Wooden Rods Research Articles

Comparative analysis of modeled femoral fractures osteosynthesis stability

Aim. To perform the comparative analysis of osteosynthesis stability in splintered fractures on the example of modeled fractures of femur with metalwork. Methods. Bone fragments fixation methods using internal fixators, blocking intramedullary nails, external fixation devices. Round wooden rod with external diameter of 35 mm, internal diameter of 25 mm, which was saw in the middle with two cuts directed at an angle of 45° to the rod axis to form the triangle fragment, was picked for femur model for the purpose of experiment. The stability of bone fragments fixation using plates with angle stability, pin- and nail-type external fixation devices and blocking intramedullary nails was assessed. To test the stability of the «bone-fixing device» complex, torsional test machine КМ-50-1 №66, power press П-10 №92, pull test machine Р-10 №1677 were used. Results. Compared to external fixation device, fixation using plates with angle stability was 6 times more stable at axial load and by 43.5% at lateral load. The stability of blocking intramedullary nail at axial load was higher compared to external fixation device. At rotary load, the stability of blocking intramedullary nail was 2 times lower compared to external fixation device. Conclusion. On a model of splintered double-lever femur fractures, fixation using plates with angle stability was the most stable fixation mode.

К вопросу оптимизации узлов деревянных стержневых конструкций

The problems of the optimization of the wooden rod systems is considered. The classification of nodes and connections wooden structures is given. The types of optimization problem are also considered.

Karakteristik Hidrolisat Protein Tambelo (Bactronophorus sp.) yang Dihidrolisis Menggunakan Enzim Papain

Tambelo is one type of wood eating worm that live in the dead mangrove tree and suffered a decomposition process. Tambelo who lived in a wooden rod Rhizophora sp has a sweet taste and very good for consumption. Tambelo nutrient content showing potentially in the development of highquality aquatic products, but this has not been done. In order tambelo can be used widely, it is necessary to make a new innovation in processing Tambelo meat into new face. Tambelo meat processing in a protein hydrolyzate as a source of flavor enhancer, which not only serves to create a sense of savory (umami) in food but also provides the role of nutrition and safe for the body considered very precise.This study aimed to examine the potential characteristics tambelo protein hydrolyzate (Bactronophorus thoracites). The experiment was conducted in two stages, the first stage of making a protein hydrolyzate treated hydrolyzate time (1, 2 and 3 hours) using the papain enzyme 0.5% (w/w) and temperature of 550C, pH 7. The best results are based on the content of the highest total protein become a reference in the second stage of the process. The second stage is a producing flavor enhancer, which further analyzed to measure the percentage of yield, amino acids, fatty acids and components of flavor. Proximate analysis to measure the highest total protein content of tambelo meat which hydrolyzed by the papain enzyme with optimum concentration at temperature of 55 ° C, pH 7. One hour hydrolysis showed the highest total protein content of 22.09% ± 0.19, yield hydrolyzate produced from the best treatment is 53.29% ± 7.36, hydrolysis process runs perfect for being able to produce 17 kinds of amino acids consisting of essential amino acids and non-essential with increased levels, and the hydrolysis process causes a significant fatty acid composition decreasing.Keywords: hydrolysis, papain enzyme, Tambelo protein

A sonic crystal diode implementation with a triangular scatterer matrix

This paper investigates a nonreciprocal sound transmission effect provided by a triangular lattice two-dimensional sonic crystal made of rods in a triangular cross-section. This sonic crystal (SC) device works as a frequency selective acoustic diode operating at a frequency of 8950Hz. The scatterer matrix of the sonic crystal diode prototype was composed of triangular shaped wood rods that break the symmetry of the spatial inversion and provide nonreciprocal wave transmission with a contrast rate of 89% in experiments. This acoustic diode device can provide a high contrast, narrow band, one-way sound transmission for acoustic wave control applications.

Effect of Military Conflicts on the Formation of Emergency Medical Services Systems Worldwide

This article briefly reviews the evolution of medical support during wars and conflicts from ancient to modern times and discusses the effect warfare has had on the development of civilian health care and emergency medical services (EMS). Medical breakthroughs and discoveries made of necessity during military conflicts have developed into new paradigms of medical care, including novel programs of triage and health assessment, emergency battlefield treatment and stabilization, anesthesia, and other surgical and emergency procedures. The critical role of organizations that provide proper emergency care to help the sick and injured both on the battlefield and in the civilian world is also highlighted.

Comparing the In Vitro Stiffness of Straight-DCP, Wave-DCP, and LCP Bone Plates for Femoral Osteosynthesis.

