Longitudinal Arrangements Research Articles

Hydrodynamic analysis of sea-crossing bridge piers subjected to freak waves

Coastal areas are witnessing a surge in critical infrastructure development, such as sea-crossing bridges, to support growing populations and economic activities. However, these structures face ongoing challenges in harsh marine environments. Therefore, understanding the hydrodynamics of bridge structures under extreme freak wave conditions is imperative for designing effective countermeasures. This study investigates pier hydrodynamics using a three-dimensional numerical flume simulated by OpenFOAM, focusing on loading characteristics and wave climb differences under freak and linear waves. Results show that freak waves induce larger surges and forces compared to linear waves, with a notable “bell vibration” effect near the wave surface. Moreover, peak forces and bending moments increase nonlinearly with the wave height-to-significant wave height ratio. For double-column piers, transverse alignment concentrates wave climb on the rear side of the front pier, with forces increasing with spacing, while those on the rear pier decrease. Conversely, longitudinal arrangements show amplified loading effects. These findings provide valuable insights into the hydrodynamic behaviour of bridge piers under freak wave conditions, offering practical implications for the design and protection of sea-crossing bridges.

Recent insights into the morphology, molecular characterization and tissue localization of the caprine Sarcocystis species infecting domestic goats (Capra hiricus): Sarcocystis moulei, Sarcocystis capracanis, and Sarcocystis hircicanis

Ninety-seven (64.67%) out of 150 domestic goats (Capra hiricus) carcasses were found to be infected by Sarcocystis moulei, Sarcocystis capracanis, and Sarcocystis hircicanis sarcocysts. Sarcocystis moulei macrosarcocysts were detected in the cardiac, esophageal, skeletal, lingual, and diaphragmatic muscles of seven goats (4.67%) out of the 150 examined animals, whereas the microscopic Sarcocystis species were found in (90/150 = 60%). Two morphotypes of S. moulei were observed. Morphotype (I) macrosarcocysts were large-sized oval, ovoid, spherical, and measured 2–7 mm in length x 2–6 mm in width. Sarcocystis moulei morphotype (II) macrosarcocysts were spindle-shaped, spheroid, sometimes elongated, and measured 1.8–6 x 0.5–2 mm. By TEM, all S. moulei morphotypes were ultrastructurally the same and had a sarcocyst wall that was characterized by highly branched or cauliflower-like villar protrusions (VP) with dumbbell-like structures. The VP interior was packed with well-developed microtubules in longitudinal and cross arrangements. Sarcocystis moulei cyst wall was 3–6 μm thick. Sarcocystis capracanis microsarcocysts detected herein had a cyst wall that ranged from 4–8 μm in thickness. The VP was upright finger-like or cylindrical. The PVM had electron-dense corrugations in the region of the VP. Few amounts of microfilaments were detected inside the cores of VP. Sarcocystis hircicanis had a thinner cyst wall (~1–3 μm) with hairy long VP that ranged from 1 to 7.5 μm in length. Microtubules were missing inside the cores of the VP. The three caprine Sarcocystis species were molecularly characterized on the level of the 18S rRNA, 28S rRNA, and Cox1 genes.

Detecting landslide vulnerability using anisotropic microtremors and vulnerability index

The vulnerability of the Nan-Shi-Keng landslide area in Taiwan is investigated via single-station horizontal-to-vertical spectral ratio analysis. The measurement stations in the area are arranged as follows: (1) a transverse arrangement through the landslide site along Highway No. 175 (Case 1) and (2) two longitudinal arrangements down the slope (Case 2). In Case 1, the distribution of the vulnerability index along the highway indicates that the risk of surface deformation is high on sections of the highway located outside the potential sliding zone. The low vulnerability index of highway sections within areas where the protection measures have been taken indicates that they successfully stabilize the highway and the upper slope area. In Case 2, the deformation-prone directions (i.e., the directions with the maximum vulnerability index) evaluated at various stations using anisotropic microtremor measurements of the landslide site correlate strongly with the local sliding directions obtained using conventional inclinometer measurements and telemetry monitoring. The value of the vulnerability index is related to the highway damage and soil movement behavior. Therefore, the vulnerability index serves as a useful warning parameter to locate sites with a high probability of slope failure.

