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Durability and Hardened Characteristics with SEM Analysis of Eco‑Efficient Self‑Compacting Concrete Partially Contained Waste Walnut Shell Particles as Fine Aggregate
(Springer Nature, 2023-07-23) Nahla Hilal; Hadi H. Edan; Nadhim Hamah Sor; Taher A. Tawfik
Substituting waste materials for natural aggregate in SCC can lead to the discovery of ecological building materials. Walnut shell (WS) is one of the agricultural byproducts that can be substituted for aggregate in SCC. In this study, WS was used as a replacement for fine aggregate in SCC by employing five different volume fractions ranging from 8 to 40% in incre ments of 8% while maintaining a constant percentage of limestone powder (10% by weight of cement). All SCC mixtures were evaluated for the fresh properties (slump flow, slump flow duration, V-funnel, L-box, and wet density) tests, hardened characteristics (compressive strength, splitting tensile strength, flexural strength, Schmidt rebound hammer, and ultrasonic pulse velocity) tests, scanning electron microscopy (SEM) analysis, and the effect of H2SO4 and MgSO4 solution with 5% concentration for one month period on the density, compressive and splitting tensile strengths. The hardened properties were performed at 28 and 56 curing periods. The results revealed that the workability and hardened properties of SCC mixtures decreased with increasing WS content, but the workability outcomes were within the standard specifications of SCC, except for the L-box test. The lowest compressive strength of 23.7 MPa was recorded for the mix containing 40% of WS, greater than the lower strength required for structural purposes. On the other hand, the density, compressive and splitting tensile strengths of all SCC mixes decreased after exposure period for both sulphate attacks. The investigation with SEM reveals that the increasing amount of WS produced more voids and less dense concrete compared to the control mix.
الايثار المالي لأغنياء الصحابة في عهد النبوة
(2024) م.م محمد حسن صالح المحمدي
كان الإسلام في بداية الدعوة ضعيفا وبطور التكوين ويحتاج الى المال لتثبيت دعائمه وتلبية متطلباته ووتقويته، لان اغلب اتباعه هم من الضعفاء والفقراء والعبيد في بداية الامر فقد شجع الإسلام على تحرير العبيد الذين دخلو الإسلام حديثا واعده واحدا من الاعمال الفاضلة وخصوصا بعد تعرضهم للتعذيب من اسيادهم مما دفع اغنياء الصحابة أمثال أبو بكر الصديق وعثمان بن عفان وعبد الرحمن بن عوف وغيرهم ان يؤثروا على هذه الطبقة المنعدمة في المجتمع المكي ويحررونهم من اسيادهم ومن جهة أخرى شجع الإسلام النفقة والصدقة على الفقراء والمساكين والضعفاء وفيما يخص الدعوة فقد اثرو بأموالهم فداء للاسلام ونصرة للدين فنجد منهم من انفق امواله كلها لتجهيز الجيوش كما فعل ابي بكر الصديق رضي الله عنه ومنهم من انفق نفقة عظيمة لم ينفق احد مثثلها كما فعل عثمان بن عفان رضي الله عنه
The Effect of Organizational Strategies on Physics Achievement Among Third-Grade Middle School Students
(2024) Etmad. N. Fayadh; Sameerah Adnan Thrther
The research aims to identify the effect of organizational strategies on the achievement in physics among third-grade middle school female students. The study is limited to third-grade middle school female students in Al-Anbar province for the academic year 2019–2020, covering the first five chapters of the first semester of the physics textbook for third grade. The research sample consisted of 60 students, with 30 students in the experimental group and 30 in the control group. Statistically, students who had previously failed were excluded to ensure equivalency due to their additional experience compared to their new peers. After applying the research tool and processing the data using appropriate statistical methods, the results showed significant differences between the average scores of the experimental and control groups in the achievement test following the application of organizational strategies.
