Head Shaft Research Articles

Bond strength of different wood-plastic hybrid components prepared through back injection moulding

Golf tees with a plastic head and wooden shaft were prepared by back injection moulding of a beech wood (Fagus sylvatica) shaft with different polymers (i.e. ionomer, polypropylene, and polyamide). In order to facilitate adhesion between the polymer melt and the wood surface, the wooden shafts were pre-treated with different primer substances, including a commercially available primer for ABS edges, a 10% solution of alkyl ketene dimer (AKD) in toluene and tumbling lacquer. The mechanical strength of the wood-plastic interphase was characterized by applying a pull-out test. Bond strength values of more than 9 N/mm² were observed for polyamide, whereas ionomer and polypropylene specimens achieved values between 0.7 and 3.8 N/mm². Surprisingly, the used primers failed to improve interfacial adhesion with the exception of the ionomer sample pre-treated with the commercial ABS-primer. Although light microscopy and SEM revealed some differences in the penetration behaviour of the different polymers as well as in the extent of plastic wood deformation imposed during injection moulding, the chemical nature of the polymer seems to be the most important determinant for the bond strength of wood-plastic hybrid components.

Numerical Simulation on Hydraulic Characteristics of Nozzle in Waterjet Propulsion System

As an important over-current component of the waterjet propulsion system, the main function of a nozzle is to transform the mechanical energy of the propulsion pump into the kinetic energy of the water and eject the water flow to obtain thrust. In this study, the nozzle with different geometry and parameters was simulated based on computational fluid dynamics simulation and experiment. Numerical results show a good agreement with experimental results. The results show that the nozzle with a circular shape outlet shrinks evenly. Under the designed flow rate condition, the velocity uniformity of the circular nozzle is 0.26% and 0.34% higher than that of the elliptical nozzle and the rounded rectangle nozzle, respectively. The pump efficiency of the circular nozzle is 0.31% and 0.14% higher than that of the others. The pressure recovery and hydraulic loss of the circular nozzle are superior. The hydraulic characteristics of the propulsion pump and waterjet propulsion system are optimal when the nozzle area is 30% times the outlet area of the inlet duct. Thus, the shaft power, head, thrust, and system efficiency of the propulsion pump and waterjet propulsion system are maximized. The system efficiency curve decreases rapidly when the outlet area exceeds 30% times the outlet area of the inlet duct. The transition curve forms greatly affect thrust and system efficiency. The transition of the linear contraction shows improved uniformity, and the hydraulic loss is reduced. Furthermore, the hydraulic performance of the nozzle with a linear contraction transition is better than that of others.

Efficacy of open reduction and locking plate fixation via subacromial anterolateral approach for proximal humerus fracture

Objective To investigate the clinical efficacy of subacromial anterolateral small incision approach with open reduction and internal fixation with proximal humeral locking system (PHILOS) for proximal humeral fractures. Methods A retrospective case-control study was conducted to analyze the complete medical records of 76 patients with proximal humeral fractures admitted to the Department of Traumatic Surgery, Fujian Provincial Hospital from April, 2013 to December, 2017. There were 22 males and 54 females, aged from 25 to 89 years [(60.4±16.4)years]. All patients had closed fractures. According to Neer classification, there were 12 patients of type II, 46 patients of type Ⅲ, and 18 patients of type IV. The duration from injury to operation ranged from 1 to 10 days [(4.4±1.9)days]. All patients received treatment of open reduction fixation with PHILOS. Forty patients received subacromial anterolateral small incision approach with percutaneous interactive reduction and internal fixation of humerus head and humerus shaft, including four patients of Neer type II, 26 patients of type III, and 10 patients of type IV (minimally invasive group). Thirty-six patients received the deltopectoral approach with reduction and internal fixation, including eight patients of type II, 20 patients of type III, and 8 patients of type IV (conventional group). The total length of incision, the operation time, intraoperative blood loss, hospitalization time, review of the neck angle with X-ray 1 week after surgery, and the fracture healing after 6 months, the ipsilateral Neer shoulder joint function score at 6 months after surgery and complications were compared. Results All patients were followed up for 3-12 months [(9.2±1.7)months], and there were six patients lost to the follow-up including four of the minimally invasive group and two of the conventional group. In the minimally invasive group and the conventional group, the total length of incision was 6.0(6.0, 6.8)cm and 11.5(10.0, 15.0)cm ( P 0.05), the intraoperative blood loss was 100(80, 150)ml and 175(100, 200)ml (P 0.05), the neck-shaft angle was (134.7±2.5)° and (134.6±2.6)°(P>0.05). A total of 70 patients obtained good bone healing. At 6 months after operation, the Neer shoulder function score of the affected side in the minimally invasive group was excellent in 30 patients, good in four patients, and fair in two patients, with the excellent and good rate of 96%, and for conventional group the score was excellent in 20 patients, good in eight patients, and fair in six patients, with the excellent and good rate of 84%(P<0.05). There was no complication in the minimally invasive group, but axillary nerve injury was found in one patient in the conventional group. Conclusion For the proximal humerus fracture, compared with the traditional deltopectoral approach, the subacromial anterior lateral small incision approach with percutaneous humeral head and humeral shaft reduction and interal fixation has the advantages of smaller incision, less bleeding and better functional recovery, which is a minimally invasive and effective treatment. Key words: Humeral fractures; Acromion; locking plate

