External Shape Research Articles

The influence of a pipe impeller external shape on the pump parameters

Multi-piped impellers (name proposed by the authors) represent an innovative approach to the design of rotodynamic pumps operating at the specific speed of nq<10. In such a construction the energy increase is caused by the flow of liquid through the internal impeller passages as well as by an external flow around the passages, and sensible designing of such a construction is extremely difficult. The study investigates the flow phenomena and impact of the external shape of a multi–pipe impeller on the efficiency of the process of energy transfer into liquid. The main research method involves computational fluid dynamics (CFD) simulations.

Atomic-level ablation of Au@Ag NRs using ultrafast laser excitation.

Metallic nanorods (NRs) are an important class of materials with widespread applications because of their appealing tunable plasmon resonances, high photothermal conversion efficiency, and chemical stability. It is essential to control the shape and atomic structures of metallic NRs for practical applications. Laser processing of metallic NRs relying on light-matter interactions provides many opportunities. However, the atomic-level fabrication of NRs remains a challenge, and the understanding of laser-induced ablation is still limited. Here, we proposed the atomic-level ablation of Au@Ag NRs using ultrafast laser excitation, which suggests that the near-field effect plays a key role in comparison with thermal evaporation. Through ultrafast laser pulse excitation, abundant atomic steps are fabricated in Au@Ag NRs, which can enhance the surface activity. We suggest that this study highlights the role of the laser near-field effect and also provides a facile strategy to tailor the external shape of metallic NRs at the atomic level, opening a pathway to design metallic NRs for energy and environmental applications.

Numerical Investigation of Response of the Post-Tensioned Tapered Steel Beams with Shape Memory Alloy Tendons

The external post-tension technique is one of the best strengthening methods for reinforcement and improvement of the various steel structures and substructure components such as beams. In the present work, the load carrying capacity of the post-tensioned tapered steel beams with external shape memory alloy (SMA) tendons are studied. 3D nonlinear finite element method with ABAQUS software is used to determine the effects of the increase in the flexural strength, and the improvement of the load carrying capacity. The effect of the different parameters, such as geometrical characteristics and the post-tension force applied to the tendons are also studied in this research. The results reveal that the external post-tension with SMA tendons in comparison with the steel tendons causes a significant improvement of the loading capacity. According to this, using SMA tendon for the reinforcement of the tapered beams causes a decrease in weight of these structures and as a consequence causes economic benefits for their application. This method can be used extensively for steel beams due to low executive costs and simplicity of the operation for post-tension.

Determination of the parameters of an ellipsoidal electrode tip for treating agricultural animals using UHF – therapy methods

The use of non-medicamentous means of treating farm animals presupposes the presence of not only an ultra-high frequency electromagnetic radiation generator but also a rectal emitter, which is directly inserted into the animal's rectum. The effectiveness of the treatment carried out using UHF therapy methods largely depends on the shape of the emitter tip. When choosing the external shape of the emitter tip in the form of half of an ellipsoid of revolution, it becomes necessary to optimize the parameters of this ellipsoid. The goal of optimization is to minimize the resistance force of the living tissue of the animal when a cylindrical emitter with a tip is inserted into the rectum.

Stiffness modulation for soft robot joint via lattice structure configuration design

Soft materials have been applied on the soft robots built with high deformation and compliance. Additive manufacturing (AM) technology has the ability to fabricate functional soft materials or structures. However, soft robots generally have shortages in strength to manipulate relatively heavy objects. This paper proposes a novel concept on the application of lattice structure configuration for the lightweight functional spherical joint of soft robotics with variable stiffness modulation. A novel active spherical joint driven by air pressure is mainly composed of a rigid ball and soft porous socket. The stiffness can be adjusted by changing air pressure in the soft socket. In order to obtain a high-speed response performance and large-scale linear stiffness, the socket is divided into inner and outer layers. Parametric uniform strut-based lattice structures are populated within the inner layer of the socket to guarantee the flow of air. Trimmed TPMS-based lattice structures are infilled within the outer to keep the stable external shape of the socket. The manufacturability for two lattice structure configurations is also analyzed. In order to achieve a linear variable stiffness, the type and size of lattice unit cells and the thickness of lattice struts can be changed parametrically.

