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Open-source technological development is well-known for rapid innovation and providing opportunities to reduce costs and thus increase accessibility for a wide range of products. This is done through distributed manufacturing, in which products are produced close to end users. There is anecdotal evidence that these opportunities are heavily geographically dependent, with some locations unable to acquire components to build open hardware at accessible prices because of trade restrictions, tariffs, taxes, or market availability. Supply chain disruptions during the COVID-19 pandemic exacerbated this and forced designers to pivot towards a la carte-style design frameworks for critical system components. To further develop this phenomenon, a case study of free and open-source solar photovoltaic (PV) racking systems is provided. Two similar open-source designs made from different materials are compared in terms of capital costs for their detailed bill of materials throughout ten locations in North, Central and South America. The differences in economic optimization showed that the costs of wood-based racks were superior in North America and in some South American countries, while metal was less costly in Central and South America. The results make it clear that open hardware designs would be best to allow for local optimization based on material availability in all designs.

This work presents the study of the effectiveness of different inert gases applied during racking to prevent oxygen uptake by wine. Inert gases were used for the purging of empty tanks and hoses before the start of each racking, as well as for blanketing in the full racked tank. After analyzing these operations with the different inert gases, the required volumes of each gas were optimized. The CO2:Ar (20:80) mixture proved to be the most effective for the complete purging of the empty tank, while CO2 was the most cost-effective gas. Purging the empty tank with 25% vessel volume gas was sufficient to achieve useful inerting with all the gases studied, as well as to maintain low levels of dissolved oxygen (DO) in the wine filling the tank. Applying 0.5 of vessel volume of Ar, CO2:Ar (20:80), and CO2 gases during blanketing allowed the headspace oxygen (HSO) of the racked tank to be protected throughout. During the racking of a white wine in a commercial winery, Ar showed the highest efficiency, compared to N2, for both the inerting of empty hoses and destination tank and for maintaining low levels of DO and HSO in the tank.

The consequences of pumping on food quality are poorly understood, and wine is a good example. Therefore, the present paper examines the use of four pumps and the application of inertization on wine quality. We develop a novel, physical qualitative index (PQI), which is the ratio between pumping specific energy and the net positive suction head, and examine the correlation with wine quality characteristics. Four pumps (a flexible impeller pump, a lobe pump, a peristaltic pump, and a rotary piston pump) that are widely-used in wine cellars were compared over a wide array of chemical-physical variables, during conventional racking, with and without inertization. The analysis found a correlation between the PQI and some quality variables, and this finding was confirmed by a conventional statistical analysis (ANOVA-GLM). Overall, the flexible impeller pump performed slightly differently compared to the other pumps with respect to some color-related parameters. All pumps behave differently as a function of inertization (or not). Inertization was effective in minimizing volatile losses.

We present a comparative study of the different racking systems used in photovoltaic power systems, with a new methodology for determining the total energy produced by each one under usual weather conditions (not clear-skies). In systems without solar tracker, the tilt angle is a major factor contributing to the energy production, and its optimization is essential. We study the effect of tilt update frequency (daily, monthly, or constant) on the total irradiation received by a plane surface, and present a method for computing the optimal tilt angle, which we validate using previous studies. This method is easily implemented, accurate, and valid for any location. We compare all the systems with the most energy-productive one, the dual-axis tracker, in two ways: with respect to energy production, and to levelized cost of energy, both in 39 cities around the World. The results provide a new insight on the relative and objective value of trackerless systems, and some remarkable properties arise, which may be relevant in budgetary consideration.

In this paper, we have designed a signal tracking microwave notch filter at X-band (8 GHz-12.4 GHz) which is tunable. The experimental notch frequency is 9.42 GHz and a 3-dB bandwidth of this filter is 105 MHz. The theoretical response agrees well with the experimental response of this notch filter. The frequency can be tuned by tuning the Gunn oscillators. The Gunn oscillators being injection –locked to the input signal make the notch filter tracking in character.

Rapid decline in the cost of solar photovoltaic (PV) modules and associated electronics has elevated the significance of structural balance of systems (BOS) in the system cost composition. In this study tensegrity, a bio-inspired structure made of bars as compression members and strings as tensile members, is evaluated as an economical racking solution for solar photovoltaic arrays. For the first time, the electrical aspects of solar photovoltaic system design have been unified with the structural aspects of tensegrity through a novel algorithm. The end-to-end system design framework is validated through modelling of a practical system with System Advisor Model (SAM), a standard design tool by National Renewable Energy Lab (NREL), in congruence with the minimal mass planar bridge tensegrity model implemented in MATLAB. This algorithmic demonstration establishes tensegrity as a technically viable system design approach and assesses the significant reduction in racking material weight leading to maximum cost savings up to 77%. The technical compatibility, ease of installation, logistic efficiency and economic benefits of tensegrity-enabled racking would accelerate wide-scale adoption of solar energy across the world. It is also conducive to high-impact applications of solar energy such as water canal covering and shaded agriculture. Additionally, tensegrity configuration provisions the use of locally grown timbers like bamboo as the compression member which benefits developing regions through local sourcing, fast installation, carbon capture and farming incentive. Tensegrity also unlocks the research avenue for adding modularity and portability to solar PV systems leveraging its controllable dynamic properties.