ذكر الدولة العثمانية ببالد الروم ودولة الادارسة من سوس الى طرابلس من خلال مخطوط الفرائد المنتقاة من تاريخ صاحب حماة )نسخة الناسخ
(مجلة كلية التربية للبنات / الجامعة العراقية / العدد الرابع والعشرون )24( - السنة الحادية عشر– آذار 2024 م - الجزء الرابع )4 المجلد3( – التاريخ), 2024-03-11) م.م. سراب مجيد صالح عبدالله المحمدي
يتقصى هذا البحث سلاطين الدولة العثمانية ، وملوك دولة الادارسة ، وتعد الدولة العثمانية آخر دولة إسلاميه حكمت بالد المسلمين وواحدة من الدول الإسلامية الكبرى التي لعبت دو ارً في تاريخ الإنسانية عامة، وتاريخ العالم الاسلامي بصفة خاصة، أستمر حكمها حوالي ستمائة سنة ، وتعود أصولها الى الاتراك ، وقد بلغت أوج قوتها وعزها ومجد ها في القرنين السادس عشر والسابع عشر ، وامتدت دولتها لتشمل أهم قارات العالم ومنها قارة آسيا وافريقيا وأوربا ، وقد أطلقت عليها عدة تسميات منها السلطة العثمانية والدولة العلية ، اذ أصبحت قوى كبرى فكان لها شأن عظيم خلال العصر الحديث
Characterization and use of activated carbon synthesized from sunflower seed shell in the removal of Pb(II), Cd(II), and Cr(III) ions from aqueous solution
(Springer Nature, 2024-03-13) Nahla Hilal; Ibtihal A. Mawlood; Wahran M. Saod; Ahmed S. Al‑Rawi; Abdulsalam M. Aljumialy
In this work, carbon-based nanomaterials such as active carbon which is prepared from com mon sunflower (Helianthus annuus) seed shell, and the characterization of the activated carbon NPs were studied using FTIR (Fourier transform infrared spec troscopy), XRD, SEM, EDS, and DTA techniques. Activated carbon NPs have been used in the adsorp tion of Pb(II), Cd(II), and Cr(III) ions from the aque ous phase. The results showed the highest adsorption efficiency was 99.9%, 92.45%, and 98% for Pb(II), Cd(II), and Cr(III) ions respectively at a tempera ture of 25 °C, pH = 7–9, and a time of 60 and 180 min, in addition to the accordance of the adsorption models for activated carbon with the Freundlich iso therm model at the value of R2 (0.9976, 0.9756, and 0.9907) and Langmuir isotherm model (0.966, 0.999, and 0.9873) of the Pb(II), Cd(II), and Cr(III) ions,
The influence of nanosunflower ash and nanowalnut shell ash on sustainable lightweight self‑compacting concrete characteristics
(Springer Nature, 2024-04-24) Nahla Hilal; Nadhim Hamah Sor; , Marijana Hadzima‑Nyarko; Dorin Radu; Taher A. Tawfik
The absence of biodegradability exhibited by plastics is a matter of significant concern among environmentalists and scientists on a global scale. Therefore, it is essential to figure out potential pathways for the use of recycled plastics. The prospective applications of its utilisation in concrete are noteworthy. The use of recycled plastic into concrete, either as a partial or complete substitution for natural aggregates, addresses the issue of its proper disposal besides contributing to the preservation of natural aggregate resources. Furthermore, the use of agricultural wastes has been regarded as a very promising waste-based substance in the industry of concrete manufacturing, with the aim of fostering the creation of an environmentally sustainable construction material. This paper illustrates the impact of nano sunflower ash (NSFA) and nano walnut shells ash (NWSA) on durability (compressive strength and density after exposure to 800 °C and sulphate attack), mechanical properties (flexural, splitting tensile and compressive strength) and fresh characteristics (slump flow diameter, T50, V-funnel flow time, L-box height ratio, segregation resistance and density) of lightweight self-compacting concrete (LWSCC). The waste walnut shells and local Iraqi sunflower were calcinated at 700 ± 50 °C for 2 h and milled for 3 h using ball milling for producing NSFA and NWSA. The ball milling succeeded in reducing the particle size lower than 75 nm for NSFA and NWSA. The preparation of seven LWSCC concrete mixes was carried out to obtain a control mix, three mixtures were created using 10%, 20% and 30% NWSA, and the other three mixtures included 10%, 20% and 30% NSFA. The normal weight coarse aggregates were substituted by the plastic waste lightweight coarse aggregate with a ratio of 75%. The fresh LWSCC passing capacity, segregation resistance, and filling capability were evaluated. The hardened characteristics of LWSCC were evaluated by determining the flexural and splitting tensile strength at 7, 14 and 28 days and the compressive strength was measured at 7, 14, 28 and 60 days. Dry density and compressive strength were measured after exposing mixes to a temperature of 800 °C for 3 h and immersed in 10% magnesium sulphate attack. The results demonstrated that the LWSCC mechanical characteristics were reduced when the percentages of NWSA and NSFA increased, except for 10% NWSA substitution ratio which had an increase in splitting tensile strength test and similar flexural strength test to the control mixture. A minor change in mechanical characteristics was observed within the results of LWSCC dry density and compressive strength incorporating various NSFA and NWSA` contents after exposing to temperature 800 °C and immersed in 10% magnesium sulphate attack. Furthermore, according to the findings, it is possible to use a combination of materials consisting of 10–20% NSFA and 10–20% NWSA to produce LWSCC.
