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Iron-based superconductors have strong potential for magnet applications through their very high upper critical field, low anisotropy and manufacturability through the powder-in-tube (PIT) route. The engineering critical current density (Je) is a key parameter for measuring the maximum current density that superconducting materials can withstand in practical applications. It serves as a bridge between theoretical research and practical applications of superconductors and has great significance in promoting the development and application of superconducting technology. In this study, Ag sheathed Ba0.6K0.4Fe2As2 (Ba-122) iron-based superconducting tapes were prepared by using the process of drawing, flat rolling and heat treatment by hot pressing (HP). For the first time, the filling factor of the tapes increased to about 40%, leading to a reduction in the volume fraction of Ag, consequently lowering the overall cost. The optimal parameters for achieving high transport Je were obtained by comparing the effects of different HP pressures on the properties and micro-morphology of the tapes. The prepared mono-filament tapes are capable of carrying the transport Je of 4.1 × 104 A/cm2 (Ic = 350 A) at 4.2 K, 10 T, marking the highest Je reported for Ba-122 wires and tapes to date. Our results show that high transport Je can be obtained in Ba-122 superconducting tapes, and iron-based superconductors have a promising future in practical applications. [ABSTRACT FROM AUTHOR]

This paper presents experimental investigation of the axial behaviour of built-up (BU) (I-section) cold-formed steel doubly-symmetric channel with single-/double-layer sheathing on both sides configuration. Fifteen (15) monotonic concentric axial compression tests were performed on 7-BU sections with single-layer sheathing, 7-BU sections with double-layer sheathing, 1-BU section stud without sheathing. The experiments aim to enumerate ultimate axial strength, buckling interactions, failure pattern and strength enhancement due to sheathing for BU section stud members. The novelty of the study is that, for the first time an attempt is made to investigate the axial behaviour of single-/double-layer sheathed BU section panels using seven different sheathing boards.        Results indicate large range of deformation behaviour, with local-global and distortional-global interaction buckling phenomena. Failure is also observed due to failing of screws in specimens with sheathing of thickness ≥ 9 mm and modulus of elasticity > 6400MPa. Also, for the first time, efficacies of four semi-analytical methods based on rational extension of direct strength method (DSM) are presented. Results suggest the insufficiency of current AISI design specifications, whereas predicted results obtained using the new modified DSM methodology are within the adequate variation range as the adopted methodology considers desired buckling interaction. The efficacy of the recommended design methodology is verified through reliability analysis. [ABSTRACT FROM AUTHOR]

As an important technique for manipulating particles in fluid–solid channel flows, inertial focusing encourages the design of the channel geometry to enhance particle radial aggregation. Traditional methods typically use exquisite sheathes or elbows to create constricted flows, which ultimately increase flow resistance and lower fluid–solid separation efficiency. This paper presents a slippery wall modification technique that, by regulating the channel flows, is expected to induce nontrivial particle lateral migrations. More specifically, interface-resolved simulations are performed using the lattice Boltzmann method. A slip boundary condition is applied to the redesigned hydrophobic bottom wall. It is observed that the typical bifurcate migration, i.e., particles moving divergently toward the upper and lower equilibrium positions around a crucial location (CL), does not occur along the channel centerline. The CL is always below the centerline, and it decreases consistently with an increase in Kn or Re. By increasing Re, particles are prone to approach the channel centerline. With larger Kn, particles in the higher equilibrium position are affected in the same way, but their lower counterparts are drawn to the bottom wall. [ABSTRACT FROM AUTHOR]

Cellulosic fiber board (CFB) is a lightweight form of sheathing that contains 94% post-consumer recycled materials. The viability of CFB sheathed shear walls as an alternative to Oriented Strand Board (OSB) walls is the focus of this study. A total of 23 walls and 10 connection samples were tested under cyclical loading to determine their overall behavior and capacity. The walls consisted of 2.44 m high by 3.66 m long CFB and OSB sheathed walls with and without openings. The design capacity of each wall was calculated and compared to the experimental results. For the walls with openings, the effects of blocking and strapping on their behavior were also evaluated. It was found that CFB is a viable alternative to OSB; however, some adjustments to the current design values and processes are required as the current procedure results in safety factors that are significantly lower than those for OSB walls. [ABSTRACT FROM AUTHOR]

In practical applications, it is typical for different types of sheathings (referred to as dissimilar) to be connected at both flanges of the stud (lipped channel-section) in cold-formed steel (CFS) panelised construction (e.g. one-side has interior sheathing and the other exterior sheathing). However, limited studies are available on the axial behaviour of CFS studs with different combinations of sheathings present at both-flanges of a stud. This novel experimental study investigates the structural behaviour of fourteen (14) CFS panels with sheathing on one-side only and different sheathing on both flanges of the wall panel using combinations of seven (7) different sheathing boards [fibre-cement boards (FCB) (8 mm/10 mm/12 mm thick); calcium silicate boards (CSB) (12 mm thick); and heavy duty FCB (6 mm/9 mm/12 mm thick)]. The ultimate axial strength, load-deformation behaviour and failure patterns are the parameters compared. Analytical/semi-analytical design methodologies namely; Rayleigh-Ritz (R-R) method, finite-strip method based on direct strength method (DSM) and differential equation of equilibrium method (DEEM) are validated based on the experiments. Limited studies are available to verify the efficacy of these methods to estimate the axial strength of CFS wall panels with dissimilar sheathing on both flanges. Results establish that DSM may be used efficiently rather than the R-R method and DEEM. [ABSTRACT FROM AUTHOR]