Macroscopic And Microscopic Diagnostic Features Of Erythrina Subumbrans (Hassk.) Merr

This study provides a deep insite on thePhytomorphology and Plant anatomy of Erythrina subumbrans (Hassk.) Merr family- Fabaceae. Phytomorphology deals with external shape, structure and physical form, while plant anatomy deals with internal structure mostly at microscopic/cell level. Both Anatomy and morphology play a vital role in that physical characteristic of an internal and external plant during different ages of plants. The purpose of this study is to understand the techniques and basic principal of histochemical and anatomical localization of metabolites in Erythrina subumbrans (Hassk.) Merr- a widely distributed plant in Western Ghats of India. Using a simple microscope, the initial phase of Phytomorphologyand shape of the vegetative part of leaf were determined which are collected during phenological phase of the flowering period. The current study investigated the anatomical characterization of the lower and upper epidermis and characterized the lamina and petiole of the vegetative part of a leaf. Primary and secondary metabolites of a leaf of Erythrina subumbrans (Hassk.) Merr was carried out with the aim in improving the Quality, Safety and Efficacy of the herbal medicine. Established macroscopical and microscopical diagnostic features, which will prevent misuse and to avoid process adulteration. The information about this species and this manuscript brings additional data which are studies for the first time according to the author's knowledge. Considerable macroscopical and microscopical, Quantitive and powder microscopic features of the vegetative part of Erythrina subumbrans (Hassk.) Merr were described in detail.

Design and analysis of a linear servo-actuated variable-span morphing wing

Morphing aircraft are multi-role aircraft that change their external shape substantially to adapt to a changing mission environment during flight. Current interest in morphing vehicles has been increased by advances in smart technologies such as materials, sensors and actuators. These advances have led to a series of breakthroughs in a wide variety of disciplines that, when fully realized for aircraft applications, have the potential to produce large improvements in aircraft safety, affordability, and environmental compatibility. Morphing wing designs include rotating, sliding and inflating based on shape change mechanisms. The current trend in technology development shows that there is lots to improve with regards to aircraft size, flying range and flight performance envelope. There should be a balance between shape change and the penalties in cost, complexity and weight. Final performance of the morphing aircraft depends heavily on how such balances in design, manufacture and morphing mechanism can be achieved. This paper was an attempt to design and perform a further analysis of an efficient variable span wing for aircraft and fixed wing UAVs.

Comparison of egyptian innovation in affordable housing with global models

In these work Survey about different types of affordable housing was dond with the advantages and disadvantages of each type. The combtability of each type with sustainable in construction according to national and international standards was considered. The risk assessment related to this type of construction was evaluated. The Egyptian innovation in the affordable housing which is registered as patent in the egyptian patent office is studied. The new building has one floor with spherical external shape for energy conservation, it is consists of multilayers movable walls moving on the streams. The metalic structure is installed in the soil surface by fixation elements, it is equipped with sensors which is controlled automatically to detect climate changes. the movement of successive layers can be controlled manual or automatic according to climate changes, The movement of insulated layers is done by sliding on dedicated channels, It is equipped with upper and lower ducts located on several axes positioned at the top and bottom of the ball so that the upper and lower positions are located on one axis. The unit has conical top contain the layers folded to the top and prevent the accumulation of dust and water. The layers can be stored inside the conical top. The Egyptian patent model is compared with the common global models of affordable housing to explain its advantages and disadvantages.