On the Post-Heat Behavior of Cement Mortar Containing Mechanically Modified Ground Coal Bottom Ash
(Salud, Ciencia y Tecnología – Serie de Conferencias., 2024-05-31) Nahla Hilal; Fadzli Mohamed Nazri; Haneen Abdel Jabar; Khairunisa Muthusamy; Rahimah Embong; Mohammad I. Al Biajawi
Coal is widely recognized as a significant and essential fuel source due to its capacity to undergo combustion and produce heat in many different regions worldwide. Over the course of many decades, there has been a notable rise in power usage among individuals, thus resulting in an upsurge in the utilization of coal. The growth of mankind has a parallel rising trajectory with the utilization of cement in the building industry, as well as a corresponding rise in cement manufacturing. These two phenomena significantly contribute to the escalation of carbon dioxide (CO2 ) emissions and the improper disposal of coal ash, both of which pose significant environmental hazards. Coal-fired thermal power plants generate many waste products from industry, including coal-bottom ash (CBA), which may be effectively used in the production of mortar or concrete. This practice not only promotes the adoption of sustainable construction materials but also encourages the utilization of these wastes. In contrast, it is worth noting that cement manufacture yields a significant quantity of carbon dioxide emissions, so exerting a detrimental influence on the ecosystem. The reduction of environmental deterioration may be achieved by substituting cement with waste products. The substitution of Portland cement with reutilized coal combustion products has the potential to provide significant environmental and infrastructural advantages. This study presents an experimental investigation into the post-heat performance of cement mortars including ground coal bottom ash (CBA). To achieve this objective, an investigation was conducted to assess the strength qualities, residual strength, and mass losses of mortar specimens. These specimens comprised varying proportions (10 %, 20 %, 30 %, and 40 %) of CBA as a substitute for cement. To perform the heating procedure, samples were subjected to temperatures of 200°C, 400°C, and 600°C, which corresponded to room temperatures. The findings indicate that the use of ground CBA up to a proportion of 20 % yields mortar with the maximum value of compressive strength compared with the control sample. The use of a substantial amount of ground CBA has been shown to produce the most significant reduction in mass and decrease in strength when subjected to high temperatures. As a result, the residual strength of concrete experiences a decrease of 33,65 % when exposed to a temperature of 600°C in conventional concrete while for CBA in concrete decreases around 40,9 %. In general, the integration of ground CBA alternatives as an alternative to cement would result in a decrease in the need for the manufacture of cement and the environmental pollution associated with CBA discharge.