Fixed-tilt mechanical racking, consisting of proprietary aluminum extrusions, can dominate the capital costs of small-scale solar photovoltaic (PV) systems. Recent design research has shown that wood-racking can decrease the capital costs of small systems by more than 75% in North America. To determine if wood racking provides enough savings to enable labor to be exchanged profitably for higher solar electric output, this article develops a novel variable tilt angle open-source wood-based do-it-yourself (DIY) PV rack that can be built and adjusted at exceptionally low costs. A detailed levelized cost of electricity (LCOE) production analysis is performed after the optimal monthly tilt angles are determined for a range of latitudes. The results show the racking systems with an optimal variable seasonal tilt angle have the best lifetime energy production, with 5.2% more energy generated compared to the fixed-tilt system (or 4.8% more energy, if limited to a maximum tilt angle of 60°). Both fixed and variable wooden racking systems show similar LCOE, which is only 29% of the LCOE of commercial metal racking. The results of this study indicate that the novel variable tilt rack, whether used as a small-scale DIY project or scaled up to fulfill larger energy demands, provides both the lowest cost option even when modest labor costs are included and also may provide specific advantages for applications such as agrivoltaics.

Although small solar photovoltaic (PV) systems avoid most soft costs, they still have a relatively high $/W value due to racking costs. In order to fulfill the promise of small-scale plug-and-play solar, a do-it-yourself PV rack design is provided and analyzed here for six criteria: (1) made from locally-accessible renewable materials, (2) 25-year lifetime to match PV warranties, (3) able to be fabricated by average consumers, (4) able to meet Canadian structural building codes, (5) low cost and (6) that it is shared using an open-source license. The open-source wood-based fixed-tilt ground-mounted bifacial photovoltaic rack design evaluated here was found to be appropriate throughout North America. Economic analysis of the bill of materials showed the racking system ranges from 49% to 77% less expensive compared to commercial proprietary racking in Canada. The racking design, however, is highly dependent on the cost of lumber that varies widely throughout the world. Even for an absolute lower-cost design in Togo due to a lower fixed tilt angle and lower loads from lack of snow, it was not found to be economic because of the relatively high cost of wood. The recent volatile lumber market warrants local evaluation from those considering the use of the open-source design. This design, however, provides for a PV rack that can be manufactured with distributed means throughout most of the world enabling more equitable access to solar energy to support a circular bioeconomy.

Damage cases show that during earthquakes, the sharp stiffness mutation of subway station-tunnel junction structures can lead to dislocations at the connections. To address this, shaking table tests were conducted followed by numerical simulations of a typical junction structure with rigid connections. The modeling method was verified based on the test results. Furthermore, numerical models of junction structures with rigid and flexible connections, single stations, and single tunnels were built, and deformation modes and stress distributions were comparatively analyzed. Combining the experimental and numerical results, it is found that there exists an intensive deformation inconsistency between the stations and the tunnels responsible for the junction structures’ dislocation failures. The station operates in both racking and distortion deformation modes when the tunnel undergoes ovaling deformation. The tunnel bends relative to the end wall at the connection. The junction structure with rigid connections is most at risk at the point located at the tunnel section connected to the end wall and near the bottom plate-sidewall joint. With flexible connections, the tunnels integrally translate relative to the end wall, and the stress response of the end wall openings can be larger than those with rigid connections.

Vertical bifacial solar photovoltaic (PV) racking systems offer the opportunity for large-scale agrivoltaics to be employed at farms producing field crops with conventional farming equipment. Unfortunately, commercial proprietary vertical racks cost more than all types of conventional PV farm racking solutions. To overcome these cost barriers, this study reports on the development of a new wood-based PV racking design. The open-source design consists of a hinge mechanism, which reduces mechanical loading and enables wood to be used as the main structural material, and is the first of its kind. This open-source vertical wood-based PV rack is (i) constructed from locally accessible (domestic) renewable and sustainable materials, (ii) able to be made with hand tools by the average farmer on site, (iii) possesses a 25-year lifetime to match PV warranties, and (iv) is structurally sound, following Canadian building codes to weather high wind speeds and heavy snow loads. The results showed that the capital cost of the racking system is less expensive than the commercial equivalent and all of the previous wood-based rack designs, at a single unit retail cost of CAD 0.21. The racking LCOE is 77% of the cost of an equivalent commercial racking system using retail small-scale component costs, and is 22%, 34%, and 38% less expensive than commercial metal vertical racking, wood fixed tilt racking, and wood seasonal tilt racking costs, respectively. Overall, wooden vertical swinging PV racking provides users with a low-cost, highly available alternative to conventional metal vertical racking, along with a potential increase in energy yield in high wind areas thanks to its unique swinging mechanism.

Introduction: Wine is an alcoholic drink made from fermented grapes. The process of wine making involves fermentation of fruits in which case the wine is qualified by the fruit which it is made from such as apple wine, orange wine.Purpose of the Study: This research shows the possibility of producing wine from fruits using bakers’ yeast (Saccharomyces cerevisiae).Methodology: The fruits used were Apple (Malus domestica), Orange (Citrus sinensis), and Pineapple (Ananas cosmosus).They were washed and blended. The strained juices were poured into plastic bottles to cool for 15mins before additives and yeast were added. The “must” was then allowed to ferment for four days. After four days, racking was done to remove sediments. Then egg white was added as a clarifying agent, and left to stand fifty days, for it to age and then bottled.Findings: Apple wine was found to be more alcoholic (11.4%) while orange wine had 8.9%. Apple had the highest pH (4.0) while orange had 2.0. The solubility test showed that apple had the highest solubility with 98% while orange had 94%. Apple had the least sugar content with 9.90ml while pineapple had22.0ml. Orange had a specific gravity of 0.99g while apple had0.98g.Recommendation: It is observed that all the fruits in the market today can give the qualities needed for alcoholic wine in the absence of grape fruit. All these satisfactory qualities of this study show that an acceptable wine from pineapple, apple and orange can be locally produced.

