Alrafidain University College

ABSTRACT Enhancing heat transfer during the charging process of latent heat thermal energy storage (LHTES) systems remains a critical challenge due to the low thermal conductivity of phase change materials. This study presents an experimental and numerical investigation of a finned LHTES unit employing paraffin RT82 enhanced with 0–10 vol.% Al 2 O 3 nanoparticles. Longitudinal fins and multiple heating configurations were examined to elucidate their effects on conduction‐ and convection‐dominated heat transfer during melting. A transient enthalpy–porosity model was developed and validated against experimental data, with temperature deviations remaining within 3%. Dual‐sided heating provided the most uniform thermal distribution, achieving complete melting within 4 h at an HTF inlet temperature of 90°C and a mass flow rate of 37.5 kg/min. The dispersion of Al 2 O 3 nanoparticles increased the effective thermal conductivity of the PCM to 0.265 W/m·K at 10 vol.%, accelerating heat diffusion and reducing charging time, particularly under external and dual‐sided heating. Axial temperature measurements revealed reduced thermal gradients due to the combined effects of fin‐assisted conduction and nano‐enhanced heat transport. Under transient HTF inlet conditions, optimal thermal response occurred at a flow rate of 29.4 kg/min, reflecting a balance between convective transport and residence time. A nearly constant HTF inlet–outlet temperature difference during melting indicated stable latent heat absorption. The analysis is limited to charging behavior under controlled conditions. Uncertainty analysis confirmed high measurement reliability, with onset and peak melting temperatures of 70.13°C ± 0.15°C and 82.18°C ± 0.05°C, respectively.

The increasing demand of a wireless s connection and spectrum space has introduced CRNs into the vocabulary of energy-efficient communication. The article presents a unified dynamic spectrum management system in CR networks to support adaptive sensing, utility-based access, real-time power management and predictive channel allocation. Unlike the current schemes which have been based on modular component-level optimization, the current architecture emphasizes on cross-layer design to realize greater energy efficiency, less cross-layer interference, and more reliable networks overall deployment environments. Adaptive sensing module allows the nodes to adjust their detection threshold according to the variance of noise and signal-to-noise ratio and as such the node consumes less energy but retains spectral awareness. The utility function controlling the spectrum access mechanism takes into consideration the energy of the node, the latency of the node and the history of transmission in order to provide a fair and effective allocation of resources. A dynamic power control model is used to set the levels of power to attain desired SNRs and to eliminate interference. Moreover, ARIMA-GRU integrated predictor is aimed at forecasting channel availability and prevent overlapping sensing slots. Experimental outcomes on urban, rural, industrial, and mixed-network deployment conditions prove the enhancements of energy saving, throughput and lifetime of the network. The system is highly robust in different environments and is a scaled and workable solution to CRNs. Such outcomes will enhance self-sustaining wireless systems that can work in a spectrum limited and power constrained environment.

The article addresses the linkage between sustainable branding and experiential marketing and how they can be utilized to influence brand equity in consumers today. Even though the previous studies have isolated the strategies separately, there has been minimal empirical evidence to indicate the integration of the strategies and how they will impact on the loyalty, advocacy and the brand trust. The research design will be mixed research design; that is, the researcher will utilize both survey research data (1,200 consumers) and 25 in-depth interviews to determine the independent and interactive impact. Hierarchy regression and interaction models reveal that the effects of sustainability practices and experiential marketing on the brand equity are positive; more so, a combination of the two has a significant impact as compared to each of the two. The final customer loyalty, Net Promoter Scores, and trust was achieved through sustainable brands as a part of the immersive consumer experiences. The further expectations of qualitative sentiment analysis are that experiential interfaces can render sustainability initiatives more legitimate and emotionally connected, and the level of skepticism is not so high concerning greenwashing. The study will be an addition to the theory of brand equity as well as the existing sustainability and experiential marketing theories because it empirically models the connection between sustainable branding and experiential engagement. The findings make a recommendation to managers who would wish to establish long term brand equity in the responsible and touchable market through integrating sustainability commitments in the meaningful customer experience.

ABSTRACT Thermal energy storage (TES) systems play a vital role in enhancing energy efficiency and reducing dependence on nonrenewable resources. This study investigates the synergistic integration of triangular fins and nanoparticle‐infused phase change materials (PCMs) to enhance heat transfer in a large triplex tube heat exchanger (TTHX). Numerical simulations, conducted using ANSYS Fluent 15 software, supported by experimental validation with an average deviation of around 2%, were used to evaluate fin placement, fin geometry, and the effect of 10 wt% Al 2 O 3 nanoparticles into the PCM. Results show that triangular fins significantly improve heat transfer, with external fins providing the fastest melting. The addition of nanoparticles increases thermal conductivity by nearly 25% and, when combined with optimized fins, reduces the melting time to 163 min. Energy‐performance analysis confirms that nano‐PCM accelerates charging due to enhanced conductivity, while pure PCM retains higher total stored energy. The optimal configuration, where eight external copper fins of 141 mm length and an 18% aspect ratio, delivered the best overall performance. These findings demonstrate that combining fin‐geometry optimization with nanoparticle enhancement substantially improves TES efficiency. The proposed approach is well‐suited for solar thermal systems, industrial waste‐heat recovery, and compact TES applications.

In this study, we have investigated Tsallis entropy of a multivariate controlled autoregressive fractional integrated moving average (MCARFIMA) system. A characteristic function of this system state is derived using the corresponding its residual characteristic functions. Furthermore, an analytical expression for the Tsallis entropy of system process is established under independent condition between the control process and moving average. An algorithm is proposed to calculate the values of Tsallis entropy of system process when it is influenced by Gaussian and Cauchy processes. The results are discussed and analyzed to demonstrate the fractional integrated on the system’s informational structure and dynamical behaviour. Finally, an example is given to illustrative the proposed algorithm and information behaviour of proposed system under Gaussian process.

Objective: Human oocytes collected for in vitro fertilization (IVF) vary in morphologic features and measurements. This study aimed to describe the morphology of human oocytes that failed to cleave after intracytoplasmic sperm injection (ICSI). Materials and Methods: Oocytes that failed to cleave post-ICSI were collected from IVF cycles. The oocytes were microscopically examined and the cytoplasmic diameter, zona pellucida thickness, perivitelline space (PVS) size, and first polar body (PBI) size were measured. The granularity pattern of cytoplasm; the color of cytoplasm; the presence of smooth endoplasmic reticulum (sER) aggregates, vacuoles, refractile bodies, and pronuclei; and, the status of polar bodies were all recorded. Results: A total of 142 oocytes were analyzed. The mean cytoplasmic diameter was 119.15±9.06 μm (range: 90.66-137.79 μm). The mean zona pellucida thickness was 19.29±3.69 μm (range: 12.86-33.69 μm). The mean PVS size was 3119.08 μm2 (range: 765-6448 μm2). The mean PBI size was 225.48±106.03 μm2 (range: 53.56-703.65 μm2). The cytoplasm showed fine (42.7%), dispersed (40.3%), central (14.5%), and uneven (2.54%) patterns of granulation. Other cytoplasmic abnormalities included refractile bodies (33.3%), sER aggregates (5.6%), vacuoles (5.6%), and dark cytoplasm (14.5%). A significant inverse correlation was found between the oocyte cytoplasmic diameter and PVS size. Conclusion: The morphologic abnormalities in oocytes that failed to cleave after ICSI are not significantly different from those observed in the general population of human oocytes. The oocyte cytoplasmic diameter was found to significantly inversely correlate with PVS size.