Search Results (46)

This study examined how mechanical, electrical, and plumbing (MEP) practitioners understand and apply quality and safety management in construction projects in Taiwan. It focused on the gap between what practitioners know about best practices and what they can carry out on site, defined here as the “Cognitive–Execution Gap.” A mixed-methods design was used, combining a questionnaire survey of 130 MEP practitioners with semi-structured interviews with six senior experts. Practitioners with MEP-related academic backgrounds scored significantly higher in professional knowledge and practice than those from unrelated fields, with mean differences of 0.87 and 0.78 points on a 5-point scale, respectively (both p < 0.001). In contrast, awareness of management optimization strategies was high and similar across all demographic groups. Interview findings suggest that schedule pressure, the lower organizational status of MEP compared with civil engineering, and persistent talent shortages prevent practitioners from applying the practices that they recognize as necessary. The results provide evidence consistent with a Cognitive–Execution Gap and suggest that bridging it requires organization-level reforms, including prospectively evaluated BIM-based coordination, clearer standard operating procedures and performance indicators, and structured mentorship programs to strengthen professional capacity in MEP engineering. Full article

Chlorophylls are the major light-harvesting pigments in photosynthetic organisms. Their biosynthesis requires the coordinated supply of metabolic intermediates from two independent upstream branches: the methylerythritol 4-phosphate (MEP)-derived terpenoid pathway, which supplies the phytyl side chain via geranylgeranyl diphosphate (GGPP), and the tetrapyrrole biosynthesis pathway (TBP), which provides the porphyrin ring. How flux through these two branches is coordinated remains poorly understood. In this study, we report the identification of a direct protein–protein interaction between δ-aminolevulinic acid dehydratase (ALAD), the second enzyme of the TBP, positioned immediately upstream of the first metabolic branch point, and the Type II small subunit of GGPP synthase (SSUII), a key regulator of terpenoid flux toward chlorophyll biosynthesis. ALAD was identified as a candidate SSUII-interacting protein by co-immunoprecipitation coupled with LC-MS analysis of rice leaf tissue, with a sequence coverage of 57.04%. The interactions between OsALAD1 and OsSSUII in rice, and between AtALAD1 and AtSSUII in Arabidopsis thaliana, were validated by yeast two-hybrid assay and bimolecular fluorescence complementation (BiFC) in Arabidopsis protoplasts. BiFC imaging demonstrated that the interaction is localized to the chloroplast. Sequence analysis revealed that plant ALAD proteins are highly conserved, with 92% similarity between OsALAD1 and AtALAD1, and 76.9% similarity between OsALAD1 and the green alga Chlamydomonas reinhardtii CrALAD1, indicating cross-species conservation of the ALAD–SSUII interaction. In vitro enzyme activity assays showed that AtSSUII does not directly alter AtALAD1 catalytic activity, suggesting the interaction operates through post-translational rather than direct catalytic mechanisms. Overexpression of AtALAD1 caused severe chlorosis and seedling lethality, while AtSSUII overexpression produced no distinct phenotype; neither transgene altered the transcript level of the other. Together, our results reveal a conserved cross-pathway protein–protein interaction linking the terpenoid regulatory machinery to the early TBP, suggesting a molecular possibility for the coordinated regulation of chlorophyll biosynthesis. Full article

In the Industry 4.0 era, the Architecture, Engineering, Construction, and Operation (AECO) sector faces a strategic challenge in integrating Mechanical, Electrical, and Plumbing (MEP) systems during early design stages, where a lack of “Design for Maintainability” contributes to building defect rates of up to 28%. These failures not only incur significant resource waste but also undermine long-term building sustainability. This study evaluates a digital innovation framework synthesizing Serious Games and Cooperative Problem-Based Learning (CPBL) via Minecraft to foster systemic thinking and spatial reservation logic at Level of Development (LOD) 100–150 as a catalyst for digital transformation. Utilizing a mixed-methods design (n = 25), the curriculum employed a “Mirror Mapping” mechanism, translating game physics into real-world electrical and plumbing logic. While results showed 93% management competency, a significant 13% “Symbolic Transformation Gap (STG)” (80% in system analogy) persisted, indicating that symbolic fluency does not automatically yield professional engineering reasoning. These findings validate the framework’s potential for spatial externalization and emphasize the necessity of “bridging activities” and Digital Twin linkages to optimize building lifecycle performance and reduce carbon footprints, ultimately achieving sustainable building goals. Full article

