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多步微纳米压印工艺对COC环状烯烃共聚物弹性变形回复影响研究

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多步微纳米压印工艺对COC环状烯烃共聚物弹性变形回复影响研究

作者： hamzah mohammed Ali Almadani 宁波大学

学位级别：硕士

本文主要研究多步微纳米热压印工艺对COC环状烯烃共聚物弹性变形回复的影响研究。微纳米热压印技术是一种的连续成形、高效的加工方法,在微机电系统领域有着广泛的应用,近年来,微纳米压印复制方法在材料、结构和集成方面都取得了很大的... 详细信息

本文主要研究多步微纳米热压印工艺对COC环状烯烃共聚物弹性变形回复的影响研究。微纳米热压印技术是一种的连续成形、高效的加工方法,在微机电系统领域有着广泛的应用,近年来,微纳米压印复制方法在材料、结构和集成方面都取得了很大的进展。微纳米热压印技术成型温度通常选在材料的玻璃化转变温度以上20C至50C,由于聚合物在玻璃化转变温度附近具有粘弹特性,机械性能复杂,不易控制;因此玻璃化转变温度附近的微纳米热压印技术研究方兴未艾,特别是成型工艺对材料的弹性变形回复影响的研究甚少。本研究利用广义麦克斯韦模型描述玻璃化转变温度附近的材料特性,以确定离散弛豫时间谱,并借助于非线性有限元软件ABAQUS模拟成形过程。首先,基于滞后和磨损两种现象,建立了聚合物在玻璃化转变温度附近的粘弹性模型,并分析了其力学状态与温度的关系。其次,利用遗传算法对聚合物粘弹性模型的参数进行了计算和优化。描述了遗传算法的结构、步骤和设计方法,以拟合修正的广义麦克斯韦粘弹性本构模型。在实现最优解的过程中,将拟合结果与实验结果的偏差度作为评价函数,在特征搜索空间中搜索广义麦克斯韦粘弹性模型的参数。对遗传算法与最小二乘法在参考温度下拟合实验结果进行了比较,结果表明遗传算法的拟合效果较好。利用平移原理获得参考温度下的主曲线,将获得的prony系列模型参数输入ABAQUS有限元软件,为后续变形分析的微观结构处理提供材料参数。再次,采用数值方法研究了不同深度比、不同轧辊数下的多步压痕对弹性变形恢复的影响。为了评价微观结构的弹性恢复,计算了热印前后微通道的横截面积,并进行了数值比较。对模拟结果进行了分析,结果表明,采用优化成形后,微结构的弹性回复率明显降低。最后,通过分析表面不同位置节点的弹性恢复速率,得出工艺参数对聚合物的弹性恢复特性对微结构形状变化的影响。根据热压印的数值模拟结果,计算了弹性回复前后的面积和回复速率。分析了温度、预紧力、空腔间距和压印速度对微结构形状的影响。利用该方法获得了减小弹性回复对微结构影响的最佳工艺参数。

关键词：卷对板热纳米压印广义麦克斯韦模型弹性变形回复

苜蓿与聚乙烯化学链共气化制备高氢碳比合成气研究

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苜蓿与聚乙烯化学链共气化制备高氢碳比合成气研究

作者： AL-QADRI, BASHAR mohammed hamzah 东南大学

学位级别：硕士

据报道,2020年新冠肺炎疫情导致塑料废物的日产量增加了约5.4万吨。生物质废物是另一种常见的废物,其中农业和农林业、森林和木材加工以及城市垃圾都是主要的生物质废物来源。化学链共气化是一种新型转化技术,基于此技术有望开发出长期... 详细信息

