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Biochar is a porous, high-surface-area, black carbon-rich product that offers a cost-effective and environmentally friendly option to replace conventional charcoal. However, its specific structure and limited biodegradability pose challenges for its widespread applications. Photocatalysis is suggested as an alternative approach to harness solar energy and transform it into solar fuels. Interestingly, nanomaterials-based photocatalysts with tailored energy band properties and non-toxic characteristics, high surface areas, enhanced stability, and tunable pore sizes, have gained attention for their potential in diverse applications. Therefore, existing research on biochar-based photocatalysis systems (BBPs) aims to address different environmental issues. Interestingly, BBPs offer benefits such as excellent electrical conductivity, versatile functional groups, large surface area, and multiple surface-active sites, promoting high charge mobility, electron reservoir, superior charge separation, and small bandgap. This review provides a comprehensive overview of BBPs developments, including synthesis methods and properties. The fusion of BBPs is used in CO2 conversion, photocatalytic H2 generation, CO2 reduction, pollutants, dyes, and pharmaceutical degradation. Although the intermarriage of BBPs has potential benefits, their effectiveness may be compromised when modified photocatalysts are incorporated, which may negatively influence carrier generation efficiency and overall performance. Therefore, there is empty room for further research on their physical properties, effectiveness, long-term stability, and reusability of BBPs.

Neuroleptic malignant syndrome (NMS) is a severe adverse reaction associated with neuroleptic or antipsychotic drugs. This case report discusses a 43-year-old man with a history of bipolar disorder and polysubstance abuse who presented with altered mental status, autonomic dysfunction, and muscular rigidity. The patient had recently started on ziprasidone, a second-generation antipsychotic, leading to an atypical presentation of NMS. Unlike classic findings associated with NMS induced by first-generation antipsychotics, this case lacked high fever, lead pipe rigidity, or elevated creatine kinase levels greater than 1000 on initial presentation. The delay in diagnosis was attributed to the milder symptoms and absence of typical findings, resulting in extensive diagnostic workup and interventions. The patient responded positively to treatment with lorazepam based on the Woodbury severity stage guidelines. This case underscores the complexity of diagnosing NMS induced by second-generation antipsychotics and highlights the need for awareness and tailored treatment approaches for atypical presentations.

In this study, a Floating Parallel Marine Robot (FPMR) is studied while it is subjected to external forces generated by the sea waves. Two FPMR cable-bundles’ configurations are used. The 6–6 Stewart-Gough parallel manipulator configuration is compared with a new cable-bundles’ configuration called 6–3-3 FPMR. The effect of changing cable-bundles’ configuration is explored to enhance the workspace and the dynamic behavior of the FPMR. This study is performed using six DOFs FPMR having twelve cables i.e. 6 bundles. Over the FPMR workspace, the dynamic response and platform stiffness are investigated. The workspace and the dynamic analysis of FPMR are enhanced using the new 6–3-3 cable-bundles’ configuration.

Abstract Platelets play a crucial role in cancer and thrombosis. However, the receptor-ligand repertoire mediating prostate cancer (PCa) cell-platelet interactions and ensuing consequences have not been fully elucidated. Microvilli emanating from the plasma membrane of PCa cell lines (RC77 T/E, MDA PCa 2b) directly contacted individual platelets and platelet aggregates. PCa cell-platelet interactions were associated with calcium mobilization in platelets, and translocation of P-selectin and integrin αIIbβ3 onto the platelet surface. PCa cell-platelet interactions reciprocally promoted PCa cell invasion and apoptotic resistance, and these events were insensitive to androgen receptor blockade by bicalutamide. PCa cells were exceedingly sensitive to activation by platelets in vitro, occurring at a PCa cell:platelet coculture ratio as low as 1:10 (whereas PCa patient blood contains 1:2,000,000 per ml). Conditioned medium from cocultures stimulated PCa cell invasion but not apoptotic resistance nor platelet aggregation. Candidate transmembrane signaling proteins responsible for PCa cell-platelet oncogenic events were identified by RNA-Seq and broadly divided into 4 major categories: (1) integrin-ligand, (2) EPH receptor-ephrin, (3) immune checkpoint receptor-ligand, and (4) miscellaneous receptor-ligand interactions. Based on antibody neutralization and small molecule inhibitor assays, PCa cell-stimulated calcium mobilization in platelets was found to be mediated by a fibronectin1 (FN1)-αIIbβ3 signaling axis. Platelet-stimulated PCa cell invasion was facilitated by a CD55-adhesion G protein coupled receptor E5 (ADGRE5) axis, with contribution from platelet cytokines CCL3L1 and IL32. Platelet-stimulated PCa cell apoptotic resistance relied on ephrin-EPH receptor and lysophosphatidic acid (LPA)-LPA receptor (LPAR) signaling. Of participating signaling partners, FN1 and LPAR3 overexpression was observed in PCa specimens compared to normal prostate, while high expression of CCR1 (CCL3L1 receptor), EPHA1 and LPAR5 in PCa was associated with poor patient survival. These findings emphasize that non-overlapping receptor-ligand pairs participate in oncogenesis and thrombosis, highlighting the complexity of any contemplated clinical intervention strategy.