TOPOGRAPHIC-ANATOMICAL PECULIARITIES OF THE RENAL CALIXPELVIS SYSTEM IN THE FETAL PERIOD OF A HUMAN ONTOGENESIS

The study of the features of the topographic anatomy and individual anatomical variability of the renal calix-pelvis system (RCPS) during the fetal period of a human being intrauterine development (IUD) is important for elucidation and understanding of the complex transformations of their structure, syntopy and skeletotopy, in particular, to explain the causes and time of appearance of the structural variants, possible origin of the congenital malformations of the organ. Purpose of the work: to find out the dynamics of topographic and anatomical changes and anatomical variability of the renal calyx-pelvis system in the fetal period of human ontogenesis. Material and methods. 102 biomannequin of a human being fetuses of 160.0-480.0 mm parietal-coccygeal length (PCL) (4-10 months of IUD) were studied. A complex of methods of morphological research was applied, which included anthropometry, morphometry, injections of blood vessels with X-ray contrast mixtures, X-ray techniques, dissection, microscopy, three-dimensional reconstruction and statistical analysis. Results. It has been found that a lobar structure of the kidneys of human fetuses is observed on all specimens. Two main variants of their external structure were revealed – bean-shaped and oval-shaped. At the beginning of the fetal period of human ontogenesis, the oval shape of the kidney is most often observed, but from the 6th month of the IUD, the bean-shaped form begins to prevail, and from the 8th month of the IUD it is determined almost twice as often. Two variants of the structure of the renal hilum were observed – their open and compact forms. Until the 6th month of IUD, the open form of the renal hilum prevails, and from the end of the 7th month and at the beginning of the 8th months of IUD, a compact form of the organ hilus was revealed on most preparations. In 10-month-old human fetuses, the compact form occurs almost three times more often than the open one. Simultaneously with changes in the shape of the renal hilum, changes in their holotopy occur: in 4-7-month-old fetuses, the hilus is directed forward and medially, and from the 8th month of IUD they are reoriented and placed already on the medial surface of the kidney. Among the variants of the structure of the RCPS, we observed ampullar and branched types. During the study of the renal pelvis skeletotopy, it has been found that at the beginning of the fetal period (4-5-months-old fetuses), the right and left renal pelvis are located almost at the same level in relation to the spine – approximately at the level of the interval between the II and III lumbar vertebrae, but starting from the 6th month, they "rise" on the left to the level of the middle third of the II lumbar vertebra, and on the right, on the contrary, "descend" to the middle third of the III lumbar vertebra. Syntopy of the renal pelvis and pyelo-ureteral segment with renal vessels on the right and on the left is almost the same, and in the dynamics of the fetal period of IUD does not change significantly. Conclusions. 1. The topography of the renal calyx-pelvic system is largely determined by the peculiarities of the spatial structure of the kidney – its external shape, size, skeletotopy, individual features of the hilum of the organ, their syntopy with the renal vessels. 2. Close syntopy of the renal pelvis and pyelo-ureteral segment with renal vessels with a compact form of the renal hilum may be an anatomical prerequisite for impaired urodynamics, provided there are variants of renal vessels branching or the existence of an abnormal vessel in the renal hilum region. 3. Variants of the structure of the kidneys and their structures are clearly observed from the beginning of the fetal period of human intrauterine development, significantly affect the topography of the calyces and pelvis, and in some cases can cause impairment of urodynamics.

Cortical Processing of Multimodal Sensory Learning in Human Neonates.

Following birth, infants must immediately process and rapidly adapt to the array of unknown sensory experiences associated with their new ex-utero environment. However, although it is known that unimodal stimuli induce activity in the corresponding primary sensory cortices of the newborn brain, it is unclear how multimodal stimuli are processed and integrated across modalities. The latter is essential for learning and understanding environmental contingencies through encoding relationships between sensory experiences; and ultimately likely subserves development of life-long skills such as speech and language. Here, for the first time, we map the intracerebral processing which underlies auditory-sensorimotor classical conditioning in a group of 13 neonates (median gestational age at birth: 38 weeks + 4 days, range: 32 weeks + 2 days to 41 weeks + 6 days; median postmenstrual age at scan: 40 weeks + 5 days, range: 38 weeks + 3 days to 42 weeks + 1 days) with blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (MRI) and magnetic resonance (MR) compatible robotics. We demonstrate that classical conditioning can induce crossmodal changes within putative unimodal sensory cortex even in the absence of its archetypal substrate. Our results also suggest that multimodal learning is associated with network wide activity within the conditioned neural system. These findings suggest that in early life, external multimodal sensory stimulation and integration shapes activity in the developing cortex and may influence its associated functional network architecture.

