Millimeters In Size Research Articles

Effect of Different Shot Peening Treatments on Fatigue Life in Ti Alloy

The effects of peening conditions on the surface characteristics and fatigue life of titanium alloy was investigated using microshot peening, ultrasonic shot peening, and multiple shot peening. The use of microshot peening technology with minute media has become more widespread in consideration of the reduction of the notch effect in the material surface. The ultrasonic shot peening that uses media of several millimeters in size with ultrasonic vibration has attracted attention as a means to reduce the surface roughness. In the present study, an air-type and an ultrasonic type machine were used. In the microshot peening process, the media used was high-carbon cast steel and the hard powder, with an average diameter of 0.1 mm. The workpiece was commercial titanium alloy Ti-6Al-4V. In the microshot peening (MSP), work hardening was evident to the depth of approximately 0.3 mm from the surface. This depth was approximately three times the diameter of the media. However, the influence of the peening time on the hardness distribution was not great. In the ultrasonic shot peening (USP), work hardening was deeper in the material. This is because the diameter of the media used for ultrasonic machining was large. On the other hand, in the combined shot peening (CSP), a degree of hardness was higher at the top surface. However, the hardness patterns and values were pretty much identical to ultrasonic shot peening. The fatigue limit was thought to be greater in the microshot peening experiment because the work-hardened layer was formed near the workpiece surface.

Single-crystal growth of the iron-based superconductor La0.34Na0.66Fe2As2

We report single-crystal growth of a La0.34Na0.66Fe2As2 iron-based superconductor several millimeters in size. The samples were accidentally obtained in trying to grow LaFeAsO1−yFy (y ≥ 0.8 ) single crystals with NaAs and NaF flux. The sample shows both antiferromagnetic and structural transitions at 106 K. The superconducting transition temperature is about 27 K with a superconducting anisotropy of about 1.9. These values and the temperature dependence of the Hall coefficient suggest that La0.34Na0.66Fe2As2 belongs to the hole-doped ‘122’ families of iron pnictides with the doping level slightly lower than optimal doping. Compared with previous reports on the polycrystalline samples, our results suggest that either the Tc of the this system can be further increased, or the superconducting dome may not be well formed in this system. In either case, the La0.5−xNa0.5+xFe2As2 system provides a new platform to study the antiferromagnetic and superconducting properties of iron-based superconductors.

Multi-scale study of ductility-dip cracking in nickel-based alloy dissimilar metal weld

A ductility-dip-cracking (DDC)-concentrated zone (DCZ) in a width of about 3 mm was observed adjacent to the AISI 316 L/52 Mw fusion boundary (FB) in 52 Mw. The morphology, microstructure, mechanical and thermal properties and corrosion behavior in simulated primary water of DDC/DCZ were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), 3D X-ray tomography (XRT), 3D atom probe (3DAP), slow strain rate tensile (SSRT) testing and thermal dilatometry. The results indicate that DDCs are random-shaped and disc-like cavities with corrugated structure of inner surface and are parallel in groups along straight high-angle boundaries of columnar grains, ranging from micrometers to millimeters in size. Large-size M23C6 carbides dominate on the grain boundaries rather than MC (M=Nb, Ti), and thus the bonding effect of carbides is absent for the straight grain boundaries. The impurity segregation of O is confirmed for the inner surfaces of DDC. The oxide film formed on the inner surface of DDC (about 50 nm) is approximately twice as thick as that on the matrix (about 25 nm) in simulated primary water. The yield strength, tensile strength and elongation to fracture of 52 Mw-DCZ (400 MPa, 450 MPa and 20 %, respectively) are lower than those of 52 Mw-MZ (460 MPa, 550 MPa and 28 %, respectively). The intrinsic high-restraint weld structure, the additional stress/strain caused by the thermal expansion difference between AISI 316 L and 52 Mw as well as the detrimental carbide precipitation and the resulting grain boundary structure all add up to cause the occurrence of DCZ in the dissimilar metal weld.