Abstract Background Delirium is a highly prevalent and morbid syndrome in mechanically ventilated intensive care unit (ICU) patients. Music is a promising non-pharmacological intervention with beneficial effects on anxiety and stress, while its effects on delirium duration and severity are not well understood. Methods/design Our study is a two-arm, randomized parallel-group, clinical trial to evaluate the efficacy of music intervention compared to a silence-track attention control on delirium/coma duration in mechanically ventilated critically ill older adults. One hundred sixty mechanically ventilated adults 50 years of age or older will be randomized to one of two arms within 72 h of ICU admission: (1) 1-h music listening sessions twice daily through noise-canceling headphones, or (2) 1-h sessions of a silence track twice daily through noise-canceling headphones. Our primary aim is to compare delirium/coma-free days after randomization during the 7-day study intervention phase using the Confusion Assessment Method for the ICU (CAM ICU) and the Richmond Agitation Sedation Scale (RASS) for delirium and coma. Secondary outcomes include pain and anxiety evaluated twice daily during the intervention phase and throughout the duration of ICU stay using the Critical Care Pain Observation Tool (CPOT) and visual analog scale-anxiety (VAS-A). Enrolled participants will be followed after hospital discharge to further measure cognition as well as screening for depression and anxiety using the following telephone-based instruments: Indiana University Telephone-Based Assessment of Neuropsychological Status (IU TBANS), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7). Discussion This randomized clinical trial will measure the efficacy of a music listening intervention for delirium and coma duration early in the intensive care unit among older adults. Trial registration. ClinicalTrials.gov. NCT04182334 .

Fresh water is one of the prime necessities of a society; however, its availability is becoming a major concern with the increasing population. There are not enough sources of fresh water at present due to the high rate of population increase. Many regions worldwide face limited access to fresh water. Given economic limitations, there is an urgent need to create and market technologies enabling households to generate their fresh water. In areas with abundant solar energy and proximity to seawater or well-water sources, solar still technology, if developed and commercialized, offers a cost-effective solution for freshwater needs. Thus, the current study is focused on exploring the potential of solar stills for producing fresh water. A single-slope solar still is designed, fabricated and experimentally tested for the production of fresh water. The results of the analysis indicate a maximum production of 2.88 L/day with an energy efficiency of 52.42% and an exergetic efficiency of 7.04%. Overall, the current study reveals significant potential in utilizing solar stills for producing fresh water, which could be increased further if research is conducted on modifying its basic design to increase its productivity.