Wood is known for its complex hygroscopic properties. Previous studies show that both the temperature-dependency and the hysteresis in sorption should be included in the physical models, if the most accurate results are desired from simulations of building assemblies with wood-based materials. Literature is scarce on the topic, where the significance of these aspects on the reliability of mould-risk assessments is inspected. Exterior walls with glass wool insulation and LDF-sheathing were studied by using two different models with previously measured material data. Over 300 hygrothermal simulations were carried out, where mould-indices were computed on the warm side of the sheathing. According to both conventional and more sophisticated model, the studied walls perform well in cold climate if no driving rain leaks in. Temperature-dependent and hysteretic model yields slightly smaller mould-indices in general, but for certain leaky cases the difference is significant, which indicates the importance of sophisticated sorption-properties in modelling. [ABSTRACT FROM AUTHOR]

The temperature dependency of the adsorption isotherm renders its significance as one of the primary input parameters in models dealing with moisture transport. The present study involved the determination of the adsorption isotherm of sixteen building materials from various categories, including cladding, building paper, wood, sheathing boards, and insulations. The measurements were conducted under nine climatic conditions, a combination of three temperatures (3 °C (37.4 °F), 21 °C (69.8 °F), 45 °C (113 °F)) and three relative humidity levels (50%, 70%, 90%). The study indicated that relative humidity increased the building materials' equilibrium moisture content (EMC). In opposition, an increase in temperature decreased the EMC of the tested materials. It was discovered that cellulose fiber and wood-based materials had a greater capacity to store moisture than others. Conversely, the minimum moisture content was observed in brick, Densglass gold gypsum, and EPS products. Furthermore, we used the ABC model as an adaptable mathematical equation for a novel nonlinear surface fitting of adsorption isotherms of tested materials to make optimal use of the experimental data and effectively analyze the simultaneous impact of all temperatures and relative humidities. Tested against the measured experimental data, we obtained the best R-squared values from the second-order polynomial Equation. [ABSTRACT FROM AUTHOR]

Prefabricated wood construction relies heavily on efficient material handling, yet rigging system design for floor panels remains understudied. This study introduces a novel rigging device that attaches to prefabricated wood I-joist floor panels using self-tapping screws, avoiding potential damage caused by predrilled holes in the sheathing panels and framing members. To establish allowable lifting capacities and optimal installation practices, comprehensive withdrawal tests were conducted on 114-floor panel specimens. Factors influencing withdrawal capacity, such as anchor plate placements, flange materials and width, screw type and quantity, and sheathing panel thickness, were systematically evaluated. Results indicate that withdrawal capacity does not scale linearly with screw quantity and that anchor plates with eight screws centered on the flange enhance performance by up to 20% compared to four-screw configurations. Unexpectedly, thinner sheathing panels yielded higher capacities, potentially due to increased screw penetration depth in the joist flange. In addition, anchor plate orientation, flange width, and flange materials also impact capacity. These findings provide essential data for designing reliable and efficient rigging systems in prefabricated wood construction. [ABSTRACT FROM AUTHOR]

Constructing powerful anode/cathode interphases by modulate ion solvation structure is the principle of electrolyte design. However, the methodological and theoretical design principles of electrolyte/solvation structure and their effect on electrochemical performance are still vague. Here, we propose a cationic weakly coordinating-intervention strategy for modulating the Na+ solvation sheathes and constructing robust anode/cathode interphases in sodium-metal batteries. Unlike the local highly concentrated electrolytes, 1,2-difluorobenzene can weakly coordinate with Na+ thus transforming the solvation structure into Na+-anion-incorporated structures and strengthening anode/cathode interphases formation by combining with salt decomposition. Furthermore, the correlations between the electrode interface properties and solvation structure are revealed, which can be tuned by the weakly coordination. Ultimately, the modulated electrolyte achieves 97.5% Coulombic efficiency for 600 cycles in Na‖Cu cells at 1 mA cm−2 and a beneficial lifetime (2500 h) in Na‖Na cells. Meanwhile, Na‖PB cells have achieved long-term operation at 4.8 V, along with operation at wide temperatures. Here, authors propose a weakly coordinating-intervention strategy to modulate the Na+ solvation sheath and construct a robust interphase in sodium-metal batteries. Correlation between electrode interface properties and solvation structure is also stated. [ABSTRACT FROM AUTHOR]