Despite its potential to enhance construction quality, efficiency, and sustainability, modular construction continues to experience defects that hinder its broader adoption. Understanding and mitigating defects is essential for maximising the sustainability benefits of modular construction by reducing material waste, minimising rework and improving lifecycle performance. Existing research remains fragmented, with limited synthesis integrating defects with their root causes across the project lifecycle. To address this gap, this study investigates defect types, lifecycle-based causes, and mitigation strategies in modular building projects through a PRISMA-guided systematic literature review of 61 peer-reviewed journal articles published between 2015 and 2025 and retrieved from Scopus and Web of Science. Six major defect categories were identified: geometric and dimensional; material and component; joint and connection integrity; envelope performance and durability; structural; and mechanical, electrical, and plumbing (MEP) defects, with geometric and dimensional defects emerging as the most prevalent, accounting for 26.7% of reported cases. Lifecycle root-cause mapping indicates that poor workmanship during on-site assembly is the dominant contributor, accounting for 44.1% of identified root causes, with manufacturing errors (26.8%) and design limitations (13.4%) acting as critical upstream sources. Mitigation strategies cluster into three groups: general recommendations (39% of reported strategies), mainly focusing on low-cost organisational measures such as logistics coordination and workforce training; structured risk-management frameworks (9.1%), including assembly sequencing and tolerance planning; and digital and data-driven technologies (51.9%), such as laser scanning, AI-based inspection, and digital twins, enabling proactive quality assurance across the lifecycle. The study proposes an integrated lifecycle–defect–mitigation framework to strengthen quality governance and advance sustainable modular delivery. Full article

Accurately reconstructing Mechanical, Electrical and Plumbing (MEP) systems from laser-scanned point clouds is often hindered by structural occlusions, sensor noise, and extreme scale imbalance between large pipes and small fittings. This study presents a hybrid framework, driven by both knowledge and data, for automated pipeline BIM updating. To tackle scale variance, we implement a coarse-to-fine segmentation strategy using Density-Based Spatial Clustering of Applications with Noise (DBSCAN) to isolate pipeline instances before segmentation with PointNeXt. Furthermore, a logic-based refinement module integrates geometric and topological priors from the design BIM to correct coordinate deviations in incomplete datasets. Finally, graph isomorphism analysis enables automated topological mapping between unstructured point cloud instances and structured BIM components. Experimental results from a dense shopping center case study demonstrate that the framework achieves a semantic segmentation mIoU of 74.45% and reduces the average spatial coordinate error to within 7 mm. Notably, the automated workflow compressed the modeling time from 3–5 days to approximately 3 h, offering a robust solution for digital twin-oriented facility management. Full article

Hybrid railway assets such as workshops and depots combine building, mechanical, electrical and plumbing (MEP)/industrial, and linear infrastructure domains, increasing coordination complexity and challenging continuity from the Project Information Model (PIM) to the Asset Information Model (AIM). Although Employer’s Information Requirements (EIR), Asset Information Requirements (AIR), and the BIM Execution Plan (BEP) prescribe deliverables and processes, a persistent gap remains between documentary prescriptions and the auditable evidence needed to support traceable decisions within the Common Data Environment (CDE). This paper proposes an ISO 19650-aligned governance framework that operationalizes the EIR/AIR → BEP → CDE transition by: (i) structuring the asset using Functional Units (FUs) as a stable anchor for PIM → AIM continuity; and (ii) implementing a pre-Published Quality Gate that separates control into three non-substitutable dimensions (spatial, semantic, and data). The approach is implemented as a tool-neutral, reproducible workflow (inputs → checks → outputs → publish) and produces a minimal, persistent evidence package in the CDE (file-level report, package summary, publish/hold decision record, and Nonconformity Report (NCR)/BIM Collaboration Format (BCF) traceability), with explicit roles governing the Shared → Published transition. Across 22 Industry Foundation Classes (IFC), deliverables from two depot cases and multiple delivery states, All Gates Pass ranged from 25.0% to 44.4% depending on Case × State; overall, 14/22 deliverables (63.6%) would be held pending correction under the gate. Although validated on Spanish railway depots, the framework is grounded in ISO/openBIM standards and is designed for transferability to other international contexts and complex asset types where multidisciplinary federation and PIM → AIM continuity pose similar challenges. Full article