This study examined the racking performance of poplar laminated veneer lumber (LVL) frames using bolted steel filling plates to connect beam-column joints, poplar LVL frames using the embedment bars to connect beam-column joints, and frame-shear hybrid walls made of poplar LVL studs and oriented strand board (OSB) sheathing panels. A new design load spreader beam was used on the side of the top of a specimen to apply monotonic and cyclic loadings. It was found that the lateral force resistance, stiffness, and ultimate loads of poplar LVL pure frames with bolted steel filling plate connections and closed rod connections were much lower than those of the poplar LVL frame-shear wall hybrid structure. The highest initial stiffness of the poplar LVL hybrid frame-shear wall was 1.77 kN/mm, which was 24% and 22% lower than that of the conventional shear wall made with spruce-pine-fir studs and OSB or plywood sheathing panels, respectively. The poplar LVL frame-shear wall hybrid structure showed lower degradation in stiffness than the conventional shear wall. The hybrid frame-shear wall structures made of poplar LVL could meet the requirements of Chinese standard; however, diagonal braces were required in use of poplar LVL pure frames.

This paper introduces smart tracking-based self-service technologies (STB SSTs) as a new category of self-service. STB SSTs allow brand customers to voluntarily perform feedback-seeking that targets their brand-related consumption occurring in a connected environment, provided they consent to share private data with their brand. Despite an increasing deployment, this category of self-service is not well defined in the literature. In addition, we have little understanding of consumer motivations to use these technologies. The present work attempts to fill these gaps by performing an interpretive literature review. Our literaturereview highlights the necessity to distinguish between core and peripheral use of the smart feedback system in the service offer. In addition, our synthesis of acceptance antecedents outlines privacy concerns, new forms of social influence, and interaction goal alignment as an emergent facilitating condition when using STB SSTs instead of other SSTs. This work is also a roadmap for future research. In particular, this study calls for greater consideration of the smart feedback system as a characteristic of STB SST in future research.

Glazing and window systems in New Zealand have been shown to be susceptible to significant damage as evidenced by the past decade of earthquakes. The seismic performance of glazing and window systems has resulted in considerable financial loss, disruption in business and physical injuries following earthquakes. In order to investigate the vulnerability of residential windows in typical light timber framed buildings racking testing was conducted on six wall configurations. Numerous observations of window performance were made during the testing and from these results fragility functions were developed for timber and aluminium framed windows. These fragility functions suggest that even at low displacement levels damage can occur to windows that can potentially affect weather-tightness and require repairs following an earthquake. These functions can inform decisions around designing for resiliency in residential structures in New Zealand.

The heat treatment of aluminum (Solution Heat Treatment, Quenching and Aging) are critical processes to insure that the desired mechanical and corrosion properties are achieved. Of these steps, quenching is perhaps the most critical of all the operations. If quenching is too fast, properties are met, but the part may have excessive distortion or residual stresses. This can result in shortened life due to residual stresses, or result in additional non-value added straightening of the component and this increases cost and cycle time. In this paper, the mechanism for distortion of aluminum is explained, and methods (racking and quenchants) are shown that can reduce distortion and residual stresses in heat treated components.

One of the most common systems in non-automated warehouses, is drive-in pallet racking with a shared storage policy (which is usually based on the duration-of-stay). Such scheme targets towards an ...

In the cyclic racking evaluation of curtain wall systems, physical testing with instrumentation is the standard method for collecting performance data by most design professionals. The resulting testing of full-scale mockups can provide many types of data, including load and displacement values at different stages of loading through failure. While this type of data is valuable for product/system development/fabrication and design, such data can also provide a means for simulation validation of the curtain wall cyclic performance under simulated earthquake loading. Once the simulation study is validated using the test results, then parametric studies by designers can be conducted with greater ease, ideally with commercial software packages, without the need for testing. For the results of this research study, a practical industry formulated finite element modeling (FEM) approach was used to predict the performance of the curtain wall mockups. Here, unitized four-sided structural sealant glazing (4SSG) curtain wall system mockups that incorporate a re-entrant corner were subjected to cyclic racking displacements per the American Architectural Manufacturers Association (AAMA) 501.6 Structural Sealant protocol. System performances, including displacements, were obtained from the FEM study and used to calculate the effective shear strain of the structural silicone and the drift capacity of the system. This paper describes the details of the techniques developed for FEM, the analysis results, and shows an example application of the numerical modeling approach for mockups with racking test results available. The goal of this modeling approach was to create and test methods that practicing consulting engineers can quickly conduct in their offices on common commercially available software often available to them.