Investigation of the surface morphology in glass scribing with a UV picosecond laser

This study reports the investigation of the morphology of the surface damaged during the laser scribing of glass and the analysis of the corresponding interaction mechanism between the laser and glass. In this study, the soda lime glass of 1.1 mm thick is scribed by an ultraviolet (UV) picosecond laser (Nd:YVO4) by varying laser power, scan speed and number of scans. From the analysis of experimental results, it is found that the surface morphology can be classified as three groups such as swelled surface, wave pattern (either shallow or deep) and groove depending on the accumulated laser energy per unit beam spot. The accumulation of the large laser energy (12–30 × 10−4 J) into the material induces volume meting and local vaporization below the surface without material removal, which makes bubbles inside glass volume and swelled surface through volume expansion. With the decrease of the energy accumulation (4.2–9 × 10−4 J), the surface morphology is changed into shallow wave pattern by slight material removal. With further decrease of the laser energy accumulation (1.4–3 × 10−4 J), either deep wave or groove morphology is obtained due to the increase of the material removal. Under very low laser energy accumulation region (0.3–1.05 × 10−4 J), the groove shape is only formed. In particular, the groove morphology without cracking is successfully produced within the range of 0.3–0.5 × 10−4 J. The threshold laser energy accumulation for surface damage is found to be around 0.25–0.3 × 10−4 J. Below this energy accumulation, modification in the surface morphology doesn’t occur. It is also found that the groove morphology is hard to obtain by even multiple laser scans if it is not well formed by single laser scan. The cracks produced during the scribing process can be characterized with several propagation morphologies. At the region of the relatively low laser energy accumulation, cracks propagating across the scan direction are only generated. However, cracks propagating both across and along the scan direction are found with the increase of the laser energy accumulation. Huge cracks (arc or sinusoidal curve shape) of several millimeters in size are produced under the very large laser energy accumulation.

Dynamics of crystallization of solid ethanol

Experimental studies of the kinetics of phase transitions of C2H5OH ethyl alcohol samples from amorphous to crystalline phase demonstrated that their transition rate and energy characteristics strongly depend on the size and composition of the samples (rectified alcohol, absolute alcohol). Almost all bulk amorphous samples of rectified alcohol that were several millimeters in size crystallized into the monoclinic phase within few hours at a temperature of T ∼ 125 K, while in amorphous nanocluster samples consisting of clusters of the order of tens nanometers in size, a similar transition was observed at T ∼ 110 K. Characteristic transition times from one crystalline phase to another also differed greatly. Temperatures at which the transition from the plastic to the monoclinic phase occurred for both bulk and nanoclusters samples of absolute alcohol were lower (100–105 K), and crystallization of nanocluster samples occurred much more rapidly. The exponent moduli in time dependence of x ∼ tn in the JMAK model (crystallization of an amorphous substance) strongly depended on temperature, and for nanocrystallites were of the order of one or less. However, for massive samples, the exponent modulus n turned out to be closer to two for both rectified and absolute alcohol.

Size effect on splitting strength of hardened cement paste: Experimental and numerical study

Cement paste possesses complex microstructural features including defects/pores over a range of length-scales, from nanometres to millimetres in size. As a consequence, it exhibits different behaviour under loading depending on the size. In this work, cubic specimens in a size range of 1: 400 were produced and tested by a one-sided splitting concept using different testing instruments. The smallest specimen with size of 100 μm showed a high nominal splitting strength (18.81 MPa), an order of magnitude higher than the measured strength of 40 mm specimen (1.8 MPa). The test results were used to fit existing analytical size effect models. Although a good fit can be found for the existing size effect models, special attention should be given to the physical meaning behind these empirical parameters. In addition, a multi-scale modelling strategy that considers microstructural features at different length scales was adopted to model the trend of decreasing strength with specimen size observed in experiments. A good agreement between experimental observations and modelling results indicates that the featured material structure dominates the observed size effect on measured strength in the size range considered.

