Search Results (261)

This study examines the feasibility of predicting net repair costs (Estimated Cost, PLN) for multi-family residential buildings from data extracted from technical inspection reports. Rather than merely comparing algorithmic performance, the analysis was designed as a diagnostic sequence aimed at identifying the sources of prediction error. Four machine learning algorithms (Extra Trees, Random Forest, XGBoost, and GBM) were first applied to direct regression of repair cost. We then tested whether the difficulty of estimating exact cost values stems from the high variability of the target variable and whether this limitation can be mitigated by a two-stage approach: assigning observations to one of three cost-risk bands (Low, Moderate, High) and subsequently estimating cost within the assigned band. The empirical cost distribution was strongly right-skewed (median: 4500 PLN; mean: 63,402 PLN; maximum: 3,680,524 PLN). The best direct regression model achieved an R² of 0.452, while the best fully deployable two-stage model, combining an XGBoost classifier with a Random Forest regressor, achieved an R² of 0.392. When it was assumed that the actual cost-risk bands were known, an R² value of 0.839 was obtained, indicating that the main source of error is not regression within the bands, but rather the initial stage of assigning the bands. These results demonstrate that reporting a single global R² for highly skewed, weakly identifiable cost data can be misleading, and that decomposing predictive performance into band-assignment and within-band regression components provides a more informative evaluation. This article also points to concrete directions for improving the underlying database, particularly through the inclusion of variables describing repair quantity, unit of measure, and detailed repair scope. Full article

HS-1-associated protein X-1 (HAX-1) is a ubiquitously expressed, multifunctional protein that regulates Ca²⁺ homeostasis and cell survival in cardiac muscle. In addition to its well-established anti-apoptotic function, HAX-1 has recently been implicated in autophagy regulation. In the present study, we explored the molecular mechanisms underlying HAX-1-mediated autophagy modulation in cellular models, including cardiac-derived H9c2 myotubes. HAX-1 overexpression enhanced autophagic activity, as evidenced by decreased sequestosome-1 (p62), increased microtubule-associated protein light chain 3-II (LC3-II), enhanced LC3 puncta formation, and elevated autophagic flux. Conversely, HAX-1 knockdown attenuated autophagic activity. Mechanistically, co-immunoprecipitation assays showed that HAX-1 associates with both p62 and LC3. Bioinformatic analysis of the HAX-1 protein sequence identified two conserved LC3-interacting region (LIR) motifs within its N-terminal domain. Deletion of this LIR-containing region (HAX-1ΔLIR) reduced LC3 association, decreased autophagic activity, and impaired autophagy-dependent clearance of HAX-1 itself following autophagy induction, suggesting the importance of these motifs. At a cardiac-relevant level, HAX-1 promoted a chloroquine-sensitive reduction in protein levels of its known binding partner, phospholamban (PLN), a key regulator of sarcoplasmic reticulum (SR) Ca²⁺ cycling. These findings indicate a previously unrecognized LC3/LIR-dependent mechanism underlying HAX-1-mediated autophagy modulation and suggest a potential role for HAX-1 in SR protein proteostasis. Full article

Land-use conflicts in non-urbanized areas are fundamentally governance problems rather than purely environmental ones: sustainability outcomes increasingly depend on integrated, cross-sectoral decision-making reconciling forestry, agriculture, tourism, infrastructure, and urbanization within a finite land resource. This study examines whether statutory land acquisitions by a public forest administration can be understood as such a governance instrument rather than simply forest-area expansion, using an original transaction-level database of 911 land purchases by the Polish State Forests (Lasy Panstwowe) through statutory pre-emption rights between 2022 and mid-2026. The database covers 2806.1 hectares and, for the 903 transactions with a determinable price, approximately 114.2 million PLN. Using descriptive statistics, concentration indices (Gini, Herfindahl–Hirschman), an exploratory hedonic-style log–log regression of unit price on parcel area with location and year fixed effects, and a spatial-autocorrelation analysis (Moran’s I), the study examines spatial concentration, price differentiation, and parcel-size effects. Results show pronounced sub-regional concentration (county-level Gini = 0.615, more than double the voivodeship-level value of 0.284), a systematic price premium for parcels below 0.5 ha, and a dominant role of location over parcel size in explaining price variation (R-squared rising from 0.042 to 0.198 with location fixed effects); these are descriptive associations rather than causal estimates, given the absence of parcel-level quality covariates and a fully specified spatial–econometric model. The findings support interpreting statutory pre-emption purchases as a market-based institutional mechanism contributing to boundary rationalization, ownership consolidation, and mediation of competing land-use pressures, with implications for county-level monitoring and cross-sectoral coordination with spatial planning. Full article

