IRIS UNIME
Not a member yet
103940 research outputs found
Sort by
A Structured Approach to Address the Storage Location Assignment Problem: A VIKOR-Based Solution
No full textThe allocation of Stock Keeping Units (SKUs) within warehouses is a crucial factor influencing a company’s logistical efficiency. Identifying the best location for each SKU is a tricky task for warehouse managers, as it directly affects key operational factors such as picking speed, travel distances, and internal flow. The allocation strategy depends on the company’s specific needs, as well as the characteristics of the SKUs. This problem is widely recognized in the literature as the Storage Location Assignment Problem (SLAP). Given the multi-criteria nature of this problem, the VIKOR decision-making method is proposed to address it in a two-dimensional context. The methodology was developed in collaboration with a Sicilian logistics serving the Italian market
Speed-controlled printing strategy for functionally graded TPMS structures: A process optimization perspective
No full textThis work introduces a novel, process-driven strategy for manufacturing functionally graded Triply Periodic Minimal Surface (TPMS) structures via fused filament fabrication, based on controlling local density through printhead speed modulation. Unlike conventional approaches that rely on geometric variation or toolpath complexity, this method maintains a constant slicing geometry while adjusting the printhead velocity to vary material deposition rate: slower speeds generate higher density, while faster speeds result in reduced material accumulation. Compared with uniform counterparts, the graded specimen reduced build time by ∼28 %. Moreover, for the same target density map, replacing line-multiplication grading with speed-modulation can yield up to ∼80 % shorter slicer-estimated build time. Mechanical behavior was assessed through three-point bending tests on specimens with constant densities (10 %, 20 %, 30 %) and on functionally graded samples with an average density of 10 %. Results show that graded structures, despite their low material content, achieved significantly improved performance over uniform low-density samples, approaching the strength and stiffness of denser configurations. These findings highlight the potential of velocity-based deposition control as an effective tool for rapid manufacturing of lightweight, architected materials with tailored mechanical properties. The approach provides a transferable insight into process optimization for additive manufacturing, supporting the development of faster and more efficient design-to-production workflows
Mortality and its predictors among adolescents and adults on antiretroviral therapy in the era of test-and-treat, Ethiopia: a retrospective cohort study
No full text
Environmental distribution and biodegradability of persistent organic pollutants in an open burning municipal solid waste site
No full textThe open dumping and burning of municipal solid waste (MSW) remain prevalent due to their low cost, despite posing serious
risks to environmental and human health. This study assesses the contamination levels and the distribution of 22 persistent organic
pollutants (POPs), including 13 polychlorinated biphenyls (PCBs) and 9 polycyclic aromatic hydrocarbons (PAHs) in and around
an open burning MSW site in Mahdia, Tunisia. POP concentrations were quantified across different environmental matrices (i.e.
surface water, sediment, soil, soil–leachate, fly ash and mallow plants) using gas chromatography coupled with single quadrupole
mass spectrometry (GC-MS/MS). Furthermore, the OECD 301F manometric respirometry test was employed to evaluate the
biodegradability of these compounds. Results revealed significant accumulation of POPs, particularly in fly ash and plant samples.
