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INNOVATING DAIRY ALTERNATIVES: THE PRODUCTION AND EVALUATION OF PLANT-BASED YOGURT SUBSTITUTES
(An-Najah National University, 2025-02-26) Ibrahim, Ayah
Background
The demand for plant-based food alternatives has increased in recent years, driven by growing health consciousness, and environmental concerns. Among these alternatives, plant-based yogurt has become increasingly popular as a dairy substitute.
Objectives
The primary objective of this study is to evaluate the impact of blending four distinct plant-based milk varieties (oat milk (OM), almond milk (AM), coconut milk (CM), and quinoa milk (QM)) at varying concentrations on the physicochemical properties and sensory and nutritional characteristics of plant-based yogurt following fermentation with lactic acid bacteria.
Methodology
Various plant-based milks were selected for yogurt production and blended at different ration (T1: 30% OM, 30% AM, 20% CM, 20% QM, T2: 30% OM, 20% AM, 40% CM, 10% QM, T3: 50% OM, 25% AM, 15% CM, 10% QM, T4: 30% OM, 30% AM, 10% CM, 30% QM, T5: 25% OM, 20% AM, 35% CM, 20% QM). The blended plant-based milk were fermented by using (Lactobacillus Bulgaricus and Streptococcus Salivarius subsp. Thermophilus) at 45°C for 6 h. To avoid the Syneresis phenomena stabilizers, pectin and xanthan gum and their mixture was added. The quality of the milk was assessed through pH measurements, total titratable acidity, and zeta potential particle size and polydispersity index were also measured to ensure the stability of the formulations. Blended plant-based yogurt were evaluated for their viscosity and sensory evaluations and acceptability index. Moreover, the nutritional composition of the blended plant-based yogurts was analyzed.
Results
The plant-based milk was successfully extracted and blended in different ratios. Fermentation ended when the pH reached 4.6. Before fermentation, the acidity ranged from 0.04% to 0.6% as lactic acid, increasing to 0.15%–0.2% during fermentation. T1 had the highest acidity due to its 30% oat and 30% almond milk, while T2 had the lowest with 40% coconut milk and 30% oat milk.
Stabilizer addition influenced zeta potential and particle size. Xanthan gum alone significantly improved zeta potential and reduced particle size in T1 and T2 compared to pectin alone or their combination. However, pectin and xanthan gum together further reduced particle size and enhanced stability in T3, T4, and T5. T5, with 35% coconut and 25% oat milk, was the densest and thickest, whereas T1 had the lowest viscosity.
Sensory analysis showed that T3 and T5 scored highest in appearance and viscosity, while T5 had the highest overall acceptance. Nutritionally, T1 had the lowest calorie content (49 kcal), while T1, T3, and T4 had the highest protein content (1.2%–1.3%).
Discussion
Higher acidity in T1 is likely due to increased fermentable sugars in oat and almond milk, while T2's lower acidity may be attributed to coconut milk’s lower sugar content. Stabilizers influenced texture, with xanthan gum improving stability and the pectin-xanthan combination further enhancing viscosity.
Sensory results aligned with physicochemical findings, with T5’s balanced composition (coconut, oat, almond, quinoa) yielding optimal mouthfeel and texture, leading to higher acceptance. The low-calorie content of T1 may appeal to health-conscious consumers, while T1, T3, and T4’s higher protein content suggests nutritional benefits. Overall, formulation significantly affected fermentation, stability, and acceptability, highlighting the potential of optimized plant-based yogurt.
Conclusions
In this study, oat, almond, coconut, and quinoa milk were combined to successfully create blended plant-based yogurt. It is possible that this plant-based yogurt will be a good substitute for dairy yogurt, especially for customers who are vegan, lactose intolerant, or intolerant to dairy proteins. Upgrading formulations for commercial use and increasing production should be the main goals of future research.
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THE IMPACT OF DEMAND SIDE MANAGEMENT ON THE UTILIYU ACTIONS FOR IMPROVING THE OPERATION OF DISTRIBUTION SYSTEMS CONSISTING PV GENERATOR
(An-najah national university, 2025-02-04) Hanhan, Malaka
This thesis investigates the impact of demand-side management (DSM) strategies on utility actions for improving the operation of distribution systems with high photovoltaic (PV) penetration. A case study was conducted using OpenDSS software, applying the IEEE 30-bus test network. A 50 MW PV system was integrated into bus 21, demonstrating its ability to reduce total electrical losses in transmission lines from 9308.34 kW to 7742.83 kW.
Meanwhile, the study examined the application of various DSM strategies to further enhance network performance after hosting the PV system. Direct Load Control (DLC) reduced network losses to 5365.5 kW, while the Time-of-Use (TOU) tariff strategy significantly reduced losses to 3736.9 kW. Additionally, the Conservation Voltage Reduction (CVR) strategy improved overall network voltage profiles, particularly decreasing the voltage at bus 21 from 1.0524 p.u. to 1.0442 p.u. and at bus 11 from 1.0819 p.u. to 1.0748 p.u.
The hosting capacity analysis revealed that increasing PV penetration initially reduced electrical losses, with significant reductions observed at penetration levels of 15 MW, 30 MW, 50 MW, and 70 MW, corresponding to losses of approximately 9830 kW, 8000 kW, 7000 kW, and 5800 kW, respectively. However, beyond a hosting capacity of 70 MW, further increases in PV penetration led to a rise in losses, reaching 7900 kW at 150 MW and exceeding 12,200 kW at 200 MW. The use of DSM strategies effectively mitigated these losses even at higher penetration levels. For instance, DLC reduced losses to approximately 6000 kW, and TOU reduced them further to 5000 kW at a 200 MW PV hosting capacity. These findings highlight the critical role of DSM strategies in enhancing the operational efficiency and reliability of distribution systems with high PV integration
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NEBRAS: A RAG-BASED QUESTION ANSWERING SYSTEM FOR ISLAMIC AND LEGAL GUIDANCE
(An-Najah National University, 2025-02-27) Al-Huwari, Samer
Question answering (QA) systems are essential tools in natural language processing (NLP), designed to interpret user queries and generate relevant answers. These systems have evolved over time from rule-based models to advanced machine-learning-based approaches. The emergence of the transformers architecture and Large Language Models (LLMs) have set the stage for modern QA systems.