Performance comparison of tube and plate-fin circular and elliptic heat exchangers for HVAC-R systems

This work seeks to improve HVAC-R systems technology by experimentally quantifying energy efficiency increase due to the utilization of elliptic instead of circular tubes in the evaporator. For that, a performance comparison is conducted in a 12000-Btu h−1 split air conditioning system. A finned elliptic tubes evaporator was built in the laboratory, based on the optimized geometry found in previous studies published by the same authors for maximum heat transfer density, i.e., S/2b, e,φfopt≅(0.5, 0.6, 0.094), which accounts for tube-to-tube spacings, tube eccentricity and fin density. The finned circular tubes evaporator (e = 1) was also built in the laboratory to replace the original component made by the equipment manufacturer, with S/2b = S/D, e,φfopt≅(0.5, 1, 0.094), i.e., same tube-to-tube spacings, and fin density as the elliptic evaporator. In this way, the two heat exchangers had the same shape to minimize their geometric differences. Additionally, the evaporators were designed to fit in the same evaporator unit as the original evaporator, with exactly the same external shape and number of tubes, thus the refrigerant circuit was the same, being the only component to be replaced in the experimental apparatus for comparing the two systems. The objective functions utilized for performance comparisons were the coefficient of performance, COP, and the dimensionless heat transfer volumetric density, q~. The experiment was carried out through the operation of the system installed as specified by the manufacturer, with the evaporation unit placed inside a test chamber, and the condenser unit in a surrounding environmentally controlled ambient. The compressor energy consumption was directly measured by an electric power meter. The results indicate that the optimized elliptic in comparison to the circular geometry shows a gain of approximately 13 and 15% in Q̇evap, 9 and 13.5% in COP, 12.5% and 19.2% in qevap″, 13% and 16.6% in h¯, 14.3% and 16.7% in St¯, and 11.4 and 14.5% in q~, for Re2b = 1030 and 2060, respectively. In conclusion, the sole gain due to the elliptic with respect to the circular geometry is significant. An empirical correlation was introduced to extend the validity range of a previous one to 1030⩽ReD=Re2b⩽10600, and was made available for design engineers in order to predict heat transfer performance. The more the heat exchanger geometry departs from the optimized one, i.e., in terms of tube-to-tube spacings and fin density, the higher the gains are expected to be.

Shape Optimum Design by Basis Vector Method Considering Partial Shape Dependence

Regarding the case of complicated structural shape optimization, there are cases where there are partial shapes such as holes and irregularities inside the structure. Concerning the complex structural optimization shape, the relationship between the external boundary shape and the internal local shape should be maintained, and how to change the internal partial shape while maintaining a subordinate relationship with the external form has become an important issue. Currently, there is no good solution to this kind of problem using general optimization design software. Therefore, this paper proposes to use the basic vector method to solve the local shape dependency problem of partial shapes. First, this paper classifies the subordinate problems of partial shape into three primary patterns, theoretically proving a method for controlling subordinate relationships of partial forms, respectively. Then, the research also provides two classical application examples: shape optimization of a steam turbine implantation section and stress distribution optimization of an engine mount bracket. The results show that the optimization method is effective for the partial shape subordination problem in complex structural shape optimization problems. Finally, the study examines the problem of making a vectorial vector, a correlation between the basis vector and the remeshing problem of the analysis model in shape optimization, and further substantiates the validity of the method proposed by the body using the analysis result of the actual structural shape optimization case.

The Transnational Literary Field between (Inter)-nationalism and Cosmopolitanism

Abstract Various external and internal factors shape and condition the literary field: education, the book market, the nation state, political movements, international organizations (like UNESCO), and specific authorities such as prizes. These factors are examined in this article at different spatial scales: “international,” “transnational,” “global,” “world,” “cosmopolitan,” which are defined in the first section of the article in order to identify the agents that participate in the formation and functioning of the literary field at these different levels, and thus enable us to better understand the mechanisms of scale-shifting. Three periods are then examined: the era of “inter-nationalism,” running from the end of the nineteenth century to the Second World War, the period of “developmental” policy, during which the borders of the transnational literary field were extended beyond the Western world, and the era of “globalization.”