The effect of femoral orientation on the measurement of the head shaft angle: an ex-vivo study.

This laboratory study evaluates head shaft angle (HSA) reliability using ranges of simulated femoral orientation often seen in children with cerebral palsy. A dry femur was mounted in a jig that enabled the bone to be positioned in a range of internal and external rotation (-40° to + 40°) and flexion (0°-60°), alone or in combination. A metal wire was placed as a surrogate physis to give two HSA angles of 140° and 160°. Radiographs were taken of the femur in differing combinations of rotation, flexion and the two HSA angles. The HSA was measured by four independent observers on two separate occasions. Intraclass correlation coefficients (ICCs) were used to assess interobserver and intraobserver reliability. The HSA was accurately measured within ± 5° when the femur was positioned between 20° internal rotation and 40° external rotation. Flexion up to 60° did not affect the accuracy of the measurement. The interobserver reliability for the HSA was excellent with an ICC of 0.9970 [95% confidence interval (CI): 0.9995-0.9983] for the first measurement and 0.9988 for the second (95% CI: 0.9979-0.9993, all P < 0.01). The intraobserver reliability was also excellent with an ICC of not less than 0.990 for all four observers (95% CI: 0.9806-0.9986, all P < 0.01). There was excellent interobserver and intraobserver reliability when measuring the HSA in an experimental model provided femoral rotation lay within 20° internal and 40° external rotation and less than 60° of flexion.

Analyzing risk factors for recurrence of developmental coxa vara after surgery.

PurposeTo evaluate the risk factors for developmental coxa vara (DCV) recurrence following valgus osteotomy of the proximal femur.MethodsWe retrospectively reviewed records of 32 DCV patients (46 hips) treated surgically (2005 to 2012). Recurrence-related factors, including age at initial surgery, side, sex, fixation methods, diagnosis of coxa vara, premature capital femoral physeal closure and postoperative Hilgenreiner epiphyseal (HE) angle, head-shaft (HS) angle, medial femoral offset and posterior slope angle (PSA) were analyzed.ResultsAt 4.7-year mean follow-up, 12 hip deformities recurred (26%). Postoperative HE angle > 41° and negative offset were statistically significant univariate and multivariate risk factors for the deformity recurrence. Increased PSA was common preoperatively, which accounted for 59% of hips. Postoperative PSA > 20° was associated with a high recurrence rate in the univariate analysis. Age was another univariate risk factor for the recurrence. Recurrence rate was 52% in the < 6.5-year age group versus 4% in the > 6.5-year age group. Other factors were not statistically significantly related to recurrence.ConclusionDCV is a 3D deformity. To prevent recurrence, HE angle should be restored to < 41° in the coronal plane. Sagittal malalignment (abnormal PSA) should be corrected concurrently, so that, the direction of surgical correction is along the true deformity plane. During valgus osteotomy, the distal fragment should be lateralized to maintain a normal mechanical axis.Level of EvidenceIV