LLMs have transformed QA by leveraging vast datasets to generate human-like responses across various domains and their ability to understand complex linguistic patterns. However, LLMs often generates plausible but incorrect answers particularly in specialized domains like law and religion where accuracy is critical. This phenomenon is known as “hallucination”. The risk of “hallucination” is increased when dealing with a complex language like Arabic. Arabic language, with its rich morphology, diverse dialects, and its dependency on diacritics, present significant challenges for LLMs primarily trained on Western languages.
Fine-tuning LLMs for domain-specific tasks is time-intensive, and computationally-expensive, given their massive parameters size, demanding innovative approaches to mitigate the LLMs hallucination issue without extensive re-training.
This thesis introduces Nebras, a generic multi-domain QA system leveraging a Retrieval-Augmented Generation (RAG) framework, LLM agents, and a hybrid retrieval approach. Nebras’s knowledge base can be dynamically extended by following simple guidelines and using its built-in mapping component, enabling it to adapt to any textual dataset. By employing an Agentic RAG pipeline, Nebras optimizes each processing stage using specialized agents. Furthermore, it utilizes pre-trained LLMs without fine-tuning, enhancing scalability and reducing computational costs.
Experimentation results demonstrated Nebras’s performance in Arabic domain-specific QA. In the Islamic fatwa domain, it achieved a BERTScore-F1 of 70.94%, a METEOR of 13.49%, with 9 accepted fatwas compared to only 7 accepted from GPT-4o. In the university help-desk domain, Nebras achieved a BERTScore-F1 of 75.80%, METEOR of 40.20%, and BLEU of 9%, significantly outperforming the BLEU score of 2.3% from GPT-4o's. These results highlight Nebras's ability to enhance factual accuracy, confirming its potential as a scalable Arabic QA solution.
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THE ASSOCIATION BETWEEN WAR RELATED AND POLITICAL POSTS IN SOCIAL MEDIA AND MENTAL HEALTH OUTCOMES AMONG PALESTINIANS:THE MEDIATING ROLES OF RESILIENCE, SOCIAL SUPPORT AND RELIGIOSITY
(An-Najah National University, 2025-02-27) Amireh, Balqis
The current study investigated the correlation between war-related political posts on social media and mental health outcomes and whether social support, religiosity, and resiliency mediate the correlation between the two variables among Palestinians living in society during the war era.
The study sample consisted of 431 Palestinian adults, consisting of 112 men and 319 women, and were recruited using probabilistic convenience sampling methods in the region of historical Palestine territories.
The study suggests a positive correlation between war-related political posts in social media (WRP-SM) with depression, stress, and anxiety and a negative correlation between resilience and mental health outcomes. Social support, resiliency, and religiosity mediated the correlation between war-related political posts on social media and mental health outcomes. The study identified substantial variations in mental health scores among Palestinians, with females displaying higher levels of depression, stress, anxiety, and overall mental health. Married individuals also reported higher resilience, social support, and religiosity scores. The findings highlight the need for mental health interventions for women, resilience building programs for single individuals.
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POTENTIAL SOURCES AND MITIGATION MEASURES FOR NITRATE CONTAMINATION USING GIS AND GROUNDWATER VULNERABILITY ANALYSIS: A CASE STUDY OF YABAD EASTREN WELL (PALESTINE)
(An-Najah National University, 2025-02-04) Asaf, Ahmad
The main source of fresh water for Palestinians is groundwater. Monitoring and evaluating its quantity and quality are essential. Recent research has shown that the nitrate contamination of the Eocene Aquifer's (EA) continues to trend upward. High fertilizer use, wastewater seepage are the main cause of nitrate contamination of groundwater. The problem has appeared in Yabad Eastern Well, where the nitrate concentration exceeds the allowable limit according to World Health Organization (WHO) and Palestinian guidelines. This research aims to identify the source of nitrate contamination for the well and to recommend the most relevant management options.
It is important to understand this problem by employing the proper methodology. The methodology consists of five steps, starting with studying the historical nitrate contamination of the well. Samples taken from the surrounding wells show that the nitrate concentration is below the Maximum Contamination Level (MCL), and this indicated that the problem had been limited to the well. The study area relevant to the well was determined based on many considerations in order to figure out the contamination occurrence. The research analyzed the groundwater flow direction to determine upstream and downstream areas using ArcGIS. The vulnerability of groundwater to contamination was identified to determine the potential locations of access for the contaminants to aquifer. The assessment of vulnerability was done by using the Geology, Overlying materials, Depth to groundwater (GOD) method.
By evaluating the variables affecting contamination at the well, different layers were overlaid. Each layer represents a specific variable, such as groundwater flow direction, vulnerability, and land use. This process helped identify the areas most exposed to contamination. Activities in these areas were classified based on their potential to pollute the aquifer with nitrate. The contamination pathways were also analyzed.
The results show that the old town was the most vulnerable location within the study area. This area suffers from high population and poor sewer system. Finally, this research recommends establishing a sewer network. This research suggests utilizing the isotopic method for future studies related to this case to better track the contamination sources for Yabad Eastern Well.