The objective of this study was to compare the Locking Compression Plate (LCP) with the more cost-effective straight-dynamic compression plate (DCP) and wave-DCPs by testing in vitro the effects of plate stiffness on different types of diaphyseal femur fractures (A, B, and C, according to AO classification). The bending structural stiffness of each plate was obtained from four-point bending tests according to ASTM F382-99(2008). The plate systems were tested by applying compression/bending in different osteosynthesis simulation models using wooden rods to simulate the fractured bone fragments. Kruskal-Wallis test showed no significant difference in the bending structural stiffness between the three plate models. Rank-transformed two-way ANOVA showed significant influence of plate type, fracture type, and interaction plate versus fracture on the stiffness of the montages. The straight-DCP produced the most stable model for types B and C fractures, which makes its use advantageous for complex nonosteoporotic fractures that require minimizing focal mobility, whereas no difference was found for type A fracture. Our results indicated that DCPs, in straight or wave form, can provide adequate biomechanical properties for fixing diaphyseal femoral fractures in cases where more modern osteosynthesis systems are cost restrictive.

Simulation of Rockfill Materials Using Aggregates of Cement Ellipsoids

AbstractParticles of natural rockfill materials come in various sizes and shapes, resulting from natural processes, and their mechanical properties are affected by a multitude of interdependent factors. As a result, it is very difficult to investigate an individual factor. Therefore, most studies are conducted by using substitute materials such as glass beads, gypsum rods, wooden rods, steel balls, and metal rods. However, these commonly used materials have properties that are often quite different from natural rockfill materials, e.g., in particle shape, particle strength, modulus, and grading. This paper suggests a more suitable substitute to simulate rockfill materials by using cement ellipsoids in different sizes cast with cement paste. Results from triaxial compression tests show that this kind of proxy material can reproduce the basic behavior of natural rockfill materials.

Dynamic coefficient of friction and granular drag force in dense particle flows: Experiments and DEM simulations

The vertical granular drag force on objects held stationary in a moving bed of nickel pellets with diameters in the range 1–10mm has been measured and compared with Discrete Element Method (DEM) simulations. Experiments were carried out with horizontal wooden rods, and horizontal and vertical thin plates made of mild steel or Teflon. The experimental data are correlated by semi-empirical equations based on the “supported mass” of pellets in the region above the object, and dynamic friction coefficients acting on vertical surfaces from least-squares regression. Dynamic coefficients of friction for nickel on steel and nickel on Teflon are reported. The correlation is compared with an expression based on Janssen's equation using the experimentally determined coefficients of friction. These results are compared with DEM simulations, which examine the effects of particle size distribution, mass flow rate, plate friction coefficient μ and the simulation parameter K1, which is analogous to a spring constant. The correlation follows the trends of the data and the DEM results agree well with the experimental data over a wide range of conditions. The DEM simulations were carried out on Graphics Processing Units (GPU) that enabled a speed-up factor of ~40, and some aspects of the implementation on GPUs are discussed.

Comparison of acoustic sensor systems for quality analysis of asparagus using scanning laser vibrometry for visualization

Automatic detection of hollow white asparagus spears (Asparagus officinalis L.) is a severe issue. One promising approach is the computerized acoustic resonance analysis. The principal components of newly developed acoustic sensor systems were investigated for their technical usability to stimulate and measure asparagus vibrations. Each tested measurement setup included a sample holder with an integrated sensor (piezo film or condenser microphone) and a mechanical excitation device (piezo actuator, midget solenoid, tiny hammer). Non-contacting scanning laser vibrometry was used as an appropriate tool to measure characteristic properties of the experimental setups. Without altering vibration conditions, this technology allowed to visualize vibration response of test specimens (asparagus spears and wooden rods) as well as to evaluate coupling properties between sample and sample holder and the sensitivities of sensors.Each setup enabled free vibration of samples investigated. In addition, reference sensors were proved to be placed at suitable positions for signal detection away from nodal points of oscillation. From the presented results, it turned out that, compared to piezo film sensors, specifically the chosen microphones have the better adapted frequency characteristic considering the vibration behavior of asparagus spears.The measured frequency characteristic of the piezo film sensors suggests that attention has to be focused on the coupling conditions between sample, sample holder and machinery.

VIBRATION STUDY OF MAGNETORHEOLOGICAL FLUID FILLED SANDWICH BEAMS

The concept of vibration mitigation in flexible structures using smart fluids has attracted researcher’s interest in the last few years. Significant research work has been done on the structures with electrorheological fluids, but there has been a little work with the magnetorheological fluids. This study investigates the vibration controllability of MR fluid filled cantilever beams under externally applied magnetic fields. The adaptive structures were fabricated by adding a MR fluid layer between the adjacent elastic layers and the properties of two different types of sandwich beams were studied. In the first type, free and forced vibration responses of aluminium beam with partial treatment were evaluated and compared with fully filled beam. The controllability of vibration response was observed in terms of variations in vibration amplitudes and shifts in magnitudes of the resonant natural frequency. In second type, a composite cylindrical sandwich cantilever beam with end plate was fabricated. It consisted of outer stainless steel hollow pipe with end mass, inner wooden rod and an embedded MR fluid. Inner rods with different diameters were used to vary the thickness of MR fluid layer. Forced vibration response of such beams exhibited increased damping under increased magnetic fields.

