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Improving the strength and lateral stiffness values of the reinforced concrete structure can be done by installing the brick wall. The capacity of the reinforced concrete structure cannot be predicted if the wall equipped with openings. Developing the modeling using the diagonal strut method was done in this analytical model for wall with openings in this research. The analytical modeling results will be verified with experimental and analytical models of brick walls with two openings and a door opening show comprehensible results with deviations of 19% and 7.9% for IFOW1, IFOP and IFOW2, respectively. In other words, the analytical equations developed are successfully applied.

The sustainability and economic development is intertwined with the energy consumption and conversion processes. To suffice the ever-increasing demand of energy consumption amid environmental concerns, energy conservation and recovery along with the harnessing of renewable energy has been mandated by the policy regulators. In any energy conversion process, heat exchangers are vital operation component and has been part of any energy conversion process since the Nineteenth century. However, due to the increased energy demand, requirement of high efficiency and space and material constraints, the need for miniaturized light-weight heat exchangers with adequate heat transfer characteristics persists. Traditional heat exchangers are outdated because of its large space requirements and comparatively less heat removal rate. Theminiaturized micro channel heat sink (MCHS) with tubes of about less than 1mm have a tremendous potential to further enhance the heat transfer performance. However, its simple design doesn't cope with the modern requirements of heat removal. Therefore, many researchers have tried to improve its performance using different techniques. The present study reviews some of the most important techniques applied to MCHS. These techniques include, coolant types used in MCHS, MCHS shapes, flow conditions, numerical methods used for this research, andmaterials used tomanufacture MCHS.Moreover, some recommendations have been given to provide opportunities to researchers for future aspects. [ABSTRACT FROM AUTHOR]

descriptive (adj.) “serving or aiming to describe,” 1751, from Late Latin descriptivus, from descript-, past-participle stem of describere “to write down, copy; sketch, represent,” from de “down” (see de-) + scribere “to write” (from PIE root *skribh- “to cut”). Related: Descriptively; descriptiveness. 1Online Etymology Dictionary https://www.etymonline.com/word/descriptive © 2001-2024 Douglas Harper analytical (adj.) “employing analytic methods,” 1520s, with -al (1) + Medieval Latin analyticus, from analyticus, from Greek analytikos “analytical,” from analytos “dissolved,” from analyein “unloose, release, set free,” from ana “up, back, throughout” (see ana) + lysis “a loosening,” from lyein “to unfasten” (from PIE root *leu- “to loosen, divide, cut apart”). 2Online Etymology Dictionary https://www.etymonline.com/word/analytical © 2001-2024 Douglas Harper

There are a few kinds of research about box section Reinforced Concrete (RC) beams under the effect of combined shear and torsional stresses. In the present research, the concept of adding external strengthening, in the transverse direction, is adopted. The paper focuses on using Glass Fiber Reinforced Polymer GFRP ropes as near-surface mount stirrups. Nine box-section concrete specimens were decanted and tested. Three variables are adopted, (1) GFRP stirrups diameter, (2) GFRP stirrups inclination, and (3) GFRP stirrups spacing. The experimental results showed considerable enhancement in the shear capacity of the strengthened beams by 8 to 56% depending on the effectiveness of the studied parameters. Ductility and toughness were improved when more intensive strengthening schemes were adopted. The shear capacity of all tested beams based on Egyptian code ECP 208�2019 is calculated and compared with that from American code ACI 440�2019 and Canadian code CSA-A23.3-04. The shear capacity from both Egyptian and American codes compared with experimental loads. The analytical results are conservative in some cases and unconservative in others while the analytical results in general are conservative. The Canadian code CSA-A23.3-04 is unconservative compared to the experimental results for the range of the studied parameters and specimens.

This article discusses the use of Near-Surface-Mount (NSM) Glass Fiber Reinforced Polymer (GFRP) Stirrups to retrofit box section concrete beams and improve their resistance to shear and torsion. The authors conducted experiments on nine concrete specimens and found that the diameter, inclination, and spacing of the GFRP stirrups significantly affect the behavior of the strengthened beams. The use of GFRP stirrups improves the stiffness, shear capacity, ductility, and load-bearing capacity of the beams, transforming the failure mode from brittle shear to semi-ductile failure. The authors conclude that external strengthening with GFRP stirrups is an effective method to enhance the toughness of reinforced concrete beams. [Extracted from the article]