This study evaluated the axial capacity of cold-formed racking upright sections strengthened with an innovative reinforcement method by finite element modelling and artificial intelligence techniques. At the first stage, several specimens with different lengths, thicknesses and reinforcement spacings were modelled in ABAQUS. The finite element method (FEM) was employed to increase the available datasets and evaluate the proposed reinforcement method in different geometrical types of sections. The most influential factors on the axial strength were investigated using a feature-selection (FS) method within a multi-layer perceptron (MLP) algorithm. The MLP algorithm was developed by particle swarm optimization (PSO) and FEM results as input. In terms of accuracy evaluation, some of the rolling criteria including results showed that geometrical parameters have almost the same contribution in compression capacity and displacement of the specimens. According to the performance evaluation indexes, the best model was detected and specified in the paper and optimised by tuning other parameters of the algorithm. As a result, the normalised ultimate load and displacement were predicted successfully.

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This paper is the result of both experimental and numeric analyses on pallet rack components. Two cyclic testing protocols for beam-end connectors of adjustable racking systems are compared; such experiments are named as “code type” and “Castiglioni”. Both protocols share the same test mock-up: an assembly of a doubly-pinned upright segment with a cantilever beam specimen. These tests consist in an up-to-failure increasing push-pull process at the free beam end. In the “code type” test, the imposed displacement loops are centered around zero; conversely, in the “Castiglioni” tests, both upward and downward displacement segment runs are centered around a vertical static equilibrium situation (to take the gravitational load into account). The “code type” test is expected to result in a higher number of cycles than the “Castiglioni” one because of the two following features of the latter: (i) the gravitational load is always present, thus resulting in a higher demanding test, and (ii) the failure point is precisely predefined and usually produced before the total breakdown. This paper describes and compares experiments using both protocols. Additionally, these tests are numerically simulated.

This paper presents the results of an experimental campaign investigating the seismic behaviour of full-size cross laminated timber (CLT) wall systems with sound-insulated shear-tension angle brackets. The main aim of the study was to investigate the influence of more and less flexible soundproofing bedding under the CLT wall. The paper shows a comparison of lateral load-bearing capacity, displacement capacity, ductility and stiffness obtained from racking tests on uninsulated specimens and specimens with various types of bedding insulation and levels of vertical load. Moreover, an analytical procedure to estimate the lateral load-displacement response of CLT walls with bedding insulation is proposed. This model is verified by direct comparison to the experimentally determined lateral load-displacement backbone curves. The results show that the elastomeric bedding does not have a significant effect on the bearing capacity of the wall system tested, but it reduces the stiffness and increases the displacement capacity. Due to the large decrease in stiffness, the insulation causes an overall reduction in ductility. The analytical estimation proposed was able to capture the reduction in lateral stiffness and adequately predict the load-bearing capacity.

Circuit breaker is a device used to disrupt the flow of current when an abnormal condition occurs in switchgear. These withdrawable breakers are regularly disconnected for maintenance, testing and replacement. A novel design of a portable, electrically driven racking mechanism which is easy to mount on circuit breaker without any modifications in its enclosure, is presented in this work. The performance of the designed racking mechanism is verified by conducting finite element analysis (FEA) simulation and experimental studies. A prototype is constructed based on the analysis result, and the performance is validated in an actual circuit breaker.

Timber-framed shear walls are designed to resist the lateral loads on a building from wind and earthquake. Many regions around the world have developed standard test methods for evaluating the performance of timber-framed shear walls. Currently, Australia has no such standard test method for timber-framed shear walls. The aim of this study is to develop a standard loading protocol for evaluating the performance of timber-framed shear walls in Australia that is informed by the concerns of both earthquake engineers and wind engineers. To achieve this aim, the key objective of this study is to compare the performance of a standard timber-framed shear wall under three different monotonic (groups M1, M2 and M3) and four different cyclic (groups C1, C2, C3 and C4) loading protocols according to their respective standards. The number of test panels in each group was three ( 3 ) for a total number of 21 individual tests. Structural performance characteristics of the standard test panel, such as ultimate and yield strength and global stiffness, were found to be strongly dependent on the loading protocol. For example, ultimate strength was lower for test panels subject to monotonic loading (i.e., 5.99 , 6.41 and 6.34 k N / m for groups M1, M2 and M3 respectively) compared to test panels subject to cyclic loading (i.e., 6.70 , 6.73 , 8.03 and 8.11 k N / m for groups C1, C2, C3 and C4 respectively). Internal stiffness was found to be relatively consistent regardless of loading protocol. The higher ultimate and yield performance of group C3 (CUREE protocol) and C4 (Cyclone Testing Station protocol) is statistically significant, at the 5 % significance level, compared to results from all other test methods (i.e., AS1720.1, EN 594, ASTM E564, BRANZ P21 and ISO 16670). Differences in boundary conditions between the loading protocols might explain some of the differences in results; however, this hypothesis is not strongly supported by the evidence. These results are used to inform our recommendations for developing an Australian standard test method for evaluating the structural performance of timber-framed shear walls.