A PROPOSED VISION FOR DEVELOPING AGRICULTURAL EXTENSION CENTERS IN CENTRAL IRAQ
(Society for the Advancement of Breeding Researches in Asia and Oceania (SABRAO), 2024-06-05) A.I. KHAMIS; N.S. ALI; J.M. SALEH
The research aimed to prepare a theoretical vision, including a set of proposed standards for developing work in Agricultural Extension Centers in the Central Governorates (Baghdad, Diyala, Babylon, Al-anbar, and Salah al-Din), within seven important guiding areas. Using the descriptive approach to conduct this study, the sample community included all agricultural extension workers working in research centers of central Iraq governorates, totaling 95 respondents. The two-part questionnaire served as a tool for collecting data from the respondents. The first part represented opinions of agricultural extension agents about the extent of application and adoption of suggested standards in the work of agricultural extension centers. Meanwhile, the second part included the respondents’ opinions about the degree of their approval of the proposal to develop the extension centers. The study concluded a large proportion of the respondents believe a weakness existed in the level of application of the recommended standards in the operation of the agricultural extension centers. It is evident in not adopting the principle of decentralization when formulating the goals of the extension centers.
Studying the usability of recycled aggregate to produce new concrete
(Faculty of Engineering, Cairo University (CUFE), 2024-06-11) Nahla Hilal; Ola Adel Qasim; Mohammad I. Al Biajawi; Nadhim Hamah Sor; Taher A. Tawfik
One of the most significant environmental issues worldwide is garbage, particularly waste from construction materials, which is generated in substantial numbers. How ever, in the building industry, the significant extraction of natural resources such as cement, natural sand, and natural gravel poses a critical environmental challenge, depleting these resources at an alarming rate. There are some solutions that devel oped countries are resorting to, namely the division of construction waste into groups, where it is reused under the name of recycling construction waste to produce new, environmentally friendly building materials. The aim of this research includes a labora tory process study as it includes the use of the following ratios: 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%, under the process of replacing coarse plain aggregates includ ing coarse recycled aggregates and studying the most important mechanical proper ties of concrete. This research was carried out using fresh concrete properties such as workability tests and hardened concrete properties such as compressive strength, splitting, and flexural tensile strength examined at the durations of 7, 14, and 28 days. The research includes the investigation of the three main properties of concrete. After conducting the tests, the results have shown that the main property of recycled concrete is lower strength than that of conventional concrete, but it can be said that it is within the limits that can be used for construction. The results also showed that com pared to normal aggregates, development in the recycled aggregate percentage rates reduces the operational workability of concrete. The research proved that the maxi mum decrease in compressive, flexural, and tensile strength, density and the slump were 19.4, 18.3, 19.6, 19.5, and 25.0% respectively compared to the control concrete samples. Keywords: Compressive strength, Flexural strength, Tensile strength, Natural aggregate, Concrete, Recycled material, Waste materials
الجارية عُريب ودورها في الخلافة العباسية(193هـ - 813م / 232هـ -861م)
(-مجلة نسق / مجلد (42) في 30 حزيران 2024 م -1445ه, 2024-06-30) م.م. سراب مجيد صالح عبدالله المحمدي; م.م. اسراء باسم محمد عباس المحمدي
يتناول هذا البحث القاء الضوء على شخصية مهمة كان لها أثر كبير ودور مهم خلال فترة الخلافة العباسية، وهي الجارية عريب اذ بدأت حياتها مثل كثير من النساء بسوق النخاسيين، فاشتهرت كثيراً، اذ انها تمتعت بصفات كثيرة، وكانت تجيد الغناء والشعر واتصفت بحسن الوجه والجمال فضلا عن ذلك انها كانت تجيد لعب الشطرنج والضرب على العود والطرب، وكان النخاسيين يحرصون على ان يدربوا جواريهم على اللغة وقول الشعر وحسن الأداء وسرعة البديهة، وجمال الصوت لذلك نلاحظ ان الجارية عريب لعبت دور واضح ومهم في حياة الكثير من الخلفاء العباسيين، فذاع صيتها بين الخلفاء وتقاتلوا على شرائها، فبدأت حياتها كجارية في قصور الخلفاء في عهد الخليفة الأمين ثم انتقلت بعد مقتله الى قصر الخليفة المأمون، ولقبت نفسها بعريب المأمونية، ثم انتقلت بعد وفاته بين الخلفاء واولادهم، اذ عاصرت عشرة من الخلفاء العباسيين كمغنية وشاعرة لهم لا كزوجة ، وتمتعت بمكانة ومنزلة عالية لديهم، ولكن بقي اسمها عريب المأمونية.