This study investigates the protective performance of a triazole-based Mannich base corrosion inhibitor, 4-((1,2,4-triazolyl)methyl) dibutylamine (TZMBA), on P110 carbon steel in dissolved oxygen environments. TZMBA was synthesized via a Mannich reaction, and its molecular structure was confirmed by Fourier transform infrared spectroscopy (FT-IR). The corrosion inhibition behavior and underlying mechanisms were systematically explored through weight loss measurements, surface characterization, and multiscale molecular simulations. Weight loss results indicated that TZMBA significantly mitigates the corrosion of P110 steel, with inhibition efficiency reaching 81.5% at 1.67 mmol/L and 82.0% at 2.14 mmol/L. Adsorption thermodynamic analysis revealed that the process follows the Langmuir isotherm model. The calculated standard Gibbs free energy ${∆G}_{ads}^0$ of −38.69 kJ/mol suggests a spontaneous, mixed-type adsorption mechanism involving both physisorption and chemisorption. Scanning electron microscopy (SEM) observations confirmed a marked reduction in surface degradation, characterized by suppressed corrosion products and minimized localized attack. X-ray photoelectron spectroscopy (XPS) further verified that TZMBA anchors to the metal surface through chemical coordination, forming a robust organic-inorganic composite film. From a theoretical perspective, frontier molecular orbital (FMO) analysis showed that TZMBA’s high E_HOMO and narrow energy gap facilitate efficient electron transfer. Combined Fukui function and molecular electrostatic potential (MEP) maps identified the nitrogen atoms in the triazole ring and amine group as the primary active sites. Furthermore, molecular dynamics (MD) simulations demonstrated that TZMBA molecules adopt a nearly parallel configuration on the Fe surface. The high negative interaction energy obtained from MD simulations confirms a strong binding affinity and a potent inherent driving force for the formation of a stable protective layer. Overall, the integration of experimental data and theoretical calculations establishes TZMBA as an effective inhibitor that provides superior protection by forming a stable, compact adsorption film on P110 carbon steel. Full article

Achieving reliable interoperability between architectural and structural models remains one of the main challenges in BIM-based design workflows. Despite the widespread adoption of Building Information Modeling, the automatic transfer of information between modeling software and FEM analysis tools continues to generate inconsistencies, information loss, and the need for manual interventions. This study examines these issues through the case study of a reinforced-concrete residential building located in Palermo, used to evaluate BIM-to-FEM exchanges between Revit^®, Robot Structural Analysis^®, PRO_SAP^®, and JASP^®. The interoperability tests highlight significant limitations in both native and IFC-based workflows. The direct Revit–Robot link ensures good geometric consistency but still requires manual correction of analytical axes, connections, and boundary conditions. Indirect transfers via IFC exhibit greater instability: both IFC2x3 Coordination View 2.0 and IFC4 Reference View show difficulties in correctly interpreting structural elements and do not adequately preserve analytical relationships, resulting in unconnected slabs, disconnected nodes, and missing constraint information. In PRO_SAP^®, several elements are also absent after IFC import. To address these issues, the study proposes a workflow based on the integration of Revit^® and JASP^® aimed at generating a reliable federated model. This model was further validated in Navisworks^®, Solibri Anywhere^®, BIM Vision^®, and Enscape^® to assess its correct interpretation across different software environments. This approach enhances interdisciplinary coordination, supports clash detection, facilitates immersive VR-based review, and centralizes architectural, structural, and MEP models into a unified environment. The results show that structured workflows and careful management of native and IFC transfers significantly improve model reliability and reduce design inconsistencies. Full article

Salt stress is a major abiotic factor limiting wolfberry (Lycium barbarum) growth. As a high-value medicinal and edible crop, wolfberry relies on its carotenoid content, a critical determinant of fruit quality and nutritional value. To elucidate the expression regulatory mechanisms of key genes in the carotenoid biosynthesis pathway under salt stress, this study systematically identified 17 structural genes within the L. barbarum carotenoid pathway using genomic and transcriptomic approaches. Comprehensive analyses were conducted on gene structure, chromosomal distribution, conserved domains, and cis-acting elements. The results revealed that these genes were clustered on chromosomes Chr08 and Chr10 and exhibit strong collinearity with tomato (18 syntenic pairs). Their promoters were enriched with light-responsive (G-box) and stress-responsive (ABRE, DRE) elements. Tissue-specific expression analysis demonstrated high expression in mid-to-late fruit developmental stages (LbaPSY1, LbaPDS) and in photoprotective genes (LbaZEP, LbaVDE) in leaves. Under 300 mM NaCl stress treatment, the genes exhibited a staged response: Early stage (1–3 h): upstream MEP pathway genes (LbaDXS, LbaGGPS) were rapidly induced to supply precursors. Mid-stage (6–12 h): midstream genes (LbaPSY, LbaPDS, LbaZDS) were continuously upregulated, promoting lycopene synthesis and preferentially activating the β-branch (LbaLCYB). Late stage (12–24 h): downstream xanthophyll cycle genes (LbaBCH, LbaZEP, LbaVDE) were significantly enhanced, facilitating the accumulation of antioxidant compounds like violaxanthin and neoxanthin. This coordinated regulation formed a synergistic “precursor supply–antioxidant product” network. This study revealed the phased and coordinated regulatory network of carotenoid biosynthesis genes under salt stress in L. barbarum. It also provided potential target genes for the new cultivar selection with enhanced salt tolerance and nutritional quality. Full article