Velocity dependent dislocation drag from phonon wind and crystal geometry

The mobility of dislocations is an important factor in understanding material strength. Dislocations experience a drag due to their interaction with the crystal structure, the dominating contribution at high stress and temperature being the scattering off phonons due to phonon wind. Yet, the velocity dependence of this effect has eluded a good theoretical understanding. In a previous paper, dislocation drag from phonon wind as a function of velocity was computed from first principles in the isotropic limit, in part for simplicity, but also arguing that macroscopically, a polycrystalline metal looks isotropic. However, since the single crystal grains are typically a few microns up to a millimeter in size, dislocations travel in single crystals and cross boundaries, but never actually see an isotropic material. In this work we therefore highlight the effect of crystal anisotropy on dislocation drag by accounting for the crystal and slip plane geometries. In particular, we keep the phonon spectrum isotropic for simplicity, but dislocations are modeled according to the crystal symmetry (bcc, fcc, hcp, etc.). We then compare to the earlier purely isotropic results, as well as to experimental data and MD simulations where they are available.

Characterization of the Martensitic Transformation in NiPtAl Alloy Using Digital Holographic Imaging

Surface reliefs due to phase transformations in a 56.8Ni-5.6Pt-37.6Al at. pct alloy were characterized in situ using digital holographic imaging during thermal cycling from room temperature up to 405 K (132 °C). The 3D images of the surface revealed that the austenite plates formed during heating are exactly the same for each cycle, which is not the case for the martensite plates formed during cooling. The martensite start temperature was found to vary by up to ~ 20 K from one grain to another within the same specimen. The absence of Ni3Al γ′ precipitates, due to the relatively high Al content, results in the propagation of the martensitic transformation over grains up to a millimeter in size. Bright-field optical imaging showed the formation of large martensite plates in some grains, with cracks perpendicular to these plates, upon cycling. Cracks were also observed at grain boundaries and could be related to the height variations across the grain boundaries.

Experimental tests and design of rubberised concrete-filled double skin circular tubular short columns

The adequacy of rubberised concrete (RuC) for use in structural columns is, currently, investigated experimentally through the use of cold-formed double-skin circular steel tube confinement. The RuC is of particular interest because the aggregate can be sourced from recycled tyres, so it is a form of sustainable concrete, and it possesses superior mechanical properties to conventional concrete such as increased ductility and energy absorption. Rubberised concrete does have one major issue in that it has a low compressive strength compared to normal concrete, which limits its application. The aim of this study is to evaluate the effectiveness of confinement in overcoming this mechanical deficiency by using rubberised concrete-filled double-skin tubes (RuCFDST). The experimental program involves testing and measurements of key mechanical properties including compressive strength, hoop and axial strains, and compressive load-deflection curves. A total of 15 composite specimens were examined to ascertain the varying properties of single-skin, double-skin, confined, unconfined, standard and rubberised concrete. Recycled rubber particles ranging from two to seven millimeters in size were used to replace 15% and 30% of the fine and coarse concrete aggregate by weight. The rubber particles were treated with sodium hydroxide solution resulting in increased bonding strength to the concrete. Circular hollow section (CHS) configurations of different internal and external dimensions were also examined to further understand the mechanics of double-skin confinement. Confinement in RuCFDST showed significant improvements in strength and ductility properties. Experimental results proved to be in agreement with design ultimate axial strength predictions proposed by existing methods and design codes. Given the exceptional ductility, energy dissipation and improved strength of RuCFDST, this study shows the potential viability of RuCFDST as structural columns particularly in areas that are prone to seismic activity.

Switching of Current Rectification Ratios within a Single Nanocrystal by Facet-Resolved Electrical Wiring.

