Suhad Dawood Salman

Vinyl ester composites reinforced with treated coconut (shells and fibers) and glass (powder and fibers) have been investigated using numerical, experimental, and statistical methods. Tensile and bending tests were applied. Numerical simulation was conducted using the Finite Element Method (FEM) with the ABAQUS CAE 2019 program for tensile and flexural samples. Experimental values were analyzed using the statistical analysis from the Minitab Statistical Software 2022 program. The simulation results illustrate the great convergence between numerical and experimental values. By analyzing the experimental results, the 30% and 40% filler ratios prevailed in all the vinyl ester composites reinforced with coconut and glass. The strength values obtained from the simulation did not exceed the experimental laboratory values by more than 5% in the tensile test and 10.6% in the bending test. Additionally, scanning electron microscopy (SEM) has demonstrated improved adhesion in synthetic fiber, displaying holes formed by the removal and pulling of fibers and particles from the polymer. The mechanical properties of these composites encourage their further study, as they can be used in many structural industries.

1. The growing global emphasis on environmental sustainability and resource efficiency has accelerated the development of lightweight, environmentally friendly and cost-effective composite material...

Automotive companies are now concentrating on finding new materials that are light, eco-friendly and affordable to help improve fuel economy and lower the industry’s impact on the environment. The thermo-mechanical properties of epoxy-based composites with almond shells are studied at five different weight fractions (10%, 20%, 30%, 40% and 50%). Alkali (NaOH) was used to modify the surface characteristics of almond shells, and the results were examined in terms of their tensile strength, chemical interactions, and thermal stability. Tensile testing, Fourier Transform Infrared Spectrometry (FTIR), and Thermo-Mechanical Analysis (TMA) were used to study the materials in detail. The results demonstrate the significant benefits of the alkali treatment. Tensile strength was markedly improved, with treated composites showing enhancements of up to 38.5% at a 10 wt% fraction (150 µm particles) compared to their untreated; the optimal formulation (20 wt%, 150 µm) achieved a peak tensile strength of 27.50 MPa. Thermo-Mechanical Analysis (TMA) revealed a dramatic increase in stiffness, with the peak modulus of treated samples increasing by over 239% in certain configurations. Fourier Transform Infrared Spectrometry (FTIR) confirmed the chemical basis for these improvements, showing the successful removal of amorphous hemicellulose and lignin from the filler surface. These findings highlight that composites reinforced with NaOH-treated almond shells are a high-performance, lightweight, and eco-friendly material suitable for various automotive applications. Field Emission Scanning Electron Microscopy revealed that NaOH surface treatment significantly enhanced interfacial bonding and particle dispersion.

In the field of engineering, 3D printers are indispensable due to their high precision. This study focuses on the construction and optimization of a 3D printer using aluminum T-slotted bars for the frame, Raspberry Pi 4 for control, and Lightburn software for image printing and machine control. After assembling the main components and programming with Marlin firmware, the machine was tested for vibration and noise reduction. The research compared the vibration of a diode laser and spindle during printing, revealing significantly lower vibration with the laser compared to the spindle. These findings demonstrate the effectiveness of the constructed 3D printer in reducing vibration and noise during operation.

Natural and hybrid composites are the preferred use at present and in the future in terms of enhancing environmental sustainability and reducing the use of non-biodegradable synthetic materials. From this perspective, vinyl ester reinforced chemically treated coconut and glass in powder, chopped, and fiber in weight fractions (20, 30, 40, and 50%) have been investigated to study their ability to absorb moisture by immersing them in water for 21 days and measuring their weight every day. The experimental density was less than the theoretical density across all samples, ranging from 0.249% in NSP at 40% weight fraction to 7.075% in NSF at 20% weight fraction. Additionally, the experimental density increased with the weight fraction, reaching a maximum of 1.406 g/cm ³ in hybrid NSP composites at a 50% weight fraction, making them suitable for structural applications requiring high density and moisture resistance. In addition, the chemical composition of the composites was explained through Fourier Transform Infrared (FT-IR) Spectroscopy. Based on these results, the water absorption showed that hybrid composites reduced moisture uptake by 45% compared to natural composites, with the lowest absorption recorded in glass-reinforced composites. Among the tested samples, six composites have the best-balanced combination (the lowest ability of moisture absorption with little void content) among 36 types; SP20 1.19% with void content 1.775%, SCH40 1.739% with void content 2.922% and NP50 2.5% with void content 0.690%.