The sustainability and economic development is intertwined with the energy consumption and conversion processes. To suffice the ever-increasing demand of energy consumption amid environmental concerns, energy conservation and recovery along with the harnessing of renewable energy has been mandated by the policy regulators. In any energy conversion process, heat exchangers are vital operation component and has been part of any energy conversion process since the Nineteenth century. However, due to the increased energy demand, requirement of high efficiency and space and material constraints, the need for miniaturized light-weight heat exchangers with adequate heat transfer characteristics persists. Traditional heat exchangers are outdated because of its large space requirements and comparatively less heat removal rate. The miniaturized micro channel heat sink (MCHS) with tubes of about less than 1 mm have a tremendous potential to further enhance the heat transfer performance. However, its simple design doesn’t cope with the modern requirements of heat removal. Therefore, many researchers have tried to improve its performance using different techniques. The present study reviews some of the most important techniques applied to MCHS. These techniques include, coolant types used in MCHS, MCHS shapes, flow conditions, numerical methods used for this research, and materials used to manufacture MCHS. Moreover, some recommendations have been given to provide opportunities to researchers for future aspects.

Piezoelectric thermoset composites (PTCs) are the class of material having the ability of transformation between mechanical energy and electric energy. In addition to having the advantages of high strength, easier processing, lower temperature, pressure requirement and unlimited storage, PTCs also have high stiffness, high elastic modulus and high strain coefficients. This review presents the advances and approaches used in PTCs and their applications. Various techniques, such as analytical, finite element and experimental methods for analyzing the coupled piezoelectric responses, are also reviewed. This paper also includes current applications of PTCs in strain sensing, vibration control, actuation, energy harvesting, structural health monitoring and biomedical fields. The studies of PTCs and its applications are in the emerging phase, and the review permits to find new notions for interface studies and modelling progresses for PTCs. In addition to that, these reviews pave the way for various research potentials towards the flourishing pertinent application zones of PTCs. Also, this review highlights the relevance of the particular research area and preliminary work under its different approaches, necessitates the need for more researches.

Top-and-seat angle connections are a conventional type of steel moment connection. However, their capacity in accommodating columns loss is rarely studied. In this study, five multistory steel moment subframes using top-and-seat angle connections were fabricated and tested to investigate their performance while subjected to various column-removal scenarios, including: (1) a middle column loss, (2) a penultimate column loss, and (3) a corner column loss. Moreover, the effects of the thickness of steel angle on load resistance were quantified. The test results indicated that load-resisting capacity increased significantly with the increase of angle thickness. In both middle column and penultimate column removal scenarios, catenary action was developed in the frames. It was also noticed that flexural action dominated the load-resisting mechanism of the frames under a corner column loss scenario. For beams in different stories, similar flexural resistance was developed. However, the beams in the first story were able to develop larger catenary action than that in the second story. It is worth noting that, for a corner column missing scenario, Vierendeel action helps to enhance the flexural action significantly. [ABSTRACT FROM AUTHOR]

One of the most important parameters necessary in the seismic force determination is the building's fundamental vibration period, which is also useful in "health monitoring" procedure for the existent buildings, during their exploitation. The fundamental vibration period can be determined by theoretical, empirical or experimental methods. In particular, the experimental method it is known as AVT (Ambiental Vibrations Tests) procedure, which intensively studied today. In this paper it was performed a comparative analysis between fundamental vibration periods values, determined for an existent building, by using a numerical method (finite elements program - ETABS), some direct methods (empirical formulas), and an experimental method (dynamic recordings, based on AVT), using special devices as accelerometers from KINEMETRICS brad. The existent building has "house flats" destination, and it is historic monument, located in Bucharest city, which it was built in ~1930 period, and it has basement and 4 floors. The building's structure is done half by masonry walls with concrete slabs and half by RC frames (columns and beams), with concrete slabs. The main goal of the analysis is to emphasize the advantages and disadvantages of each studied method. [ABSTRACT FROM AUTHOR]

Piezoelectric thermoset composites (PTCs) are the class of material having the ability of transformation between mechanical energy and electric energy. In addition to having the advantages of high strength, easier processing, lower temperature, pressure requirement and unlimited storage, PTCs also have high stiffness, high elastic modulus and high strain coefficients. This review presents the advances and approaches used in PTCs and their applications. Various techniques, such as analytical, finite element and experimental methods for analyzing the coupled piezoelectric responses, are also reviewed. This paper also includes current applications of PTCs in strain sensing, vibration control, actuation, energy harvesting, structural health monitoring and biomedical fields. The studies of PTCs and its applications are in the emerging phase, and the review permits to find new notions for interface studies and modelling progresses for PTCs. In addition to that, these reviews pave the way for various research potentials towards the flourishing pertinent application zones of PTCs. Also, this review highlights the relevance of the particular research area and preliminary work under its different approaches, necessitates the need for more researches. [ABSTRACT FROM AUTHOR]