Study on Size Design of Shaft Protection Rock/Coal Pillars in Thick Soil and Thin Rock Strata

To prevent serious shaft deflection disasters under asymmetric mining conditions, it is urgent to solve the problem of designing shaft protection rock pillar (SPRP) sizes in thick soil and thin rock strata. In this paper, based on the parallel mining model and the perpendicular mining model, a dynamic prediction model that can describe the horizontal movement of the shaft was established by the probability integration method and the Knothe time function. Next, according to the measured data of the shaft deflection in the Guotun Coal Mine, a back analysis was used to calculate the prediction parameters that were suitable for the deep soil strata. Based on the mining model, the variation law of the horizontal deflection displacement of the shaft and SPRP size was obtained. The results showed that the final displacements of the shaft under the two ideal mining models were equal, while the parallel mining model was superior to the perpendicular mining model at the initial stage of mining. The horizontal displacement of the shaft head had a nonlinear negative correlation with the SPRP, and the SPRP size in thick soil and thin rock strata calculated by the parallel mining model was more reasonable. For the Guotun Coal Mine, when the soil movement angle was 57.8% of the actual value, the horizontal displacement of the main shaft head was reduced by 87%. The results have important theoretical and practical value in preventing shaft deflection in thick soil and thin rock strata.

OSTEOMETRY OF FEMUR WITH ITS CLINICAL IMPLICATIONS

Introduction: Femur osteometry is important for establishing individual identity, designing of prosthesis for hip replacement surgeries, nail application, and determination of age and sex. Review of previous study showed a lack of extensive database. This study was undertaken to build baseline data for femur osteometry in North Indian population. Material &amp; Methods: One hundred and fifteen dry human femur of undetermined age and gender were collected for this study. Parameters namely length of femur, vertical diameter of head, transverse diameter of head, epicondylar breadth and neck shaft angle were measured using a vernier calliper. Data was analysed statistically using SPSS 19 software. Results: The mean values for length, vertical diameter head, transverse diameter head , epicondylar breadth and neck shaft angle were 418.16+27.34 mm, 38.43 ± 3.87mm, 35.41 ± 3.76mm, 72.06 ± 6.55mm and 121.5 º ± 6.14 respectively for the studied population. Conclusion: Study signifies the importance of collecting ostemetric data of femur for a specific population due to ethnic and environmental factors affecting it.

Field and theoretical analysis of response of axially loaded grouted drilled shafts in extra-thick fine sand

Research on post-grouted drilled shafts has focused primarily on post-grouted tips. Here, four full-scale shaft load tests were conducted to investigate the behaviors and performance of combined tip-and-side grouted superlong and large-diameter drilled shafts in extra-thick fine sand layers. The enhanced mechanism of the combined grouted drilled shafts is analyzed, and a rational approach for analyzing their load–displacement response is presented. The side and base resistance of the combined grouted drilled shafts exhibited significant strengthening, substantially increasing the bearing capacity and effectively controlling settlement. Under the ultimate load, &gt;60% of the shaft head displacement was caused by shaft compression; a relatively small load proportion was carried by the shaft base. The superlong and large-diameter drilled shaft can be treated as a friction shaft, and the combined tip-and-side grouting cannot change the bearing characteristics. The hyperbolic model describes the relationship between the side resistance and relative shaft–soil displacement and captures the base resistance–displacement response. The proposed approach is verified with a case history, and the bearing behaviors of a large-diameter drilled shaft under an extra-thick fine sand layer are analyzed. These results clarify the bearing characteristics of combined grouted shafts and can help guide the design of post-grouted shafts.

Full-Scale Load Testing of 75–90-m-Long Post-Grouted Drilled Shafts in Suzhou Stiff Clay

