High Speed Automobiles Research Articles

Hierarchical nested honeycomb-based energy absorbers: design factors and tailorable mechanical properties.

This study presents a novel hierarchical nested honeycomb drawing inspiration from the hierarchical structures found in energy-absorbing citrus peels. Our investigation reveals that integrating secondary hierarchical units into primary honeycomb cells results in energy absorption profiles featuring two distinct plateaus. Notably, we found that these profiles can be finely tuned by adjusting the thickness of primary and secondary cell walls. Additionally, our study demonstrates a strategic removal of cell walls at key positions, reducing material consumption without compromising specific energy absorption. By establishing comprehensive structure-property relationships, we offer valuable insights into the design and optimization of hierarchical cellular materials. Compared with traditional honeycomb structures, the nested honeycomb structure shows a twofold increase in compressive strength and a fivefold increase in specific energy absorption, positioning them as promising candidates for applications requiring two-step impact protection and tunable performance, ranging from packaging to high-speed automobiles.

Causes, Types and Management of Fracture of Dentate Region of Mandible

Aim: The mandible fracture ranks as the second most often occurring facial fracture. The advent of high-speed automobiles has led to a significant increase in the frequency of accidents in recent times. Mandibular fractures are observed as a notable occurrence of maxillofacial trauma in the region of Multan. Purpose: To determine the Causes, types and management of fracture of dentate region of mandible fracture. Method: The present research is an observational and descriptive investigation including a sample of 52 patients diagnosed with mandible fractures. The study was done at the Nishter Institute of Dentistry in Multan, Pakistan, spanning from September 2021 to February 2023. Following the endorsement of the research by the Ethical Review Board of the hospital, patients were recruited using a non-probability sequential sampling method. This research included patients who had a history of trauma and were admitted to Nishter Institute of Dentistry in Multan, Pakistan, as well as those from the surrounding districts of Multan. The assessment of mandibular fractures included doing extra-oral and intra-oral clinical evaluations, as well as obtaining panoramic and posterior-anterior radiographs of the mandible to establish a diagnosis. The data collected was then subjected to statistical analysis. Result: Among the sample of 52 individuals diagnosed with mandibular fractures, the age group of 21-30 years had the greatest proportion, with a notable male preponderance. The leading causes of fractures were road traffic accidents and assault, with the parasymphysis being the most often affected anatomical region. The occurrence and aetiology of mandibular fracture are indicative of the prevailing trauma patterns in a given population and may serve as a valuable resource for informing the development of initiatives aimed at mitigating and managing such injuries. Conclusions: Patients in the older age (51 years and over) exhibited a higher prevalence of fracture sites in comparison to patients in the younger age. This observation might perhaps be ascribed to the presence of a larger tooth-to-bone ratio. As a result, a decrease in bone density was seen among participants in the younger age category, whereas those in the older age category exhibited an elevation in bone frailty Keywords: Dentate fracture, mandible, trauma

LATERAL COMPRESSION SPLINTS AND VACUUM FORMED SPLINTS IN CLOSED REDUCTION AND FIXATION OF MANDIBULAR FRACTURES

Introduction: In the current fast moving lifestyle, the use of high speed automobiles, violence and sports-related injuries have alarmingly increased maxillofacial trauma in the past few decades. Mandible is at a prominent position on the face which makes it vulnerable to injuries in such situations and is therefore, one of the most commonly fractured facial bones.
 Aim: To compare the efficacy of Vacuum-formed Splints with conventional Lateral Compression Splints in the closed reduction and fixation of mandibular fractures on the basis of clinical parameters and radiographic evaluation.
 Methods: Total of 30 patients, both male and female, with minimally displaced mandibular fractures were considered for this study.
 Results: Patients were randomly divided into 2 Groups (Group A-Study Group; treated with Vaccum-formed Splints and Group B-Control Group; treated with Lateral Compression Splints), with 15 patients in each Group. Group A included 15 male (100%) patients, while Group B comprised of 14 male (93.33%) and 1 female (6.66%) patients.
 Conclusion: Early diagnosis and precise treatment is advocated in management of fractures of the mandible. In the present study statistically significant values were found in patient’s pain experience and gingival health in vacuum-formed splint over lateral compression splint. To prevent residual effect of trauma an oral surgeon must have an extremely broad knowledge of orthopedic appliances, a good understanding of the fundamental principles of occlusion, the altered physiology, pathology and the surgical principles involved.