Mechanical performance of eco-friendly self-compacting concrete (SCC) mixtures and two-way slabs partially containing cement kiln dust as cement replacement and internally reinforced with waste plastic mesh
(Elsevier, 2024-08) Nahla Hilal; Ayad S. Aadi; Sheelan Mahmoud Hama; Weiwen Li; Nadhim Hamah Sor; Walid Mansour
A large quantity of cement kiln dust (CKD) is produced annually during the production of Portland cement. The majority of the produced CKD remains unused except in specific cases related to soil stabilization projects. The current research investigates the production of self-compacting concrete (SCC) mixtures, in which CKD is used as a substitute for cement in different weight proportions, 3 %, 6 %, 9 %, 12 %, and 15 %. The hardened mechanical properties of SCC, such as compressive strength, splitting tensile strength, and flexural strength, as well as the fresh state characteristics (i.e., slump flow diameter, T500, V-funnel, and L-box tests), were recorded and compared with the control mixture which was entirely cast using cement. Results revealed that with an increase in the CKD content beyond 6 %, the slump flow diameter of SCC mixtures significantly decreased. Also, the increase ratios in the V-Funnel flow time for self-compacting concrete mixtures, when replacing cement with CKD ratios of 3 %, 6 %, 9 %, 12 %, and 15 %, were 13.3 %, 30 %, 46 %, 58 %, and 66.7 % respectively, compared with the reference mixture. Additionally, the impact behavior of two-way SCC slabs cast using CKD ratios ranging from 3 to 15 % and internally strengthened using various patterns of recycled plastic mesh was inves tigated. Strengthening the SCC slabs using two layers of recycled plastic grids proved to be effective in preventing the projectile from penetrating the whole thickness of the SCC slabs, regardless of the CKD content.
The Impact Resistance of Fire Shooting for Self-Compacted Concrete Slabs Containing Ceramic Powder and Reinforced by Novel Waste Nylon Fiber
(Annales de Chimie - Science des Matériaux, 2024-08-04) Nahla Hilal; Aseel S. Mansi; Ayad S. Aadi; Taghreed Khaleefa Mohammed Ali; Haider A. Abdulhameed
In the present study, nylon waste fibers (NWF) were utilized for the first time to improve the impact resistance of self-compacting concrete (SCC) slabs against pistol shooting. Six ratios of NWF were used in the range of (0.25- 1.5 at an increment of 0.25) % with three different lengths (50, 70, and 90) mm for each ratio. The fresh properties, compressive strength, and Utara sonic pulse velocity (UPV) of SCC were also measured. The results indicate the positive role of NWF in improving compressive strength. However, the fresh properties are affected negatively by using NWF. The best impact resistance of the slab occurred when 1% of NWF with a length of 90 mm was utilized.
Effect of glass and nylon fibers on drying shrinkage of alkali activated blast furnace slag mortars
(Taylor & Francis, 2024-08-13) Nahla Hilal; Salih Taner Yildirim; Ahmet Kaan Yildirim
The environmental consequences of Portland cement (PC) manufacturing have prompted the exploration of alternative binders, such as the alkali activation of blast furnace slag (BFS), which is generated as a byproduct during the extraction of iron. While alkali-activated blast furnace slag (AAS) binders have some benefits over regular PC binders, they also suffer from disadvantages such as significant drying shrinkage. The study investigated the impact of Na dosage and curing conditions on alkali-activated blast fur nace slag mortar (AASM). The consistency of the specimens was tested for fresh, hardened properties, and was conducted. The optimum Na dosage and curing conditions were selected. In the second stage, 0.1% and 0.2% glass and nylon fibers were added to the selected optimum mortar. Consistency, fresh, mechanical, and durability properties tests were con ducted on the fiber mortars. The results showed that increasing the Na content increased the compressive and flexural strengths of AASM speci mens. Thermal curing provided high compressive and flexural strengths, whereas fiber addition reduced water absorption and drying shrinkage. The drying shrinkage value was reduced by 26.82 % for AASM specimens with 0.2 % nylon fibers by volume compared to AASM without fibers.