The chemical industry is a broad sector that encompasses all the different types of industry that produce products that rely on the intensive use of chemicals. The aim of the paper was to analyze the development of the chemical industry in Poland against the background of the EU. The Polish chemical industry produces many products, which can be divided into different categories based on their application. The most important include organic and inorganic chemicals. Organic chemicals include carbon compounds such as ketones, alcohol, carboxylic acids, and cyclic compounds. They are used in the production of solvents, varnishes, paints, and adhesives, as well as in the production of drugs in the pharmaceutical industry and others. The Polish chemical industry employs over 300,000 people. The financial profit achieved by companies specializing in the production of chemicals and chemical products was PLN 9.99 billion in 2022, compared to PLN 8.16 billion in 2021. The financial profit for producers of plastic and rubber products was PLN 9.56 billion, compared to PLN 8.68 billion in 2021. These increases in profits were very noticeable for individual companies, where the scale of growth compared to the previous year was often impressive. The chemical industry is a key sector in the European Union, being the fourth largest industry in the EU. There are approximately 30,000 chemical companies in the EU, directly employing approximately 1.2 million people. Europe is the second largest producer of chemicals in the world, generating a high percentage of global sales. Full article

The rapid expansion of photovoltaic capacity in Poland has exposed distribution-grid constraints and increased the incidence of non-market curtailment. This paper examines a 1 MW ground-mounted photovoltaic plant in Zalesie, north-eastern Poland, using complete documentation. The study combines a spatial multi-criteria site-suitability assessment based on the Weighted Sum Model, a sensitivity analysis of criteria weights, an analysis of 28 curtailment compensation applications, and a transparently parameterised LCOE/NPV/IRR model under four curtailment-severity scenarios. The results indicate a high and weight-robust site-suitability score (S = 4.45/5.00; sensitivity range 4.35–4.55), with curtailment concentrated in spring: 68% in April and May. Economic modelling shows that, under merchant market conditions and without support schemes, profitability is already constrained in the baseline case (IRR 4.2–6.4%), while increasing the share of unsold energy from 0% to 10% raises LCOE by approximately 3–11% and deepens the already negative NPV by a further PLN 0.09–0.36 million. A Monte Carlo simulation confirms that the NPV stays negative across the whole plausible parameter range. This case study demonstrates that classical spatial suitability may be a necessary but insufficient condition for the economic security of PV investments unless grid-related and regulatory risks are incorporated into the planning stage. Full article

In this article, static durability testing is combined with an economic analysis of selected furniture manufactured from solid oak residues. Durability was assessed under the EN 1728 and EN 12520 static-load procedures, and dimensional stability was examined using statistical process-control tools (normality analysis, kurtosis and Shewhart control charts). Chairs intended for children were tested for the body mass of five-, seven- and nine-year-old children, as well as for an adult (seat force F1 = 250–850 N, backrest force F2 = 90–290 N). The tested chairs met the strength and durability requirements of the applied standards, and none overturned or tended to tip. A manufacturing cost and profitability analysis then quantified the cost structure. Material accounted for only 10–31% of manufacturing costs, with labour as the dominant component, reflecting the labour intensity of upcycling irregular residues into individually designed furniture. Manufacturing costs per item ranged from PLN 108 to PLN 251 against trial sale prices of PLN 250 to PLN 1300, yielding net profit margins of 46–81%. The findings indicate that upcycling post-production residues can improve the economic and potential environmental performance of furniture enterprises and support circular-economy objectives by reducing demand for virgin timber. Full article