To produce eco-friendly composite materials suitable for defence and structural components, it is necessary to investigate how the mechanical characteristics degrade with moisture absorption, which is affected by immersion time. This research examines the effects of moisture absorption on the mechanical properties of hybrid sugarcane/carbon reinforced polyvinyl butyral (PVB) composites, aiming to balance performance and sustainability for defence and structural applications. Various mechanical tests, including tensile, flexural, compression and Interlaminar shear strength (ILSS), with more focus on the moisture absorption for various stacking sequences of sugarcane and carbon, were employed to analyse property degradation. Furthermore, Fourier Transform Infrared Spectroscopy (FTIR) and morphology of the fracture surface under tensile stress were analysed to investigate the failure mode. Findings indicate that the fibre contents and layering configurations were shown to obviously influence the hybrid mechanical behaviours and the failure mechanisms of hybrid composites. The significant reduction in mechanical properties for the SCS composite can be attributed to the outer sugarcane layer being more affected by water absorption, resulting in up to 45% reduction in mechanical properties. Optimal stacking sequences and sugarcane content ratios are identified to achieve a balance between mechanical performance and sustainability goals, with potential applications in eco-friendly defence and structural materials, with configurations like CSC and CSCS demonstrating better resistance to water-induced degradation.

أصبحت طابعات الليزر خيارًا شائعًا للشركات والمكاتب المنزلية، ولكنها قد تسبب إزعاجًا كبيرًا. لكن يُمكن تحسين ضوضاء طابعات الليزر من خلال ضبط مكوناتها وتحليلها. للحد من الضوضاء التي تنبعث من طابعات الليزر ثلاثية الأبعاد، يُعتبر تحسين مكونات الطابعة أمرًا بالغ الأهمية. يُمكن تحقيق ذلك من خلال ضبط مكونات الطابعة وتحليل الضوضاء المتولدة عنها. في هذا البحث، تم تصميم وتصنيع طابعة ليزر تستخدم تقنية الطباعة ثلاثية الأبعاد للمواد المختلفة. تم استخدام لوحة البرمجة وRaspberry Pi 4 كنظام تحكم ولوحة ذكاء اصطناعي للتحكم في عملية الطباعة بالليزر. علاوة على ذلك، يُقدم هذا البحث طريقة لتحسين الضوضاء الصادرة من طابعات الليزر. تتضمن هذه الطريقة ضبط مكونات الطابعة وتحليل مستويات الضوضاء المتولدة. يُمكن تحقيق ذلك من خلال تعديل قيم السرعة والتسارع للجهاز دون التأثير على الدقة. تم قياس مستويات الضوضاء باستخدام جهاز قياس الضوضاء، وأظهرت النتائج أنه يُمكن تقليل الضوضاء بشكل كبير من خلال تعديلات في التسارع وبعض المكونات مثل محركات الحركة. تم مقارنة النتائج وتحليلها باستخدام برمجيات التحليل. استُخدمت نتائج الاختبارات لتحديد...

In the current research, tensile, flexural, and compression were done, as well as the effect of water absorption on dimensional stability, to study the effect of adding different weight fractions of Macadamia nutshell about (10, 20, 30, and 40 wt %) to Polyvinyl Butyral composites. Different average grain sizes of Macadamia nutshell (75 µm, 150 µm, and 300 µm) were used. In addition, both FTIR analysis and morphological observation of composites were conducted. Findings reveal that M7501 (10% filler, 75 µm) consistently achieves the highest mechanical properties, including tensile strength (35% higher), Young’s modulus (15% higher), toughness (40% greater), tensile strain (25% greater), flexural strength (29% higher), and compressive strength (20% higher) compared to M7504 (40% filler). Conversely, composites with larger particle sizes and higher filler content, such as M3004 and M1504, exhibited significant reductions in mechanical properties, with up to 43% lower flexural strength and 41.7% lower compressive strength compared to their counterparts with lower filler content. Higher filler contents exacerbated this issue by increasing the likelihood of particle clustering, which creates weak points and voids that compromise the structural integrity of the composite. Additionally, larger particle sizes (150 µm and 300 µm) showed more pronounced agglomeration and void formation compared to smaller particles (75 µm), further highlighting the challenges in achieving a homogeneous composite structure with larger fillers. SEM investigation demonstrated that increasing filler amounts led to noticeable particle agglomeration, aggregation and void formation, negatively impacts the composites, leading to weaker mechanical properties.