To improve the seismic behaviour of cold-formed steel (CFS) walls, a novel infilled CFS wall covered with different wall sheathings (gypsum wallboard, oriented strand board and fibre cement board) was assessed. Four full-scale specimens were tested under cyclic lateral loads to investigate the impacts of the wall sheathings on the seismic performance of the CFS wall. The failure process, failure mode, load–displacement curve, strength degradation, stiffness degradation, energy dissipation, deformation and strain variation of the walls were investigated. The failure modes of the walls were found to be failure of the connections between the CFS frame and the sheathing as well as crushing of the infill material. Compared with a specimen without sheathing, the peak load and lateral stiffness of the walls with sheathing were increased by 1.25–1.72 times, indicating that the sheathings played an important role in the lateral resistance of the wall. An analysis model and formulas for predicting wall lateral stiffness were developed. Comparisons between the calculations and experimental data showed that the proposed theoretical method was able to predict the lateral stiffness of the infilled CFS walls accurately. [ABSTRACT FROM AUTHOR]

Air-permeable multilayer cladding (vinyl siding, roof pavers, discontinuous metal roofing, solar panels, etc.) are one of the most common types of building components in North America. Their defining aerodynamic feature is that they have an air cavity separating the component from the sheathing, studs, or interior layer. Due to air-permeability, external wind loads can transfer into the air cavity between the layers. Although these cladding systems have similar geometries in many ways, design loads are not generally available for such systems. This study aims to synthesize the available literature on the pressure equalization factor, which is the proportion of external load acting on the cladding and provide a framework for design wind loads on air-permeable multilayer cladding systems. To accomplish this, the many factors that affect the pressure equalization factor, such as the gap-to-cavity-depth ratio, panel size, and exposure are discussed. Then, the pressure equalization factors from multiple studies are combined to examine the effect of effective area on the pressure equalization factor. Finally, recommendations for implementing these guidelines into design standards are provided. [ABSTRACT FROM AUTHOR]

Purpose: To establish typical clinical and radiological profiles of primary low-grade parotid cancers in order to tailor therapeutic strategy. Materials and methods: Retrospective study of 57 patients operated on for primary parotid cancer between 2010 and 2021, with review of preoperative MRI and histopathology according to a standardized scoring grid. Objective: To study prognostic factors and determine the preoperative clinical and radiological profile of low-grade cancers. Results: Good prognostic factors for specific survival were: staging ≤ cT3 (p = 0.014), absence of adenopathy on cN0 MRI (p < 0.001), superficial lobe location (p = 0.033), pN0 (p < 0.001), absence of capsular rupture (p = 0.004), as well as the absence of peri-tumoral nodules (p = 0.033), intra-parotid adenopathies (p < 0.001), vascular emboli (p < 0.001), peri-neural sheathing (p = 0.016), nuclear atypia (p = 0.031), and necrosis (p = 0.002). It was not possible to define a reliable clinical and radiological profile for low-grade cancers (sensitivity 38%, specificity 79%). Conclusion: Our study demonstrated multiple factors of good prognosis, but it was not possible to define a clinical and radiological profile of patients likely to benefit from more limited surgery, nor to diagnose, a priori, low-grade cancers. [ABSTRACT FROM AUTHOR]

This case report describes a case of retinal vasculitis in a patient with Rhupus, which has not been reported earlier in the literature. A 39-year-old female patient with a history of Rhupus presented with sudden vision loss in her left eye. The patient was treated earlier, for her polyarthritis, with oral corticosteroids, hydroxychloroquine, and oral methotrexate, which were discontinued after 1 year of treatment. At presentation, fundus examination of the left eye revealed mild vitritis, perivenous sheathing, and hemorrhagic periphlebitis. The patient was administered three doses of pulse corticosteroid, resulting in a reduction in retinal vasculitis and macular edema. The patient was continued on oral corticosteroids and started on oral methotrexate and hydroxychloroquine. At 6-week follow-up, the patient's vision had improved to 6/9, and fundus examination revealed resolving phlebitis and retinal hemorrhages. This case also highlights the importance of prompt diagnosis and treatment of retinal vasculitis in patients with Rhupus. [ABSTRACT FROM AUTHOR]

The purpose of this study is to determine the material properties of CFRP composites in the form of a fabric for the construction of racing car bodywork. This work focused on the determination of the strength and tribological properties as well as investigating the effects of the operating environment on the developed material. Three material variants, differing in the number of layers used to produce the reinforcement, were used in this study. The tests were carried out on two-/three-/four-layer sheets produced by infusion. Due to the later use of the tested composites for the sheathing of a racing car, the results obtained were analysed in terms of the most favourable strength properties while keeping the weight as low as possible. In this study, the hardness, impact strength, and tensile and bending stresses of the developed composites were examined. In addition to the strength properties, the density, the effects of immersion in water, and the composite's resistance to staining and friction in the presence of aggressive media were also checked. The structure and the breakthroughs resulting from the strength tests were observed using a stereoscopic microscope. The material's resistance to sunlight and UVB was also tested. [ABSTRACT FROM AUTHOR]