Correlation between experimental and analytic approaches to study the erosion rate of aluminum-metal matrix composites

The incorporation of a ceramic particles like SiC, Al2O3, and TiO2 into aluminum matrices results in Aluminum composite better mechanical and physical properties that make them attractive for various applications such as Aircraft, Helicopter, High-speed automobile, and Submarine. In this study, the erosion properties of the aluminum composite were studied in dry conditions using sand blast-erosion test rig. Impact velocity, standoff distance, particle size, particulate (wt. %), and impingement angle were preferred as control factors. Taguchi method, Grey relational and regression analysis were considered for optimizing the erosion process parameters. L27 orthogonal array was determined for the experimental trials. The most significant factors in the process were identified. Nonlinear regression model has been developed for Grey Relational Grade in relation to the different erosion parameters. An optimization schema is established based on a correlation between analytic and experimental results.

Study of management of sub trochanteric fractures of the femur in adults using proximal femoral nails

Introduction: Among the femoral shaft injuries upper femoral fractures present a peculiar problem of securing effective neutralization of deforming forces. The mechanical stresses at this level are very high.Conclusion: The incidence of Subtrochanteric fractures of the femur is on the raise because of fast and high speed automobiles and modern lifestyles and increased life expectancy of the elderly age group patients.

Mathematical Models for in-Plane Moduli of Honeycomb Structures-A Review

Honeycomb structures are light weight cellular structures having high strength to weight ratio with enormous applications in aerospace industry, high speed automobiles, computers and other electronics equipment bodies and recently as flexible structures and mechanisms. In this paper a review of mathematical models for stress strain behaviour of two dimensional honeycomb structures is presented. As proposed by different authors, expressions for in-plane Elastic Moduli and shear Modulus are presented and compared on same scale dimensions. In addition to that, effects of number of unit cells on effective in plane and out of plane Moduli of the testing specimen for regular honeycombs and open and closed cell foams, are also reviewed.

Transportation and the Experience of Travel

Improvements in transportation over the years have consistently diminished the experience of traveling. Many writers have noted that the progression from horses and bicycles to high-speed automobiles and airliners has reduced the rewards of travel. Because traveling can be an enjoyable and humanizing experience, transportation should be modified to benefit travelers. EXPERIENCING a new place can be exciting, and it should be fun. Travel to such a place should be stimulating and enjoyable. But is it? In early times travel was often an arduous and even dangerous undertaking. The French antecedent, travail, means exhausting labor or exertion. Over the years travel has become easier and easier, until today it may have become so easy that it provides little pleasure and substance. There must have been a happier midpoint in this progression, a time when the traveler no longer had to fear bandits and pirates or to be battered and bruised in a stagecoach, yet not a period when travel was largely a process of being hurtled through space in a sealed container. What is the best mode of travel has always been a debatable point, and sensitive and curious travelers have often vigorously objected to new forms of transportation that they consider to provide less rewarding journeys. Generally they have complained that a new or improved facility tended to separate them from the land that they were passing through, that the route was limiting and perhaps its construction had damaged the view, or that the trip went so fast and so far that a traveler was numbed. Travelers who reacted with disapproval to each new improvement in transportation might have been manifesting the normal human resistance to change, or they might have been most soberly agreeing with the philosophical observation by Ogden Nash that progress is all very well, only it's gone on too long. After a lifetime of travel to remote corners of the world, my father wrote to me of his childhood in rural Ohio at the beginning of the twentieth century. When I was a little boy you could see the landscape only by walking or bicycling or by horse and buggy or train. Walking and bicycling, especially as there were very few good roads, were very limited in compass. Horse and buggy were less so, but still quite limited and also very expensive. Railroads, aside from the dirt, flying cinders and romance, were pretty much as they are today: you saw a margin of the countryside, but it wasn't very real, and it certainly was not representative. The result was a Mystery of Landscape. Just going on some road a little further * DR. SIDDALL is a professor of geography at Kansas State University, Manhattan, Kansas

An Investigation of High-Speed Automobile Steering Response

SUMMARY The significance of the effects of steering compliance and aerodynamic life on high speed automobile's steering response was investigated on two vehicles, a Ford Falcon XW (1969) station-wagon and a GM-Holden Kingswood HQ (1974) sedan. An aerofoil was mounted above the front bumper bar of the Ford Falcon to enable the simulation of vehicles with very degraded aerodynamic characteristics. Mathematical analysis showed the importance of the inclusion of steering compliance effects in determining stability factor, and hence the vehicle's high speed yaw rate sensitivity. Both experiments and theory showed that the actual high speed yaw rate response is not significantly less than that predicted from a low speed skid pad test, however, slight errors were found which are likely to be due to steering system nonlinearity and the effects of aerodynamic lift.

Cervical Tracheoesophageal Fistula Due to Steering-Wheel Injury

n this era of high-speed automobiles the incidence of steering wheeI injury to the chest of the driver is increasingly frequent. In 1949 I the first case of tracheoesophageal fistula due to steering-wheel injury was reported by Albi and Gilcrist [2]. Since that time there have been 17 cases of tracheoesophageal fistula associated with indirect violence to the chest, and all but 4 have been due to steering-wheel injuries [l-181. This paper is concerned with the eighteenth case of tracheoesophageal fistula due to steering-wheel injury; it is a unique case in that the tear occurred at the level of the clavicle rather than at the bifurcation of the trachea.