Mathematical Modelling for Effects of Fineness Ratio, Altitude and Velocity on Aerodynamic Characteristics of an Airship Design using Computational Analysis

The external shape design change of an airship can be appropriately captured by design fineness ratio, which is defined as the ratio of airship's length to its maximum width. However, there is a lack of aerodynamic models that have been established for airship design purposes. In conjunction to this realization, the aim of this research work is to establish the effects of design fineness ratio of an airship towards its aerodynamic performance. The Atlant-100 airship is chosen as the reference design model for this study. In total, 36 simulation runs are executed with different combinations of values for the fineness ratio, altitude and velocity. The obtained CFD simulation results are then statistically analysed using Minitab software to evaluate the significance of the design fineness ratio effects. From the results, it has been found that smaller fineness ratio corresponds to higher aerodynamic lift and drag forces. As in the case simulated in this study, the smallest fineness ratio of 0.93 has been shown to correspond to the highest value of generated lift coefficient while having comparable value of generated drag coefficient with the other fineness ratios. This highlights that a smaller fineness ratio of the airship design is more suitable. The constructed mathematical models to capture these effects have also been validated with a few goodness-of-fit tests. For the regression model of fineness ratio impact on the lift coefficient, it has R2 value of 0.941. When its predictive accuracy is tested with few simulated random cases, the maximum error obtained is only 6%. On the other hand, for the regression model of the fineness ratio impact on drag coefficient, the R2 value is 0.962 and maximum predictive error from the simulation random cases test is only 9%. Overall, it can be concluded that the constructed regression models have good predictive capability on the impact of design fineness ratio on the aerodynamic performance of the airship under this study.

A Brief Analysis on Application of the Half Pavilion in Garden

The half pavilion exists as a special form of pavilion, and its application is the perfect interpretation of Chinese traditional philosophical thought of “harmony between the heaven and human” in the gardens, which is the crystallization of the wisdom of ancient people. In the Chinese classical gardens, the particularity of the half pavilion gives viewers a sense of experience with thousands of pavilions. Every scene and every half pavilion has a new experience and aesthetic feeling. In addition to its own aesthetic value, the external shape of the half pavilion is also of exploratory significance in its integration with the surrounding environment, showing its concept of adapting to local conditions, harmony between the heaven and man, and interacting with the surrounding environment. This paper studies the half pavilion preserved from ancient times in the Chinese gardens, and explores from the external characteristics of the half pavilion and spatial layout of the gardens. In terms of how to use it in the gardens, so as to find inspiration and provide new heuristics for modern designs.

Structural elasticity for tensile deformation of a single human hair and the comparison with it for the bending deformation

Human hair is a multi-layered structure, which consists of the inner medulla, middle cortex, and outer cuticle. Therefore, the mechanical properties of the hair are related not only to the Young's modulus of each layer but also to the internal structures. Although the tensile test of a human hair has been performed elsewhere, the deformability of the hair for the tensile deformation is determined as the Young's modulus of the hair structure, which is similar to that of metals. In this paper, the structural elasticity of a single human hair for the tensile deformation, which expresses the deformability of a hair by tension without being dependent on external dimensions and shape, is defined based on the theoretical model, and is measured by performing the tensile test under the digital microscope observation. The values of the structural elasticity for the tensile deformation of the hair samples collected from healthy persons are compared with the values obtained for bending deformation. The structural elasticity for the tensile deformation of the hair sample is found to be lesser than that of the bending deformation, and this is verified to be always valid provided the Young's modulus of the outer cuticle is greater than that of the middle cortex.

Evaluating Congou black tea quality using a lab-made computer vision system coupled with morphological features and chemometrics

The feature of external shape in tea is a vital quality index that determines the rank quality of tea. The potential of a lab-made computer vision system (CVS) coupled with morphological features and chemometric tools is investigated for evaluating Congou black tea quality. First, Raw images of 700 tea samples from seven different quality grades are acquired using the CVS. The original images collected are processed by graying, binarization, and median de-noising. Then, six morphological parameters (viz. width, length, area, perimeter, length-width ratio, and rectangularity) from the samples are extracted by the shape segmentation of each tea leaf image, and the corresponding feature histogram is obtained. Finally, support vector machine (SVM) and least squares-support vector machine (LS-SVM) are utilized to build identification models based on the histogram distribution characteristic vectors. Three kernel methods (linear kernel, polynomial kernel, and radial basis function kernel) are compared for monitoring tea quality. The results show that the optimal LS-SVM model has a 12% higher correct discrimination rate (CDR) than the SVM model. The polynomial kernel LS-SVM model yields satisfactory classification results with the CDR of 100% based on selected six shape features in the calibration and prediction sets. This work demonstrates that it is feasible to discriminate Congou black tea quality using CVS technology along with morphological features and nonlinear chemometric methods. A new perspective on the sizes of morphological characteristics is proposed as an identifier of Congou black tea quality.