Equivalent linear time history analyses are conducted to calculate the seismic response of various types of cut-and-cover single box tunnels. A finite-element numerical model is calibrated against the results of centrifuge tests. The calculated tunnel responses compare favourably with the measurements. A validated model is then used to quantify the seismic response of box tunnels. The flexibility ratio (F) is illustrated to have a governing influence on the tunnel response. It is shown that the previously developed relationship betweenFand the racking ratio (R) is applicable for a wide range ofFup to 20. It is also shown that an increase inFaccompanies corresponding increase inR, the spectral acceleration in the tunnel lining, and the shear stress along the tunnel lining-soil interface. The thrust in the tunnel lining is also revealed to increase withF, although the calculated value is significantly lower than the pressure on yielding walls. Additionally, the surface settlement is shown to increase with an increase inF.

The goal of this study is to develop a racking model of plasterboard-sheathed timber walls as part of the efforts towards performance-based seismic engineering of low-rise light timber-framed (LTF) residential buildings in New Zealand. Residential buildings in New Zealand are primarily stand-alone low-rise LTF buildings, and their bracing elements are commonly plasterboard-sheathed LTF walls. It is an essential part of performance-based seismic designs of LTF buildings to be able to simulate the racking performance of plasterboard walls. In this study, racking test results of 12 plasterboard walls were collected and studied to gain insight into the seismic performance of plasterboard-sheathed LTF walls. The racking performance of these walls was examined in terms of stiffness/strength degradation, displacement capacity, superposition applicability and failure mechanisms. Subsequently, a mathematical analysis model for simulating racking performance of LTF plasterboard walls is developed and presented. The developed racking model is a closed-form wall model and could be easily used for conducting three-dimensional non-linear push-over studies of seismic performance of LTF buildings.

Simplified equivalent static methods are widely used in seismic design and analysis of underground structures. The relative shear deformation of the soil is usually considered as the main earthquake load in the existing simplified methods, including the free-field racking deformation method, flexible coefficient method, response displacement method, response acceleration method, and pushover analysis method. However, the inertia force of the overburden soil caused by the vertical earthquake motion does not attract sufficient attention in many design specifications. The recent studies revealed that the large vertical inertia force made a significant influence on the shear strength and deformation capacity of the support components in the underground structures, especially for the shallow buried ones. Firstly, based on the earthquake damage investigation of shallow buried rectangular underground structures and the analysis model of response displacement method (RDM), this paper proposes the vertical inertia force-response displacement method (VIF-RDM), in which the vertical inertia force of overburden soil is taken into account. The calculation methods of two critical parameters of the VIF-RDM are described in detail, including the coefficients of the foundation springs around the structure and the maximum vertical inertia force of the overburden soil. Afterwards, the integral vertical inertia force-response displacement method (IVIF-RDM) is put forward to reduce the computational complexity and calculation error of the foundation springs. The surrounding soil model is directly used to calculate the equivalent earthquake loads, which are caused by the relative displacement of the free field. The two proposed simplified methods and RDM are compared with the time-history analysis method (THAM) in a real underground structure. The results show a significant difference in the axial force of the central column between the two proposed methods and RDM. The proposed methods reflect the internal forces of the structure under the strong earthquake more accurately. Therefore, it can be used to evaluate the seismic safety performance of the shallow buried rectangular underground structures in the future.

Current design methodologies for underground structures subjected to earthquake action are based on closed-form solutions of the so-called racking coefficient, which relates the soil free-field distortion deformation to the structure distortion deformation. Existent closed-form expressions for this racking coefficient are derived for circular tunnel geometries embedded in an elastic and homogeneous medium, while expressions for rectangular geometries are based on analogies of the circular case. In this paper, a new and intuitive methodology derived from first principles to obtain a closed-form expression for the racking coefficient for rectangular-like tunnel geometries buried at a sufficient depth is presented, and it is shown that it provides a good fit to finite element analyses results. Similarly, a procedure to obtain closed-form expressions for the rocking rotation of the structure, and the racking deformation profile at different distances from the soil-tunnel interface is presented.

Shear walls are the major components of the lateral-force-resisting system (LFRS) in light-frame wood buildings. With the growing popularity of mid-rise prefabricated light-frame wood construction, engineers need basic design information on the shear walls to design and produce safe structures in case of high winds and earthquakes. The racking resistance of light-frame shear walls depends on many factors, including sheathing and hold-down devices and, most importantly, sheathing-to-framing fastenings. While the performance of nailed shear walls has been studied extensively, and design information is included in the design codes, there is little information on stapled shear walls, specifically in the US and Canada. The cost of staples is significantly less than that of equivalent nails; hence, the use of staples instead of nails would allow cost savings in mass production if they provide sufficient resistance and displacement capacity in the engineered shear walls. This paper presents the results of a pilot study which was focused on the comparison of the performance of nailed and stapled shear walls in laboratory tests under monotonic and cyclic loading in accordance with ASTM E564 and E2126, respectively. Several series of tests were performed on 2.4-m (8-ft) square shear walls with 11-mm (7/16-in) OSB sheathing with various hold-downs and various spacing of sheathing staples and nails on the perimeter of the sheathing panels (5-cm (2-in), 10-cm (4-in) and 15-cm (6-in)) and 19-mm and 10-mm edge distances. The staples were 16-gauge (50-mm (2-in) long with 11-mm (7/16-in) crown). The nails were 8d box steel wire nails (63-mm (2½-in) long with 2.87-mm (0.113-in) diameter). The test results revealed a similar performance of the nailed and stapled shear walls, and the need for careful detailing. Therefore, prefabrication of walls in the factory settings is preferable to the on-site construction to allow the production quality control.