Net-zero energy optimization of solar greenhouses in severe cold climate using passive insulation and photovoltaic

To take into account the crop growth of greenhouse and reduce energy consumption, this study investigated to optimize and retrofit a typical solar greenhouse in the severe cold climate of China into a net-zero energy solar greenhouse (NZESG). The envelope passive insulation measure and roof flexible photovoltaic (PV) technique are innovatively combined and some optimization cases were proposed based on simulation and analytical studies. The foamed cement insulation boards with different thicknesses and envelope positions were added as 11 passive insulation retrofit cases. The flexible PV panels in checkerboard (PV1), horizontal (PV2) and longitudinal (PV3) arrangements were positioned on the greenhouse roof and their electrical energy was estimated through PVsyst software. The optimal case was obtained based on the local technical standard for nearly zero energy consumption buildings and energy-saving, carbon reduction, payback period and cost multi-objective entropy weight method. The key finding is that passive energy-saving retrofit Case (a) & PV1 has the highest comprehensive score and is the optimal NZESG case. Its investment cost and payback period of Case (a) & PV1 are 45526.40 CNY and 5.23 years respectively. Case (a) adopts 50 mm foamed cement board with external insulation. Although the effect of energy-saving and CO2 reduction is poor, Case (a) has the shortest payback period and the lowest cost. PV1 has the lowest investment and higher power generation. It also shows that the investment payback period and cost weight are high, which are the key parameters for comprehensive evaluation of the retrofit cases; The entropy weight method is objective and scientific. The retrofit measures and optimization method can facilitate the promotion and application of NZESGs.

Better governance starts with better words: why responsible human tissue research demands a change of language

The rise of precision medicine has led to an unprecedented focus on human biological material in biomedical research. In addition, rapid advances in stem cell technology, regenerative medicine and synthetic biology are leading to more complex human tissue structures and new applications with tremendous potential for medicine. While promising, these developments also raise several ethical and practical challenges which have been the subject of extensive academic debate. These debates have led to increasing calls for longitudinal governance arrangements between tissue providers and biobanks that go beyond the initial moment of obtaining consent, such as closer involvement of tissue providers in what happens to their tissue, and more active participatory approaches to the governance of biobanks. However, in spite of these calls, such measures are being adopted slowly in practice, and there remains a strong tendency to focus on the consent procedure as the tool for addressing the ethical challenges of contemporary biobanking. In this paper, we argue that one of the barriers to this transition is the dominant language pervading the field of human tissue research, in which the provision of tissue is phrased as a ‘donation’ or ‘gift’, and tissue providers are referred to as ‘donors’. Because of the performative qualities of language, the effect of using ‘donation’ and ‘donor’ shapes a professional culture in which biobank participants are perceived as passive providers of tissue free from further considerations or entitlements. This hampers the kind of participatory approaches to governance that are deemed necessary to adequately address the ethical challenges currently faced in human tissue research. Rather than reinforcing this idea through language, we need to pave the way for the kind of participatory approaches to governance that are being extensively argued for by starting with the appropriate terminology.

玉米联合收获机纵置滚刀式茎秆切碎装置的设计与试验

At present, the quality of chopping stalks with the use of a corn combine harvester needs improvement. Therefore, this study aims at designing a hob-type stalk chopping device to be installed under the header which can realize multiple groups of parallel longitudinal arrangements. Moreover, the device will be able to cut and crush the root and the middle and upper parts of the stalks. The performance of a finite element analysis corroborated the satisfactory strength and stiffness of the designed chopping blade as the mechanical requirements. Moreover, the influencing working and structural parameters were determined using a theoretical analysis. Regarding the test factors, i.e., the tip angle of the blades, fixed angle and the rotational speed of chopper shaft, single-factor and central composite design tests were also performed. Furthermore, the percentage of the qualified length of chopped stalk and the power consumption of cutting stalk were taken as the evaluation indexes. Accordingly, the results revealed the influencing parameters to be ordered as the spindle speed > fixed angle > tip angle of the blades. Subsequently, the parameters were optimized using the response surface method. Based on the obtained results, the optimized parameters including the spindle speed, the fixed angle and the tip angle of the blades were specified as 1050 r/min, 56°, and 40°, respectively. The experimental validation was also carried out on the optimal combination of the parameters. The qualified lengths of the chopped stalks were found to be 92.9%, which were consistent with the predicted results of the model. Hence, the test results met the design requirements.

Effect of the Anode Structure on the Performance of Oily Sludge Sediment Microbial Fuel Cells.