Counting electricity connections is easy. Understanding what those connections actually do for people is harder—and more important. This study examines how a 450 kWp Smart Grid Hybrid Microgrid on Semau Island, East Nusa Tenggara, Indonesia, shaped the daily lives and economic futures of a community in one of the country’s most geographically isolated 3T territories (Frontier, Outermost, Underdeveloped), using a sequential explanatory mixed-methods design (SEM-AMOS, n = 123; key informant interviews, n = 4)—and we find that forty percent of households have shifted from passive consumption to productive agricultural use within five years of grid connection, a rate that challenges common assumptions about rural electrification in eastern Indonesia. The data also reveal a troubling pattern at the heart of Indonesia’s subsidy architecture: the 450 VA tier, which absorbs the highest per-kWh State Budget subsidy (IDR 10,518/kWh; 96.2% of Cost of Supply), is associated with the weakest welfare returns. Meanwhile, an estimated IDR 1.87 billion per year in lost capacity—a figure we term the Governance Maintenance Loss (GML)—is linked to governance shortfalls rather than hardware failure. SEM-AMOS results (χ²/df = 1.613; RMSEA = 0.049; CFI = 0.973; TLI = 0.983; SRMR = 0.043) indicate that, among the constructs examined, Energy Diversification Policy shows the strongest association with community welfare (β = 0.718, p < 0.001)—more so than the physical infrastructure itself. In response, this study proposes three governance instruments: the MIDEK framework, a Knowledge Transfer Mandate (KTM), and a Productive Energy Tariff (PET). Together, these tools offer a replicable, low-cost pathway for Indonesia’s 1200 planned island installations under Presidential Regulation No. 112/2022—one that is simultaneously revenue-positive for PLN, budget-positive for the State, and welfare-positive for the communities these systems are meant to serve. Full article

Increasingly stringent regulations regarding climate policy and the sustainable development paradigm determine the transformation of contemporary multi-family housing typology, manifested by a growing share of single-aspect micro-apartments (units with exterior exposure on only one facade). This article identifies the phenomenon of the energy-efficiency paradox, wherein highly insulated buildings successfully trap winter heat but inadvertently escalate summer cooling demands. Consequently, the primary operational challenge becomes limiting excessive solar heat gains in summer, which directly translates into high cooling energy demand, rather than solely mitigating heat losses in winter. Sustainable construction requires moving beyond the narrowly defined reduction of envelope thermal transmittance towards holistic adaptation to climate change and ensuring adequate indoor environmental quality. The methodology is based on a coupled energy-economic analysis, evaluating thermal balances and their direct financial implications for end-users. The variant analysis of solar heat gains conducted for a reference 30 m² dwelling in Warsaw proves that architectural optimization should not be determined solely by short-term investment profit maximization. Effective engineering optimization in construction requires the implementation of a full building life cycle perspective. Unfavorable glazing orientation and the lack of cross-ventilation necessitate the use of energy-intensive air-conditioning systems, which directly increases the building’s carbon footprint and generates hidden operating costs (differences reaching over 145 PLN annually for heating and approximately 70 PLN for cooling). The findings highlight the necessity for a critical reevaluation of design priorities for compact apartments, integrating social justice (by reducing information asymmetry in the real estate market, where buyers are often unaware of these future cooling burdens) with long-term economic rationality and the resilience of the built environment to extreme weather events. Full article

Risk assessment frameworks for renewable energy projects are predominantly designed for liberalised electricity markets, leaving state-dominated and single-buyer systems analytically underserved. This systematic literature review (SLR) synthesises 116 peer-reviewed studies (2015–2026) following a PRISMA-compliant, Kitchenham-guided protocol to identify and critically evaluate project-level risks and assessment methodologies across diverse electricity market structures. Three contributions are made: (i) a market-structure-differentiated risk taxonomy showing how risk profiles differ structurally across liberalised, hybrid, and single-buyer markets; (ii) the Integrated Risk Assessment Framework for Renewable Energy Projects (IRAF-REPs), a five-layer architecture connecting market structure context, risk category taxonomy, assessment methods, project lifecycle phases, and risk-register standards (ISO 31000/COSO); and (iii) a structured three-horizon future research agenda. Market/price risk (~68%) and policy/regulatory risk (~58%) dominate the reviewed literature, while counterparty/PPA risk—dominant in single-buyer contexts—is largely absent from quantitative frameworks. Monte Carlo simulation and real options analysis lead quantitative practice in liberalised-market studies; the hybrid Monte Carlo-System Dynamics (MC-SD) combination appears in fewer than 4% of studies despite its conceptual suitability for single-buyer contexts. Five research gaps are identified. Findings advance SDG 7, SDG 13, and SDG 9, with direct governance relevance for Indonesia/PLN and comparable Global South economies. Full article