This research conducts dynamic time-history analysis and a modified cross-section racking deformation (MCSRD) method to analyze the collapse mechanism of the Daikai Subway during the 1995 Kobe earthquake using FLAC2D. A simplified approach to consider the nonlinear behavior of a structure element is imported and combined with the FLAC2D built-in nonlinear soil constitutive models to accurately consider the nonlinear interaction between the soil material and structure. Based on the proposed framework, the damage evolution process of the Daikai Subway station can be traced by the dynamic time-history analyses. The collapse pattern roughly agrees with field observation. Regarding the MCSRD method, the critical member of the “central column” is identified but the internal forces did not reach its limit state; this may be because inertial force is neglected, which is a characteristic of the pseudo-static method. Therefore, it is recommended to conduct dynamic time-history analysis for a shallow buried tunnel in soft soil because the inertial force may largely influence the seismic characteristics.

Purpose This paper aims to study the lateral behavior of cold-formed steel walls with K-shaped bracing by finite element modeling. Design/methodology/approach The braces which have the same section as those for studs and tracks are connected to the frame by screw connections. By pushover analysis, lateral performance of two frame categories, with different dimensions and bracing arrangements, is examined, and the force-displacement diagram and the ultimate strength of walls are extracted. Probable failure modes during lateral loading including distortional buckling of studs, buckling in braces and failure of connections are simulated in the numerical model, and some strengthening suggestions would be offered to prevent brittle failures and, therefore, to increase the lateral strength of the walls. Findings The strengthened walls are examined, and their seismic behavior is compared with the original walls. Finally, a parametric study is carried out to evaluate the effect of factors such as thickness of frame members, frame height and yield tension of members on lateral behavior of the shear walls. Originality/value In the present research, lateral strength and failure modes of nine types of cold-formed steel shear walls with different arrangements of K-shaped bracing are examined by non-linear finite element analysis, and a parametric study is carried out to extract the effect of the wall frame characteristics on the lateral behavior. Shear walls are classified into two series.

Phenolic compounds of the first and second racking wine lees, including anthocyanins, were qualitatively and quantitatively analyzed by HPLC–DAD–MS. Wine lees from both rackings displayed similar chromatographic profiles. Therefore, it was impossible to differentiate the qualitative results regarding phenolic compounds. On the other hand, those from the second racking presented, on average, concentration of polyphenols twice as high. While the ones from the first racking displayed ca. 1600 mg phenolic compounds and 400 mg anthocyanins per kg of dry matter, those from the second racking have shown ca. 3300 mg phenolic compounds and 700 mg anthocyanins per kg of dry matter. These outcomes indicate that, although the wine lees from the first racking can be employed as a resource for phenolic compounds recovery, those from the second racking are more appropriate for this purpose.

Accurately determining the transverse shear stiffness of steel storage rack upright frames is essential in calculating the elastic buckling load, performing earthquake design and serviceability checks. International racking design specifications recommend different approaches to evaluate this stiffness. The Rack Manufacturers Institute (RMI) specification conservatively uses an analytical solution based on Timoshenko and Gere's theory while the European (EN15512) and Australian (AS4084) specifications recommend experimental testing to be conducted. Previous studies have shown that Finite Element Analyses (FEA), solely using beam elements, fail to reproduce experimental test results and may overestimate the transverse shear stiffness by a factor up to 25. This discrepancy is likely attributed to the local deformations occurring at the bolted joints. In this paper, a model to capture the transverse shear stiffness of upright frames is developed using shell elements and advanced FEA. Its accuracy is verified against published experimental test results performed on three commercially used upright frame configurations with lip-to-lip bracing pattern. The model accurately reproduces the experimental stiffness, with differences ranging from 2% to 17%. Based on the FE model, the factors contributing to the transverse shear deformation of the frames are quantified and discussed for both lip-to-lip and back-to-back bracing patterns. For lip-to-lip upright frames, results show that the local deformations at the end of bracing members contributes the most to the shear deformation of the frames. For back-to-back upright frames, bolt bending and axial deformation of braces contribute the most to the shear deformation of the frames. Results from this paper would assist the racking industry in improving their products by focusing on the factors influencing the most the behaviour of the frames.

In tunneling practices, it is vital to have an accurate estimate of the depth of embedment of the tunnel; lining thickness and shape of the tunnel, which enables resisting of stresses; and deformation generated by the surrounding soil under seismic loading conditions. The present study highlights the behavior of shallow tunnel in soft soil under seismic conditions by using the finite element (FE) analysis. The developed numerical model is compared with available analytical solutions. Thereafter, a series of parametric studies are carried out by varying the tunnel embedment ratio, soil-tunnel interface conditions, lining thickness, shape of the tunnel, and input ground motion. It has been observed that distortion in the tunnel lining is dependent on the depth of embedment and the flexibility ratio of the tunnel. Ovaling (in a circular tunnel) and racking (in a rectangular tunnel) are found to decrease significantly when embedment ratio is greater than 2. Nearly 6–18% of greater distortion and 20% of greater bending moment are obtained in the full-slip interface condition when compared to the no-slip interface condition. The maximum induced bending moment in the tunnel lining is directly proportional to its flexural rigidity. An unconventional square tunnel with rounded corners, yields 55% lesser bending moment than the square tunnel under the same seismic loading condition. This study also highlights the importance of the input ground motion characteristics that govern the development of the maximum dynamic earth pressure around the lining of the tunnel, and the heaving of the ground surface just above the crown. The outcomes of the present study will be useful in design through understanding the effects of various influencing parameters that control the stability of the tunnel in soft soil under seismic loading conditions.