The bovine horns is an anatomical region that has been poorly studied from an anatomical and physiological point of view. The lidia bull is an iconic animal and its horns a mythological symbol of integrity, to such an extent that farmers resort to applying synthetic resins covers to preserve it from any manipulation. With the present work it is intended to study the histological structure of the horn of the lidia bull, analyzing the possible influence of the practice of "sheathing" on it. To this end, horns have been collected from 30 bulls (4-5 years old) in bullrings in, with a control group of 15 animals not sheathed. After the analyses, the normal histological structure of the bull's horns is described and the lesions observed in some animals, such as spongiosis in the stratum spinosum, cellular disorganization of the stratum basalis or the presence of multiple neovessels in the dermis, are described. No effect of sheathing is detected at the histological level. [ABSTRACT FROM AUTHOR]

This study introduces gypsum-wheat-straw composite (GWC) as an innovative sheathing panel to enhance the fire resistance of light wood frame (LWF) walls, addressing the limitations of conventional gypsum board (GB) which can crack and compromise wall integrity when exposed to fire. Through a series of numerical simulations and experimental studies on mesoscale walls, we evaluated the thermal performance and fire resistance of GWC at elevated temperatures. The investigation focused on the impact of embedded compression strips, the number of sheathing layers, and panel types on fire resistance. The findings indicate that GWC sheathing panels significantly delay the temperature rise within walls compared to GB. Specifically, the walls sheathed with single-layer GWC showed a 20-minute delay in reaching charring temperature versus GB-sheathed walls. In double-layer configurations, the addition of GWC beneath an outer GB layer extended the time to charring temperature by an additional 17–30 min. During fire resistance tests, GWC maintained its integrity with only minor cracks, in contrast to GB which cracked and peeled off at high temperatures. This comparative analysis demonstrates that GWC-sheathed walls exhibit superior fire resistance, effectively mitigating the risk of fire-related failures in LWF structures. The results provide valuable insights for the effective application of GWC in LWF, offering a promising material solution that enhances fire safety and structural integrity under extreme conditions. The innovative use of GWC in sheathing could set a new standard for material performance in fire-resistant building design. • Novel gypsum-wheat-straw composite (GWC) sheathing improves fire resistance of wood frame walls. • GWC sheathing delays charring temperature by 20–30 min compared to gypsum board (GB). • GWC sheathing exhibits minimal cracking and maintains high integrity under fire conditions. • Mesoscale wall simulations confirm GWC sheathing's superior thermal performance over GB. [ABSTRACT FROM AUTHOR]

• Formulas for the shear resistance evaluation of wood panel-to-steel sheet screw connections has been calibrated based on a wide experimental database. • The Easley et al. [1] method has been validated for shear walls with wood sheathing covered by 2nd-generation of Eurocode 8 on the bases of a wide experimental database. • The partial safety factor for in-plane horizontal resistance evaluation of shear walls with wood sheathing has been defined according to the limit state design within the Eurocode format. • The overstrength factor for SWWS belonging to Ductility class 3 (DC3) according to prEN1998-1-2 (CEN, 2022) [2] has been derived according to the capacity design within the Eurocode format. Within the 2nd-generation of Eurocodes several new lateral force resisting systems (LFRS) typically used in lightweight cold-formed steel (CFS) buildings have been introduced, including shear walls with wood sheathing (SWWS). Therefore, extensive studies have been carried out to define the seismic design parameters according to the format of European code for seismic design, i.e. Eurocode 8. In current version of the 2nd-generation Eurocode 8 (prEN1998-1-2, CEN 2022), in case of SWWS the behaviour factor has been defined based on the FEMA P695 (FEMA, 2009) [3] methodology, whereas the other seismic design parameters have been set based on assumption validated with analyses on limited case studies. To overcome this lack, specific research devoted to defining the main seismic design parameters for SWWS belonging to Ductility class 3 (DC3) according to prEN1998-1-2 (CEN 2022) has been carried out at the University of Naples "Federico II". The research shows that the Easley et al. (1982) method gives consistent in-plane horizontal wall resistance predictions if the shear resistance of wood panel-to-steel sheet screw connections (sheathing connections) is evaluated with reliable approaches and formulas for the evaluation of the shear resistance of sheathing connections have been calibrated. Based on the results obtained from this research, a partial safety factor for resistance evaluation of SWWS according to limit state design (LSD) equal to 1.3 is proposed and an overstrength (expected resistance) factor for the design of non-ductile elements according to capacity design equal to 1.7 is recommended. [ABSTRACT FROM AUTHOR]