Benzo[ghi]perylene and phenanthrene were identified as the predominant PAHs. The highest concentrations of PCBs and PAHs
were found in fly ash (0.753 ± 3.54 μg per kg dry weight (dw) and 19.621 ± 26.76 μg per kg dw, respectively) and in plant material
(0.378 ± 1.33 μg per kg dw and 42.563 ± 74.03 μg per kg dw, respectively), whereas surface water exhibited the lowest contamination
levels. Biodegradability tests showed near-complete degradation (>90%) of POPs in surface water and mallow plant matrices over
28 days. In contrast, other matrices failed to exceed the 60% degradation threshold, classifying them as non-biodegradable
Hydrochar from garden waste enhances drought tolerance in sunflower via soil-plant-gene interactions
No full textEnhancing crop drought resilience is essential for sustainable agriculture in a changing climate. Among potential strategies, hydrochar (HC), a carbon-rich product of hydrothermal carbonization, represents a promising soil amendment. We hypothesized that HC enhances drought tolerance in Helianthus annuus L. through coordinated soil–plant–gene interactions that modulate water retention, plant hydraulics, and drought-responsive gene networks. Using a multiscale approach combining soil physicochemical analyses, plant physiology, and transcriptomics, we assessed the effects of garden waste-derived HC on H. annuus under well-watered and water- limited conditions. HC application improved soil water retention without altering key chemical parameters and enhanced plant hydraulics. Across irrigation regimes, HC-treated plants showed greater biomass accumulation and photosynthetic capacity. During drought, HC mitigated stress by maintaining leaf water potential and membrane integrity, and by promoting a more negative turgor loss point via osmotic adjustment and increased cell wall stiffness. Transcriptomic analysis revealed that HC modulated drought-responsive genes, including transcription factors (e.g., WRKY51, bZIP11) and genes involved in osmotic regulation, antioxidant defense, and hormonal signaling. The distinct molecular signature in HC-treated plants under drought suggests a priming effect that sustains physiological function under stress. This study provides novel evidence linking HC-induced soil enhancement to molecular drought responses in crops, highlighting HC’s potential as a circular input for improving adaptation and productivity in climate-resilient agroecosystems
Polychlorinated Biphenyls, Oxidative Stress, and Brain Health: Mechanistic Links to Neurodegenerative and Neurodevelopmental Diseases
No full textPolychlorinated biphenyls (PCBs) are persistent organic pollutants that remain widely detectable in the environment and human tissues decades after their ban, raising concerns for brain health. Both dioxin-like (DL) and non-dioxin-like (NDL) congeners interfere with neuronal function through partially distinct pathways, including aryl hydrocarbon receptor activation, disruption of calcium and dopaminergic signaling, oxidative stress, and epigenetic remodeling. Experimental and epidemiological studies indicate that developmental PCB exposure is associated with impaired cognition, attention, motor function, and increased risk of neurodevelopmental disorders. Furthermore, chronic exposure in adulthood has been linked to neurodegenerative diseases. At the cellular level, NDL-PCBs sensitize ryanodine receptors, alter dendritic and axonal growth, promote mitochondrial dysfunction, generate reactive oxygen and nitrogen species, and compromise blood–brain barrier integrity, thereby fostering neuroinflammation, synaptic dysfunction, and neuronal loss. This review synthesizes current evidence on the molecular and cellular mechanismtable s underlying PCB-induced neurotoxicity across the lifespan, highlighting oxidative stress as a central factor, integrating calcium dysregulation, neurotransmitter imbalance, and apoptotic and epigenetic pathways. Finally, potential neuroprotective roles of antioxidant strategies are discussed, emphasizing their relevance for mitigating PCB-related neurodevelopmental and neurodegenerative risk
Unveiling the Unknown Gela Coastal Paleoenviroments (Sicily Island, Southern Italy) During Late Holocene: New Tools for the Greek Harbour Site Location