Study of effective removal of nickel and cobalt from aqueous solutions by FeO@mSiO2 nanocomposite
(Elsevier, 2024-08-15) Nahla Naji Hilal; Wahran M. Saod; Nisreen Jassam Alaallah; Ekhlas A. Abdulkareem; Mohammad I. AlBiajawi
In many regions of the world, water pollution from potentially harmful substances like nickel (II) and cobalt (II) ions is a recurring issue. The quality of rivers and lakes’ environments, wastewater discharge, and drinking water sources are all still significantly impacted by it. Many studies are focused on developing new treatment alterna tives since, although treatment is often necessary, it is not always possible or accessible in a particular setting. Nanotechnology provides significant potential for water treatment. Although it has been demonstrated that nanomaterials may effectively remove both different type from chemical pollutants—including organic and inor ganic—from contaminated source, their removal efficacy may be diminished by their propensity to flocculate. Iron oxide loaded with mesoporous silica (FeO@mSiO2) was effectively synthesized and characterized through the use of FTIR, SEM, TGA, XRD, and UV–visible spectral analysis. Tests and evaluations were conducted to de termine FeO@mSiO2 nanocomposite ability to remove nickel (II) and cobalt (II) from solution, and the ideal re moval conditions were determined at different condition Adsorption isotherms, Freundlich and Temkin isotherms to the data. FeO@mSiO2 composite material displayed significant efficacy in the removal of Ni and Co. The best removal rates were attained at pH 7 and 180-minute contact duration.
Design an efficient neural network for solving steady state problems
(Elsevier, 2024-09) Ashraf Adnan Thirthar; Luma N. M. Tawfiq; Kamal Shah; Thabet Abdeljawad
In this article, the mathematical model of steady state problems based on horizontal radial flow in homogenous confined aquifers has been presented. Then we design efficient neural network (ANN) to solve the equation in polar coordinates. A reliable unconstrained optimization method has been used as training algorithm to get high accuracy results. The results illustrated by contour maps. The new effective Levenberg-Marquardt method (NLM) has been implemented to solve the problem. A comparison between the training, testing and validation results has been presented. The weight of the ANN will be chosen such that satisfied local minimizer. Furthermore, the quadratic convergence of NLM has been proved. The results reveal that the suggested design is effective, time saver, and applicable for solving steady state problems.
أحكام رهــن الحــوالــة التجاريــة- دراســة مقارنــة
(مجلة كلية القانون للعلوم القانونية والسياسية - جامعة كركوك, 2024-11-01) م.م. مثنى فائز عبد; م.م. أحمد فائز عبد
ُعد الرهن من التصرفات القانونية الشكلية التي ترد على الحوالة التجارية، ويتم رهنها من خلال عقد الرهن الذي يُعقد بين المدين الراهن (المظهر) والدائن المرتهن (المظهر له) الذي يتطلب تحقق الشروط الموضوعية المتمثّلة بالرضا والمحل والسبب، فضلاً عن ذلك الشروط الشكلية المتمثّلة بالكتابة وانتقال الحيازة والتوثيق، ورهن الحوالة التجارية يرتب آثاراً قانونية سواء بالنسبة لطرفي العقد (المدين الراهن والدائن المرتهن) أو بالنسبة للغير الذي لم يكن طرفاً في عقــد رهـــن الحــوالة التجـــارية.
The modified predator–prey model response to the effects of global warming, wind flow, fear, and hunting cooperation
(Springer Nature, 2024-11-11) Ashraf Adnan Thirthar; Shireen Jawad; Muhammad Aqib Abbasi
Global warming has a serious impact on the survival of organisms. Very few studies have considered the effect of global warming as a mathematical model. The effect of global warming on the carrying capacity of prey and predators has not been studied before. In this article, an ecological model describing the relationship between prey and predator and the effect of global warming on the carrying capacity of prey was studied. Moreover, the wind speed was considered an influencing factor in the predation process after developing the function that describes it. From a biological perspective, the nonnegativity and uniform bounded of all solutions for the model are proven. The existence of equilibria for the model and its local stability is investigated. The proof that the model has no periodic solution is studied, and the backward Hopf bifurcation analysis of the positive equilibrium point. Through numerical results, we can analyze the impact of periodic and chaotic nature on the species population. Furthermore, to confirm the complex dynamics like bifurcation and oscillation the numerical simulation plays an important role. Furthermore, this also helps us to visualize the dynamic results of the model. Here, we also present different numerical outcomes in terms of other parameters.