Aging buildings pose a significant concern for many large developed cities, and the operation and maintenance (O&M) of mechanical, electrical, and plumbing (MEP) systems becomes critical. Building Information Modeling (BIM) facilitates efficient O&M for MEP. However, these numerous aging buildings were constructed without BIM, making BIM reconstruction a monumental undertaking. This research proposes an automatic approach for generating BIM based on 2D drawings. Semantic segmentation was utilized to identify MEP components in the drawings, trained on a custom-made MEP dataset, achieving an mIoU of 92.18%. Coordinates and dimensions of components were extracted through contour detection and bounding box detection, with pixel-level accuracy. To ensure that the generated components in BIM strictly adhere to the specifications outlined in the drawings, all model types were predefined in Revit by loading families, and an MEP component dictionary was built to match dimensions and model types. This research aims to automatically and efficiently generate BIM for MEP systems from 2D drawings, significantly reducing labor requirements and demonstrating broad application potential in the large-scale O&M of numerous aging buildings. Full article

Two new Co(II) coordination compounds viz. [Co(H₂O)(bz)₂(μ-3-Ampy)₂]_n (1) and [Co(4-Mebz)₂(2-Ampy)₂] (2) (wherebz = benzoate, 4-Mebz = 4-Methylbenzoate and Ampy = Aminopyridine) were synthesized and characterized via elemental (CHN), electronic spectroscopy, FT-IR spectroscopy, and thermogravimetric analysis (TGA). The molecular structures were determined by single-crystal X-ray diffraction analysis, inferring that compound 1 crystallizes as a 3-Ampy bridged Co(II) coordination polymer, whereas compound 2 crystallizes as a mononuclear Co(II) compound. Compound 1 unfolds the presence of N–H⋯O, C–H⋯O, O–H⋯O, C–H⋯N and aromatic π⋯π interactions, while for compound 2, N–H⋯O, C–H⋯O, C–H⋯C and C–H⋯π interactions are observed. Both the compounds showcase scarcely reported chelate ring interactions involving the benzoate moiety (chelate ring⋯π in 1 and N–H⋯chelate ring in 2). We also conducted theoretical evaluations comprising of combined QTAIM/NCI plot analysis, DFT energy calculation and MEP surface analysis to analyze the supramolecular interactions present in the crystal structures. As per QTAIM parameters, the predominance of π-stacking interactions over hydrogen bonds in stabilizing the assembly in compound 1 is affirmed. Likewise, in compound 2, both hydrogen bonding (HBs) and C–H⋯π interactions are deemed pivotal in stabilizing the dimeric assemblies. The in vitro antiproliferative activities of compounds 1 and 2 were performed against Dalton’s lymphoma (DL) cancer cell lines through cytotoxicity and apoptosis assays, showcasing higher cytotoxicity of compound 1 (IC₅₀ = 28 μM) over compound 2 (IC₅₀ = 34 μM). Additionally, a molecular docking study investigated the structure–activity relationship of these compounds and allowed an understanding of the molecular behaviour after treatment. Full article

In the present work, we reported the synthesis and characterization [single crystal X-ray diffraction technique, spectroscopic, etc.] of two new Ni(II) and Zn(II) coordination compounds, viz. [Ni(2,6-PDC)₂]₂[Ni(en)₂(H₂O)₂]₂[Ni(en)(H₂O)₄]·4H₂O (1) and [Zn(2,6-PDC)(Hdmpz)₂] (2) (where 2,6-PDC = 2,6-pyridinedicarboxylate, en = ethylene-1,2-diamine, and Hdmpz = 3,5-dimethyl pyrazole). Compound 1 is found to crystallize as a multicomponent Ni(II) compound with five discrete complex moieties, whereas compound 2 is isolated as a mononuclear Zn(II) compound. A deep analysis of the crystal structure of 1 unfolds unusual dual enclathration of guest complex cationic moieties within the supramolecular host cavity stabilized by anion–π, π-stacking, N–H⋯O, C–H⋯O, and O–H⋯O hydrogen bonding interactions. Again, the crystal structure of compound 2 is stabilized by the presence of unconventional C–H⋯π(chelate ring) interactions along with C–H⋯O, C–H⋯N hydrogen bonding, π-stacking, and C–H⋯π(pyridyl) interactions. These non-covalent interactions were further studied theoretically using density functional theory (DFT) calculations, molecular electrostatic potential (MEP) surfaces, non-covalent interaction (NCI) plot index, and quantum theory of atoms in molecules (QTAIM) computational tools. The computational study displays that π-stacking or H bonds greatly tune the directionality of compound 1, although non-directional electrostatic forces dominate energetically. For compound 2, a combined QTAIM/NCI plot analysis confirms the presence of unconventional C–H⋯π(chelate ring) interactions along with other weak interactions obtained from the crystal structure analysis. Further, the individual energy contributions of these weak yet significant non-covalent interactions have also been determined computationally. Full article