Trauma of the larynx.

THERE WERE 49,000 people killed on the American highways in 1965. This amounted to 134 people each day, or 5.6 every hour, or roughly one person killed every 10 minutes. During this same period, there were 1,800,000 injuries. 1 When these figures are compared to the 34,000 2 lives lost in the entire Korean conflict or the 53,000 3 lost in World War I, it becomes apparent that the more serious of current battles is here on the nation's highways. It is this battle we are losing each year and the losses are becoming staggering. One of the injuries that is being seen more frequently in association with auto accidents is injury to the larynx and the upper respiratory tree. This injury has been seen in urban areas since the advent of the high speed automobile. We are now beginning to see these accidents in rural areas. How often does

An Experimental Study of Human Operator Models and Closed-Loop Analysis Methods for High-Speed Automobile Driving

The investigation described in this paper was aimed at obtaining information about the way in which the human being controls an automobile at high speed on a winding road. A dynamic systems approach was taken, and three different classes of models were postulated. The optimal models in these classes were then obtained for data taken from three subjects in a driving simulation which projected a large moving roadway image.

高速自動車の操縦安定性(高速道路特集(建設機械と自動車))

高速自動車の操縦安定性(高速道路特集(建設機械と自動車))

The Management of Jaw Fractures

The most frequently fractured of the facial bones is the mandible. Pathological fractures, the indirect result of disease, are not uncommon, but the majority of mandible fractures are traumatic. The advent of the high-speed automobile has changed our ideas of the etiology of fractures of the facial bones but, with rubber and gas rationing and reduced speeds, this hazard will be largely eliminated, at least for the duration, and fists and falls will probably take first place as causes of mandible fractures in civilian practice. War injuries, unfortunately, will be of severe type, taxing the skill and ingenuity of the surgeon. Fractures of the mandible may be partial, involving the alveolar processes or individual teeth, or they may be complete and of the same varieties as fractures of other bones—single, double, or comminuted. Single fractures occur most frequently, predominating over double fractures in the ratio of two to one. They are located at the angle or the mental foramen. Of the double fractures, those occurring at the angle on one side and mental foramen on the other are by far the most common (about 75 per cent). Fractures in the region of the symphysis menti or condyle are less frequent. The sites of predilection, in the order of their frequency, are the angle, mental foramen, molar region, symphysis, condyle, and coronoid process. Areas of anatomic weakness in the mandible determine the location of a fracture. In children with unerupted teeth the cuspid region is most frequently the site of fracture. Fractures of the body of the mandible when teeth are present are invariably compound. The diagnosis of fracture of the jaw is usually not difficult. There is a history of injury and the patient often presents a characteristic appearance; the head is carefully held, with the mouth open and an increased flow of saliva and drooling because of pain elicited by the muscular pull on fragments and a natural disinclination to swallow. There is some swelling; localized pain is variable but may be severe. Difficulty in opening or closing the jaws may be due to disinclination or to the displacement of fragments. Because of this displacement, the alignment of the jaws may be disturbed, with abnormal occlusion of the teeth. Anesthesia of the lower lip and gums may be discovered. Unnecessary movement of parts should be avoided, but crepitus may be elicited and a false point of motion felt. X-ray examination is the best means of determining the extent of injury. It is possible to examine the entire mandible from the temporo-mandibular joint on one side, around the jaw, to the joint on the other side, and this examination should be made in every case. Treatment of Fracture of the Mandible The objectives of treatment are the care of the injured soft tissues to prevent or minimize infection and the reduction of fragments to normal position, which usually results in the restoration of occlusion of the teeth. The restoration of the normal tooth occlusion is of the greatest importance in gaining a good functional result.

ALCOHOLIC INTOXICATION

The increasing popularity of high speed automobiles during the past decade has raised the problem of alcoholism above the level of morality and made it an issue of life and death. In 1936 motor vehicle deaths totaled 37,800. There were also 1,300,000 nonfatal traffic injuries, about 100,000 of them representing disabilities of a permanent character. In addition there were nearly 6,000,000 property damage only accidents. The total economic loss due to motor vehicle accidents for 1936 is conservatively estimated as $1,640,000,000. All summaries now available on fatal accidents show, on the average, that 7 per cent of the drivers and 11 per cent of the pedestrians had been drinking or were intoxicated.1In spite of the importance of establishing responsibility in accidents involving individuals who have been imbibing alcoholic beverages, the physician and the law still quibble about what constitutes alcoholic intoxication and what criteria are acceptable for establishing

Elements of High-Speed Automobile Engine Design

Elements of High-Speed Automobile Engine Design