The added mass is referred to as an extra mass of fluid accelerates with the body caused by body acceleration in the fluid. Surge added mass of ships is relatively low in comparison with their mass which does not have considerable influence on ship manoeuvrability. That is why less research have focused on the surge added mass. This research deals with the surge added mass of planing hulls by model experiment as well as approximates by quasi-analytical method. A benchmark test has been conducted for the surge added mass measurement of Series60 hull form. On that basis, test procedure and set-up have been concluded and verified for planing hulls. The results of model testing and approximate analytical method are compared. This study shows that the surge added mass coefficient of a planing craft may reach up to 10% of the craft mass. [ABSTRACT FROM AUTHOR]

• An algorithm/guideline was extended to predict impacts of baffle/tube-type on STHE performance. • A number of analytical-experimental correlations were derived to accurately predict the STHE performance. • Suitable experiments were designed and conducted to validate the derived correlations. • Various STHEs with different disk-doughnut-baffles and dimpled-tubes were examined to find the best case. • The increase in the tube mass flow rate promotes using the DBST-STHE. • It is quite justifiable to use the SBDT-STHE in low tube mass flow rates. At the beginning of a new shell and tube heat exchanger (STHE) design, it is valuable to know which combination of tube and baffle types will yield the highest possible hydrothermal performance, considering all the defined ranges of working conditions. This becomes crucial for the compact STHE, which are extremely squeezed to smaller sizes. This promotes the researchers to develop suitable software, which can largely help the design engineers to make critical decisions at the early stages of their designs. This study extends a hybrid analytical-experimental algorithm, which can greatly help the STHEs' engineers to readily predict the impact of using disc-doughnut baffle and dimpled tube features on enhancing the hydrothermal performances of their base STHEs, i.e., those equipped with segmental baffles and smooth (or no dimple) tubes. In this regard, a number of analytical-experimental correlations is derived to straightforwardly perform such calculations and readily come to a decision. However, this requires validating the derived correlations against available experimental/numerical data. Because of the complexity of the main STHE configuration and unavailable experimental data, suitable experimental setups are carried out to provide the required database. After ensuring the accuracy of derived correlations, a number of different STHE configurations are modeled and their performances are calculated and compared with each other under various proposed working conditions. The main contribution of this work is that the present developed algorithm can readily find the best combination of tube and baffle types, which leads to optimum hydrothermal performances for the STHE at the proposed working conditions and existing constraints. A guideline is also developed to follow the steps in this algorithm readily. The developed algorithm is suitably examined by testing a complex STHE equipped with various combinations of baffle and tube choices. As the most important finding in these tests, the use of dimpled tubes with either segmental or disc-doughnut baffles can enhance the mean heat transfer rate of the base STHE by about 15.6 and 22.4 %, respectively. [ABSTRACT FROM AUTHOR]

This work examines the experimental and analytical investigation of impact on the carbon/epoxy laminates of various stacking sequence. The impact tests were carried out by using gas gun equipped with high-speed camera. Projectile velocities selected were 80 m/s and 30 m/s where 80 m/s was above ballistic limit velocity and 30 m/s was below ballistic limit velocity. The impact process was recorded with high-speed camera which facilitated to identify different energy absorbing mechanisms. High-speed images were also used to measure pre-impact and post-impact velocities of the projectile accompanied by photo diode and aluminum foil method. Total energy absorbed by the laminates, which is the difference between pre-impact and post-impact kinetic energy of the projectile, was calculated for the laminates with different stacking sequences. Damage extent in the laminates of different stacking sequences were also assessed by C-Scan of the laminates. Then effect of stacking sequences on damage extent and energy absorbing capacity was established. An analytical model was proposed to predict the residual velocity of the projectile at above ballistic limit velocity, which was based on the total energy absorbed by different energy absorption mechanisms. The analytical model was validated with experimental results for different stacking sequences. Additionally, effect of fiber orientation on damage shape at below ballistic limit velocity was also studied. [ABSTRACT FROM AUTHOR]

