EBA) Departamento de Biodiversidad y Biologia Experimental Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires and IEGEBA (UBA- CONICET). Ciudad Universitaria Pabellon II 4° Piso (C1428EHA). Ciudad Autonoma de Buenos Aires Argentina Centro de Estudios Parasitol6gicos y de Vectores (CEPAVE) CCT-CONICET-LA PLATA-UNLP. Calle 120 entre 61 y 62 S/N La Plata (B1902CHX) Buenos Aires Argentina

In temperate agroecosystems, avian responses in abundance and distribution to landscape attributes may be exacerbated by the coupling of natural seasons and farming practices. We assessed the sea- sonal roles of field type, field use in the surroundings, and distance from a field to the nearest woodlot on the abundance of seed-eating birds in a 225,000 km2 study area in the Pampas of central Argentina. During spring-summer and autumn of 2011-2013, we randomly selected 392 fields and used transect samples to collect data on abundance and presence of seed-eating bird species. We recorded a total of 11,579 individuals belonging to 15 seed-eating bird species. We used generalized lineal mixed models to relate bird abundance to field type, field use in the surroundings, and distance to the nearest woodlot. In spring-summer （breeding season） most bird responses were associated with their nesting requirements. Species that build their nests in trees, such as eared doves Zenaida auriculata, picazuro pigeons Patagioenas picazuro, and monk parakeets Myiopsitta monachus, were more abundant in fields closer to woodlots, whereas grassland yellow-finches Sicalis luteola, which nest at areas with tall grasses, were more abundant in fields with livestock use patches in the field surroundings. In au- tumn （non-breeding season）, most bird responses were associated with foraging and refuge needs. The high abundance of eared doves in crop stubbles and the association of pigeons at field surroundings dominated by croplands or at crop stubbles surrounded by livestock use fields revealed the intimate association of these species to sites with high availability of food resources. In addition, both picazuro pigeons and spot-winged pigeons Patagioenas maculosa were associated with woodlots, which provide suitable roosting sites. Our results show that in temperate agroecosystems, the relationships between field characteristics and seed-eating bird abundances vary with season.

关键词： field surroundings field type granivorous birds stubbles temperate agroecosystems woodlots.

Pregnancy Preferences in Females of Reproductive Age with Sickle Cell Disease at Laquintinie Hospital: A Cross-Sectional Analysis

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Open Journal of Obstetrics and Gynecology 2024年第5期14卷 744-757页

作者： Eposse Ekoube Charlotte Jeannette Disso Massako Mangala Fulbert Nkwele Mandeng Ma Linwa Edgar Puepi Djike Yolande Merlin Boten Bounyom Erero F. Njiengwe Épée Patricia Hassanatou Iyawa Dora Mbonjo Bitsie emmanuel Heles Nsang Soumaiyatou abba Ngo Linwa Esther Eleonore Ndolo Kondo Astrid Grâce Tocki Toutou Moustapha Bilkissou Essome Henri Faculty of Medicine and Pharmaceutical Sciences University of Douala Douala Cameroon Paediatric Unit Douala Laquintinie Hospital Douala Cameroon Faculty of Health Sciences University of Bamenda Bamenda Cameroon

Introduction: Females with sickle cell disease (SCD), despite having a delayed pubertal development, are subject to many worries relating to their abilities to conceive, their capacity to maintain a maternofetal-risk-free pregnancy till term and give birth to healthy children without sickle cell disease. Knowing that unplanned pregnancies are more likely to increase maternofetal morbidity and mortality, we sought out to explore the pregnancy preferences in female patients with sickle cell disease to promote healthy conception and childbirth in this vulnerable population. Methodology: We conducted a cross-sectional study involving female patients of child-bearing age with sickle cell disease followed at Laquintinie Hospital Douala or who were members of a local sickle cell association. Pregnancy preferences were determined using the Desire to Avoid Pregnancy (DAP) scale. Factors associated with pregnancy preferences were determined using multivariable linear regression model. Threshold for significance was set at p Results: Seventy-seven patients were included with a mean age of 24.71 ± 5.53 years. Forty patients (51.95%) had one sexual partner and thirteen women (32.5%) used contraceptive methods. Most patients (46.0%) responded “Strongly Agree” or “Agree” to the statement “it would be a good thing for me if I became pregnant in the next 3 months”. The mean DAP score was 1.63 ± 0.91 [1.28 ± 0.82 in those who had a sexual partner and 1.99 ± 0.86 in those who had no sexual partner]. Factors that were positively associated with DAP score were students (b = 0.32, 95% CI [0.21, 0.95], p = 0.003), monthly income ≥ 100,000 FCFA (b = 0.24, 95% CI [0.07, 0.81], p = 0.022), and not having a sexual partner (b = 0.26, 95% CI [0.11, 0.85], p = 0.012). Conclusion: Most female patients with SCD have a low desire to avoid pregnancy. This is especially true for patients who are not students, have a partner and have a low monthly income.