Here we show that within a single polyhedral metal oxide nanoparticle a nanometer-scale lateral or vertical sliding of a small metal top contact ( e. g., <50 nm) leads to a 10-fold change in current rectification ratios. Electron tunneling imaging and constant-force current-potential analysis in atomic force microscopy demonstrate that within an individual p-n rectifier (a Cu2O nanocrystal on silicon) the degree of current asymmetry can be modulated predictably by a set of geometric considerations. We demonstrate the concept of a single nanoscale entity displaying an in-built range of discrete electrical signatures and address fundamental questions in the direction of "landing" contacts in single-particle diodes. This concept is scalable to large 2D arrays, up to millimeters in size, with implications in the design and understanding of nanoparticle circuitry.

The Role of Dust Mites in Allergy.

House dust mites are an unsurpassed cause of atopic sensitization and allergic illness throughout the world. The major allergenic dust mites Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei, and Blomia tropicalis are eight-legged members of the Arachnid class. Their approximately 3-month lifespan comprises egg, larval, protonymph, tritonymph, and adult stages, with adults, about one fourth to one third of a millimeter in size, being at the threshold of visibility. The geographic and seasonal distributions of dust mites are determined by their need for adequate humidity, while their distribution within substrates is further determined by their avoidance of light. By contacting the epithelium of the eyes, nose, lower airways, skin, and gut, the allergen-containing particles of dust mites can induce sensitization and atopic symptoms in those organs. Various mite allergens, contained primarily in mite fecal particles but also in shed mite exoskeletons and decaying mite body fragments, have properties that include proteolytic activity, homology with the lipopolysaccharide-binding component of Toll-like receptor 4, homology with other invertebrate tropomyosins, and chitin-cleaving and chitin-binding activity. Mite proteases have direct epithelial effects including the breaching of tight junctions and the stimulation of protease-activated receptors, the latter inducing pruritus, epithelial dysfunction, and cytokine release. Other components, including chitin, unmethylated mite and bacterial DNA, and endotoxin, activate pattern recognition receptors of the innate immune system and act as adjuvants promoting sensitization to mite and other allergens. Clinical conditions resulting from mite sensitization and exposure include rhinitis, sinusitis, conjunctivitis, asthma, and atopic dermatitis. Systemic allergy symptoms can also occur from the ingestion of cross-reacting invertebrates, such as shrimp or snail, or from the accidental ingestion of mite-contaminated foods. Beyond their direct importance as a major allergen source, an understanding of dust mites leads to insights into the nature of atopy and of allergic sensitization in general.

Micro‐Macroporous Composite Materials – Preparation Techniques and Selected Applications: A Review

Pores, on several orders of magnitude in size, control the properties of a solid material to a large extent. This is just as true for materials containing pores in the sub‐nanometer range like zeolites as for cellular foam structures with pores of several millimeters in size. All these porous materials have their distinct potential application ranging from heterogeneous catalysis to metal melt filtration. In many cases, the (hierarchical) combination of pores with different size regimes can improve the performance of the respective porous material or can lead to entirely new properties and applications. This review addresses the preparation and properties of microporous‐macroporous composite materials based on cellular foam supports (ceramic, metal, polymer) with a coating of a microporous compound (zeolite, zeotype framework, metal‐organic framework). The manufacturing of these materials can either be performed by dispersion‐based techniques, where the microporous coating is applied from a dispersion onto the cellular support (ex situ), or in situ by crystallization of the microporous compound directly onto the struts of the foam structure. In both cases, the general procedure can be modified by a pretreatment of the cellular support in order to improve the coating layer adherence, the overall amount of deposited material, or to control of the crystal morphology of the microporous compound.