Flow structure around a row of vertical rods in a floodplain

This paper presents the results of an experimental study to determine the effect of a row of vertical cylindrical rods on the structure of turbulent flow inside a symmetrical rectangular compound open channel. The coherent turbulent flow structure or bursting events and associated shear stresses play an important role in sediment entrainment and bed instability in an open channel. Therefore, in this study, three-dimensional bursting analysis is used to find the turbulent flow structure at the edge of a floodplain. The study used a model of a symmetrical rectangular compound channel in which ratio of the main channel width B to the floodplain width b was 1·5. A row of cylindrical wooden rods was installed on the floodplain bed at different distances d from the edge of the floodplain (d/b = 0, 0·1, 0·2, 0·3 and 0·4). Three-dimensional flow velocities were measured using an acoustic Doppler velocity meter (micro-ADV). For different experimental tests, the contribution probability of bursting events to the Reynolds shear stress was computed at different points of the flow depth. Minimum values for the contribution probability of shear stress were found for internal, external sweep and ejection events at the edge of floodplain for d/b equal to 0·1. Furthermore, the transition probability of internal, external sweep and external ejection events for d/b = 0·1 decreased at the intersection of the floodplain and main channel. Although scaling of the experimental results requires further study for application to wide rivers, these findings may be useful in practical applications for narrow rivers.

Liquid Crystals and Development of Natural Science Competences

Understanding physical phenomena in education often requires a good three-dimensional (3D) imagination. Visualization software mainly uses either active 3D virtual simulations or static two-dimensional cross-sections for presenting real physical systems. We performed a comparative study of students’ comprehension of both visualization approaches in the field of fundamental liquid crystal (LC) phases. We also developed a mechanical teaching tool—three boxes with wooden rods attached on vertical strings, in order to simulate the transitions between LC phases. We found that both the software and mechanical visualizations are efficient for representation of LC phases as well as training natural science competences.

Dowsing from the Late Middle Ages to the Twentieth Century: The Practices, Uses and Interpretations of an Element of European Magic

Dowsing was an element of European folk magic. With the help of simple wooden rods persons with special magical abilities were supposed to be able to find hidden objects, from buried treasures to subterranean springs. The rise of dowsing can be traced to its use in the emerging mining centres of Central Europe around 1500. However, dowsers soon claimed nearly universal magical knowledge. Even though dowsing encountered strong scepticism, a number of early modern scholars and scientists tried to explain the alleged efficacy of the rod in a number of different ways, ranging from demonological arguments to the atom theory, and the idea of an all-encompassing world spirit. From the eighteenth century onwards, scientific mining techniques marginalized dowsing. However, the practice lingers on to the present day, mostly in the forms of water-witching and pseudo-medicinal diagnostics. The key to the continued popularity of dowsing is its cheapness and its simplicity. Insofar as it promises quick success without formal education, it is the very opposite of science. Dowsing is an example of the successful adaptation of magic with medieval roots to the esotericism that flourishes on the margins of Europe’s supposedly rational worldview.

Living Machines: Some Assembly Required

If you were a new student arriving at Massachusetts Institute of Technology (MIT) in Cambridge during the early 1970s with an expressed interest in mechanical engineering, you would have been advised to enroll in a class called “Introduction to Design.” Students in this class were provided components such as wooden spools and metal rods, and were told to build a useful device from these parts.

Conservation of Jiaohe ancient earthen site in China

Earthen sites, which are mainly made of earth, are cultural heritages with historical, artistic and scientific values. Many extremely valuable earthen sites have been preserved in the arid areas in China. The earthen site of Jiaohe Ancient City is one of the earliest National Protected Important Cultural Heritage Sites. The Jiaohe Ancient City site exhibits all kinds of deteriorations, which can be found in the earthen sites in arid environments in China. Through a case study of the Jiaohe ancient earthen site, we present in this paper the comprehensive conservation technologies, including the mud bricklaying and reparation, wooden rod anchorage, crack grouting, surface potassium silicate (PS) penetration consolidation, and suspended steel beam ceiling, etc. Results of this case study showed that better conservation effects could be achieved by selecting proper PS penetration and crack grouting processes based on the deterioration characteristics of the earthen sites. The technology of mud bricklaying and reparation was also an effective method for preventing the earthen body from collapsing. Compared with traditional conservation technologies, the suspended steel beam ceiling technology could effectively reduce the negative impacts to the original state of the earthen site. As for unstable cliffs, a new method using composite anchor rod of bamboo and steel with massive loose earth was applied. Deformation monitoring and temporary supports were critical and indispensable measures for the safe of site conservation projects. Through years of monitoring and practical operation at the Jiaohe ancient earthen site, deterioration at the site has been effectively controlled.