关键词： Pregnancy Preferences Sickle Cell Disease Laquintinie Hospital Cameroun

Genesis and magma fertility of gold associated high-K granites:LA-ICP-MS zircon trace element and REEs constraint from Bakoshi–Gadanya granites in NW Nigeria

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Acta Geochimica 2022年第3期41卷 351-366页

作者： Safiyanu Muhammad Elatikpo Huan Li Yuanlin Chen Hafizullah abba Ahmed Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South UniversityChangsha 410083China Department of Geology Ahmadu Bello UniversityZariaNigeria Department of Geology Modibbo Adama University of TechnologyP.M.B.2076YolaNigeria

High-K granites dominate the rock units in the Bakoshi and Gadanya areas located in the northwestern Nigerian subshield,part of the Trans-Saharan Belt,West *** this contribution,the LA-ICP-MS zircon trace element revealed the fertility of magma responsible for the high-K granites that hosts the Bakoshi–Gadanya gold *** likely metallogenic granites types are 1)Gadanya alkali granite,with high Ce^(4+)/Ce^(3+)(mean 1485)and limited range of Eu anomalies may likely be associated with the gold mineralization,and 2)Bakoshi porphyritic granite,Jaulere biotite granite,Shanono coarsegrained granite,and Yettiti granite,all have low Ce^(4+)/Ce^(3+) ratios(mean\100,except second Bakoshi granite D2-1)with wider ranges of Eu/Eu^(*) values,thus are considered reduced *** reduced granites have oxygen fugacity values and Eu anomalies comparable to reduced granites associated with tin belts in Myanmar and Zaaiplaats granites in Bushveld Complex,South ***-inZircon thermometric study revealed two thermal regimes during the crystallization of the Bakoshi–Gadanya granites:the high temperature(746–724℃):Shanono coarsegrained granite,Bakoshi granite D2-1,and Jaulere biotite granite;and relatively low temperature(705–653℃):Bakoshi porphyritic granite D1-1,Yettiti medium-grained granite,and Gadanya alkali *** trace elements including U,Yb,Y,Nb,and Sc ratios constraint the magma source of Bakoshi–Gadanya granites to an enriched mantle metasomatized during the subduction process before its *** for Gadanya alkali granite,fractionation of titanite and apatite dominate the magma evolution with limited amphibole *** that crystallized Gadanya alkali granite is rather saturated in zircon without accessory titanite or apatite.

关键词： Bakoshi–Gadanya area Zircon trace element Europium anomalies Gold mineralization Oxygen fugacity Cerium ratio

Methanolic extract of Clausena excavata promotes wound healing via antiinflammatory and anti-apoptotic activities

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Asian Pacific Journal of Tropical Biomedicine 2020年第5期10卷 232-238页

作者： Shaymaa Fadhel abbas Albaayit Abdullah Rasedee Noorlidah Abdullah Yusuf abba Department of Biology College of ScienceUniversity of BaghdadBaghdad-Iraq Department of Veterinary Laboratory Diagnosis Faculty of Veterinary MedicineUniversiti Putra Malaysia43400SerdangSelangorMalaysia Institute of Biological Sciences Faculty of ScienceUniversity of Malaya50603 Kuala LumpurMalaysia Department of Veterinary Pathology and Microbiology Faculty of Veterinary MedicineUniversiti Putra Malaysia43400 SerdangSelangorMalaysia