Forming process in sheet metal working refers to the manufacturing of products by deforming the material in the required die cavity without being broken or local necking. Defects such as wrinkling, local necking, and cracking may occur during the process. These are the results of either reduction or increase in sheet thickness while the material is being stretched inside die cavity. Prevention of defects is important during forming and is challenging if the thicknesses of forming sheets is less than 100 microns. These sheets are applied in the manufacturing of components having two dimensions of less than millimeter size, an operation known as micro-forming. Miniaturization has attracted many fields such as medical instrumentation, mobile manufacturing, automotive, and aerospace. Appropriate strain distribution in forming ensures products with better quality. Forming limit diagram (FLD) has been invented to plot major and minor strains along with forming limit curves. In other words, FLD shows wrinkling, localized necking as well as safe zones with various strain paths, and it proves to be a basic tool for understanding rupture characteristics of the material. There are three approaches for plotting FLD such as empirical (analytical), numerical, and experimental. The research work presents experimental micro-forming investigations on an ultra-thin brass sheet of 90 microns, to plot FLD, using the limit dome height test according to ASTM E2218-02 standard. The experimental setup was designed and developed to micro-form standard specimens applying 15 mm hemispherical punch. FLD plotted with experimental and empirical approaches shows agreement on failure limit curve. [ABSTRACT FROM AUTHOR]

Abstract This study investigates the performance of high-modulus near-surface-mounted (NSM) fiber-reinforced polymer (FRP) laminates in strengthening of existing concrete columns. The focus of this study is on the compressive and buckling characteristics of carbon FRP (CFRP) laminates installed on short columns for strengthening to validate their sufficiency for further studies on slender columns. In this paper, an experimental study was designed to consider the effect of eccentric loading on short concrete columns (500 × 150 × 150 mm3) strengthened with four longitudinal NSM CFRP laminates (1.2 × 10 mm2). All specimens were tested symmetrically under the eccentricity to width ratios of 0, 10, 20, and 30% to give a single curvature bending combined with axial load. The experimental results showed no buckling/debonding failure of CFRP laminates, while some of the CFRP laminates reached to crushing points long after the peak load. Moreover, material coupon tests showed that the strength and elastic modulus of the CFRPs in compression were 34% and 86% of those in tension, respectively. The average compressive strain of NSM CFRP laminates for all column specimens under eccentric loading at peak load and after 15% drop from the peak load was 41% and 84% of their ultimate compressive strain obtained from compression coupon tests, respectively. Furthermore, a robust analytical model was developed considering the material and geometrical nonlinearities and it was verified against experimental results. Overall, the results indicated that strengthening short concrete columns with NSM CFRP laminates improved the capacity of the columns without any premature buckling, debonding, or crushing of CFRP laminates. The results will open new avenues in the FRP strengthening of concrete columns, especially slender columns, where the high-modulus NSM system can also enhance the lateral stiffness of the columns for buckling control. [ABSTRACT FROM AUTHOR]

• The capture efficiency of scoops may increase up to 10%, if the oil jet splashes against the outer scoop contour. • The best efficiency is obtained when the jet is aimed to hit the outer scoop contour at a fixed point near the rear side. • An analytical splashing criterion is developed to predict the range of operating conditions at which the jet is aimed to hit the rear scoop side. • Basic assumption of the paper is that the best efficiency curve is correlated to the splashing criterion, which is confirmed by experiments. • Visualization tests have shown that the main efficiency losses are due to 1) the missing of plumes, and 2) centrifugal losses. Scoops are used in aero-engines to capture oil and direct the oil flow for the lubrication of bearings, where a direct oil injection is not effective or possible. The design of scoops focuses on the capture of oil to aim for the highest capture efficiency. The operating conditions are usually chosen such that splashing of the oil jet against the outer side of scoops is avoided. In this paper it is shown that some degree of splashing may be beneficial and results in an increase of the scoop capture efficiency. An analytical approach is presented to describe the range of operating conditions at which the jet is aimed to hit a specific fixed point on the outer or inner scoop contour. These operating conditions are introduced as splashing and capture conditions, respectively, and described in terms of a dimensionless velocity ratio and the jet angle. A "splashing criterion" is introduced to describe the operating conditions at which the jet is aimed to hit the rear side of the scoop. A "capture criterion" is introduced to describe the operating conditions at which the jet is aimed to hit the scoop tip. The basic assumption in this paper is that the best scoop capture efficiency is correlated to the splashing criterion and not to the capture criterion. The correlation is confirmed by a series of experiments on a scoop, performed at different jet angles and a range of velocity ratios. From the match of the correlation curve with the experiments, it is concluded that the best scoop efficiency is obtained when the jet is aimed to splash on the outer scoop contour at a point near the rear side. It could be proven that this splash point does not change with the jet angle. The fact that this point of "best efficiency" remains a fixed splashing point on the scoop contour may be helpful in the design of scoops. [ABSTRACT FROM AUTHOR]