Dynamics of Dust Particles of Different Structure: Application to the Modeling of Dust Motion in the Vicinity of the Nucleus of Comet 67P/Churyumov–Gerasimenko

We consider the estimates of the main forces acting on dust particles near a cometary nucleus. On the basis of these estimates, the motion of dust particles of different structure and mass is analyzed. We consider the following forces: (1) the cometary nucleus gravity, (2) the solar radiation pressure, and (3) the drag on dust particles by a flow of gas produced in the sublimation of cometary ice. These forces are important for modeling the motion of dust particles relative to the cometary nucleus and may substantially influence the dust transfer over its surface. In the simulations, solid silicate spheres and homogeneous ballistic aggregates are used as model particles. Moreover, we propose a technique to build hierarchic aggregates—a new model of quasi-spherical porous particles. A hierarchic type of aggregates makes it possible to model rather large dust particles, up to a millimeter in size and larger, while no important requirements for computer resources are imposed. We have shown that the properties of such particles differ from those of classical porous ballistic aggregates, which are usually considered in the cometary physics problems, and considering the microscopic structure of particles is of crucial significance for the analysis of the observational data. With the described models, we study the dust dynamics near the nucleus of comet 67P/Churyumov–Gerasimenko at an early stage of the Rosetta probe observations when the comet was approximately at 3.2 AU from the Sun. The interrelations between the main forces acting on dust aggregates at difference distances from the nucleus have been obtained. The dependence of the velocity of dust aggregates on their mass has been found. The numerical modeling results and the data of spaceborne observations with the Grain Impact Analyzer and Dust Accumulator (GIADA) and the Cometary Secondary Ion Mass Analyzer (COSIMA) onboard the Rosetta probe are compared at a quantitative level.

Arteriovenous malformation in the sigmoid colon of a patient with Cowden disease treated with laparoscopy: a case report

BackgroundCowden disease is a genetic disorder associated with a mutation of the PTEN gene and is known to be easily complicated by generalized vascular malformations and malignant tumors. However, only a few reports have investigated the relationship between Cowden disease and vascular malformations. We present a case of Cowden disease along with a review of the literature.Case presentationThe patient was a 48-year-old man who visited our hospital complaining of fresh blood in his stools and shortness of breath. Hematological tests showed the patient had severe anemia. On physical examination, white papules—several millimeters in size—were observed between the patient’s eyebrows. White papules were also observed on the left corner of his mouth and buccal mucosa. An upper gastrointestinal endoscopy showed densely-packed, white, flat protrusions in the esophagus. While lower gastrointestinal endoscopy revealed a mass accompanied by arterial pulsation in the sigmoid colon. A diagnosis of Cowden disease was confirmed and a laparoscopic sigmoidectomy was performed to address the arteriovenous malformations in the sigmoid colon. Post-surgery, the patient had an unremarkable recovery and was discharged 7 days later.ConclusionsWe present a very rare case of Cowden disease with arteriovenous malformations occurring in the colon. Surgical resection is believed to be the first choice for treating congenital arteriovenous malformations of the intestines. However, the arteriovenous malformations in the colon in our patient were treated under laparoscopic guidance, making ours the first report describing laparoscopic treatment of colonic arteriovenous malformations occurring in the inferior mesenteric artery. Thus we demonstrate that laparoscopic treatment of arteriovenous malformations in the intestines is a minimally invasive and can be successfully applied in such cases.

Advanced Fabrication of Single-Crystal Diamond Membranes for Quantum Technologies.

Many promising applications of single crystal diamond and its color centers as sensor platform and in photonics require free-standing membranes with a thickness ranging from several micrometers to the few 100 nm range. In this work, we present an approach to conveniently fabricate such thin membranes with up to about one millimeter in size. We use commercially available diamond plates (thickness 50 m) in an inductively coupled reactive ion etching process which is based on argon, oxygen and SF. We thus avoid using toxic, corrosive feed gases and add an alternative to previously presented recipes involving chlorine-based etching steps. Our membranes are smooth (RMS roughness <1 nm) and show moderate thickness variation (central part: <1 m over ≈200 × 200 m). Due to an improved etch mask geometry, our membranes stay reliably attached to the diamond plate in our chlorine-based as well as SF-based processes. Our results thus open the route towards higher reliability in diamond device fabrication and up-scaling.