This study addresses the increasing need for flexibility in the Polish Power System (PPS), particularly in the context of growing price volatility on the Day-Ahead Market (DAM) resulting from the rising share of renewable energy sources (RESs). The aim of the study was to assess the feasibility of implementing demand-driven operation in an existing linear biogas plant in Poland and to develop a Decision-Making Model (DMM) for optimizing its operation based on electricity price forecasts. A machine learning model based on Extreme Gradient Boosting (XGBoost) was developed using historical electricity price, demand and weather data and integrated into the DMM to generate hourly operating schedules. The model achieved high predictive accuracy, with a Mean Absolute Error (MAE) of approximately 51 PLN/MWh, and effectively captured nonlinear price dynamics. Based on predefined decision thresholds—biogas production rate, current biogas storage level, upper and lower limits of pressure in biogas storage capacity, maximum biogas storage duration, power quotient (PQ) and electricity price levels—optimal operating strategies were determined. The results indicate that while demand-driven operation is technically feasible and enables better alignment with market signals, its economic viability remains limited under current market and regulatory conditions. Investment in additional cogeneration capacity was not justified, as costs significantly exceeded potential revenues. Consequently, a more viable approach involves optimizing existing infrastructure through flexible production strategies. Full article

A short-term performance test of blended biodiesel (FAME), green diesel (HVO), and diesel was experimentally assessed in a 100 kW Cummins 6BTAA5.9-G12 diesel engine under multiple load conditions. The objective was to determine the technical feasibility, operational trade-offs, and optimal blend formulations for renewable energy deployment in diesel power plants. All tested blends operated stably without engine modification, confirming the “drop-in capability” of FAME–HVO mixtures for existing diesel engines. Specific fuel consumption (SFC) increased notably at high loads, with penalties up to 15.15% for B30D20 and B35D15 relative to neat diesel, although overall efficiency improved with load. Among the ternary fuels, B30D10 and B30D20 provided the most balanced compromise between combustion reactivity and flow properties. Exhaust gas temperatures rose with load for all fuels, with FAME-rich blends exhibiting higher temperatures than neat diesel, while coolant-side analysis showed D100 and D50 as thermally favorable and B50–B100 imposing the highest cooling demand. The results emphasize the need for injection system recalibration on an energy basis for HVO-rich fuels, and for strengthened filtration and maintenance practices for FAME-rich blends to avoid filter clogging and injection instability. Considering performance, operability, and system stability up to 100 kW, B30D10 and B35D15 are identified as optimal compromise blends. The study highlights the necessity of future work on long-term durability, fuel system compatibility, supply chain robustness, and techno-economic viability to safely scale green diesel use in Indonesian stationary power generation. Full article

Background/Objectives: Diabetic cardiomyopathy (DCM) is largely driven by severe oxidative stress and calcium dyshomeostasis. We examined the targeted antioxidant and therapeutic effects of zinc sulfate (ZnSO₄) on contractile dynamics, oxidative damage, calcium turnover, and apoptosis/fibrosis in aged female rats with type 2 diabetes. Methods: Thirty-two aged female Wistar rats were divided into Control, Control + ZnSO₄, Diabetes (DM), and DM + ZnSO₄ groups. DM was induced via high-fat diet and 30 mg/kg streptozotocin. After a 4-week complication period, treatment groups received 10 mg/kg/day ZnSO₄ (i.p.) for 6 weeks. Left ventricular papillary muscle contraction, oxidative/antioxidant markers (MDA/GSH), and gene expressions (SIRT1, GLUT4, SERCA2a, RyR2, Cav1.2, PLN) were evaluated. Myocardial architecture, fibrosis, and apoptosis were analyzed immunohistochemically. In DM rats, contractile force (CF) and velocities (±dF/dtmax) significantly declined. Results: Concurrently, SIRT1, GLUT4, SERCA2a, RyR2, Cav1.2, and antioxidant GSH decreased, while oxidative lipid damage (MDA), PLN, Caspase-3 activity, Collagen I, and fibrosis increased (p < 0.001). ZnSO₄ treatment in diabetic rats acted as a potent antioxidant modulator; it restored redox balance, activated the SIRT1/GLUT4 pathway, protected calcium-handling proteins from oxidative degradation, and significantly improved contractile dynamics. It also preserved myocardial architecture by reducing apoptosis and fibrosis. In healthy rats, ZnSO₄ caused mild stress and early fibrosis. Conclusions: In conclusion, while inducing mild stress in healthy myocardium, zinc supplementation provides robust antioxidant protection in diabetic hearts. It activates SIRT1, suppresses oxidative damage, maintains calcium homeostasis, and restores contractile dynamics, demonstrating strong antioxidant therapeutic potential against DCM. Full article