Effects of predator cooperation in hunting and prey fear in a generalist predator–prey model that includes global warming phenomena
(Springer Nature, 2024-11-26) Ashraf Adnan Thirthar; Bipin Kumar; Sushil Kumar Verma
Emissions of greenhouse gases from humanactivities are the cause of global warming. Some of the repercussions include habitat loss, altered competitive relationships, and temperature and ecosystem changes that are too large for migration. According to this study, the carrying capacity is affected by global warming. Furthermore, by developing a predation function that accounts for the effects of hunting cooperation and global warming, its influence on predation has been examined. The interaction between prey, predators, and global warming is described by a system of ordinary differential equations that includes the components listed above. During our investigation, we examine the existence and stability of equilibrium points, which reveals the model’s dynamic behaviors. Our model shows a range of bifurcations, including Hopf, transcritical, and saddle-node bifurcations, which mark critical shifts in system dynamics. To confirm these bifurcations, we derive and verify transversality conditions. Additionally, we construct one- and two-parameter bifurcation diagrams to visualize stability changes across the parameter space, identifying regions with distinct steady states and dynamic behaviors. Notably, our model also exhibits switching behavior, where shifts in parameters lead to transitions between different dynamic states, highlighting the complexity and richness of prey-predator interactions.
المركز القانوني لمحكم الطوارئ
(مجلة الكوفة للعلوم القانونية والسياسية, 2024-12) أ.م.د مجيد أحمد ابراهيم; م. نور حسين علي
ان نظام التحكيم الطارئ من الاليات الحديثة لفض المنازعات التجارية بعيدا عن قضاء الدولة خاصة في بيئة الاعمال التجارية التي تتطلب خصوصية في التعامل والسرية في حل المنازعات والسرعة في اجراءات التحكيم ومحكم الطوارئ هو المحور الاساسي في عملية التحكيم لمل له من دور فعال في حل المنازعات المعروضة عليه بعيدا عن اجراءات القضاء العادي واتخاذ التدابير المؤقته قبل تشكيل الهيئة التحكمية
Durability and hardened characteristics of cement mortar incorporating waste plastic and Polypropylene exposed to MgSO 4 attack
(Elsevier, 2024-12) Nahla Hilal; Osamah Mohammed G. Al-Kerttani; Sheelan Mahmoud Hama; Nadhim Hamah Sor; Qais Sahib Banyhussan; Taher A. Tawfik
Annual waste plastic disposal has grown, harming nature. Utilising this waste in concrete production may help preserve building resources. This study tested cement mortar with polyvinyl chloride (PVC) and polypropylene (PP) substituted for sand aggregate at 0, 5, 10, 15, and 20 %. The samples were nevertheless exposed to a 10 % and 20 % MgSO4 solution for a month. The properties of both fresh and hardened materials under these cir cumstances have been evaluated and contrasted with those evaluated under typical circumstances. For mixes including PP and PVC, the flow diameter increased. The rounded plastic particles provided fewer contact surfaces and less friction among mixtures, which reduced water consumption and improved workability, leading to an increase in slump flow. As the amount of plastic aggregate increases, the compressive strength decreased. Moreover, this pattern might be explained by the weakening of the bond between the surfaces of the plastic aggregate and cement paste. The hydration of cement may also be hampered by the hydrophobic properties of plastic aggregate. Like compressive strength, the splitting tensile strength decreased as the replacement level of plastic ratio increased regardless of its type under all conditions (normal and exposing to MgSO4 ). PP and PVC fine aggregate in mortar increases sorptivity under all situations. Following screening, those circumstances and PVC have the most impact on compressive strength. increasing PVC and PP at 10 % for each of them leads to lower values of compressive and tensile strength. An optimization process was implemented to determine the optimum value of PVC, PP, and MgSO4 . It shows that using PVC of 3.9 %, PP of 10.1 %, and MgSO4 leads to maximum compressive and tensile strength with the minimum cost and CO2 emissions.