Nano-fertilizers are superior to conventional fertilizers, but their effectiveness has not yet been adequately explored in the field of agriculture. In this study, silver nanoparticles using leaves extract of an Alnus nitida plant were synthesized and further doped with urea to enhance the plant biomass and metabolic contents. The synthesized Alnus nitida silver nanoparticles (A.N-AgNPs) and urea-doped silver nanoparticles (U-AgNPs) were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy, Powder X-ray Diffraction, and Energy Dispersive X-ray. The wheat seeds were grown in media under controlled conditions in the plant growth chamber. The effectiveness of nanoparticles was studied using different A.N-AgNPs and U-AgNPs concentrations (0.75 μg/ml, 1.5 μg/ml, 3 μg/ml, 6 μg/ml, and 15 μg/ml). They were compared with a control group that received no dose of nanoparticles. The plant biomass, yield parameters, and wheat quality were analyzed. The effect of silver nanoparticles and U-AgNPs were examined in developing wheat seeds and their potency in combating biotic stresses such as nematodes, herbivores, fungi, insects, weeds and bacteria; abiotic stresses such as salinity, ultraviolet radiation, heavy metals, temperature, drought, floods etc. In the seedlings, six possible phytochemicals at a spray dose of 6 μg/ml of U-AgNPs were identified such as dihydroxybenzoic acids, vanillic acid, apigenin glucosidase, p-coumaric acid, sinapic acid, and ferulic acid whereas in other treatments the number of phenolic compounds was lesser in number as well as in concentrations. Moreover, various parameters of the wheat plants, including their dry weight and fresh weight, were assessed and compared with control group. The findings of the study indicated that A.N-AgNPs and U-AgNPs act as metabolite elicitors that induced secondary metabolite production (total phenolic, flavonoid, and chlorophyll contents). In addition, U-AgNPs provided a nitrogen source and were considered a smart nitrogen fertilizer that enhanced the plant biomass, yields, and metabolite production.

The Zika virus (ZIKV), which originated in Africa, has become a significant global health threat. It is an RNA virus that continues to mutate and accumulate multiple mutations in its genome. These genetic changes can impact the virus’s ability to infect, cause disease, spread, evade the immune system, and drug resistance. In this study genome-wide analysis of 175 ZIKV isolates deposited at the National Center for Biotechnology Information (NCBI), was carried out. The comprehensive mutational analysis of these isolates was carried out by DNASTAR and Clustal W software, which revealed 257 different substitutions at the proteome level in different proteins when compared to the reference sequence (KX369547.1). The substitutions were capsid (17/257), preM (17/257), envelope (44/257), NS1 (34/257), NS2A (30/257), NS2B (11/257), NS3 (37/257), NS4A (6/257), 2K (1/257), NS4B (15/257), and NS5 (56/257). Based on the coexisting mutational analysis, the MN025403.1 isolate from Guinea was identified as having 111 substitutions in proteins and 6 deletions. The effect of coexisting/reoccurring mutations on the structural stability of each protein was also determined by I-mutant and MUpro online servers. Furthermore, molecular docking and simulation results showed that the coexisting mutations (I317V and E393D) in Domain III (DIII) of the envelope protein enhanced the bonding network with ZIKV-specific neutralizing antibodies. This study, therefore, highlighted the rapid accumulation of different substitutions in various ZIKV proteins circulating in different geographical regions of the world. Surveillance of such mutations in the respective proteins will be helpful in the development of effective ZIKV vaccines and neutralizing antibody engineering.

Abstract The purpose of this research was to determine the efficacy of iron oxide nanoparticles (Fe3O4-NPs) using microalgal products as a plant growth stimulant and antifungal agent. The work was conducted with the phyco-synthesis and characterization of Fe3O4-NPs using 0.1 M ferric/ferrous chloride solution (2:1 ratio; 65 °C) with aqueous extract of the green microalga Chlorella K01. Protein, carbohydrate and polyphenol contents of Chlorella K01 extract were measured. The synthesized microalgal Fe3O4-NPs made a significant contribution to the germination and vigor index of rice, maize, mustard, green grams, and watermelons. Fe3O4-NPs also exhibited antifungal activity against Fusarium oxysporum, Fusarium tricinctum, Fusarium maniliforme, Rhizoctonia solani, and Phythium sp. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size analysers (PSA), and zeta potential (ZP) measurements were used to characterize these green fabricated magnetite NPs. FTIR analysis showed that the synergy of microalgal proteins, carbohydrtates and polyphenols is responsible for the biofabrication of iron nanoparticles. A spheroid dispersion of biosynthesized Fe3O4-NPs with an average diameter of 76.5 nm was produced in the synthetic process.