The co-gasification of biomass and municipal solid waste (MSW) has high potential for sustainable energy generation and waste-to-energy applications. Calliandra calothyrsus (CC) and MSW pellets have complementary thermochemical properties, although there are few experimental studies on their co-gasification in downdraft reactors. This study analyzed the effect of the feedstock composition on the temperature distribution inside the reactor, the syngas composition, and the quality of syngas energy in a 1–2.5 kg/h downdraft gasifier during co-gasification. Six feedstock blend compositions were experimentally evaluated: they were 100 CC, 70 CC–30 MSW, 60 CC–40 MSW, 40 CC–60 MSW, 30 CC–70 MSW, and 100 MSW. The criteria considered for measuring include reactor temperature distribution, syngas composition (CO, H₂, CO₂, and C_nH_m), and lower heating value (LHV). The results indicated that the 70 CC–30 MSW blend had the best syngas performance with a higher oxidation-zone temperature, greater CO concentration, reasonably steady H₂ generation, lower C_nH_m concentration, and the highest syngas LHV compared to other feedstock compositions. In the gasification process, the increase in the proportion of CC was beneficial to char reactivity, oxidation–reduction reaction, and tar cracking. The increase in MSW fractions decreased syngas quality due to the increase in ash and moisture content. The results show that co-gasification of Calliandra calothyrsus and bio-dried MSW pellets can increase syngas quality and provide practical insight into the optimization of biomass–MSW blending for downdraft gasification systems. Full article

In this study, Lactiplantibacillus plantarum XHQ-007, sourced from fermented pineapple pomace, was investigated using whole-genome sequencing (WGS) and systematic phenotypic assays to evaluate its biosafety and functional potential in food applications. The strain showed a 79.94% reduction in detectable tyramine under complex fermentation conditions. In the absence of pH-matched abiotic controls, this reduction cannot be exclusively attributed to enzymatic degradation and may also involve chemical or acid-mediated matrix effects. Further studies are required to distinguish biological degradation from physicochemical contributions. Genomic analysis suggested that this capability may be associated with a putative candidate tyramine-associated metabolic pathway involving the multicopper oxidase cueO and the putative hpa gene cluster, rather than conventional amine oxidases. Furthermore, the isolate displayed strong resilience against gastrointestinal stressors, such as acidic conditions and bile salts. Safety assessments confirmed the absence of hemolytic activity and mobile antibiotic resistance genes. Notably, WGS also identified a plantaricin (pln) operon containing regulatory elements (plnABCD) and structural genes (plnMNOP), suggesting genomic potential for bacteriocin-related functions. The identification of poxL and nox2 may further indicate energy metabolism and redox homeostasis. Overall, this study provides a genome-informed and phenotype-supported characterization of L. plantarum XHQ-007 in a fermentation context. However, all mechanistic interpretations remain putative and require further experimental validation. Full article

Background/Objectives: Sickness absence due to breast cancer generates significant indirect costs. This nationwide registry-based study aimed to evaluate temporal patterns and the population-level burden of sickness absence, rehabilitation benefit utilization, and social insurance expenditures related to breast cancer among women in Poland between 2020 and 2024. Methods: This nationwide analysis is based on the Social Insurance Institution registry. Data on females unable to work due to breast cancer were analyzed (ICD-10: C50). Short-term sickness absence was analyzed. Results: The number of sick leave days due to breast cancer varied from 1,241,223 in 2021 to 1,444,863 in 2024. The number of sick leave certificates increased every year: from 55,732 in 2020 to 79,979 in 2024. The most dynamic growth between 2020 and 2024 occurred in the 45–49 group, where sick leave days increased +33.4% and certificates increased +70.6%. There were significant regional differences. The sickness absence days per certificate due to breast cancer decreased over time, from 23.5 days in 2020 to 18.1 days in 2024. The total number of medical certificates on rehabilitation benefit due to breast cancer varied from 4811 in 2021 to 5281 in 2024. Social insurance expenditures on sickness absence varied from 112,064.9 thousand PLN (approximately 25.24 million EUR) in 2020 to 207,687.9 thousand PLN (approximately 48.3 million EUR) in 2024 and expenditures on rehabilitation benefits varied from 56,812.8 thousand PLN (12.8 million EUR) in 2020 to 89,692.6 thousand PLN (20.83 million EUR) in 2024. Conclusions: This population-based registry study revealed a high economic burden of sickness absence due to breast cancer in Poland. Full article