Abstract The dynamic behavior of counter flow heat exchangers is studied using the harmonic response. To solve the set of partial differential equations the complex notation is used so that these equations become ordinary differential equations. In an appendix it is shown that assuming a uniform temperature in a cross section of the separating wall is correct for the example used as comparison. Experimental results dealing with a double pipe heat exchanger are compared with results obtained by assuming the correlations to be used for the convection heat transfer coefficients. The comparison is satisfactory when the excitation is applied to the inner tube fluid. It is less accurate when the excitation is applied to fluid flowing in the annulus. Finally it is shown that the residence time of the fluids is linked to a peak in the response curves. [ABSTRACT FROM AUTHOR]

In this study, multi-objective optimization of a Gamma type Stirling refrigerator is carried out based on the experimental and analytical results. The cooling capacity and the coefficient of performance (COP) are experimentally investigated for helium and air. Beside to helium and air, carbon dioxide is also considered as the working fluid in the simulation. A non-ideal adiabatic analysis is developed for the simulation. The experimental and simulation results showed that the cooling capacity increases continuously with the rotational speed where the COP has a maximum value. The optimum COP value for helium occurs at higher rotational speed than that of the air. The Design of Experiment (DOE) method is used for multi-objective optimization. Three parameters namely COP, cooling capacity and pressure drop are investigated in this optimization study. Only helium and carbon dioxide are considered for optimization because of their higher specific heat capacity and enthalpy with respect to air. The optimum working pressure for the carbon dioxide takes place at lower pressure than that of helium. When the importance and weight factors equal one, the optimum point for helium is obtained at working pressure and rotational speed of 9 bar and 451.1 rpm, respectively. Where, the optimum point for carbon dioxide is found at working pressure and rotational speed of 3.3 bar and 798.5 rpm, respectively. [ABSTRACT FROM AUTHOR]

Humidification dehumidification (HDH) desalination system is a thermal-based desalination technology that is suitable for small-scale water desalination applications. In this paper, we present an experimental and thermodynamic analysis of the energetic performance of two HDH cycles. The HDH cycles considered are the basic open-air open-water (OAOW) cycle and the modified closed-water open-air (CWOA) cycle with the options of brine recirculation. An experimental investigation is performed on the modified cycle to validate the theoretical model that is used to assess the energetic performance of both the basic and modified cycles. The theoretical model is found to be in a good agreement with the experimental data with a maximum percentage deviation of 5% from the experimental data. Furthermore, limiting cases of the system are explored. Within the limiting cases, the modified cycle recorded about 100% improvement in the energy performance over the basic cycle due to heat recovery process associated with the modified cycle. Additionally, a cost analysis was performed to determine the cost of freshwater production by the presented desalination cycles. Results show that the freshwater price varied from 4.10 to 6.55 $/m 3 and 0.79 to 2.25 $/m 3 for the basic OAOW HDH cycle and the modified CWOA HDH cycle, respectively. [ABSTRACT FROM AUTHOR]

Abstract In the present study, the rheological behavior of Fe 3 O 4 -MWCNTs/ethylene glycol hybrid nanofluid was investigated for different volumetric fractions (0.1, 0.25, 0.8, 1.25, and 1.8%) comprising equal amounts of suspended iron oxide (Fe 3 O 4) nanoparticles and multi-walled carbon nanotubes (MWCNTs) within the temperature and shear ranges of 25 to 50 °C and 12.24 to 73.44 s−1, respectively. The results indicated that the nanofluid demonstrates a Newtonian behavior at volume fractions of 0.1, 0.25, 0.45, and 0.8%, whereas it demonstrates a non-Newtonian behavior at volume fractions of 1.25 and 1.8% similar to the power law model with an exponent lower than 1. Moreover, it was observed that viscosity is directly proportional to volume fraction, and inversely proportional to temperature. Then, the effect of nanoparticles and nanotubes on the thermal performance of ethylene glycol inside a pipe of heat exchanger was evaluated and the results revealed that an increase in the volume fraction at all temperatures leads to increased pressure drop and heat transfer coefficient. Finally, the results were used to develop an experimental equation as a function of temperature and volume fraction to estimate nanofluid viscosity in the simulations. The predicted values by the equation were in a very good agreement with the experimental results. Highlights • Investigating the rheological behavior of Fe 3 O 4 -MWCNTs/EG hybrid nanofluid • Nanofluid demonstrates a Newtonian behavior at volume fractions of 0.1, 0.25, 0.45, and 0.8%. • Nanofluid has non-Newtonian at volume fractions of 1.25 and 1.8% similar to the power law model. • Evaluation of effect of nanoparticles and nanotubes on the thermal performance of EG inside a pipe • Developing an experimental correlation as a function of temperature and volume fraction to estimate nanofluid viscosity [ABSTRACT FROM AUTHOR]