The anode is considered to be a key factor to improve the single-chamber bioelectrochemical system’s efficiency to degrade oily sludge in sediment while generating electricity. There are few studies on the effect of the anode structure on the performance of oily sludge MFCs systematically. In this paper, an oily sludge bioelectrical system was constructed using carbon felt and carbon plate as anode materials, adjusting the anode material arrangement as transverse and longitudinal, and using different anode materials from single to sextuple anodes. The results of this study showed that the rate of degradation of oily sludge was greater with carbon felt (17.04%) than with the carbon plate (13.11%), with transverse (23.61%) than with the longitudinal (19.82%) arrangement of anodes, and with sextuple anodes (33.72%) than with a single anode (25.26%) in the sediment microbial fuel cells (SMFCs). A similar trend was observed when the voltage, power density, and electromotive force (EMF) of SMFCs were estimated between the carbon felt and carbon plate, transverse and longitudinal arrangements, single and sextuple anodes. It is concluded that the proper adjustment of anode arrangements, using carbon felt as an anode material, and increasing the number of anodes to six may accelerate the rate of degradation of oily sludge in oily sludge sediment microbial fuel cells (SMFCs). Furthermore, the electricity generation performance was also improved.

Impact of fin type and orientation on performance of phase change material-based double pipe thermal energy storage

In this study, a numerical analysis using computational fluid dynamics (CFD) is performed on a proposed horizontal concentric (DPHX) filled with N-eicosane phase change material (PCM), investigating the impact of fin type and orientation, on charging (melting PCM) and discharging (solidification PCM). In this study, various Cases including fin orientation (longitudinal and transversal arrangement) and fin types (corrugated and flat fins) are simulated and compared for best thermal and heat transfer performance. The results captured are based on Liquid Fraction, temperature, and velocity streamline contour illustrations. The contours show that natural convection positively affects the melting performance in the upper region during the melting/charging process, however, conduction is the main mode of heat transfer in the solidification/discharging process. For the melting process, the transversal corrugated fin arrangement outperforms the other Cases with over 88% reduction in melting time as opposed to the unfinned base Case. The longitudinal corrugated fin Case had a 58% reduction in melting time, which was 2% slower than the longitudinal flat fin Case and overall, transversal corrugated fin Case 11.5 times faster than unfinned Case. In the solidification process, the transversally arranged fins releases the stored energy at a faster rate with reduced time for total solidification. The longitudinal flat finned Cases perform similarly for discharging with improved discharging rate and slightly less solidification time than the unfinned Case. The transversal corrugated fin design is shown to have greater improvement in charging and discharging compared to all other Cases, with the shortest overall processing time. Significant results are also seen in the total process time with the longitudinal flat finned arrangements 1.2 times faster and the transversal flat finned arrangements 8.7 times faster than the unfinned Case.

Experimental Investigation on Punching Shear Mechanism of Concrete Interior Slab-Column Connections without Shear Reinforcement

The punching shear failure of reinforced concrete flat plates has puzzled researchers for a long time due to the complexity of the punching shear mechanism and the difficulty of direct measurements of the internal failure mechanism. Measurements from previous punching shear tests cannot provide sufficient experimental evidence for revealing the failure mechanism. In this study, an industrial endoscope and specially designed strain measuring rods were installed inside small holes reserved in slabs around columns to track the occurrence and propagation of internal cracks of five isolated slab-column connections with different longitudinal reinforcement arrangements. The results indicated that critical shear cracks developed from internal diagonal cracks initiated at midheight of the slabs and unevenly distributed around the columns. The propagation of the internal diagonal cracks was independent of flexural cracks initiated at the slab tension faces but closely related to the unloading of radial strains of concrete at the slab compression faces. At the moment of punching failure, the critical shear cracks propagated from compression to tension zones, forming a punching failure cone. Moreover, the failure process was progressive, that is, the continuous weakening of the compression zone by the critical shear crack resulted in the shear splitting of the compression zone, which triggered the final failure of the connections. The experimental evidence obtained can provide a physical background and new ideas for modeling the punching shear mechanism of slab-column connections.