In lightweight timber frame buildings, the horizontal stability against, for instance, wind loads is mainly ensured by shear diaphragms. These shear walls are typically constructed using a timber frame and a load-bearing sheathing layer on one or both sides of the framework. An atypical construction method uses double sheathing panels on top of each other, e.g. because of acoustic or fire safety reasons. However, no design rules are provided for such structures: the respective current and upcoming European standard (Eurocode 5 part 1-1) does not consider the structural contribution of both sheathing panel layers. Therefore, in this study, an experimental campaign is performed to enhance the knowledge of such double-sheathed shear walls, and two analytical calculation methods are proposed. The experimental campaign tests eight full-scale configurations through a racking resistance test with monotonic loading. Sheathing materials include load-bearing and non-load-bearing gypsum plasterboards and resinoid-bonded particle boards. All sheathing panels are connected to the fully anchored frames using staples. Results demonstrate that adding a second sheathing layer of the same material, with the same fastener disposition as the inner layer does not fully double the racking capacity and racking stiffness. Secondly, using a non-load-bearing gypsum plate as the inner layer creates a long plateau phase at the post-peak loading response, producing a less brittle failure behavior. The experiments are used as a benchmark to develop an analytical model based on Blaßand Gebhardt's method for calculating the shear capacity of dowel-type connections with an interlayer. The proposed method introduces an interaction factor that takes into account that the connections of the outer sheathing layer, which pass through the inner sheathing layer, also contribute to the sheathing-to-framing connection of the latter. A simplified model is also presented, using a combination factor that aligns with the current Eurocode 5 design method for walls with sheathing panels on both sides of the framing. Different values for the respective interaction and combination factors are verified to determine a safe value for each tested configuration. • Racking behavior tested of timber frame walls with single-sided double-layered panels. • Two analytical models to determine the racking resistance are proposed and verified. • Doubling sheathing panel layers on the same side does not double racking resistance. • Non-load-bearing gypsum plates as inner layer lead to a less brittle failure behavior. [ABSTRACT FROM AUTHOR]

Timber-framed shear walls play a crucial role in providing stiffness and resistance to timber buildings subjected to horizontal forces induced by wind or earthquakes. Enhancing the load-carrying capacity of a timber-framed shear wall subjected to horizontal forces, is achieved most effectively by reinforcing the connection between sheathing and framing members. Since however, the shear resistance of such a wall is determined by the resistance of the individual wall elements, strengthening the sheathing-to-framing connection is possible only to an extent where the shear resistance is not limited by the resistance of the sheathing panel. This study presents experimental investigations of the shear resistance of OSB/3 panels, when used as sheathing material in timber-framed shear walls, which revealed that the shear resistance of the OSB/3 sheathing was reduced in comparison to the shear strength of the OSB/3 panels themselves. The reduction is attributed to additional stresses in the panel, and is accounted for in design rules specified in the German National Annex of Eurocode 5 (DIN EN 1995-1-1/NA:2013-08) and in the CEN Enquiry (ENQ) draft of Eurocode 5 (prEN 1995-1-1:2023-09). The results of the investigations confirm the reduction factor which is proposed in prEN 1995-1-1:2023-09, for wall elements with one-sided sheathings. However, the reduction factor specified for the design of wall elements with two-sided sheathings could not be confirmed. The results of this study performed with comparably massive and rigid timber framing revealed no difference in the reduction factor for timber-framed shear walls with one- or two-sided sheathings. • Tensile and shear tests on OSB/3 panels of thicknesses 12 mm, 15 mm, 18 mm and 25 mm. • Investigation of the load-carrying capacity of OSB/3 sheathed timber-framed walls. • Evaluation of the limit of OSB/3 panels in the application as sheathing material. • Comparison of results from experiments with design rules given in Eurocode 5. [ABSTRACT FROM AUTHOR]

Offering the advantages of non-combustibility, high shear strength, and high shear stiffness, a cold-formed steel (CFS) shear wall sheathed with corrugated steel sheets (CSS) is a promising shear wall system for low- and mid-rise constructions in high wind and seismic zones. As the primary lateral force-resistant component of CFS structures, the lateral response of CSS sheathed shear wall is primarily determined by the CFS-to-sheathing screwed connections. The connection performance of screws in CFS walls was determined by a combination of shear and tensile forces, with a particular focus on the shear performance parallel to the corrugation direction within the plane. The series of experiments reported in this paper characterize the hysteretic behavior of the screwed connections between CFS studs and sheathing panel under shear loading. Experimental tests were conducted in order to generate the hysteretic responses of CFS-to-CSS screwed connections with varied sheathing panel types, sheathing thicknesses, screw spacings, and edge distances. The results indicated that the test phenomena observed in the screwed connection between CFS and sheathing panel during the entire loading process were generally a combination of several failure modes, which was predominantly influenced by the sheathing thickness, the end distance, and the loading method. The peak load of the specimens under monotonic loading were greater than that under cyclic loading and increased almost linearly with the increase in sheathing thickness. Referring to North American code provisions, a calculation method for the strength of CFS-to-CSS screwed connections was proposed. Finally, based on the experimental data, a hysteretic constitutive model for CFS-to-CSS screwed connection was established. This model serves as preliminary preparation for the refined numerical simulation of corrugated steel sheathed shear wall. • The hysteretic performance of CFS-to-CSS screwed connections was investigated experimentally. • The test phenomena and failure modes of theCFS-to-CSS screwed connections were explored. • A hysteretic constitutive model for CFS-to-CSS screwed connections was established based on test data. [ABSTRACT FROM AUTHOR]