No full textThe ancient city of Gela (built in the 7th century BCE) is located in the southern sector of the Sicily Island (Southern Italy) on a Pleistocene marine terrace near the mouth of the Gela River. Gela was one of the most important Greek colonies in the Mediterranean Sea, strate-gically positioned at the crossroads of the major maritime trade routes and with a rich pro-duction of cereals thanks to the fertile Gela River alluvial plain. To reconstruct the coastal and environmental configuration during the Greek period and to improve the understand-ing of the location of the harbour basin, a multidisciplinary approach was applied to a sector of the Gela River alluvial–coastal plain. This area, located very close to the ancient city, is known as Conca (Italian for “Basin”) and was identified through the analysis of historical and modern maps as well as aerial photographs. The multidisciplinary approach includes geomorphology (derived from maps and aerial photos), stratigraphy (boreholes and arche-ological trench), paleoecology (ostracoda, foraminifera and fossil contents of selected lay-ers), geochronology (14C dating of selected organic materials) and archeology (historical sources and maps, pottery fragments extracted from boreholes and trench layers). The main results show that this area was occupied by lower shoreface environments in the time inter-vals between 4.4 and 2.8 ka, which progressively transitioned to upper shoreface environ-ments until the Greek age. During the Roman period, these environments were significantly reduced due to repeated alluvial sedimentation of the Gela River transforming the area into fluvial–marshy environments. A time interval of aeolian sand deposition was recorded in the upper part of the coastal stratigraphical succession, which can be related to climatic con-ditions with high aridity. Available data show that marine environments persisted in the Conca sector during the Greek age, allowing hypothesizing the presence of an ancient har-bour in this area. The depth of the Greek age marine environments is estimated to be be-tween 4.5 and 7 m below the current ground level. Further investigation, mainly based on geophysical and stratigraphical methods, will be planned aimed at identifying the presence of buried archeological targets
Total recovery of bacterioruberin from Arthrobacter via sustainable one-cycle extraction: A bench-scale guide to solvent selection and process intensification
No full textBacterioruberin (BR) is an uncommon C50 natural carotenoid known for its exceptional antioxidant and antibacterial properties, making it highly promising for use in the food, pharmaceutical, and cosmeceutical sectors. Despite this potential, its commercial use is hindered by challenges in downstream processing. This research offers a comparative analysis of three methods to fully recover BR from Arthrobacter sp. CP30, a microorganism that produces approximately 95 % of BR and BR-derivatives. The first strategy, utilizing traditional methanol extraction, achieved a recovery rate of about 80 %, which could be improved to 100 % with optimized conditions. The second strategy employed binary solvent mixtures of alcohols and fatty acids, allowing for complete BR recovery under gentle extraction conditions. The third strategy combined green biosolvents, such as bio-based ethanol, with microwave-assisted extraction (MAE), resulting in a 100 % recovery rate and an Eco-Scale score of
89, indicating high environmental sustainability. In all methods, solvent selection was selected by COSMO-SAC modeling, which identified favorable molecular interactions between BR and the solvents tested. Overall, this work provides an efficient, sustainable, and scalable framework for BR recovery and serves as a practical guide for researchers and professionals to tailor extraction protocols according to their specific laboratory or industrial setups, to accomplish the full potential of high-value C50 carotenoids
Using Virtual Reality to Promote Cognitive Engagement in Rett Syndrome: Eye-Tracking Evidence from Immersive Forest Tasks
No full textRett syndrome (RTT) is a rare neurodevelopmental disorder that causes severe motor and cognitive impairments, limiting voluntary communication. Gaze-based technologies and virtual reality (VR) offer innovative ways to assess and enhance attention, happiness, and learning in individuals with minimal motor control. This study investigated and compared visual-attentional and emotional engagement in girls with RTT and typically developing (TD) peers during exploration of a virtual forest presented in 2D and immersive 3D (VR) formats across four progressively complex tasks. Twelve girls with RTT and 12 TD peers completed eye-tracking tasks measuring reaction time, fixation duration, disengagement events, and observed happiness. Girls with RTT showed slower responses and more disengagements overall, but VR significantly improved attentional efficiency in both groups, resulting in faster reaction times (η2p = 0.36), longer fixations (η2p = 0.31), and fewer disengagements (η2p = 0.27). These effects were stronger in the RTT group. Both groups also showed greater happiness in VR settings (RTT: p = 0.011; TD: p = 0.015), and in participants with RTT, peaks in attention coincided with peak happiness, indicating a link between happiness and cognitive engagement. Immersive VR thus appears to enhance attention and affect in RTT, supporting its integration into personalized neurorehabilitation