Solidification performance of new trapezoidal longitudinal fins in latent heat thermal energy storage

In order to improve the solidification performance of latent heat thermal energy storage system, a new trapezoidal longitudinal outer fin distributed by Fibonacci sequence is proposed due to the low thermal conductivity of phase change material. Firstly, the solidification behavior (temperature distribution, solid fraction, and solidification time) of three trapezoidal fins and traditional quadrilateral fin are compared by numerical simulation. The fin design with the highest improvement in solidification performance is selected and the dynamic temperature analysis is carried out. The Fibonacci sequence is introduced into the fin distribution and the effect of different longitudinal fin arrangements on solidification performance is analyzed. In addition, Response surface method is used to investigate the influence of geometric parameters of the trapezoidal fin based on Fibonacci sequence arrangement, and the optimal structure is obtained after optimization. The results show that the solidification time of phase change material after using modified trapezoidal fin with Fibonacci sequence is shortened by 45.28% compared with the traditional quadrilateral fin. Finally, the temperature difference between the inner tube cold fluid and the phase change material is greater than 20 K, which can ensure the excellent solidification performance.

Sensitivity Analysis on Thermal Performance of Gas Heater with Finned and Finless Tubes using Characteristics-based Method

Natural gas must be preheated to prevent phase change and gas hydrate in pressure reduction stations. This paper aims to investigate the effect of the fins of gas tubes and their configuration, arrangement, and shape on the heat transfer and thermal efficiency of gas. To conduct a parametric study, two tube cases with fins and without fins, and in the finned case for the fin’s configuration, two longitudinal and circular arrangements, and the formation of the fins, two solid and interrupted forms were analyzed. Also, three types of cross-sections, including rectangular, convergent parabolic, and divergent parabolic, for the shape of the fins have been studied. For this simulation, the three-dimensional, incompressible, and steady flow was considered, and for analysis and discretization of convective heat equations, the characteristic-based method was applied. FORTRAN software was also used to implement and solve the equations. The results show that in solid and interrupted fins and increasing the number of fins in parallel, the dimensionless heat transfer coefficient increases. Also, the dimensional heat transfer coefficient decreases with increasing the ratio of fin height to the tube’s diameter. Also, the most significant heat transfer improvement was related to the divergent parabolic cross-section.

Molecular dynamics simulation of fluid flow through nanochannels consisting of different superhydrophobic patterns

Non-equilibrium molecular dynamics simulation has been carried out to calculate the Darcy-Weisbach friction factor of water flow through the nanochannels. The nanochannel walls were decorated by different arrays of nanoscale protrusion to generate superhydrophobic surfaces. The existence of nanostructures on the channel walls leads to trapping the air inside the nanocavities and, consequently, the system transmutes to a ternary (solid-liquid-gas) system. Our goal is to study how this transmutation affects the hydrodynamics of the fluid flow. The superhydrophobic walls were comprised of longitudinal and transversal nanoridge arrangements and results are obtained for various Reynolds numbers, pillar surface fractions and relative module widths. In this contribution, we presented correlations for the Darcy-Weisbach friction factor of water flow through the nanochannels including different superhydrophobic structures. Results indicated that the relation between friction factor and Reynolds number for the flow through the nanochannels is similar to the laminar flow through channels. Our results demonstrated that the friction factor in nanochannels decreased by employing superhydrophobic structures and also the friction factor in transversal nanoridge arrangement was significantly higher than that of the longitudinal one. We found that by decreasing the percentage of surface fraction and increasing the relative module width, the friction factor decreased.

Fused filament fabrication 3D printed polylactic acid electroosmotic pumps.

Additive manufacturing (3D printing) offers a flexible approach for the production of bespoke microfluidic structures such as the electroosmotic pump. Here a readily accessible fused filament fabrication (FFF) 3D printing technique has been employed for the first time to produce microcapillary structures using low cost thermoplastics in a scalable electroosmotic pump application. Capillary structures were formed using a negative space 3D printing approach to deposit longitudinal filament arrangements with polylactic acid (PLA) in either "face-centre cubic" or "body-centre cubic" arrangements, where the voids deliberately formed within the deposited structure act as functional micro-capillaries. These 3D printed capillary structures were shown to be capable of functioning as a simple electroosmotic pump (EOP), where the maximum flow rate of a single capillary EOP was up to 1.0 μl min-1 at electric fields of up to 750 V cm-1. Importantly, higher flow rates were readily achieved by printing parallel multiplexed capillary arrays.