据报道,2020年新冠肺炎疫情导致塑料废物的日产量增加了约5.4万吨。生物质废物是另一种常见的废物,其中农业和农林业、森林和木材加工以及城市垃圾都是主要的生物质废物来源。化学链共气化是一种新型转化技术,基于此技术有望开发出长期的废弃物管理系统,从而减少温室气体排放并提高能源回收率。本文的研究目的是探索苜蓿和聚乙烯的共气化机理,以生产高氢碳比质量的合成气,以满足费托合成工艺的需求。构建了基于固定床反应器的实验室规模化学链气化(CLG)系统,开展了对紫花苜蓿和聚乙烯的气化试验,结果表明可以生产出高H2/CO 比的合成气。研究细节如下:1.开展了紫花苜蓿(单一燃料)的化学链气化试验,以研究重要操作参数对合成气组成和质量的影响。结果表明,在较高的气化温度下,最终产物分布显著改善,因此,950℃是气化的理想温度。同时,由于水煤气变换反应,蒸气燃料比(S/AL)的增加造成了更高的H2和更低的CO 比率,最终,S/AL比为1被认为最佳。此外,载氧体燃料比(OC/AL)的增加会造成更多的炭气化;但另一方面,过量的载氧体将会促进合成气的氧化,从而导致合成气低位发热量的降低。最终,OC/AL比为0.5被认为是最理想的。2.研究了苜蓿和聚乙烯混合物的化学链共气化过程。原料中聚乙烯的存在导致了合成气产量特别是氢气产量的增加,当H2/CO 比增加到2以上后,所得的合成气可以满足费托合成的需求。当混合比为50%时,低位发热量和H2/CO 比均可达到最大值(14.05 MJ/Nm3和2.50)。通过比较单一燃料和混合燃料试验的气体产物结果,证明了化学链共气化中存在协同效应。与生物质样品相比,塑料中更高的C和H含量促进更高H2峰值浓度的实现。该共气化过程的协同效应反映在了纯样品和混合物样品之间观察到的不同趋势中。3.通过化学链氧化还原循环研究了载氧体的反应性。结果表明,铁矿石作为载氧体的循环性能相对稳定。然而,在化学链共气化循环中,H2产率逐渐降低。这可归因于在第3和第6次氧化还原循环后,OC表面上矿物元素的累积。本文研究表明,生物质与塑料的化学链共气化是实现高质量合成气生产、以及环境保护和材料回收的一个潜力途径。

关键词：化学链共气化苜蓿聚乙烯铁矿石合成气

基于亚热带沙漠气候特征的巴格达居住区规划设计策略研究

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基于亚热带沙漠气候特征的巴格达居住区规划设计策略研究

作者： Abd mohammed Ahmed hamzah Abbas 北京交通大学

学位级别：硕士

随着城市人口的增加,气候变化已成为全球共同关注的问题。人类引起的大气成分变化是全球气候变化的主要原因。在地方和区域层面,城市化和土地利用的变化也发挥着重要作用。然而,与能源使用相关的排放占这些干扰的大部分。2017年美国气... 详细信息

随着城市人口的增加,气候变化已成为全球共同关注的问题。人类引起的大气成分变化是全球气候变化的主要原因。在地方和区域层面,城市化和土地利用的变化也发挥着重要作用。然而,与能源使用相关的排放占这些干扰的大部分。2017年美国气候科学报告指出,如果年排放量继续像2000年以来那样快速上升,模型预测到本世纪末,全球平均气温将至少上升5华氏度,甚至可能上升10.2度。根据模型预测,即使到2050年年排放量逐渐上升并开始急剧下降,气温仍将比20世纪上半叶至少高出2.4度,甚至可能高出5.9度。巴格达被认为是世界上最热的城市之一,伊拉克巴格达市的特点是亚热带沙漠气候,天气炎热,夏季炎热而漫长,一年长达七个月。巴格达的每日最高温度通常接近50°C。炎热的气候使人们通过人工降温系统来调节建筑物的室内温度,不仅增加了能源消耗,而且将热能传递到建筑物周围,导致室外环境变差,室外温度升高导致城市热岛现象的出现。此外,许多研究表明,中东炎热干燥城市(如巴格达)的大部分城市形态风格都是基于当代规划技术创建的。在不考虑炎热干燥地区恶劣的当地条件的情况下,这些传统是从普遍存在温带和凉爽气候的西方环境中继承下来的。本论文的研究对象是巴格达的城市环境和住宅建筑。该研究方法依靠描述性和分析性的方法来实现其目标并达到预期目标,首先,通过研究和分析来阐明巴格达的气候特征和城市气候的影响。其次,调查城市住区外部环境、室外空间的规划要素及其遇到的问题,如朝向、开洞、植被覆盖、绿化、保温材料的使用、个体的设计特点等、建筑,以及居住区生活质量的自我评估。最后,提出了能够降低热气候负面影响的改善设计策略,并提出适合该区域的技术措施,为城市居住区规划设计和建筑设计提供参考。