Design of thermal-resistant special clothes in three-dimensional environment

The article is devoted to fundamental and applied research in the field of fire safety of textile materials. The purpose of this work is the design and creation of special-purpose clothing, involving the effects of electricity and / or elevated temperatures, by: scientifically-based selection of fabrics and accessories with protective properties. Special design solutions were developed to protect the most likely sites of injury. The authors completed the studies to assess the quality of planting samples of heat-resistant products confirmed that the magnitude of the increments, calculated taking into account the dynamic movements and properties of heat-resistant materials, provide high ergonomic characteristics and ease of use of clothing when performing professional duties in extreme conditions involving the effects of electricity and elevated temperatures. At present, the process of 3D representation of the external basic shape of the product has been studied to the greatest extent since simple silhouette shapes of the clothing can be mathematically described. The surface of the outer clothing can be described by silhouette projections in the frontal and sagittal planes, horizontal sections, as well as informative points located on the contours of the sections characterizing the silhouette. The quantitative characteristics of the shape of the designed product in three dimensions can be magnitudes of projection increases as the gap between the skin and the clothing. In addition, such parameters of horizontal section contours as the spatial gap and its angular measure facilitate the process of describing behavior of the material in the finished product relative to the surface of the person’s figure. According to the above mentioned aspect, it is obvious that the three-dimensional scanning method can be a tool not only for studying the behavior of heat-resistant materials in special clothes to protect against an electric arc, but also it allows creating an actual database of properties of heat-resistant materials.

Venous hepatic segmentation in dogs (Canis lupus familiaris-L. 1758).

The external shape of the liver is varied and determines specific vascular arrangements. This morphological relationship is important to establish hepatic segmentation in different species submitted to surgeries that aim to preserve a larger area of liver parenchyma. After observing 60 livers injected with Neoprene Latex and three plastic moulds obtained by corrosion, eight hepatic venous segments were identified, drained by six hepatic veins agrouped into segmental veins, which drained one sector (segments I, VI, VII and VIII) and intersegmental veins, which drained more than one sector (segments II/III and IV/V). They were described as follows: left intersegmental vein, formed by a segmental vein from the papillary process (segment I), two to three lateral left segmental veins that drained the segment II, and one to five left paramedian segmental veins that drained the segment III; sagittal intersegmental vein, formed by the confluence between segmental vein of the quadrate lobe (segment IV) and the medial right paramedian segmental vein, which derived from the segment V; lateral right paramedian vein drained the dorsocranial sector of the segment VI; the lateral right segmental vein, formed by one to four vessels that drained segment VII, and the segmental vein of the caudate process, which drained the segment VIII. Understanding the number and disposition of the hepatic veins in lobate livers is essential to reduce bleeding risks in surgeries. The nomenclature based on segmentation analogy of non-lobate liver could be less confusing and, therefore, be more useful in the surgical approaches of lobate livers.

Multiobjective Optimization for the Aero-Structural Design of Adaptive Compliant Wing Devices

The design of morphing structures must combine conflicting structural requirements and multiple load conditions that are related to the aerodynamic shapes aimed at optimizing aircraft performance. This article proposes a multilevel approach for the design of adaptive compliant wing devices. A set of aerodynamic shapes, and associated their loads, is defined by a shape optimization, coupled with a three-dimensional parametric technique, that can identify only feasible shape changes due to the morphing. A topology and sizing multiobjective optimization drives the Pareto-optimal structural design of the compliant structure, which is able to deform itself to match, once actuated, all of the previously defined aerodynamic shapes. Next two design levels produce a more detailed solution which is extended until the definition of the complete device. A 90 pax, twin prop green regional aircraft is used as an innovative aircraft demonstration platform for the design of the morphing droop nose to be installed on the wing. The results show the structural capabilities of this device in terms of the external shape quality and the strain requirements. This work enables the validation of the design method and prove the functionality of compliant structures when accounting for the aeroelastic effects due to the interaction with the wing-box.