Tactile rod bisection in the absence of visuo-spatial processing in children, mid-age and older adults

The effect of age on tactile rod bisection is explored in an attempt to fully understand lateralized biases that are not driven by prior experience or visual processing. In Experiment 1, a total of 549 healthy participants aged between 3 and 84 years of age, divided into eight age groups, used touch alone without vision to bisect one wooden rod. Participants across all age groups, except those approaching or in adolescence, showed pseudoneglect on tactile rod bisection. In Experiment 2 a total of 72 healthy participants aged between 6 and 96 years old, divided into three age groups, used touch alone without vision to bisect three wooden rods of different length. Experiment 2 showed pseudoneglect across the full adult life span and most notably in the oldest participants. For the youngest participants there was not a significant pseudoneglect bias but there was a significant effect of gender with females showing greater leftward bias than males. When participants scanned and bisected the rods starting from the right-hand side, pseudoneglect was significantly enhanced; again this bias interacted with age. The results suggest that the right hemisphere exerts an early capacity to orient attention contralaterally and that this capacity continues in middle and older adulthood which is inconsistent with current models of cognitive ageing. The findings are discussed in terms of how the right hemisphere preferentially orients attention leftward in the absence of direct visuo-spatial processing across lifespan and how this may be modulated by variables like gender and starting position.

A Computerised Wind Tunnel for Measuring Aerodynamic Properties of Forage Corn Stalks

Aerodynamic properties are an essential factor in the development of pneumatic facilities for separation, sorting, delivering, and drying of agricultural materials. In this paper a computerised wind tunnel system is developed to measure aerodynamic properties of agricultural materials in an effective and efficient way. The system derives the aerodynamic properties of an object through measuring the drag force applied on the object which is placed in an upward air stream. The drag force, an essential variable in the derivation, is measured using a cantilever sensor which detects the equilibrium of external forces applied on the target object. Test on a wood rod specimen shows that the measurements match textbook values at a strong degree. The test is extended to chopped fresh forage corn stalks. The terminal velocity is described as a multi-regression function of the weight and projected area of the stalks which are used as an important ration for dairy cows. The function is valuable for selecting the capacity of an air blower used in pneumatic facilities.

Unitary haptic perception: integrating moving tactile inputs from anatomically adjacent and non-adjacent digits

How do we achieve unitary perception of an object when it touches two parts of the sensory epithelium that are not contiguous? We investigated this problem with a simple psychophysical task, which we then used in an fMRI experiment. Two wooden rods were moved over two digits positioned to be spatially adjacent. The digits were either from one foot (or hand) or one digit was from either foot (or hand). When the rods were moving in phase, one object was reliably perceived. By contrast, when the rods were moving out of phase, two objects were reliably perceived. fMRI revealed four cortical areas where activity was higher when the moving rods were perceived as one object relative to when they were perceived as two separate objects. Areas in the right inferior parietal lobule, the left inferior temporal sulcus and the left middle frontal gyrus were activated for this contrast regardless of the anatomical configuration of the stimulated sensory epithelia. By contrast, the left intraparietal sulcus was activated specifically when integration across the midline was required, irrespective of whether the stimulation was applied to the hands or feet. These results reveal a network of brain areas involved in generating a unified percept of the presence of an object that comes into contact with different parts of the body surface.

How far must trees be cultivated from the edge of the flood plain to provide best river bank protection?

In this study, to find the best location to cultivate the trees for river bank protection, some experimental tests were performed. One row of trees were cultivated at five different distances from the main channel/floodplain interface in a rectangular compound open channel. In experimental model for simulating the trees, some cylindrical wood rods were attached to the bed of flood plain. The three-dimensional flow velocity of flow in a cross-section between the trees were measured in 149 nodal points using Micro-acoustic Doppler velocimeter (ADV) velocity meter. At each nodal point, 6000 velocity data for each direction were stored in a computer. From the analysis of the experimental data, it was concluded that upon cultivating trees at 10% distance of flood plain width from the edge of main channel, the minimum streamwise velocity occurred near main channel/floodplain interface, while the maximum streamwise velocity occurred far from the edge of floodplain. Therefore, the best location for cultivating the trees was found to be at 10% of floodplain width and it is suggested for river bank protection in practical applications.

Auscultation in the diagnosis of respiratory disease in the 21st century

Auscultation of the chest via a stethoscope has been an integral part of respiratory examination for the last 200 years. Hippocrates was known to “directly auscultate” the chest by placing...