关键词：规划设计策略全球气候变化居住区亚热带气候特征

Use of Topical Complementary and Alternative Medicines (CAM) in Diabetic Septic Foot Disease in Makkah Region, Western of Saudi Arabia, an Exploratory Study

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Journal of Biosciences and Medicines 2024年第3期12卷 245-258页

作者： Mohamed Elamin Salih Hatim Alrizqi mohammed Hussain Abdullah Alshumrani Ismail Alhasani Ali Alkhamisi hamzah Alsayed Fahad Alqarni Department of Surgery Faculty of Medicine University of Umm AlQura Mecca Saudi Arabia Faculty of Medicine University of Umm AlQura Mecca Saudi Arabia

Diabetes is a chronic condition that is significantly impacted daily by environment. At least one in five Saudis, suffer from diabetes. “Diabetes is a pandemic of unprecedented magnitude spiraling out of control” (Boulton). Saudi Arabia ranks the second highest in the Middle East, and is the seventh in the world for the prevalence of diabetes (WHO). Diabetes mellitus (DM) has been found to be related to high mortality, morbidity accompanied by poor general health and lower quality of life. Current Saudi diabetes patients’ behaviors, practices, and beliefs regarding foot health problems such as ulcers, are not well investigated. Diabetic patients frequently utilize natural remedies and Herbs for self-medication as a part of complementary and alternative Medicine. Aim of study: To explore the widespread use of the alternative remedies in the local communities of the Western Saudi Arabia, the drives behind using and to focus on the potential adverse effects following their usage. Method: A descriptive, cross-sectional study of 386 diabetic patients with feet problems in Makkah Region, West of Saudi Arabia during the period April - June 2023. Results: Out of the 531 participants, only 386 participants reported diabetic foot disorder (DFD). Most of the participant were above 65 years of age group (24.61 %). Male (52.08%) more than female (47.92%) in the research group. All of the participants had diabetic foot disorders at least once. The prevalence of complementary and alternative medicines (CAM) use among them was 67.88%, as solitary or in combination with hospital medicines. Honey headed the list followed by myrrh and black seeds. Acquaintances advice (59.54%) was the most reason for using the alternative medicine. 60.30% of Diabetic foot patient complained of adverse effects during CAM remedies use. Conclusion: Consumption of CAM remedies among diabetic patients for Diabetic Foot Disorder (DFD) is common. Honey headed the list followed by myrrh and black seeds. Addit

关键词： Diabetic Foot Ulcer Diabetes Complementary and Alternative Medicine CAM West of Saudi Arabia

An End-to-End Transformer-Based Automatic Speech Recognition for Qur’an Reciters

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Computers, Materials & Continua 2023年第2期74卷 3471-3487页

作者： mohammed Hadwan hamzah A.Alsayadi Salah AL-Hagree Department of Information Technology College of ComputerQassim UniversityBuraydah51452Saudi Arabia Department of Computer Science College of Applied SciencesTaiz UniversityTaiz6803Yemen Computer Science Department Faculty of Computer and Information SciencesAin Shams UniversityCairo11566Egypt Computer Science Department Faculty of SciencesIbb UniversityYemen Department of Computer Sciences&Information Ibb UniversityYemen

The attention-based encoder-decoder technique,known as the trans-former,is used to enhance the performance of end-to-end automatic speech recognition(ASR).This research focuses on applying ASR end-toend transformer-based models for the Arabic language,as the researchers’community pays little attention to *** Muslims Holy Qur’an book is written using Arabic diacritized *** this paper,an end-to-end transformer model to building a robust Qur’an *** is *** acoustic model was built using the transformer-based model as deep learning by the PyTorch framework.A multi-head attention mechanism is utilized to represent the encoder and decoder in the acoustic *** filter bank is used for feature *** build a language model(LM),the Recurrent Neural Network(RNN)and Long short-term memory(LSTM)were used to train an n-gram word-based *** a part of this research,a new dataset of Qur’an verses and their associated transcripts were collected and processed for training and evaluating the proposed model,consisting of 10 h *** recitations performed by 60 *** experimental results showed that the proposed end-to-end transformer-based model achieved a significant low character error rate(CER)of 1.98%and a word error rate(WER)of 6.16%.We have achieved state-of-the-art end-to-end transformer-based recognition for Qur’an reciters.