• Basic insights into CCPFs and the studies related to bridges supported on CCPFs are provided. • Findings categorized based on the type of loading (static, cyclic, and dynamic), and methodology (experimental, analytical, and numerical) applied to the composite foundation. • Objective is to provide an overview of the current state-of-the-art of CCPFs. Caissons and piles are two primary foundation types for deep-water bridges. Caissons are suitable for long-span bridges, deep alluvial deposits, liquefiable soils, and sufficient vessel collisions, but can be problematic due to sinking issues and inadequate earthquake resistance. Pile foundations are not suitable for deep water because of their extensive length, reduced rigidity, low vessel collision resistance, and difficulties in construction. A solution to the above problem can be a combination of caisson and piles, known as a Composite Caisson-Pile Foundation (CCPF), which considers the advantages of both foundation types, increasing their strengths without their flaws. After the caisson has reached the required depth, piles may be driven into it to construct a CCPF. Existing caisson foundations can be retrofitted using this approach. However, CCPFs have not been extensively employed due to a lack of thorough study on their geotechnical and structural behavior. This article reviews studies on CCPF systems under various loading condition types (static, cyclic, and dynamic) using different research methodologies (experimental, analytical, and numerical). Overall, this article provides basic insights into CCPFs and the studies related to bridges supported on CCPFs. The outcome of this study can benefit the foundation engineering community and provide a collective idea of this newly developed, innovative foundation system. [ABSTRACT FROM AUTHOR]

In this paper, an analytical model has been developed for modeling high velocity impact on ceramic/nanocomposite targets. In this model, penetration resistance of ceramic is determined based on cavity expansion analysis and variables during perforation of projectile onto ceramic are considered. Also the force of ceramic-composite interface is modified. Ballistic performance of the ceramic/composite target is investigated with adding and dispersing of nano particles of zirconia (ZrO2) in the matrix of back up composite. Ballistic impact tests were performed to validate the analytical predictions. These tests were performed by firing 10 mm steel flat ended projectile onto ceramic/composite target. Front layer is alumina ceramic and composite laminates of back up made of E-glass/epoxy with and without nano-zirconia particle of 5 wt%. The effect of nano-zirconia dispersion in the matrix for different failure modes is discussed. Experimental results revealed an improvement in the ballistic performance of samples with nano-zirconia particle. The analytical predictions of ballistic limit velocity and residual velocity of projectile are found to be in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive review of available models of photovoltaic panel. Modeling and simulation of photovoltaic panel (PV) in virtual environment helps in designing and performance analysis of solar based power system. This paper analyses the currently available models from two different aspects. First aspect is based on electrical characteristics of PV panel using electrical equivalent circuit or through set of mathematical equations. The other aspect is based on the characteristics of PV panel under different environmental conditions. Environmental conditions include varying temperature and non-uniform solar irradiance due to partial shading. Varying environmental conditions causes continuous change in PV panel operating point corresponding to Maximum Power Point (MPP). Therefore an accurate PV panel model built with robust control that includes these environmental conditions will certainly improve the overall performance of the solar power plant. This paper can help researchers in selecting a specific objective based PV panel model out of several models available in literature. [ABSTRACT FROM AUTHOR]