This paper presents an experimental study on the compressive and racking performance of eccentrically aligned dou-gong connections used in Chinese traditional timber structures. Four 1:3.4 scaled specimens were fabricated and tested with static compressive and cyclic lateral loading. The damage modes and load–displacement (or hysteresis) curves of the dou-gong connections as well as the influence of the composite action effect and vertical compression loading were discussed. It was found that the load–displacement curve of an eccentrically aligned dou-gong connection was nearly bilinear and the change of the vertical stiffness took place when the cap block cracked and loosened the lateral constraint on the overturning of the connection. The vertical initial compressive stiffness was nearly 70% of a concentrically aligned dou-gong connection according to a predictive formula established based on concentrically aligned dou-gong connection test results. The initial stiffness, yield load and maximum load of double dou-gong connections were found to be 262%, 332% and 373% of those of a single dou-gong connection, respectively. The composite action from the interlocked straight beams (by shear keys) and infill panel can increase the lateral stiffness by more than 55% and the energy dissipation capacity by more than 70%, though such composite action decreases with the worn out of the contact surfaces of the straight beams and the plastic deformation of the shear keys. The vertical load improved the stiffness and energy dissipation capacity of the connections mostly by the friction force. Specifically, an increase of 120% in the vertical compression load can lead to more than 50% increase in the lateral stiffness and up to 130% increase in the energy dissipation capacity.

The objective of this paper was to experimentally investigate the behavior of structural insulated panel (SIP) walls under in-plane cyclic loading and to test several panel-to-panel connections in order to measure their effect on the behavior of the walls. Each wall was constructed using two SIP panels with one top plate, one sill plate, two end plates, and a panel-to-panel connection. Each SIP panel had a 5.5 in. (14 cm) thick expanded polystyrene core sandwiched between two 4′ × 8′ (1.22 m × 2.44 m) sheets of 7/16″ (1.11 cm) oriented strand board. The top sill plates were split up between each panel in an effort to increase the potential for racking behavior of the walls and, therefore, the relative vertical displacement between the panels. In addition, as a preliminary study, three different steel connector configurations utilizing 26 gauge steel shear panels were considered in an effort to introduce additional ductility compared to more traditional block spline connection. From experimental observation of the wall with the block spline connection and the wall with no connection, the panel-to-panel connection was shown to contribute significant strength and stiffness to the wall system. The walls that were constructed with the first two configurations of the shear panels did not show any significant increase in either stiffness or ductility over the wall with the block spline. These walls also showed a decline in peak strength, which occurred at lower lateral displacements than the peak strength of the typical wall. For both of these cases, the shear panels yielded early and ruptured at the lateral deformation which caused peak load in each wall. The SIP wall implementing the third style of shear panel also did not demonstrate a significant increase in ductility as compared to the standard SIP wall. Despite the initially outlined potential, the preliminary study of implementation of the slit steel shear panels considered in this study did not significantly alter the performance of the conventionally connected SIP walls. Further study with stiff connectors capable of significant ductility prior to fracture would need to be implemented to realize the benefits of increased wall ductility.

One of the common lateral load resisting systems in multi-story timber buildings in Central Europe are reinforced concrete shear walls. The RC shear walls are not optimal for timber buildings for several reasons such as: (i) the difference in tolerance between concrete and timber construction procedures, (ii) elevated construction time caused by necessary curing of concrete, (iii) moisture of concrete affecting the integrity and mechanical properties of timber, (iv) relatively high shear stiffness resulting in increased forces in seismic design, and (v) eccentricity with regard to applied seismic forces depending on the location of the shear walls. A light-frame timber shear wall (LFTSW) with OSB sheathing stapled to glued-laminated timber framing and strong anchorages has been investigated in this research program to be used as the single lateral load resisting system being located in the perimeter of the building. Results of experiments and numerical calculations showed 20% and 37% increases in shear stiffness and shear resistance, respectively, of the investigated LFTSWs in comparison with established LFTSW configurations. In addition to the conventional racking tests, vertical loads and bending moment were applied to the edge studs in order to study their effect on the in-plane behavior of the investigated LFTSWs. A marginal decrease in shear stiffness and shear resistance was observed due to the vertical load and bending moment applied. The decrease was more significant when applying the vertical loads due to the deformation, to which the staples were exposed, before applying the lateral load. Independent from level and combination of internal forces a ductile behavior was observed experimentally on the investigated LFTSWs, where the failure was governed by ductile displacements in the stapled connection between sheathing and framing.