Objective: To determine the association of serum Homocysteine and serum vitamin D levels with depression and its severity. Study Design: Cross-sectional study. Place and Duration of Study: The study was conducted at the Department of Psychiatry, Armed Forces Institute of Mental Health (AFIMH), Rawalpindi, Pakistan, from December 2021 to May 2022. Methods: We recorded demographic data, including age, gender, and socioeconomic status of consecutively sampled 155 subjects. Depression and its severity was assessed by applying the Urdu version of the Hamilton Depression Rating Scale (HAM-D U). Blood samples were collected to assess serum homocysteine and serum vitamin D before commencing any treatment for depression; these samples were assessed at the Armed Forces Institute of Pathology (AFIP Rawalpindi). Results: The mean Hamilton Depression Rating Scale (HAM-D U) score was 17.14 ± 4.29 with minimum and maximum scores as 8 and 22. There were 97 (62.6%) cases that had mild to moderate depression, and 58 (37.4%) patients had severe depression. The frequencies of intermediate to severe Homocysteine levels were statistically higher in individuals with severe depression (p < 0.001), while vitamin D deficiency was also statistically higher in individuals experiencing severe depression (p < 0.001). Conclusion: Raised serum homocysteine levels and deficiency of serum vitamin D is associated with the severity of depression. How to cite this: Bajwa AA, Khan S, Raza H, Nazir TB. Homocysteine and Vitamin D Levels: An Association with Depression. Life and Science. 2023; 4(4): 372-378. doi: http://doi.org/10.37185/LnS.1.1.385

A novel thiazole-based Schiffbase chemosensor SB1 with N- and O- donor atoms was synthesized and characterized by different techniques (UV–vis, 13C NMR, 1H NMR, and FT-IR analysis). The chemosensor SB1 was used for the determination of Cu2+ ions in various samples. The significant spectral changes in absorption spectra of chemosensor SB1 at 220 and 416 nm and the color change from light yellow to yellowish-brown indicate high selectivity and sensitivity towards Cu2+ ions as compared to other cations (Na+, K+, Ag+, Zn2+, Ni2+, Pb2+, Mn2+, Mg2+, Co2+, Cd2+, Sn2+, Hg2+, Cr3+, Fe3+, and Al3+). The sensing mechanism of SB1 was investigated through various techniques such as FT-IR, UV–vis and 1H NMR titration experiment and further confirmed by DFT computational studies. The 2:1 binding mode between SB1 and Cu2+ ions was confirmed by Job‘s plot using UV–vis spectrophotometry. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.015 and 0.0471 µg mL−1, respectively. The percent recovery of Cu2+ from various environmental samples was found to be 95.00–103.33% at various levels. These obtained results demonstrate that chemosensor SB1 is a cost-effective, facile, selective, sensitive, and colorimetric sensing platform to detect trace amounts of Cu2+ ions in variousenvironmental and agricultural samples.

This paper presents various control system design techniques for temperature control of Magnetic Fluid hyperthermia. The purpose of this research is to design a cost-effective, efficient, and practically implementable temperature controller for Magnetic Fluid hyperthermia, which is presently under research as a substitute to the radiation and chemotherapy treatment of cancer. The principle of this phenomenon centers on the greater sensitivity of tumor cells to changes in temperature in comparison to healthy cells. Once the nanoparticles reach the desired tissue, it can then be placed in a varying magnetic field to dissipate the heat locally by raising the temperature to 45 °C in order to kill cancerous cells. One of the challenging tasks is to maintain the temperature strictly at desired point i.e., 45 °C. Temperature controller for magnetic fluid hyperthermia provides the tight control of temperature in order to avoid folding of proteins and save the tissues around the cancerous tissue from getting destroyed. In contrast with most of the existing research on this topic, which are based on linear control strategies or their improved versions, the novelty of this research lies in applying nonlinear control technique like Sliding Mode Control (SMC) to accurately control the temperature at desired value. A comparison of the control techniques is presented in this paper, based on reliability, robustness, precision and the ability of the controller to handle the non-linearities that are faced during the treatment of cancer. SMC showed promising results in terms of settling time and rise time. Steady state error was also reduced to zero using this technique.