Improved proton CT imaging using a bismuth germanium oxide scintillator

Range uncertainty is among the most formidable challenges associated with the treatment planning of proton therapy. Proton imaging, which includes proton radiography and proton computed tomography (pCT), is a useful verification tool. We have developed a pCT detection system that uses a thick bismuth germanium oxide (BGO) scintillator and a CCD camera. The current method is based on a previous detection system that used a plastic scintillator, and implements improved image processing techniques. In the new system, the scintillation light intensity is integrated along the proton beam path by the BGO scintillator, and acquired as a two-dimensional distribution with the CCD camera. The range of a penetrating proton is derived from the integrated light intensity using a light-to-range conversion table, and a pCT image can be reconstructed. The proton range in the BGO scintillator is shorter than in the plastic scintillator, so errors due to extended proton ranges can be reduced. To demonstrate the feasibility of the pCT system, an experiment was performed using a 70 MeV proton beam created by the AVF930 cyclotron at the National Institute of Radiological Sciences. The accuracy of the light-to-range conversion table, which is susceptible to errors due to its spatial dependence, was investigated, and the errors in the acquired pixel values were less than 0.5 mm. Images of various materials were acquired, and the pixel-value errors were within 3.1%, which represents an improvement over previous results. We also obtained a pCT image of an edible chicken piece, the first of its kind for a biological material, and internal structures approximately one millimeter in size were clearly observed. This pCT imaging system is fast and simple, and based on these findings, we anticipate that we can acquire 200 MeV pCT images using the BGO scintillator system.

APCVD hexagonal boron nitride thin films for passive near-junction thermal management of electronics

The ability of graphene to serve as an ultrathin heat spreader has been previously demonstrated with impressive results. However, graphene is electrically conductive, making its use in contact with electronic devices problematic from a reliability and integration perspective. As an alternative, hexagonal boron nitride (h-BN) is a similarly structured material with large in-plane thermal conductivity but which possesses a wide band gap, thereby giving it potential to be utilized for directing contact, near-junction thermal management of electronics without shorting or the need for an insulating intermediate layer. In this work, the viability of using large area, continuous h-BN thin films as direct contact, near-junction heat spreaders for electronic devices is experimentally evaluated. Thin films of h-BN several square millimeters in size were synthesized via an atmospheric pressure chemical vapor deposition (APCVD) method that is both simple and scalable. These were subsequently transferred onto a microfabricated test device that simulated a multigate transistor while also allowing for measurements of the device temperature at various locations via precision resistance thermometry. Results showed that these large-area h-BN films with thicknesses of 77–125 nm are indeed capable of significantly lowering microdevice temperatures, with the best sample showing the presence of the h-BN thin film reduced the effective thermal resistance by 15.9% ± 4.6% compared to a bare microdevice at the same power density. Finally, finite element simulations of these experiments were utilized to estimate the thermal conductivity of the h-BN thin films and identify means by which further heat spreading performance gains could be attained.

Hf-rich bulk metallic glasses as potential insulating structural material

Tremendous properties of bulk metallic glasses (BMGs) have led to numerous potential applications in the past few years. An obvious interest has been given to their potential as structural material given their high mechanical properties and their ability to be produced in bulk parts of several millimeters in size. Unlike their crystalline counterparts, they also show very promising insulating properties due to the absence of a periodic lattice. In the present work, the interest of using bulk amorphous metallic alloys as materials combining good structural properties and thermal insulation is discussed. The study of Hf-rich BMGs enables to reduce the thermal losses through a higher σc/κ performance ratio and thus shows very good potential for future insulating and structural applications.