Effects of installation location on the in-service wind load of a tower crane

Tower cranes are usually attached to buildings, which affects the crane's aerodynamic configuration, and therefore the wind loads on the tower crane are changed. In this study, a numerical simulation using computational fluid dynamics was carried out to investigate the mean force and moment coefficients of an in-service tower crane at five different locations. A single unattached tower crane was taken as the reference counterpart. The results showed that the building played an important role in reducing the along-wind load of the tower crane. In comparison with the reference tower crane, the average reductions of the along-wind load on the tower crane under longitudinal and transverse arrangements were 53·4% and 52·7%, respectively. For 90° to 180° wind directions, the torsion moments were smaller than those of the reference. The closer the crane was to the building, the smaller was the torsion moment. Among the five locations investigated, longitudinal distance was found to have less effect on the along-wind, across-wind and torsion moment loads on the tower crane than the transverse distance. However, the transverse distance had a great influence for 0° to 90° wind directions. The closer the tower crane was to the corner of the building, the more severe the wind direction deviated from the original direction.

Effect of concrete strength and longitudinal reinforcement arrangement on the performance of reinforced concrete beams strengthened using EBR and EBROG methods

Externally Bonded Reinforcement (EBR) is a common method to install fiber reinforced polymer (FRP) sheets using surface preparation approach. In recent years, a new method called Externally Bonded Reinforcement on Grooves (EBROG) has been introduced as an alternative to the EBR method to strengthen reinforced concrete (RC) beams. In the present study, eight RC beams with 250 mm width, 300 mm depth, and 2200 mm length with two different longitudinal reinforcement arrangements were cast and subjected to the four-point bending test. The specimens were divided into two groups of four specimens according to their strengthening technique, namely EBR and EBROG methods. In addition to the strengthening method, the effects of reinforcement arrangement and concrete strength were investigated. The results show normal strength concrete (NSC) beams strengthened with EBR and EBROG methods experience FRP debonding and concrete cover separation failure modes, respectively. On the other hand, in high strength concrete (HSC) beams both EBR and EBROG methods lead to FRP debonding failure mode. The results also show that the use of the EBROG method in the HSC specimens results in a substantial increase in the ultimate load-carrying capacity, mid-span deflection, and the area under the load-deflection curve up to the maximum load capacity compared to the EBR method. Finally, the comparison between load-carrying capacity obtained from the experimental tests and different analytical models are presented in the study.

Laminar flow and heat transfer of water/NDG nanofluid on tube banks with rhombic cross section with different longitudinal arrangements

In present numerical study, water/NDG (nitrogen-doped graphene) nanofluid flow in different arrangements of rhombic tube banks is investigated in a two-dimensional space. Water/NDG nanofluid is considered in mass fractions of 0, 1, 2, 4 and 6% and Re numbers of 10, 100 and 450 as cooling fluid. The arrangements of tube banks are considered as ET (equilateral triangle), RS (rotated square) and ES (equal spacing) arrangements. Results revealed that the enhancement of mass fraction causes heat transfer enhancement which is due to the increase in thermal conductivity coefficient of cooling nanofluid compared to base fluid. The increase in Re causes the enhancement of average Nu which is due to better mixture of fluid layers with the enhancement of fluid velocity in higher Re which causes the reduction in temperature gradients among fluid layers away from tubes and homogeneous temperature distribution in these areas. Among investigated arrangements, RS has the highest Nu. Also, ET arrangement, compared to ES arrangement, has higher Nu. In all of the studied arrangements, the increase in Re causes the reduction in friction factor and the maximum values of friction factor are related to RS and ET arrangements, respectively.

Concrete beams with different arrangements of GFRP flexural and shear reinforcement

This paper presents experimental research on the flexural and shear behaviour of concrete beams reinforced with glass fibre reinforced polymer (GFRP) composite reinforcement. Three-point bending tests on shear critical concrete beams reinforced with GFRP longitudinal bars and GFRP stirrups are presented. The test variables were the size and spacing of closed loop stirrups as well as the size, amount, and arrangement of longitudinal reinforcement. Twelve beams were tested with four different stirrup arrangements and three different longitudinal reinforcement arrangements. Longitudinal bars were instrumented at mid-span and stirrups were instrumented at the straight and bent portions. The beams had a shear-span-to-effective-depth ratio of 2.5 and behaved like deep beams. The beams without stirrups failed in shear-tension while the beams with stirrups failed in shear-compression with no ruptured stirrups. Longitudinal reinforcement strains showed evidence of a tied arch mechanism. The analysis found diminishing increases in shear strength with increasing shear reinforcement ratio when failure occurred as a result of crushing of confined concrete.

