Triangular Opening Research Articles

Numerical Study of Discharge Coefficients for Side-Damaged Compartments

Accurately evaluating the buoyancy and stability of damaged ships, particularly the flow rate of the water inflow through damaged openings, is of great significance for ship rescue and emergency repair. A three-dimensional simplified model of inflow for a ship’s damaged side bulkheads is established using the shear stress transport k-epsilon and volume of fluid (VOF) models by STAR-CCM+. Moreover, the flow rates of water inflow through damaged openings with different shapes, characteristic sizes, and central depths are calculated. Furthermore, the corresponding discharge coefficients are obtained, and the relevant rules are summarized. It was found that the influence of water depth on the coefficient is minimal in these work conditions, but from the perspective of the damaged opening’s characteristic dimensions and shape, the variation in the coefficient is more pronounced. Overall, the triangular opening has a higher coefficient than the circular opening, which in turn is higher than that of the square-damaged opening, and the coefficient decreases as the size of the opening increases. Lastly, empirical formulas for two different methods are provided. The research provides a reference for the rescue repair and buoyancy stability assessment of damaged ships.

An experimental study on flame characteristic of spill fire plumes for atypical openings under external sideward wind

The evolution of flame height and horizontal extending distance of the facade with atypical openings (circular and triangular) under external sideward wind is experimentally studied with a reduced-scale compartment model in this paper. The results show that: When the external sideward wind is high and reaches a certain degree, the flame horizontal extending distance will be greater than the flame height, indicating that the flame will be more likely to ignite adjacent rooms on the same floor in this case. (1) The flame height of circular and triangular openings has a linear relationship with sideward wind speed (Uw); (2) The flame horizontal extending distance of circular and triangular opening is nonlinear to the sideward wind speed (Uw); (3) Based on previous studies, a non-dimensional correlation model is constructed to predict the flame height and horizontal extending distance of circular and triangular openings.

Effect of vertical facing wall on facade flame height of under-ventilated compartment fire with triangular opening

Effect of vertical facing wall on facade flame height of under-ventilated compartment fire with triangular opening

Three-dimensional comparison of bone-borne and tooth-bone-borne maxillary expansion in young adults with maxillary skeletal deficiency.

To compare the transverse dental and skeletal changes in patients treated with bone-anchored palatal expander (bone-borne, BB) compared to patients treated with tooth and bone-anchored palatal expanders (tooth-bone-borne, TBB) using cone-beam computer tomography (CBCT) and 3D image analysis. The sample comprised 30 patients with transverse maxillary discrepancy treated with two different types of appliances: bone-borne (Group BB) and tooth-bone-borne (Group TBB) expanders. CBCT scans were acquired before (T1) and after completion of maxillary expansion (T2); the interval was 5.4 ± 3.4 and 6.2 ± 2.1months between the T1 and the T2 scans of Group TBB (tooth-bone-borne) and Group BB (bone-borne), respectively. Transverse, anteroposterior and vertical linear and angular three-dimensional dentoskeletal changes were assessed after cranial base superimposition. Both groups displayed marked transverse skeletal expansion with a greater ratio of skeletal to dental changes. Greater changes at the nasal cavity, zygoma and orbital levels were found in Group BB. A relatively parallel sutural opening in an anterior-posterior direction was observed in Group TBB; however, the Group BB presented a somewhat triangular (V-shaped) opening of the suture that was wider anteriorly. Small downward-forward displacements were observed in both groups. Asymmetric expansion occurred in approximately 50% of the patients in both groups. Greater skeletal vs dental expansion ratio and expansion of the circummaxillary regions were found in Group BB, the group in which a bone-borne expander was used. Both groups presented skeletal and dental changes, with a similar amount of posterior palate expansion. Asymmetric expansion was observed in both groups.

Directional transport of droplets impacting on superhydrophobic opening triangular groove surfaces

Directional droplet transport is of great importance to various processes including heat transfer, water harvesting and microfluidics. Here, a facile superhydrophobic opening triangular groove surface was proposed, and the directional transport behavior of droplets impacting on the surface was observed. The results show that the essence of the directional transport on the opening triangular groove surface can be attributed to the interaction between the impinging droplet and the groove sidewall, and the directional transport distance is regulated by the contact area during the interaction. Further, by controlling the depth of triangular groove, the triangular opening angle, the impacting point position and the Weber number, the contact area between the droplet and the groove sidewall during the interaction can be changed, leading to the variation of directional transport distance. This study provides a new method for directional droplet transport on superhydrophobic surfaces and offers more options for the manipulation of droplet behavior.