Abstract This article evaluates the effects of post-grouting on axial behavior of long drilled shafts in stiff clay. Static axial compression and tension load tests were conducted on four ungrouted and six post-grouted shafts to investigate the effects of post-grouting on axial capacity and load-transfer mechanism. After post-grouting, axial capacity increased more than 100 %. Prior to failure, the relationship between the normalized axial load Q/Qmax and shaft head displacement Δ/D was nonlinear for ungrouted shafts. Compared with cases presented in the literature, much greater shaft displacements were required to mobilize shaft tip resistance and skin resistance, indicating a softer load-displacement response. The contribution of tip resistance to the overall load capacity was small for both ungrouted and post-grouted shafts because of their length. Shaft load capacity was significantly underestimated by the standard penetration test (SPT)-based method and α-method and was more reasonably estimated by the β-method. The cone penetration test (CPT) direct method yielded generally reliable predictions of skin resistance mobilized in the upper stiff clay soils; however, this method significantly underestimated skin resistance in the underlying very stiff to hard clay layers. Considering uncertainties in current design methods, results of this study suggest that field load tests are needed prior to construction to obtain site-specific design parameters.

The head shaft angle is associated with hip displacement in children at GMFCS levels III-V - a population based study

BackgroundAn increased Head Shaft Angle (HSA) has been reported as a risk factor for hip displacement in children with cerebral palsy (CP) but opinions differ in the literature. The purpose of this study was to re-evaluate the relationship between HSA and hip displacement in a different population of children with CP.MethodsThe Cerebral Palsy Integrated Pathway Scotland surveillance programme includes 95% of all children with CP in Scotland. The pelvic radiographs from 640 children in GMFCS levels III-V were chosen. The most displaced hip was analysed and the radiographs used were those taken at the child’s first registration in the database to avoid the potential effects of surveillance on subsequent hip centration. A logistic regression model was used with hip displacement (migration percentage [MP] ≥40%) as outcome and HSA, GMFCS, age and sex as covariates.ResultsThe MP was ≥40% in 118 hips with a mean HSA of 164° (range 121–180°) and < 40% in 522 hips with a mean HSA of 160° (range 111–180°). The logistic regression analysis showed no significant influence of age and sex on MP in this population but a high GMFCS level was strongly associated with hip displacement. An increased HSA was also associated with hip displacement, a 10° difference in HSA for children adjusted for age, sex, and GMFCS gave an odds ratio of 1.26 for hip displacement equal or above 40% (p = 0.009) and hips with HSA above 164.5 degrees had an odds ratio of 1.96 compared with hips with HSA below 164.5 degrees (p = 0.002).ConclusionThese findings confirm that HSA is associated with hip displacement in children in GMFCS levels III-V.

Semmering Base Tunnel – Design and construction of the shaft head caverns under difficult conditions

AbstractIn contract SBT1.1 of the Semmering Base Tunnel, the single‐track main tunnels are being driven from the portal in Gloggnitz and from a temporary intermediate starting point in Göstritz. The temporary intermediate starting point in Göstritz is being constructed in order to reduce the risk to the tunnel construction time for the Graßberg‐Schlagl fault system. During the construction phase, the contractor developed optimisations of the planned logistics concept for the intermediate access point in Göstritz, which led to a redesign of the shaft head cavern system. Shortly before the excavation of the shaft head cavern, an unexpected and geotechnically relevant fault zone was encountered in the access tunnel. In order to investigate the geological situation in the area of the shaft head, extensive additional investigation measures were carried out. Due to the updated geological forecast, the layout of the shaft head cavern and the support concept had to be changed. Thanks to the measures taken, the shaft head cavern system cold be successfully excavate without any damage to the support.

Automatic Simulation Method for Performance Analysis of Kerosene-Based Turbo-Pump

Kerosene-based turbo-pump is crucial to pump-fed expansion cycle scheme of the scramjet system in aerospace applications. An automatic simulation method was developed to conduct performance analysis of kerosene-based turbo-pump at low costs. Turbulence simulation combined with a multi-species surrogate model of kerosene was employed to study objective characteristics by simulating the flow-field inside the turbo-pump at 100000 rpm. Automatic simulation process, based on Design of Experiments technique, response surface model and high-fidelity numerical simulation, was applied for similarity analysis and Pareto front analysis, respectively. Results indicate that, all the characteristic curves of pump developed head (ΔHp) and turbine shaft power (Pt) with respect to mass flow rate at various rotating speeds, agree well with Similarity Criterion; ΔHp is negatively related to the efficiency of pump (ηp) in general, but the contrary is the case for Pt and the efficiency of turbine (ηt).