This paper delves into an experimental study on the load-bearing capabilities of self-drilling screw connections in stainless steel studs sheathed with ply-bamboo panels. A total of 92 connection specimens were tested employing monotonic and cyclic loading protocols. The performance of the stainless steel-ply-bamboo connections was studied under various conditions with respect to different ply-bamboo sheathing panels, steel studs, screw features, end distances and loading rates. The failure modes and performance parameters were discussed. The test results obtained in this study indicated that double directional ply-bamboo was lower than unidirectional flat pressing ply-bamboo in terms of tensile properties, and phosphating steel screws (PTS) exhibited higher nominal bending yield moment and yield strength compared to stainless steel screws (STS). In addition, the ultimate deformation of PTS connections was lower than that of STS connections, and the ductility coefficient of PTS connections was higher than that of STS connections. The unidirectional flat pressing ply-bamboo (UF) sheathing connections had a higher tensile strength than double directional ply-bamboo (DL) sheathing connections, but the peak load, the ultimate displacement and the ductility coefficient of the UF sheathing connections exhibited a reduction compared to DL sheathing connections. Stainless steel stud connections had some disadvantages over cold-formed steel stud connections in terms of elastic stiffness and ductility coefficient, but it improved the peak load and ultimate displacement compared to cold-formed steel stud connections. Based on the connection test information, correlation analysis and analytical modeling were conducted on the self-drilling screw connections within lightweight stainless steel-ply-bamboo shear walls. • A total of 92 connection specimens were tested employing monotonic and cyclic loading protocols, which were delved into an experimental study on the load-bearing capabilities of self-drilling screw connections in stainless steel studs sheathed with ply-bamboo panels. • Performance and failure modes of the 92 connection specimens were presented. • Stainless steel stud connections, which had some advantages over cold-formed steel stud connections, have been discussed. • Correlation analysis and analytical modeling were conducted on the self-drilling screw connections within lightweight stainless steel-ply-bamboo shear walls. [ABSTRACT FROM AUTHOR]

The current research proposes defining the water requirements for (Phasheolus vulgaris var. calima) under the weather conditions of Riobamba County, Chimborazo province, Ecuador. For this, it was necessary to use a complete randomized block design whit three treatments and three repetitions. Treatment 1, irrigation sheets determinate by the drain lysimeter; treatment 2, irritation sheets determined by the evaporation tank Type A; and treatment 3, irrigation sheets determined by the empirical calculation of the evapotranspiration of the crop. In addition, the crop coefficient values were also determined and adjusted for each phonological stage. The variables evaluated were days to emergency, flowering, sheathed and harvest, plant height, WRC, number of sheath, yield, and water footprint. The adjusted crop coefficient values (Kc) were 0,65, 0,96, 1,05, 0,86 for the first, intermediate, and final development stage respectively. [ABSTRACT FROM AUTHOR]

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction. [ABSTRACT FROM AUTHOR]

The objective of this work was to compare the hygrothermal responses and the moisture performance of four wood-frame walls as predicted by four hygrothermal (HAM) simulation tools, namely: DELPHIN, WUFI, hygIRC and COMSOL. The four wall systems differ only in their cladding type; these were fibreboard, vinyl, stucco and brick. Three Canadian cities having different climates were selected for simulations: Ottawa, Ontario; Vancouver, British Columbia and Calgary, Alberta. In each city, simulations were run for 2 years. Temperature and relative humidity of the outer layer of OSB sheathing were compared amongst the four simulation tools. The mould growth index on the outer layer of the OSB sheathing was used to compare the moisture performance predicted by the respective hygrothermal simulation tools. Temperature profiles of the outer layer of the OSB sheathing were all in good agreement for the four HAM tools in the three locations. For relative humidity, the highest discrepancies amongst the four tools were found with stucco cladding where differences as high as 20% could be found from time to time. Mould growth indices predicted by the four HAM tools were similar in some cases but different in other cases. The discrepancies amongst the different HAM tools were likely related to: the material property processing, how the quantity of wind-driven rain absorbed at the cladding surface is computed and some implementation details. Despite these discrepancies, The tools generally yielded consistent results and could be used for comparing the impacts of different designs on the risk of premature deterioration, as well as for evaluating the relative effects of climate change on a given wall assembly design. [ABSTRACT FROM AUTHOR]