Artificial Biomolecular Channels: Enantioselective Transmembrane Transport of Amino Acids Mediated by Homochiral Zirconium Metal-Organic Cages.

Natural transport channels (or carriers), such as aquaporins, are a distinct type of biomacromolecule capable of highly effective transmembrane transport of water or ions. Such behavior is routine for biology but has proved difficult to achieve in synthetic systems. Perhaps most significantly, the enantioselective transmembrane transport of biomolecules is an especially challenging problem both for chemists and for natural systems. Herein, a group of homochiral zirconium metal-organic cages with four triangular opening windows have been proposed as artificial biomolecular channels for enantioselective transmembrane transport of natural amino acids. These structurally well-defined coordination cages are assembled from six synthetically accessible BINOL-derived chiral ligands as spacers and four n-Bu3-Cp3Zr3 clusters as vertices, forming tetrahedral-shaped architectures that feature an intrinsically chiral cavity decorated with an array of specifically positioned binding sites mediated from phenol to phenyl ether to crown ether groups. Fascinatingly, the transformation of single-molecule chirality to global supramolecular chirality within the space-restricted chiral microenvironments accompanies unprecedented chiral amplification, leading to the enantiospecific recognition of amino acids. By virtue of the highly structural stability and excellent biocompatibility, the orientation-independent cages can be molecularly embedded into lipid membranes, biomimetically serving as single-molecular chiral channels for polar-residue amino acids, with the properties that cage-1 featuring hydroxyl groups preferentially transports the l-asparagine, whereas cage-2 attaching crown ether groups spontaneously favor transporting d-arginine. We therefore develop a new type of self-assembled system that can potentially mimic the functions of transmembrane proteins in nature, which is a realistic candidate for further biomedical applications.

Morphological and histopathological studies of Thelandros chalcidae (Oxyuroidea: Pharyngodonidae) infecting Chalcides ocellatus from Egypt

BackgroundThelandros (Pharyngodonidae) is a gastrointestinal nematode parasite with a life cycle including lizards as main hosts. Thelandros chalcidae collected from the large intestine of the Egyptian ocellated skink, Chalcides ocellatus were described and illustrated by light and scanning electron microscopes. Seven out of fifteen (46.66%) of the examined lizards were found to be naturally infected. Also, host intestinal tissues were evaluated from hematoxylin/eosin-stained sections to describe any histopathological changes.ResultsMicroscopic examinations revealed that the recovered pharyngodonid species characterized by mouth with triangular opening and surrounded by six simple lips, the cuticle had regular transverse annulations extending from the posterior margin of the lips to the end of the body. Male was cylindrical with distinct truncated posterior end and measured 1.59–1.86 (1.64 ± 0.10) long and 0.29–0.37 (0.32 ± 0.01) in maximum width at the level of mid-body. Female measured 1.72–2.43 (1.85 ± 0.2) long and 0.36–0.49 (0.42 ± 0.01) maximum width at the mid-body level, terminated posteriorly in a short, stout spike. Histological studies observed structural alterations represented by leukocytic infiltration, villi atrophy, and muscularis degeneration. These changes were indicative of inflammatory and degenerative reaction due to Thelandros chalcidae infection.ConclusionThe present morphological study revealed that the recovered pharyngodonid species was Thelandros chalcidae causing pathological alterations in Chalcides ocellatus intestinal tissues.

Descriptions of two new species of oribatid mites (Acari: Oribatida) from Taroko National Park, Taiwan

ABSTRACT Two new species of oribatid mites are described on the basis of adult specimens sampled from soil in Taroko National Park (Taiwan). Tectodamaeus truku Ermilov sp. nov. (Damaeidae) differs from its most similar species, T. kuankuoshuiensis and T. spiniger by the presence of long propodolateral apophysis, long rostral and lamellar setae having flagellate tip and different leg setation. Kalyptrazetes kbayan Ermilov sp. nov. (Microzetidae) differs from its most similar species, K. harpezus by the presence of setiform, with flagellate tip, shortly ciliate basally rostral and lamellar setae, triangular anterior opening of the interlamellar region and sculpturing/ornamentation of the notogaster. http://www.zoobank.org/urn:lsid:zoobank.org:pub:A3939C15-3BC9-4C66-A416-784C1699ED84