Fibrous filters are commonly utilized to remove aerosols from the air to capture contaminants and pollutants prior to atmospheric release, or to clean atmospheric air itself. An ideal filter achieves the highest capture efficiency possible while providing the least airflow resistance possible. From this, the ability to predict how a filter operates based upon its functional parameters, such as filtration velocity and particle size and type, and characteristic parameters, such as its fiber size and media porosity, are integral to not only properly applying and estimating filter performance, but also facilitating the improvement and development of filtration technology. The purpose of this work is to review both classical and contemporary particle loading models to provide a comprehensive discussion built upon a foundation of first principles. The different relevant particle capture mechanisms are presented and discussed in terms of fibrous air filtration, along with the separate loading regimes. Specific loading models are then introduced considering these concepts and are separated into three categories: 1) analytical models, 2) computational models, and 3) experimental models. In short summary, analytical models have been well-covered and benefit from their ease of use but suffer from a difficulty in describing the stochastic nature of realistic particle loading. Computational models benefit from their inherent incorporation of first principles thereby addressing the dynamic nature of particle loading, however they may be difficult to apply outside of research environments due to their complexity and computationally demanding nature. Experimental models benefit from the avoidance of simplifying assumptions and the ability to correlate data describing phenomena that are difficult to quantify but are limited to applications covered by their experimental parameters and have difficulty addressing anomalies that present themselves. Suggested future work from identified research gaps focus on the lack of available data and reliable methods to measure media characteristics as well as developing models that predict the full spectrum of the loading process based upon media and particle characteristics. • Particle loading models predict filter performance from factors such as loaded mass. • Prevalent work is categorized as analytical, computational, or experimental. • Included models are presented in terms of foundational particle capture mechanisms. • Strengths and weaknesses of the model categories are presented and discussed. • Future work is identified through current research gaps. [ABSTRACT FROM AUTHOR]

Textile-reinforced mortar (TRM) is a composite material that overcomes some drawbacks of other RC (reinforced concrete) shear strengthening solutions. In this work, four different types of TRM are used as a shear strengthening system on RC beams tested until failure. A comparative study of their mechanical performance shows that the different TRM combinations used were able to increase the load bearing capacity and change their failure mode. Moreover, new methodologies that permit evaluating the bonding behaviour of TRM and the increment in flexural toughness are presented. The experimental results are compared with previous FRP and TRM analytical formulations. Finally, new formulae for calculating the shear contribution of TRM based on experimental results are proposed. [ABSTRACT FROM AUTHOR]

Prestressed steel trusses can offer efficient structural solutions for long span applications such as aircraft hangars, stadia and warehouses. In the current study, the tensile behaviour of prestressed steel elements, which comprise tubular steel members with internal prestressing cables, is investigated. The stability of the elements under prestress and the load–deformation response of the prestressed elements to the subsequent application of tensile loading are examined analytically, numerically and experimentally, with good correlation achieved between the three approaches. The benefits of prestressing, in terms of increased member strength and stiffness, are demonstrated, and optimal prestress levels are investigated. [ABSTRACT FROM AUTHOR]

Abstract: Normal forces exerted by the adhesive to the substrate during the squeeze flow occurring in compaction of bonded joints are analyzed using theoretical, numerical and experimental techniques. An analytical solution, derived from the squeeze-flow theory of a viscoplastic material, is generalized to be valid for any initial shape of the adhesive cord. The rheology of the material is modeled according to the Herschel–Bulkley model and is fitted with experimental data available from the characterization of an epoxy-based adhesive. The analytical law is compared with a numerical model, where the two-phase problem for the squeeze-flow test is solved by finite-volume methods using a commercial CFD solver. The results obtained with these two approaches show excellent agreement with experimental forces obtained for a wedge-shaped specimen. The proposed methodology can therefore be useful for the optimization of the bond lines in assembling processes. [Copyright &y& Elsevier]

New electron microprobe analyses of Sr and Ba in feldspars and coexisting experimental glasses show very strong correlations of the partition coefficients with the ternary Or content of the feldspar. The correlations therefore scale inversely with temperature, as also found in the literature. The Sr content of feldspars is maximized in mesoperthite and decreases with evolution of feldspar to the ternary minimum. The relationship of DSr/L to decreasing XAn is initially flat at a value of 1.8 but curves sharply upward past 6.5 after the arrival of apatite at An38. A similar concave-up curve at much higher values of D is found in the literature. The value of D (nine points) scales linearly with ternary Or; R² = 0.99. Experimental feldspars are consistently richer in Sr than natural ones at comparable An. They jump from 200 ppm higher to 400 ppm higher at Ap+. Experimental glass compositions are correspondingly low in Sr, so the material balance is conserved. Inversion of natural feldspars to liquid compositions using the experimental partition coefficients fails because the experimental crystals contain enhanced values of Sr from the apatite and feldspar components of the melted rock compositions. The partitioning of Ba (five points; range 0.4 to 6.1) also scales with ternary Or; R² > 0.99; and there is no systematic difference between the natural and experimental concentrations of Ba in the feldspars. The inversion of D to liquid compositions may be safe for Ba but must be approached with caution for Sr. [ABSTRACT FROM AUTHOR]