This paper presents the results of a Guarded Hot Box (GHB) experiment on a wall assembly made up of both steel stud framing and an external insulating assembly which incorporates vacuum insulation panels (VIPs) for which knowledge of the composition of the VIP barrier foil is not readily available. The purpose of the tests is to provide an experiment result for thermal resistance of a wall assembly containing several sources of thermal bridging, including those due to the barrier foil at the edge of and joint material between the VIPs and the condensation potential on the interior surface due to the steel studs. The steady-state GHB experiments were completed in accordance with ASTM C1363 for an interior air temperature of 20.9°C and an exterior air temperature of −34.9°C; this resulted in a thermal resistance for the wall assembly of 6.8 ± 0.8 m2 K/W. Surface temperature measurements on a VIP in the wall assembly indicated that increased levels of heat transfer were occurring at the edges of the VIPs as compared to the center of the panel confirming thermal bridges were present at the panel edge. Measurement of the temperature on the interior surface of the sheathing board around the steel stud indicated that the external insulation effectively minimized the risk of condensation due to the steel studs. Determining the thermal resistance and condensation risk for a wall assembly which contains VIPs for which knowledge of the barrier film is not readily available demonstrates the potential for use of such a wall assembly according to energy and building code requirements. The wall assembly and test details can also be used to compare industry standard calculation methods and detailed 2D and 3D simulations to the GHB test result. The comparison can be used to inform on the validity of using calculations and simulation methods in lieu of testing for energy and building code compliance. The comparison of calculations and simulations is not the scope of the work presented in this paper and will be explored in future publications. [ABSTRACT FROM AUTHOR]

Sustained casing pressure (SCP) in shale gas wells has been of growing interest in the industry, owing to its effects on the safety and efficiency of shale gas production. In terms of the current literature, this issue should be attributed to the elastic failure of the cement sheath under high inner pressure during the hydraulic fracturing process. However, the current calculation of cement sheath stress neglects the influence of the drilling and cementing processes and the dramatic temperature change of a well system during the hydraulic fracturing process. In this work, a novel elastic–plastic model incorporating the effects of drilling, cementing, and dramatic temperature change of the well system during the hydraulic fracturing is established to describe the stress of cement sheath. The failure mechanism of cement sheath is fully revealed. The proposed model for cement sheath integrity is successfully verified through its excellent agreement with field observations from the Fuling shale gas field, China. In addition, based on the proposed model, the impacts of the geometrical and material parameters of casing and cement are studied and analyzed. The results illustrate that the tensile failure more likely occurs at the inner face of the cement sheath, which turns out to be more severe as the true vertical depth decreases. The density of cement slurry is in favor of decreasing the tensile stress in the cement sheath. On the contrary, the thicker cement sheath would increase the risk of tensile failure in the cement sheath, which would lead to serious SCP. The extremely low elastic modulus and thermal conductivity of the cement sheath are beneficial for maintaining its integrity, which, unfortunately, is difficult to achieve in actual operations. • A new elastic-plastic model for cement sheath integrity in shale gas wells is raised. • The effects of drilling, cementing and temperature change are considered. • The reliability of new model is successfully verified through field observations. • The cement slurry density is in favor of decreasing tensile stress in cement sheath. • The cement sheath thickness has negative effect on integrity of cement sheath. [ABSTRACT FROM AUTHOR]

Prestressing strands subjected to high tensile stresses are likely to become vulnerable to hydrogen embrittlement due to stress corrosion. Corrosion protection should be selected for safety and durability of the post-tensioned concrete structure. In this study, performances of corrosion protective systems used in post-tensioning construction were evaluated by the electrochemical and weight loss measurement methods. Test specimens represented the bonded strand and unbonded strand with plastic sheathing in grouted multi-strand tendons, as well as unbonded single-strand tendon and bare-strand. Corrosion tests were carried out in accordance with PTI M55.1-12 with slight modifications. Tests conducted included: corrosion by chloride ion (Cl-) solution and corrosion by chloride ion and dissolved oxygen (Cl- + DO) solution. Test results indicated that the specimens using plastic sheathing showed 0.03 to 0.07 μA/cm2 average corrosion current densities, which can be regarded as insignificant corrosion condition in comparison with the average value of critical corrosion current densities of 0.15 or 0.17 μA/cm2 for strand-corrosion testing due to only chloride ion or both chloride ion and dissolved oxygen. Therefore, the plastic sheathing had the best protective performance among the tested specimens; even significant sheath damage was considered during the installation process. The corrosion resistances of specimens protected by cement grout and grease coating, respectively, were similar to each other. This study is expected to contribute to the selection of effective corrosion protective systems for construction of post-tensioned concrete structures requiring high durability. [ABSTRACT FROM AUTHOR]