Puithoonete ornament / Ornament of wooden buildings

In this translation of a chapter from monograph “Latvian’s Home” (“Latvieša māja”, 2014), the author provides an insight into the decorations of wooden houses in Latvia, including incisions and ornamental wall decorations and she also differentiates architectural details like the so-called ‘sun posts’ and decorated boards on sides of a triangular opening in the hip under the roof. At the beginning of the paper the author refers to the fact that the ancient geometrical ornament has been more typical of Latvians, which has been preserved also during the time when East-European nations gradually took over the ornaments depicting plants and animals. The author approaches ornamentation as one complete entity and draws attention to the perceived visual rhythm in ornamentation. The individual signs of the ornament are combined either in pairs (statically) or in odd numbers (dynamically). The more modern ornamentation is made up of geometrical ornament with plant ornaments. The author gives an overview of more widely-used signs – slanting crosses, triangles, octagons, and the chalk marking 20+K+B+m+14 widespread in Catholic regions, etc.
 Kursīte discusses one peculiar decorative element of the houses – the so-called ‘sun posts’, which in big rooms are just very practical (e.g. in houses of prayer), but which might have also carried some cosmic symbolism.
 In buildings (mainly dwelling houses and storehouses), the doors and window jambs, wider battens/boards, and the wooden window shutters were decorated. Ornamental decorations were also used on the top of the boards decorating the triangular opening in the hip under the roof, which were carved like a bird’s or a horse’s head, or shaped like a horn, sometimes even under the collar beams. The decorations were directed outwards so they would be visible. The other kind of ornament (mostly single signs) was cut on house tenons/mitre (i.e. inside). This was not visible, but the ornament had to protect the foundation of the house and the building from hazards coming from the outside (evil ghosts, evil people, natural elements, etc.).
 In conclusion it may be said that from a magical and a decorative point of view, ornamentation played an important role in the wooden architecture of Latvia.
 In the short preface the themes highlighted by Kursīte are compared with the wooden architecture of Estonia; it is stated that there are similarities but one has to work hard to find them.

Experimental study on thermal hazard and facade flame characterization induced by incontrollable combustion of indoor energy usage

Abstract Fire accidents induced by indoor energy combustion occurred frequently and caused tremendous loss. This paper investigated the evolution laws of important fire risk parameters for quantitatively assessing the thermal hazard of room with triangular windows by reduced-scale experiments. The fire hazard was characterized by the risk parameters of hot gas temperature inside the room and facade flame height. Results show that the neutral plane position is hardly affected by total heat release rate of fire source, and it mainly depends on triangular opening height rather than base width. The ratios of neutral plane height above opening bottom to opening height are about 0.25, 0.25 and 0.61 for isosceles, right and inverted right triangular openings respectively. Based on theoretical derivation, an appropriate ventilation factor for triangular opening was defined to describe air mass inflow rate during under-ventilated condition. The hot gas temperature inside the room can be predicted based on the newly defined ventilation factor. Finally, a non-dimensional correlation was proposed to characterize facade flame height as a 0.53 power function of a normalized excess heat release rate. This work is of benefits to evaluate the fire hazard of buildings and then to provide calculation basis for building fire protection design.

Scelidosaurus harrisonii from the Early Jurassic of Dorset, England: postcranial skeleton

PRISM FUND TRINITY COLLEGE CAMBRIDGE ST JOHN'S COLLEGE OXFORD SMITHSONIAN INSTITUTION (WASHINGTON DC)

Effect of valve opening shapes on the performance of a single‐stage Gifford‐McMahon cryocooler

In this work, the effect of the triangular and Gaussian‐shaped opening of the rotary valve (ie, the valve timing diagram of high‐pressure and low‐pressure valves) on the performance of a single‐stage Gifford‐McMahon (GM) cryorefrigerator is numerically investigated. In addition, the effect of waiting time of the rotary valve on its cooling power and coefficient of performance is studied for both types of opening shapes. The governing equations representing the fluid flow and heat transfer behaviors of the refrigerator are solved by using an implicit finite‐volume discretization method. The model considers both primary and secondary loss mechanisms. The developed model is first validated with the published results on GM cryorefrigerators. A very good agreement appears among them. It is observed that no significant change can be appreciated in the cooling power between 40° to 90° of waiting time for both types of opening shapes. On the other hand, in‐between 1° to 40° of waiting time, the cooling power of the Gaussian‐shaped opening of the rotary valve is higher than the one of the triangular opening.

Numerical investigation of the opening effect on the mechanical behaviours in rocks under uniaxial loading using hybrid continuum-discrete element method

Openings including their size, shape and distribution in rock play a significant role in the performance of rock related structures. The well-established knowledge in this area can contribute to the engineering practices, for example, underground space design, planning and optimisation in Civil and Mining Engineering and wellbore stability in Drilling Engineering, among others. Thus, understanding the failure mechanism of rock with openings is theoretically and practically meaningful. Laboratory testing on rock or rock-like materials with openings have been studied extensively in the literature, which, however, primarily focuses on the cracks/fractures. In this paper, a comprehensive numerical study on the effect of non-banded openings, i.e., circular, rectangular, and triangular opening, on the rock mechanical behaviour is performed using a hybrid continuum-discrete element method. It is revealed that the proposed simulation method can reproduce reasonably the crack initiation and propagation, and predict well the change of the mechanical behaviour due to the openings. In addition, the influence of the opening shape and opening ratio (=area of opening/specimen area) on the mechanical behaviour is also investigated.