Objective: To investigate the anti-inflammatory properties of methanolic extract of Clausena excavata in lipopolysaccharide(LPS)-activated macrophages(J774 A.1) and the effect on skin wound in a rat model through determining cytokine levels and gene expressions. Methods: The effects of methanolic extract of Clausena excavata on in vitro viability and TNF-α, IL-6, IL-10, and nitric oxide release by LPS-activated J774 A.1 cells were determined. In addition, relative expressions of BAX, BCL-2 and COX-2 genes were examined in healed wounds of rats. Results: The methanolic extract of Clausena excavata was not toxic to J774 A.1 cells at the highest dose of 400 μg/m L. It decreased levels of TNF-α and IL-6, while increasing IL-10 level in LPSactivated J774 A.1 cells and in the healed wounds of rats. The methanolic extract of Clausena excavata also inhibited nitric oxide production in LPS-activated J774 A.1 cells. The BAX and COX-2 genes were downregulated while the BCL-2 gene was upregulated in the healed wound of rats. Conclusions: The methanolic extract of Clausena excavata promotes wound healing via its anti-inflammatory and anti-apoptotic activities.

关键词： Clausena excavata leaves Anti-inflammatory cytokines Cytotoxicity Apoptotic genes

Effect of atmospheric pressure on physical parameters of steels and solidification conditions during PESR process:a review

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Journal of Iron and Steel Research International 2021年第12期28卷 1504-1514页

作者： Yusuf abba Yusuf Wan-ming Li Shi-shen Li Hua-bing Li Xi-min Zang School of Materials and Metallurgy University of Science and Technology LiaoningAnshan114051LiaoningChina School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina

The pressurized electroslag remelting(PESR)process has a remarkable impact on manufacturing high nitrogen steels,which can alter the physical parameters of steels and solidification conditions at different atmospheric *** principle and applications of the PESR process are *** effect of atmospheric pressure,including Gibbs free energy,nitrogen solubility,melting point,viscosity,diffusion coefficient,partition coefficient,and nucleation rate,is explicitly expressed by empirical knowledge and quantified by thermodynamic *** variation of interfacial heat transfer coefficient is discussed at different atmospheric ***,the effect of atmospheric pressure on physical parameters of steels and solidification conditions during the PESR process is still in their embryonic research stage and it is important to do further study in this research ***,a general concluding remark and suggestions for future development are proposed.

关键词： Pressure High nitrogen steel Pressurized electroslag remelting Thermodynamic Physical parameter Solidification condition

Impact of Employee Participation in Decision Making on Organizational Productivity: A Perspective of Nigeria Manufacturing Sector

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Impact of Employee Participation in Decision Making on Organ...

作者： Nabil Bello abba 湖南大学

学位级别：硕士

该研究的目的是评估员工参与决策对组织生产力的影响:尼日利亚制造业的视角。该研究利用描述性调查进行研究,从而使用从该领域收集的定量原始数据。由于研究区域的性质没有抽样框,因此该研究使用了便利抽样技术。该研究从尼日利亚拉各... 详细信息

该研究的目的是评估员工参与决策对组织生产力的影响:尼日利亚制造业的视角。该研究利用描述性调查进行研究,从而使用从该领域收集的定量原始数据。由于研究区域的性质没有抽样框,因此该研究使用了便利抽样技术。该研究从尼日利亚拉各斯州的一些选定制造业部门对一百七十（120）名受访者进行了抽样调查,回复率为100%。该研究利用斯皮尔曼等级相关和多元回归技术来分析从现场收集的数据。相关性分析表明,所有变量都与制造生产率呈显着正相关。多元回归结果表明,参与程度对制造业生产率有显着的正向影响。结果表明,当所有变量保持不变时,参与水平的提高将导致制造业生产率（PRO）提高20.6%。此外,当所有变量保持不变时,内部沟通渠道的增加将导致制造业生产率（PRO）提高33.3%。此外,当所有变量保持不变时,员工参与度（或发言权）增加1%（1%）将导致制造业生产率（PRO）增加21.2%。此外,当所有变量保持不变时,智力资本投资平均增加1%（1%）将导致制造业生产率（PRO）增加47.1%。同样,当所有变量保持不变时,管理支持平均增加1%（1%）将导致制造业生产率（PRO）增加34.5%。在这些调查结果的基础上,提出了一些建议。研究建议,管理者应更加努力地鼓励员工提出建议和有用的决定,并努力将其纳入组织的决策和政策中,管理者应考虑到这一事实,增加员工参与决策的频率和水平他们是执行主要操作工作的人,因为他们能够更好地了解这些领域的情况。