Highlights • In the context of capacity design it is indispensable to design non-ductile parts and connections with considerable overstrength. • A two-step procedure is proposed: First a sensitivity analysis is carried out using first-order reliability methods. Then overstrength values are adjusted to ensure a certain level of failure probability. • Statistical data for all parts and connections of a light-frame timber wall element are presented. Abstract To ensure ductile behavior of light frame timber wall elements in the context of capacity design it is indispensable to design non-ductile parts and connections with considerable overstrength. The determination of overstrength values based on reliability methods enables to address different target failure probabilities. A two-step procedure is proposed. First a sensitivity analysis is carried out on 972 wall configurations. Within the configuration the nail diameter, the nail spacing, the sheathing material, the thickness of the sheathing, the arrangement of the sheathing, the length of the wall elements and the vertical load is varied to assess the influence of the varied parameters. Within the sensitivity analysis the overstrength values that ensure the target failure probability P f = 0.04 within the range of P f = 0.023 to P f = 0.067 are determined using first-order reliability methods. The sensitivity analysis shows that the determination of overstrength values for different parameter configurations seems not to be necessary. For the second step the wall configurations that lead to the greatest overstrength values according to first-order reliability methods are identified. For these wall configurations the failure probability is determined using Monte-Carlo-Methods. The failure probability is determined using overstrength values within the range of γ R d = 1.0 to γ R d = 2.6 and minimum dimensions for the main load carrying parts of a timber frame wall element. The overstrength values that leads to an exact failure probability of P f = 0.067 for the wall configurations are determined. The overstrength values determined on the selected wall configurations are used to calculate the failure probability for all 972 wall configurations using Monte-Carlo-Methods. Finally, overstrength values are proposed to achieve ductile failure for all considered wall configurations for a certain level of probability. [ABSTRACT FROM AUTHOR]

Abstract Light gauge steel-framed (LSF) walls, commonly made with lipped channel studs and gypsum plasterboard sheathing, are increasingly being used in low to mid-rise buildings. Improvements have been made with respect to fire, wind/seismic and energy performance of LSF walls with the use of improved stud sections, wall configurations, different sheathing members, and insulation materials. Although the provision of sheet steel as sheathing has been found to improve the in-plane shear capacity of LSF walls, its effects on the fire performance of load bearing walls remain unknown. Three full-scale ISO 834 standard fire tests were conducted in this study to investigate the fire performance of axially loaded gypsum plasterboard and steel sheathed LSF walls made with web-stiffened studs. The results revealed that compared to the commonly used lipped channel stud, the web-stiffened stud is capable of withstanding a 57% greater axial compression load, yet yield the same fire resistance level (FRL), when sheathed only with two layers of gypsum plasterboard. Under the selected load ratio, the addition of steel sheathing caused only marginal improvements in the stud temperature development, resulting in minor improvements to the FRL of load bearing walls. However, the axial load bearing capacity improvement caused by the inclusion of steel sheathing allowed the web-stiffened stud to withstand a 10% greater axial compression load compared to the plasterboard only wall. Highlights • Investigated the effect of steel and plasterboard sheathing on the fire performance of web-stiffened stud walls. • Web-stiffened studs were able to retain their higher load bearing capacity even in fire. • Steel sheathing did not alter the stud temperature development significantly. • Steel sheathing improved the fire resistance marginally due to the opening-up of sheathing joints. • Steel sheathing allowed web-stiffened studs to withstand greater axial loads in fire than lipped channels. [ABSTRACT FROM AUTHOR]

Abstract Cold-formed steel-framed walls lined with appropriate sheathing materials are increasingly being used as vertical load bearing systems due to their many benefits. Despite this widespread use, attempts at improving their structural efficiency using either optimised studs or novel sheathing elements have been scarce. Arguably, the sustained use of lipped channel studs and conventional sheathing materials have long forestalled such improvements. Firstly, this study provides experimental evidence on the superior characteristics of the web-stiffened studs, developed specifically for load bearing steel-framed wall applications, and their ability to utilise sheathing restraints to achieve higher axial compression strengths. Secondly, it shows that the use of steel sheathing, either in isolation or together with gypsum plasterboards, significantly increases the strength of the web-stiffened stud. Thirdly, single plasterboard web-stiffened stud walls are found to be highly efficient due to the monolithic nature of the sheathing that leads to greater degrees of composite action between the studs and the sheathing. Finally, it presents a spring based analytical model capable of estimating the failure loads of sheathed web-stiffened studs conveniently. The model particularly focuses on the out-of-plane restraints provided by the sheathing, the contribution of which to the overall strength of the wall has traditionally been considered trivial, but is shown to be substantial in the case of web-stiffened studs. Using the improvements proposed, high capacity steel-framed load bearing walls can be developed with significant material and cost savings. Highlights • Web-stiffened studs reach their yield load when adequately restrained by sheathing. • Out-of-plane stiffness enhancement due to sheathing is beneficial for web-stiffened studs. • A spring based analytical model was developed for web-stiffened studs. • Degrees of composite behaviour were estimated for sheathing materials used. • LSF walls with both gypsum plasterboard and steel sheathing are structurally superior. [ABSTRACT FROM AUTHOR]