Abstract Background Delirium affects nearly 70% of older adults hospitalized in the intensive care unit (ICU), and many of those will be left with persistent cognitive impairment or dementia. There are no effective and scalable recovery models to remediate ICU-acquired cognitive impairment and its attendant elevated risk for dementia or Alzheimer disease (AD). The Improving Recovery and Outcomes Every Day after the ICU (IMPROVE) trial is an ongoing clinical trial which evaluates the efficacy of a combined physical exercise and cognitive training on cognitive function among ICU survivors 50 years and older who experienced delirium during an ICU stay. This article describes the study protocol for IMPROVE. Methods IMPROVE is a four-arm, randomized controlled trial. Subjects will be randomized to one of four arms: cognitive training and physical exercise; cognitive control and physical exercise; cognitive training and physical exercise control; and cognitive control and physical exercise control. Facilitators administer the physical exercise and exercise control interventions in individual and small group formats by using Internet-enabled videoconference. Cognitive training and control interventions are also facilitator led using Posit Science, Inc. online modules delivered in individual and small group format directly into the participants’ homes. Subjects complete cognitive assessment, mood questionnaires, physical performance batteries, and quality of life scales at baseline, 3, and 6 months. Blood samples will also be taken at baseline and 3 months to measure pro-inflammatory cytokines and acute-phase reactants; neurotrophic factors; and markers of glial dysfunction and astrocyte activation. Discussion This study is the first clinical trial to examine the efficacy of combined physical and cognitive exercise on cognitive function in older ICU survivors with delirium. The results will provide information about potential synergistic effects of a combined intervention on a range of outcomes and mechanisms of action. Trial registration ClinicalTrials.gov, NCT03095417. Registered on 23 March 2017. Last updated on 15 May 2017.

Abstract Background Patients admitted to intensive care units (ICU) with acute respiratory failure (ARF) face chronic complications that can impede return to normal daily function. A mobile, collaborative critical care model may enhance the recovery of ARF survivors. Methods The Mobile Critical Care Recovery Program (m-CCRP) study is a two arm, randomized clinical trial. We will randomize 620 patients admitted to the ICU with acute respiratory failure requiring mechanical ventilation in a 1:1 ratio to one of two arms (310 patients per arm) – m-CCRP intervention versus attention control. Those in the intervention group will meet with a care coordinator after hospital discharge in predetermined intervals to aid in the recovery process. Baseline assessments and personalized goal setting will be used to develop an individualized care plan for each patient after discussion with an interdisciplinary team. The attention control arm will receive printed material and telephone reminders emphasizing mobility and management of chronic conditions. Duration of the intervention and follow-up is 12 months post-randomization. Our primary aim is to assess the efficacy of m-CCRP in improving the quality of life of ARF survivors at 12 months. Secondary aims of the study are to evaluate the efficacy of m-CCRP in improving function (cognitive, physical, and psychological) of ARF survivors and to determine the efficacy of m-CCRP in reducing acute healthcare utilization. Discussion The proposed randomized controlled trial will evaluate the efficacy of a collaborative critical care recovery program in accomplishing the Institute of Healthcare Improvement’s triple aims of better health, better care, at lower cost. We have developed a collaborative critical care model to promote ARF survivors’ recovery from the physical, psychological, and cognitive impacts of critical illness. In contrast to a single disease focus and clinic-based access, m-CCRP represents a comprehensive, accessible, mobile, ahead of the curve intervention, focused on the multiple aspects of the unique recovery needs of ARF survivors. Trial registration NCT03053245, clinicaltrials.gov, registered February 1, 2017.

The scientific consensus is now on developing a biocontrol agent that can cause cellular metabolic reprogramming against agricultural pathogens. Biosynthesis of silver nanoparticles was performed by using phytopathogenic fungi (Alternaria sp.) isolated from banana cultivated soil. Alternaria sp. can grow very fast and produce high enough bioactive compounds. This study aims to biosynthesize silver nanoparticles (AgNPs) using fungal Alternaria sp.’s metabolites as a safe antifungal agent against plant pathogenic fungi (Fusarium spp. and Alternaria sp.). To visualize the formation of AgNPs, analytical instruments were used, such as ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, scanning transmission electron microscopy (STEM), energy dispersive X-ray (EDX), and elemental mapping. The UV-visible spectra showed a peak at 435 nm. Analysis of scanning transmission electron microscopy (STEM) micrographs evidenced that the size of synthesized silver nanoparticles ranged between 3 and 10 nm. The resulting AgNPs showed distinct antifungal activity against selected plant pathogenic fungi. Synthesized AgNPs have demonstrated remarkable potential for the use of antifungal compounds to combat plant diseases.