关键词： Attention-based encoder-decoder recurrent neural network long short-term memory qur’an reciters recognition diacritized arabic text

Keladi candik(Alocasia longiloba Miq.) petiole extracts promote wound healing in a full thickness excision wound model in rats

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Asian Pacific Journal of Tropical Biomedicine 2019年第4期9卷 140-149页

作者： Nurul Hazirah Che hamzah Arifullah mohammed KNS Sirajudeen Mohd Asnizam Asari Zulhazman hamzah Ibrahim Khalivulla Shaik Faculty of Agro-Based Industry Universiti Malaysia Kelantan Department of Chemical Pathology School of Medical Sciences Universiti Sains Malaysia Department of Anatomy School of Medical Sciences Universiti Sains Malaysia Faculty of Sains Bumi Universiti Malaysia Kelantan Faculty of Pharmaceutical Sciences UCSI University

Objective: To investigate the wound-healing effect of Alocasia longiloba(A. longiloba) petiole extract on wounds in ***: Twenty-two male Sprague-dawley rats were randomly assigned to receive 10% solcoseryl gel, phosphate buffer saline, 50% ethanol, 95% ethanol and hexane extracts of A. longiloba at 1.5%, 3% and 6% doses, respectively. A full thicknesses wound(6 mm) was created on the dorsal of the rat; and all rats were applied with the extract solutions, 10% solcoseryl gel and phosphate buffer saline once a day topically until day 12. The wound was photographed on day 1, 6 and 12, and the percentage of wound contraction was calculated. On day 12, rats were sacrificed and histological examination of granulation tissue was carried out using haematoxylin & eosin and Masson's Trichrome stain to determine the wound healing ***: In this study, 6% of 50% and 95% ethanol extracts of A. longiloba showed 82.50% and 82.32% wound contraction, respectively, and were comparable with 10% solcoseryl gel(82.30%). Meanwhile, phosphate buffer saline treated group showed the lowest wound contraction(69.86%). Histological assessment of wound treated with 6% of 95% ethanol extract of A. longiloba showed distinct epidermal and dermal layer, higher proliferation of fibroblast and more angiogenesis with collagen compared to other wound treated ***: A. longiloba petiole extracts have a wound healing potential and 6% of 95% ethanol extract of A. longiloba is more effective. Further studies are required to understand the wound healing mechanism of action of the extract.

关键词： Full thickness excision wound Rat model Sprague-dawley rat Alocasia longiloba petiole extract

An unequal clustering routing protocal for wireless sensor networks based on genetic algorithm

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Journal of Measurement Science and Instrumentation 2022年第3期13卷 329-344页

作者： WANG Lei HUO Jiuyuan Al-Neshmi hamzah Murad mohammed School of Electronics and Information Eigineering Lanehou Jiaotong UniversityLanzhou 730070China Lanehou Huahao Technology Co.Ltd Lanchou 730070China National Cryosphere Desert Data Center(NCDC) Lanzhou 730070China

The imbalance of energy consumption in wireless sensor networks(WSNs)easily results in the“hot spot”problem that the sensor nodes in a particular area die due to fast energy *** order to solve the“hot spot”problem in WSNs,we propose an unequal clustering routing algorithm based on genetic algorithm(UCR-GA).In the cluster head election phase,the fitness function is constructed based on the residual energy,density and distance between nodes and base station,and the appropriate node is selected as the cluster *** the data transmission phase,the cluster head selects single-hop or multi-hop communication mode according to the distance to the base *** we comprehensively consider the residual energy of the cluster head and its communication energy consumption with the base station,an appropriate relay node is *** designed protocal is simulated under energy homogeneous and energy heterogeneity conditions,and the results show that the proposed routing protocal can effectively balance energy consumption,prolong the life cycle of network,and is appicable to heterogeneous networks.