Two-phase modeling of nanofluid forced convection in different arrangements of elliptical tube banks

PurposeThe purpose of this study is two phase modeling of Water/Cu nanofluid forced convection in different arrangements of elliptical tube banks in a two-dimensional space.Design/methodology/approachThe arrangements of tube banks have been regarded as equal spacing triangle (ES), equilateral triangle (ET) and the rotated square (RS). The obtained results indicate that, among the investigated arrangements, the RS arrangement has the maximum value of heat transfer with cooling fluid. Also, the changes of Nusselt number and the local friction factor are under the influence of three main factors including volume fraction of slid nanoparticles, the changes of fluid velocity parameters on the curved surface of tube and flow separation after crossing from a specified angle of fluid rotation.FindingsIn Reynolds number of 250 and in all arrangements of the tube banks, the behavior of Nusselt number is almost the same and the separation of flow happens in almost 155-165 degrees from fluid rotation on surface. In RS arrangement, due to the strength of vortexes after fluid separation, better mixture is created and because of this reason, after the separation zone, the level of local Nusselt number graph enhances significantly.Originality/valueIn this research, the laminar and two-phase flow of Water/Cu nanofluid in tube banks with elliptical cross section has been numerically investigated in a two-dimensional space with different longitudinal arrangements. In this study, the effects of using nanofluid, different arrangements of tube banks and the elliptical cross section on heat transfer and cooling fluid flow among the tube banks of heat exchanger have been numerically simulated by using finite volume method.

Enhancing the efficiency of Photovoltaic panel using open-cell copper metal foam fins

In this experimental study, a passive cooling technique by open-cell copper metal foam fins was performed for a photovoltaic (PV) panel to enhance its performance by reducing the operating temperature of the PV panel. The experiment was carried out in Baghdad-Iraq climatic conditions during February, March, and April 2019. Three polycrystalline PV panels were used, two panels were equipped with the proposed cooling technique and the other without modification for the purposed of comparing. The open-cell copper metal foam fins mounted on the backside of the PV panel by thermal grease. Four longitudinal fins arrangements (4, 6, 8, and 10 fins) were investigated. The porosity of the metal foam helps the penetration of air through the fins to extract more heat from the PV panel. It was found that the adding of ten longitudinal fins can reduce the average PV panel temperature by about 8.4% and improve the power output by an average of 4.9%.

Unity in diversity: a survey of muscular systems of ctenostome Gymnolaemata (Lophotrochozoa, Bryozoa)

BackgroundMyoanatomical studies of adult bryozoans employing fluorescent staining and confocal laser scanning microscopy (CLSM) have been chiefly conducted on freshwater bryozoans. The diversity of muscular systems in the marine bryozoans is currently not well known with only two species being studied in more detail. The aim of this study is to unravel the diversity of muscle systems of 15 ctenostome bryozoans by phalloidin-coupled fluorescence stainings combined with CLSM.ResultsIn general, the myoanatomy of the selected ctenostomes shows significant similarities and consists of 1) muscles associated with the body wall, 2) apertural muscles, 3) lophophoral muscles, 4) tentacle sheath muscles, 5) digestive tract muscles and 6) the prominent retractor muscles. Differences are present in the arrangement of the apertural muscles from generally three muscles sets of four bundles, which in some species can be partially reduced or modified into a bilateral arrangement. The cardiac region of the digestive tract shows a distinct sphincter in four of the six studied clades. In some cases the cardiac region forms a prominent proventriculus or gizzard. Tentacle sheath muscles in victorelloideans and walkerioideans are arranged diagonally and differ from the simple longitudinal muscle arrangements common to all other taxa. Lophophoral base muscles consist of four sets that vary in the size of the sets and in the shape of the inner lophophoral ring, which either forms a complete ring or separate, intertentacular muscle bundles. The stolon-forming walkeridiodean ctenostomes show prominent transverse muscles in their stolons. These are always present in the shorter side stolons, but their occurrence in the main stolon seems to depend on the colony form, being present in creeping but absent in erect colony forms.ConclusionsThis study represents the first broad survey of muscular systems in adult ctenostome bryozoans and shows a certain degree of conservation in a series of diverse colony forms belonging to five major clades. However, several myoanatomical features such as the cardiac sphincter, basal (possibly transitory) cystid muscles, tentacle sheath muscles or apertural muscle arrangement vary across taxa and thus show a high potential for the assessment of character evolution within ctenostomes. As such, this study represents an essential contribution towards determining and reconstructing the character states of the bryozoan ground pattern once a reliable phylogenetic tree of the whole phylum becomes available.