A new species of Neocosmocercella Baker & Vaucher, 1983 (Nematoda: Cosmocercidae), a parasite of Phyllomedusa vaillantii Boulenger (Anura: Phyllomedusidae) in the Caxiuanã National Forest, eastern Amazon, Brazil.

Neocosmocercella bakeri n. sp. is described from the large intestine of Phyllomedusa vaillantii Boulenger collected in the Caxiuanã National Forest in the Eastern Brazilian Amazon. The new species is easily distinguished from the type-species of the genus, Neocosmocercella paraguayensis Baker & Vaucher, 1983 in possessing a triangular mouth opening with three simple lips (vs three bi-lobed lips and hexagonal mouth opening) and somatic papillae, which are absent in N. paraguayensis. The males of the new species are distinguished by the distribution of the sessile cloacal papillae and the dimensions of the gubernaculum, whereas the females are distinguished by their smaller size and opisthodelphic uterus. This study expands the diagnostic characters of Neocosmocercella Baker & Vaucher, 1983, reports the first species parasitising anurans of the Brazilian Amazon, a new host record for the genus, and the description of the second species of the genus.

Influenza Hemagglutinin Binding and Interactions with a Host Cell

The CDC estimates that during the flu season 35 to 50 million people get the flu. Hemagglutinin (HA) is one of the main proteins required for influenza virus to infect host cells. Located on the surface of the virus, HA is responsible for binding the virus to the cell, and for releasing the viral genome into the host cytoplasm. There are 17 different HA subtypes (HA1 ‐ HA17), but HA1, 2, and 3 are the only strains specific to human influenza. Even though they appear in different animals, HA binds to sialic acid, which is present on the surface of epithelial cells in the upper respiratory tract. HA is a trimer protein made of a globular and stem domain. The sialic acid binding region resides in the globular head. The binding depression surrounds the sialic acid domain with three identical primary regions. These regions are comprised of a loop‐helix‐ loop structure, which surrounds the sialic acid, forming the triangular opening into the beta‐sheet depression. The exact binding geometry between hemagglutinin and cell surface proteins differs within species, thereby accounting for the species specificity of HA. The Olathe North SMART team (Students Modeling a Research Topic) modeled HA using 3D printing technology. Program supported by a grant from NIH‐SEPA.

Primary and Secondary Closure of the Surgical Wound After Removal of Impacted Mandibular Third Molars

The present study attempted the evaluation of Primary and secondary closure techniques after removal of impacted third molars in terms of healing, post-operative pain and swelling. 60 patients with impacted mandibular third molars were randomly divided into two groups of 30. Panoramic radiographs were taken to assess degree of eruption and to asses 3rd molar angulations to the long axis of 2nd molar. Teeth were extracted, and in Group 1 the socket was closed by hermetically suturing the flap. In group II a 5-6mm wedge of mucosa distal to the second molar was removed & the flap was repositioned. Interrupted sutures were given, so as to form a triangular opening distal to second molar measuring about 5×5mm. Swelling and pain were evaluated for 7days after surgery with the VAS scale. Study results showed that post operative Sequale were comparatively less in secondary closure group than the primary closure group. Pain showed statistically significant difference between two groups. Pain was less in secondary closure group from day 1 to day 7. Swelling & trismus was also significantly less in secondary closure group. Evaluation of the complications of these two techniques showed that delayed wound healing occurred in 66.6% of cases (20 cases out of 30) in secondary closure group where as dehiscence of suture line occurred in 33.33% of cases (10 out of 30) in primary closure group. The results obtained in the present study enable us to conclude that, in cases of equal intra-operative difficulty, open healing of the surgical wound after removal of impacted third molars produces less post-operative swelling and pain than occurs with closed healing, by hermetically suturing the socket.