The resistance of glass-reinforced laminates with different thickness ratio (ratio of glass/epoxy plies thickness to aluminum sheets thickness) subjected to high-velocity impact is investigated experimentally and analytically. The tests are carried out by a light gas gun and a 14 g blunt cylindrical projectile. The ballistic limit velocity and specific perforation energy is used for comparing results. The failure mechanisms that absorbed projectile’s energy during perforation process are studied by examining the damaged samples. This examining helped us to derive an analytical expression to predict the ballistic limit and specific perforation energy. The good agreement between experimental and analytical results shows well mathematical modeling. The results indicate that global deformation of aluminum sheets had the most effect on absorbing energy. Increasing the number of composite plies may enhance the absorbed energy of a fiber metal laminate but also increases weight and cause to be away from the optimum condition. Besides these two procedures, a numerical analysis is done and the results compared with previous ones and are commented upon. [ABSTRACT FROM PUBLISHER]

Abstract: An impressive amount of investigation has been devoted to enhancing overall thermal and hydrodynamic performance of microchannel heat sinks. The small size of microchannel heat sinks and their ability to dissipate heat generated by modern electronics makes them the first choice for the electronic cooling systems in most devices. In this paper, a comprehensive review of available studies regarding non-circular microchannel heat sinks, with emphasis on rectangular microchannels, was presented and analyzed. This review looked into the methodologies used to analyze and optimize the overall performance of microchannel systems along with channel geometries, flow conditions, the coolants used, structural materials, optimization tools and finally, the form in which the final outcome of each study was presented. The review showed that earlier studies (from 1981 to 1999) were largely conducted using experimental or analytical approaches while more recent studies (from 2000 to the end of 2012) showed a dependency on numerical simulations and evolutionary algorithms. In addition, they also showed that laminar was the prevailing flow condition as out of the 69 articles reviewed, 54 employed laminar flows. Furthermore, the use of liquid coolants was preferable over gaseous coolants. Recent developments in nanofluids are providing alternative coolants that are quickly establishing as coolants to be reckoned with. [Copyright &y& Elsevier]

Abstract: Building stones, particularly sandstone and granite, are very important in the building elements of Portugal’s historical and cultural heritage. Experimental research, based on uniaxial compressive tests, was carried out on selected representative samples of lithotypes of rocks used in historic built heritage, with a view to evaluating the compressive mechanical behaviour of different building stones. The results showed that porosity plays a central role in the compressive behaviour of granites and sandstones. As porosity can be evaluated in field conditions with non-destructive tests it was decided to derive an analytical model to predict compressive behaviour based on the knowledge of porosity of the building stones. A cubic polynomial function was adopted to describe the pre-peak regime under compression to implement the model. Furthermore, a statistical correlation between mechanical and porosity data had to be defined. Good agreement between experimental and analytical compressive stress–strain diagrams, from which the mechanical properties like compressive strength and modulus of elasticity can be derived, was achieved. [Copyright &y& Elsevier]

Pulsatile flows have shown to increase the permeation flux in reverse osmosis studies and to reduce fouling that exists in using membranes for separation processes. However, this study demonstrates that permeation from the inside of a hollow fiber with a membrane boundary to the outside decreases once pulsations are added to the inside of the membranes. The increase in the axial flux due to the flow pulsations are the reason for the increased permeation in reverse osmosis and the decrease in transport from inside to outside. An analytical model for a two-dimensional system is presented along with experimental results in separating oxygen from air using polycarbonate based hollow fiber membranes. [ABSTRACT FROM AUTHOR]

The thermal behavior of composite steel-concrete slabs in fire is more or less known, however there are still a lot of different aspects in the fire design methods that need clarification. A comparison of the temperature distribution in the cross-section of steel decking concrete slabs subjected to fire is made through three different procedures: (a) experimental, (b) numerical and (c) analytical methods. The experimental tests corresponding to eight real-scale fire tests on slabs carried out by the authors. These tests have been used to calibrate numerical models for being used with the finite element software Abaqus. The analytical methods were the ones proposed in Annex D of EN 1994-1-2. The analytical steel decking temperatures showed convergence with the experimental and numerical ones. The same was not observed for the concrete, positive and negative rebar and thermal insulation temperatures. A new analytical approach for assessing the negative rebar temperatures and new factors for assessing the thermal insulation performance - alternative to EN 1994-1-2 - are proposed. [ABSTRACT FROM AUTHOR]