An Fe(III)-carbonato six-coordinate picket fence porphyrin complex with the formula [K(2,2,2-crypt)][Fe^III(TpivPP)(CO₃)]·C₆H₅Cl·3H₂O (I) has been synthesized and characterized by UV-Vis and FT-IR spectra. The structure of (carbonato)(α,α,α,α-tetrakis(o-pivalamidophenyl)porphinato)ferrate(III) was also established by XRD. The iron atom is hexa-coordinated by the four nitrogen atoms of the pyrrol rings and the two oxygen atoms of the CO₃²⁻ group. Complex I, characterized as a ferric high-spin complex (S = 5/2), presented higher Fe-Np (2.105(6) Å) and Fe-P_C (0.654(2) Å) distances. Both X-ray molecular structure and Hirshfeld surface analysis results show that the crystal packing of I is made by C-H⋯O and C-H⋯Cg weak intermolecular hydrogen interactions involving neighboring [Fe^III(TpivPP)(CO₃)]⁻ ion complexes. Computational studies were carried out at DFT/B3LYP-D3/LanL2DZ to investigate the HOMO and LUMO molecular frontier orbitals and the reactivity within the studied compound. The stability of compound I was investigated by analyzing both intra- and inter-molecular interactions using the 2D and 3DHirshfeld surface (HS) analyses. Additionally, the frontier molecular orbital (FMO) calculations and the molecular electronic potential (MEP) analyses were conducted to determine the electron localizations, electrophilic, and nucleophilic regions, as well as charge transfer (ECT) within the studied system. Full article

The reaction between 5-acetylbarbituric acid and 4-dimethylthiosemicarbazide or 4-hexamethyleneiminyl thiosemicarbazide produces 5-acetylbarbituric-4-dimethylthiosemicarbazone (H₂AcbDM) and 5-acetylbarbituric-4N-hexamethyleneiminyl thiosemicarbazone (H₂Acbhexim). Eight new complexes with different copper(II) salts have been prepared and characterized using elemental analysis, molar conductance, UV–Vis, ESI-HRMS, FT-IR, magnetic moment, EPR, and cyclic voltammetry. In addition, three-dimensional molecular structures of [Cu(HAcbDM)(H₂O)₂](NO₃)·H₂O (3a), [Cu(HAcbDM)(H₂O)₂]ClO₄ (4), and [Cu(HAcbHexim)Cl] (6) were determined by single crystal X-ray crystallography, and an analysis of their supramolecular structure was carried out. The H-bonded assemblies were further studied energetically using DFT calculations and MEP surface and QTAIM analyses. In these complexes, the thiosemicarbazone coordinates to the metal ion in an ONS-tridentate manner, in the O-enolate/S-thione form. The electrochemical behavior of the thiosemicarbazones and their copper(II) complexes has been investigated at room temperature using the cyclic voltammetry technique in DMFA. The Cu(II)/Cu(I) redox system was found to be consistent with the quasi-reversible diffusion-controlled process. Full article

In this study, a series of electron donor (–NH₂, –NMe₂ and –^tBu) and electron-withdrawing substituents (–F, –CN and –NO₂) were used to tune the nucleophilicity or electrophilicity of a series of square planar Ni²⁺, Pd²⁺ and Pt²⁺ malonate coordination complexes towards a pentafluoroiodobenzene and a pyridine molecule. In addition, Bader’s theory of atoms in molecules (AIM), noncovalent interaction plot (NCIplot), molecular electrostatic potential (MEP) surface and natural bond orbital (NBO) analyses at the PBE0-D3/def2-TZVP level of theory were carried out to characterize and discriminate the role of the metal atom in the noncovalent complexes studied herein. We hope that the results reported herein may serve to expand the current knowledge regarding these metals in the fields of crystal engineering and supramolecular chemistry. Full article