In cold-formed steel building construction, cold-formed steel shear wall panels (CFSSWPs) are used as primary lateral load resisting components, that maintain the stability and the integrity of the structure. Traditionally, a CFSSWP constits of a cold-formed steel frame with structural sheeting, such as oriented strand board (OSB), gypsum wall board (GWB), plywood or other, screwed onto it. These type of elements have some unique properties, such as high elastic stiffness, large displacement ductility, etc. On the other hand, as the studs are closely spaced - a value of 60 cm for the spacing is common - only small openings are present, hence transparency is limitted; To increase the transparency of cold-formed steel buildings, which is a tendency in contemporary architecture, load-bearing capacities of glass can be utilised by bracing the frames with glass instead of traditional sheeting. The conventional two-component structural silicone Sikasil (R) SG-500 is considered for the load-bearing cold-formed steel-glass connection. In this research, the racking behaviour of 1.5 m by 3.5 m cold-formed steel frames onto which glass panels are circumferentially bonded on both sides is determined by means of experimental tests. This paper reports about the conducted experiments and the obtained data. From the tests, a value of 32.25 +/- 0.452 kN/m was obtained for the racking strength of the considered hybrid cold-formed steel-glass panels. A comparison with traditional CFSSWPs showed that the hybrid element can obtain similar racking strengths. Therefore, the study revealed the potential of hybrid cold-formed steel-glass elements using structural silicones to provide sufficient in-plane lateral stiffeness and strength.

Relentless cost declines in solar photovoltaic (PV) modules have radically reduced system costs, but the result is that racking costs have become more important. In this study a new open source racking method using earth and shotcrete-based ground mounts is investigated in two geographic regions: (1) Boa Vista, Brazil, where PV rows have an optimized shallow tilt angle and can be close-packed and (2) Kingston, Canada, where racks can make use of low concentration in the required inter-row spacing. Models are developed for both locations with single, double and triple vertical stacked shotcrete-based ground-mounted PV racking systems. Using these models bills of materials and energy simulations are produced to provide a cost benefit analysis specifically for the shotcrete racks. The results show that for utility-scale PV systems near the equator, a shotcrete racking system could reduce racking costs by 18–22% from the least expensive conventional racking and as much as 47% reduction for more expensive commercial racking. Economics is less clear for shotcrete-based racking at higher latitudes that incorporate low-concentration reflectors as they can be both lower and higher costs than conventional racking, but would be expected to produce at least 18% more electricity per installed Watt. Overall this novel racking concept was found to be promising, particularly for desert regions where it could reduce soiling losses. The results of this study indicate a need for future work to fully evaluate the potential of shotcrete racking to reduce solar electricity costs at the utility scale.

Transferring wine is a common operation in most of the wineries in the world that depends mainly on the equipment and materials used. These contributions are widely unknown, and their knowledge is of vital importance to controlling the winemaking process. This work presents the results of characterizing the oxygen supply due to the use of hoses of different materials (Butyl Rubber, IIR, Nitrile Butadiene Rubber, NBR, Ethylene Propylene Diene Monomer rubber, EPDM, Ultra-high-molecular-weight polyethylene, UHMW, Natural Rubber, NR), dimensions (DN32, DN50), connectors (DIN 11851, Tri-CLAMP) with gaskets of different materials (NBR, EPDM, Fluorocarbon, FKM/FPM, silicone rubber, Q/VMQ, Polytetrafluoroethylene, PTFE). In addition, the use of different inert gases (N2, CO2, Ar, N2 + CO2 and Ar + CO2) for air purging of hoses and tanks, as well as for ullage blanketing during tank-to-tank racking, and their economic impact were studied. The results indicated that the IIR hoses had the least amount of O2 added to the liquid and that the Tri-clamp connectors were generally more airtight, with the FKM seals standing out. The most recommended inert gas was CO2 when the type of wine allows it, N2 being the most recommended in any case. When all these recommendations were used together the addition of O2 during tank-to-tank racking was drastically reduced.

This study aims to evaluate the performance of a steel storage pallet racking system equipped with a novel seismic isolation system, which is effective along the cross-aisle direction alone. The isolation system consists of two IsolGOODS® isolators, which are curved surface slider bearings as framed into the European Standards for anti-seismic devices. The efficiency of the proposed device in reducing the seismic effects on pallet racks is investigated. Firstly, uniaxial real-time shake table tests are performed, showing a great reduction of floor accelerations. With the help of a herein validated numerical model, advanced knowledge is obtained. Six accelerograms, two normal-fault records, two pulse-like, and two spectrum-compatible series are selected for drawing generally valid statements. As proposed in this work, the outcomes confirm that the isolation system provides substantial reduction in terms of floor accelerations. In contrast, no up-lift of the base-connections is recorded: the uprights are always engaged in compression. On the whole, the most severe condition comes from the pulse-like record (Emilia 2012), in which displacement demand must be carefully considered while defining the isolators to be put in place.

International audience

Wine is frequently reported as one of the most adulterated agro-food products worldwide. Among the traceability methods available, DNA is of particular interest providing the possibility to recognize uniquely the wine production cultivar/cultivars. Several studies carried out in controlled conditions (laboratory level or small production wineries) support the use of DNA in wine traceability, but the situation can change completely when moving from controlled to uncontrolled realities. In the present study, the entire production chain, in a large cooperative Italian winery, was followed, for a monovarietal (Pinot noir PDO) and a polyvarietal (Rosso Oltrepo TGI) production. Results support the feasibility of DNA traceability from grape delivering to the whole fermentation process and through the most common oenological operations as racking and filtration. The application of most aggressive methods (as the thermovinification process) can increase DNA degradation reducing but not hampering the possibility to apply DNA for traceability purposes. A different situation concerns the storage of wine in tanks, despite the controlled temperature and light conditions, or in bottles where DNA degradation continues strongly influencing the possibility to apply traceability.