Genetic Aspects of the Noble-Metal Mineralization at the Poperechnoe Deposit, Lesser Khingan, Russia

Bodies of cryptovolcanic rocks (fluidolites) play a significant role in the structure of the Poperechnoe ferromanganese deposit, Lesser Khingan, Russia. Fe-Mn ores in association with fluidolites are localized in ancient carbonate rocks. PGM, gold, and silver minerals up to tenths of a millimeter in size are established in the rocks and ores of the deposit. Characteristic admixtures in the platinum are iron (9-11%), with less common copper, iridium, and osmium. An intergrowth of isoferroplatinum polycrystal with forsterite is observed. There are also individual grains of Os-Ir-Ru-Rh intermetallides. The gold grains (up to 93% Au) are characterized by dendritic and clumpy morphology, frequently showing faceting elements. The grains are frequently rounded and sometimes have an almost perfect spherical shape. Native silver is distributed among the dolomites, as well as in the dolomitic fragments from the fluidolites. Ubiquitous admixtures in the silver are copper, iron, and more rarely zinc; single grains contain admixtures of molybdenum, nickel, gold, and palladium. PGM and high-fineness gold are related to the fluidolites, which are the only magmatic rocks in the studied range of the deposit. Silver, its minerals, low-fineness gold, and sulfides are confined to the rocks and ores subjected to the regional dolomitization, low-temperature hydrothermal reworking, and silicification. Samples contain up to 11.3 g/t platinum, 2.35 g/t gold, 296.2 g/t silver, which allows us to consider the studied object as economically promising for noble metals.

A Large Pedunculated Polyp With Surprising Pathology Results

We present a unique case of an inverted diverticulum mimicking a large adenomatous pedunculated polyp. Inverted colonic diverticulosis (ICD) is a rare finding described in 0.7% of colonoscopies.1 ICD is typically a few millimeters in size, located in the sigmoid colon and resembles a polyp. Our finding was unusual based on its size, location and appearance. An initial colonoscopy on a 50-year-old male found a pedunculated polyp in the transverse colon with a 2.0 cm stalk and 9 mm polypoid head. Believed to be an adenomatous polyp by inspection with a firm head, snare cautery was used to remove the polyp. The patient tolerated the procedure well without complication. Surprisingly, histology showed polypoid prolapsing mucosa fold consistent with a diverticular disease associated polyp. The differential diagnosis of a pedunculated colonic lesion is broad including an adenomatous pedunculated polyp, a mucosubmucosal elongated polyp, an inflammatory polyp, a filiform polyp associated with inflammatory bowel disease, autoamputation of a pedunculated polyp, ICD and rarely colonic intussusception of an adenoma. There can be significant overlap between inflammatory polyps and prolapse polyps, but the smooth muscle extending between glands is fairly iconic of prolapse polyps and not found in other entities. Our patient's histopathology was consistent with ICD (Figure 1b). Generally, ICD mucosal pattern on a lesion is similar to surrounding mucosa. In our case, the endoscopic appearance of the polyp head was not similar to the stalk one. Hypothetically, this could be due to vascular congestion, trauma of the polyp head, or the presence of inflammatory changes. Histologically, the latter seems to fit best as there is clear crypt architectural abnormalities seen on the head not seen on the stalk or base. ICD may appear polypoid and even present as pedunculated polyps. It is important for endoscopists to distinguish between ICD and adenomatous polyps to prevent complications that can arise with biopsy. In our patient, there was no evidence of perforation likely due to the cautery that sealed the mucosa closed. If there is suspicion of ICD after polyp removal, a resolution clip or over the scope clip could close the defect and prevent complications.Figure: Histopathology of lesion with lobulation and fibrous septa.Figure: focal epithelial denudation, hyperplastic crypt architecture with branching crypts, a lamina propria with prominent fibromuscular proliferation and smooth muscle projections between individual glands, a polymorphic inflammatory infiltrate, dilated capillaries, and hypertrophy and upward extension of the muscularis mucosae.Figure: High definition endoscopic image of transverse pedunculated polyp.