Pachytesta crenulata, a new medullosan ovule from the Pennsylvanian of Iowa

A new species of medullosan ovule, Pachytesta crenulata, is described from the latest Atokan–earliest Desmoinesian (early Moscovian) of Iowa. The ovule is approximately 5.5–6 cm long and 2.4–3 cm wide at the mid-point with three commissured primary ribs, three secondary ribs expressed at the apex, and a large number of sclerotesta ridges (18–24 between each primary rib-secondary rib pair), formed from interwoven bands of fibers. The micropyle, defined by the epidermal cuticle of the endotesta, is flared at the tip and triangular in cross section. A collar of sclerotesta and sarcotesta, 10 mm tall surrounds the micropyle. The space enclosed by the collar is a triangular prism, with a primary rib at each edge and sides approximately 2.3 mm in length. The space between the micropyle and the sclerotesta–sarcotesta collar appears to have been filled with thin-walled endotesta cells. At the ovule apex, lobes of sarcotesta associated with the primary ribs partially occlude the top of the collar, forming a triangular opening with the flared tip of the micropyle in the center. Pachytesta crenulata appears most similar to P. composita and P. illinoensis. All three ovules have tertiary ribs or ridges and secretory fibers in the sclerotesta; in both P. illinoensis and P. crenulata a collar of sclerotesta and sarcotesta surrounds the micropyle. Based on these similarities, we place P. crenulata in Taylor's [Taylor, T.N., 1965. Paleozoic seed studies: a monograph of the American species of Pachytesta. Palaeontographica, Stuttgart] P. composita– P. illinoensis group . The condition of the sclerotesta and nucellar stalk of P. crenulata may indicate its developmental stage. Ovules having hollow fibers in the sclerotesta and nucellar stalks with a convex profile appear immature relative to ovules with filled fibers in the sclerotesta and deeply invaginated nucellar stalks. Although the pollination and fertilization status of most P. crenulata ovules remains equivocal, one mature ovule probably was pollinated. All of the immature ovules showed signs of seed predation.

Transesophageal Echocardiography of a Unicuspid Aortic Valve

Transesophageal Echocardiography of a Unicuspid Aortic Valve

Hepatic venous outflow reconstruction in adult right lobe living donor liver transplantation without middle hepatic vein

It is difficult and challenging to reconstruct hepatic venous outflow in adult right lobe living donor liver transplantation (LDLT) without the middle hepatic vein (MHV). Excessive perfusion of the portal vein and venous outflow obstruction will lead to acute congestion of the graft, ultimately resulting in primary nonfunction. Although various reconstruction patterns have been explored in many countries, there is currently no clear consensus. In this study we describe a technique to prevent "chocking" of the graft at the outflow anastomosis with the inferior vena cava (IVC) in LDLT using right lobe graft without the MHV. A retrospective analysis was conducted on clinical data from 55 recipients undergoing LDLT using right lobe grafts without the MHV or reconstruction of hepatic venous outflow. The donor's right hepatic vein (RHV) was anastomosed with a triangular opening of the recipient IVC; the inferior right hepatic vein (IRHV), if large enough, was anastomosed directly to the IVC. The great saphenous vein (GSV) was used for reconstruction of significant MHV tributaries. No deaths occurred in any of the donors. Of the 55 recipients, complications occurred in 6, including hepatic vein stricture (1 case), small-for-size syndrome (1), hepatic artery thrombosis (1), intestinal bleeding (1), bile leakage (1), left subphrenic abscess and pulmonary infection (1). A total of three patients died, one from small-for-size syndrome and two from multiple system organ failure. The multiple-opening vertical anastomosis was reconstructed with hepatic vein outflow. This technique alleviates surgical risk of living donors, ensures excellent venous drainage, and prevents vascular thromboses and primary nonfunction.

Floral biology of Nuphar pumila (Timm) DC. (Nymphaeaceae) in China

Anthesis in individual flowers of Nuphar pumila (Timm) DC. occurs for four consecutive days. First-day flowers are protogynous and functionally female. Flowers can open completely on the first day of anthesis. This contrasts with all previous reports, which state that first-day flowers of Nuphar are characterized by partial expansion of the calyx, leaving a distal small triangular opening just above the stigmatic disc. Flowers close completely on the first night of anthesis and remain partially open on the subsequent three nights. During the entire anthesis period the stigmas emit a sweet, fruity odor and the petal nectaries produce visible nectar drops. The stigma of N. pumila is secretory and unicellular-papillate. Pollen grains are monosulcate with long spines. Our observations on the mating system of N. pumila indicate that neither asexual seed production nor spontaneous self-pollination occurs. Cross-pollination of second-, third- and fourth-day flowers produced few seeds. Flowers of N. pumila were mainly pollinated by sweat bees, with flies playing a minor pollination role. No beetle visits were observed. Our insect-pollination observations substantiate the view that the relative contribution of flies, bees, and beetles to pollination in a single Nuphar population depends on two factors: the relative abundance of the insects, and presence of alternative food sources.