关键词： wireless sensor networks(WSNs) genetic algorithm(GA) unequal clustering multi-hop life cycle of network energy consumption

Characteristic properties of date-palm fibre/sheep wool reinforced polyester composites

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Journal of Bioresources and Bioproducts 2023年第4期8卷 430-443页

作者： mohammed Y.Abdellah Mustafa Gamal Sadek hamzah Alharthi G.T.Abdel-Jaber Ahmed H.Backar Mechanical Engineering Department Faculty of EngineeringSouth Valley UniversityQena83523Egypt Mechanical Engineering Department College of Engineering and Islamic ArchitectureUmm AL-Qura UniversityMakkah21955Saudi Arabia New Assiut Technological University(NAUT) Assiut71684Egypt Production Engineering Department Faculty of EngineeringAlexandria UniversityAlexandria21544Egypt

In this study,we attempted to characterise the effects of date-palm fibre(DPF)and a date-palm fibre/sheep wool hybrid in polyester to enhance high-performance and low-cost composite materials that can be used in insulation building systems,automotive parts,and home *** DPF was treated using 5%NaOH solution;and the sheep wool was cleaned with 50℃hot water and *** composite specimens were prepared with different fibre contents(0%,10%,20%,30%(w))using a compression moulding *** effect of fibre reinforcement was analysed in terms of the mechanical properties(tensile,flexural,impact,and hardness)and composite ***,scanning electron microscopy(SEM)was performed on the fibres before and after treatment,and the fractured surfaces of all composite specimens were examined after tensile *** results showed that the 20%DPF/sheep wool hybrid reinforced polyester produced the best *** ultimate tensile strength and modulus were 27 MPa and 3.69GPa,*** ultimate flexural strength and flexural modulus were 35.4 and 2507 MPa,*** impact strength was 39.5 kJ/m^(2)and the hardness was 64 *** density decreased to the lowest value of 1.02 g/cm^(3)with the 30%DPF/sheep wool *** SEM showed good adhesion and interfacial bonding between DPF/sheep wool hybrid fibres and the polyester matrix,particularly at 20%fibre content.

关键词： Date-palm fibre Polyester Compression moulding Mechanical property

Novel Universal Windowing Multicarrier Waveform for 5G Systems

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Computers, Materials & Continua 2021年第5期67卷 1523-1536页

作者： Ahmed Hammoodi Lukman Audah Montadar Abas Taher Mazin Abed mohammed Mustafa S.Aljumaily Adeeb Salh Shipun A.hamzah Wireless and Radio Science Centre Faculty of Electrical and Electronic EngineeringUniversiti Tun Hussein Onn MalaysiaParit Raja86400Malaysia Department Communications Engineering University of DiyalaBaqubah32001Iraq College of Computer Science and Information Technology University of AnbarAnbar31001Iraq Department of Electrical Engineering and Computer Science University of TennesseeKnoxvilleTN37901USA

Fifth Generation(5G)systems aim to improve flexibility,coexistence and diverse service in several aspects to achieve the emerging applications *** and filtering of the traditional multicarrier waveforms are now considered common sense when designing more flexible *** paper proposed a Universal Windowing Multi-Carrier(UWMC)waveform design platform that is flexible,providing more easily coexists with different pulse shapes,and reduces the Out of Band Emissions(OOBE),which is generated by the traditional multicarrier methods that used in the previous generations of the mobile *** novel proposed approach is different from other approaches that have been proposed,and it is based on applying a novel modulation approach for the Quadrature-Amplitude Modulation(64-QAM)which is considered very popular in mobile *** new approach is done by employing flexible pulse shaping windowing,by assigning windows to various *** leads to decreased side-lobes,which are going to reduce OOBE and boost the spectral efficiency by assigning them to edge subscribers *** new subband windowing(UWMC)will also maintain comprehensively the non-orthogonality by a variety of windowing and make sure to keep window time the same for all *** addition,this paper shows that the new approach made the Bit Error Rate(BER)equal to the conventional Windowed-Orthogonal Frequency Division Multiplexing(W-OFDM).This platform achieved great improvement for some other Key Performance Indicators(KPI),such as the Peak to Average Power Ratio(PAPR)compared with the conventional(W-OFDM)and the conventional Universal Filtered Multicarrier(UFMC)*** particular,the proposed windowing scheme outperforms previous designs in terms of the Power Spectral Density(PSD)by 58%and the(BER)by 1.5 dB and reduces the Complementary Cumulative Distribution Function Cubic Metric(CCDF-CM)by 24%.

关键词： 5G waveform window-OFDM universal filtered multi-carrier key performance indicators