Several approaches have been used in the past to predict fatigue crack growth rates in T-joints of the offshore structures, but there are relatively few cases of applying structural health monitoring during the non-destructive testing of jacket platforms. This paper presents an experimental method based on the sensing of the piezoelectric sensors and finite element analysis method for studying the fatigue cracks in the offshore steel jacket structure. Three types of joints are selected in the current research work: T-type plate, T-type tube-plate, and T-type tube joints. The finite element analysis model established in the current study computes and analyzes the high stress and high strain regions in the T-type joints. The fatigue damage in the T-type joints was successfully detected by utilizing both the finite element analysis and experimental methods. The results showed that fatigue cracks of the three types of joints are prone to appear at the weld toe and spread in the welding direction. The fatigue damage location of T-type plate and T-type tube-plate joints is more concentrated in the upper weld toe area, and the fatigue damage location of the T-type tube joint is closer to the lower weld toe area.

Well logging is a significant procedure that assists geophysicists and geologists with making predictions regarding boreholes and efficiently utilizing and optimizing the drilling process. The current study area is positioned in the Punjab Territory of Pakistan, and the geographic coordinates are 30020′10 N and 70043′30 E. The objective of the current research work was to interpret the subsurface structure and reservoir characteristics of the Kabirwala area Tola (01) well, which is located in the Punjab platform, Central Indus Basin, utilizing 2D seismic and well log data. Formation evaluation for hydrocarbon potential using the reservoir properties is performed in this study. For the marked zone of interest, the study also focuses on evaluating the average water saturation, average total porosity, average effective porosity, and net pay thickness. The results of the study show a spotted horizon stone with respect to time and depth as follows: Dunghan formation, 0.9 s and 1080.46 m; Cretaceous Samana Suk formation, 0.96 s and 1174.05 m; Datta formation, 1.08 s and 1400 m; and Warcha formation, 1.24 s and 1810 m. Based on the interpretation of well logs, the purpose of petrophysical analysis was to identify hydrocarbon-bearing zones in the study area. Gamma ray, spontaneous potential, resistivity, neutron, and density log data were utilized. The high zone present in the east–west part of the contour maps may be a possible location of hydrocarbon entrapment, which is further confirmed by the presence of the Tola-01 well.

The Rub’ Al-Khali basin in Saudi Arabia remains unexplored and lacks data availability due to its remoteness and the challenging nature of its terrain. Thus far, there are neither digital geologic models nor synthetic seismic data from this specific area accessible for testing research techniques and analysis. In this study, we build a 2D viscoelastic model of the eastern part of the Rub’ Al-Khali basin and generate a corresponding dual-component seismic data set. We compile high-resolution depth models of compressional- and shear-wave velocities, density, as well as compressional- and shear-wave quality factors from published data. The compiled models span Neoproterozoic basement up to Quaternary sand dunes. We then use the finite-difference technique to model the propagation of seismic waves in the compiled viscoelastic medium of eastern Rub’ Al-Khali desert. In particular, we generate vertical and horizontal components of the shot gathers with accuracy to the fourth and second orders in space and time, respectively. The viscoelastic models and synthetic seismic datasets are made available in an open-source site for prospective re-searchers who desire to use them for their research. Users of these datasets are urged to make their findings also accessible to the geoscience community as a way of keeping track of developments related to the Rub’ Al-Khali desert.

Thermoacoustic refrigerators have huge potential to replace conventional refrigeration systems as an alternative clean refrigeration technology. These devices utilize conversion of acoustic power and heat energy to generate the desired cooling. The stack plays a pivotal role in the performance of Standing Wave Thermoacoustic Refrigerators (SWTARs), as the heat transfer takes place across it. Performance of stacks can be significantly improved by making an arrangement of different materials inside the stack, resulting in anisotropic thermal properties along the length. In the present numerical study, the effect of multi-layered stack on the refrigeration performance of a SWTAR has been evaluated in terms of temperature drop across the stack, acoustic power consumed and device Coefficient of Performance (COP). Two different aspects of multi-layered stack, namely, different material combinations and different lengths of stacked layers, have been investigated. The combinations of four stack materials and length ratios have been investigated. The numerical results showed that multi-layered stacks produce lower refrigeration temperatures, consume less energy and have higher COP value than their homogeneous counterparts. Among all the material combinations of multi-layered stack investigated, stacks composed of a material layer with low thermal conductivity at the ends, i.e., RVC, produced the best performance with an increase of 26.14% in temperature drop value, reduction in the acoustic power consumption by 4.55% and COP enhancement of 5.12%. The results also showed that, for a constant overall length, an increase in length of side stacked material layer results in an increase in values of both temperature drop and COP.