关键词：员工参与决策组织生产力尼日利亚制造业

Mathematics of dengue transmission dynamics:Roles of vector vertical transmission and temperature fluctuations

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Infectious Disease Modelling 2018年第1期3卷 266-292页

作者： Rahim Taghikhani abba B.Gumel School of Mathematical and Statistical Sciences Arizona State UniversityTempeAZUSA

A new deterministic model is designed and used to gain insight into the effect of seasonal variations in temperature and vector vertical transmission on the transmission dynamics of dengue *** model,which incorporates(among many other features)the dynamics of the immature dengue-competent mosquitoes,vertical transmission in the vector population,density-dependent larval mortality and temperature effects,is rigorously analysed and simulated using data relevant to the disease dynamics in Chiang Mai province of *** non-trivial disease-free equilibrium of the model is shown to be globallyasymptotically stable when the associated basic reproduction number of the model is less than *** simulations of the model,using data relevant to the disease dynamics in the Chiang Mai province of Thailand,show that vertical transmission in the vector population has only marginal impact on the disease dynamics,and that the effect of vertical transmission is temperature-dependent(in particular,the effect of vertical transmission on the disease dynamics increases for values of the mean monthly temperature in the range[16-28]℃,and decreases with increasing mean monthly temperature thereafter).It is further shown that dengue burden(as measured in terms of disease incidence)is maximized when the mean monthly temperature is in the range[26-28]℃(and dengue burden decreases for mean monthly temperature values above 28℃).Thus,this study suggests that anti-dengue control efforts should be intensified during the period when this temperature range is recorded in the Chiang Mai province(this occurs between June and August).

关键词： Dengue Vertical transmission Temperature Stability Reproduction number

Evaluating Manufacturing Energy Consumption for a Part Using Geometry

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Evaluating Manufacturing Energy Consumption for a Part Using...

作者： abba Ahmed Rimi 湖南大学

学位级别：硕士

在设计过程中做出的决策对零件的制造有重大影响。除了技术和功能要求,设计师还权衡了设计几何、材料和规格对能源消耗的影响。由于大部分零件的可持续性影响是在设计过程中确定的,因此工程师在整个设计过程中考虑可持续性是很重要的。...

在设计过程中做出的决策对零件的制造有重大影响。除了技术和功能要求,设计师还权衡了设计几何、材料和规格对能源消耗的影响。由于大部分零件的可持续性影响是在设计过程中确定的,因此工程师在整个设计过程中考虑可持续性是很重要的。评估设计可持续性的现有工具没有考虑设计的几何复杂性,也很少为工程师改进设计提供指导。基于更复杂的设计将需要更多的资源来制造的概念,本文提出了一种新的方法来评估制造阶段的能源消耗。本论文的主要目的是提出一个工具的框架,可以指导工程师进行更可持续的设计。新的可持续性评估工具应分析设计几何图形(即CAD文件)的复杂性,以便预测其在制造过程中的能耗。由于开发刀具的第一步是研究影响零件制造能耗的主要几何因素,因此本文研究了设计几何对数控加工能耗的影响。这项研究发现,高达98%的能源消耗的变化,在加工过程中的一个部分可以预测使用其几何特征。事实上,设计的长度、可达性得分和边界体积解释了高达75%的能耗变化。研究还发现,半精加工和球磨操作占加工总能耗的四分之三以上。研究结果可用于预测给定部件几何形状的相对制造能耗。这可以进一步完善,以开发一种工具,可以指导工程师进行更可持续的设计。本文提出的模型可以作为开发一个工具的跳板,该工具可以从CAD文件中分析设计几何,向设计工程师提供反馈,并指导他们进行更可持续的设计。根据本研究的结果,该工具应使用一个评估模型,该模型除了考虑最终零件体积和移除体积外,还应考虑几何特征,如表面积、尺寸和可达性。

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