Estimating body mass and composition from proximal femur dimensions using dual energy x-ray absorptiometry

Body mass prediction from the skeleton most commonly employs femoral head diameter (FHD). However, theoretical predictions and empirical data suggest the relationship between mass and FHD is strongest in young adults, that bone dimensions reflect lean mass better than body or fat mass and that other femoral measurements may be superior. Here, we generate prediction equations for body mass and its components using femoral head, neck and proximal shaft diameters and body composition data derived from dual-energy x-ray absorptiometry (DXA) scans of young adults (n = 155, 77 females and 78 males, mean age 22.7 ± 1.3 years) from the Andhra Pradesh Children and Parents Study, Hyderabad, India. Sex-specific regression of log-transformed data on femoral measurements predicted lean mass with smaller standard errors of estimate (SEEs) than body mass (12–14% and 16–17% respectively), while none of the femoral measurements were significant predictors of fat mass. Subtrochanteric mediolateral shaft diameter gave lower SEEs for lean mass in both sexes and for body mass in males than FHD, while FHD was a better predictor of body mass in women. Our results provide further evidence that lean mass is more closely related to proximal femur dimensions than body or fat mass and that proximal shaft diameter is a better predictor than FHD of lean but not always body mass. The mechanisms underlying these relationships have implications for selecting the most appropriate measurement and reference sample for estimating body or lean mass, which also depend on the question under investigation.

Radiological correlation with functional outcome in displaced proximal humerus fractures treated with locking plates: a prospective study of 35 cases

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; The objective of this prospective study is to investigate the relationship between the functional outcome and the radiographic results of two-, three- and four part proximal humeral fractures treated with open reduction and fixation with PHILOS locking plate.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; 35 patients (30 males and 5 females) with displaced proximal humerus fracture were treated with PHILOS plating and studied prospectively. According to Neer’s classification there were 16 two part fracture (45%), 15 three part fracture (42%) and 4 four part fracture (13%). The healing of fracture, head shaft angle (HSA) and complications were evaluated radiologically with plain radiographs whereas the functional outcome was assessed by the Shoulder Pain and Disability Index (SPADI) at 6 weeks, 3 months, 6 months and 1 year after surgery.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; In our study, patients treated with locking plates had mean forward flexion of 123°, abduction of 124°, mean external rotation of 30° and internal rotation 53° at 1 year follow-up. Maximum improvement in range of movement occurred between interval of 12 weeks to 24 weeks due to complete fracture union occurred approximately up to 12 weeks. The mean SPADI score at end of 1 year were 10.22, 10.38 and 10.20 for two, three and four part fractures respectively. Average postoperative and follow-up HSA's were 134.1±4.4 and 132.5±1.2 degrees, respectively. Varus progression was more prominent in patients with postoperative HSA &amp;lt;130 (p&amp;lt;0.001). Complications included impingement in 1 case, joint penetration by screw in 1 case, failure of fixation in 1 case and infection in 1 case.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Fixed angle locked plate is an extremely useful implant for reconstruction and salvage of proximal humeral fractures. Precise surgical technique, stable fracture fixation and restoration of anatomical reduction are absolutely necessary for improved outcome.&lt;/p&gt;

Morphology of femur, tibiotarsus and fibula of local hill fowl of Uttarakhand.

This study was conducted on femur, tibiotarsus and fibula from six adult local hill fowl of Uttarakhand. The femur of the local hill fowl was a long cylindrical bone consisted of a shaft and two extremities. The shaft was curved and twisted in appearance. The proximal extremity had spherical head separated from shaft by neck. The trochanter minor was indistinct. The distal extremity hadposteriorly medial and lateral condyles and anteriorly trochlea. The tibiotarsus was the longest bone among the leg bones. The shaft was anteriorly curved in its proximal half and posteriorly curved in its distal half. The fibular crest was well developed and on posterior-lateral aspect of it’smid-shaft very small nutrient foramen was observed. The cnemial crest was originates from cranial border of transverse ridge and extended ventro-medially. The distal extremity showed large medial and small lateral condyles separated by the deep intercondylerfossa. The fibula was a reduced long bone with distinct head and rudimentary shaft. The shaft of fibula extended up to the distal one third of the shaft of tibiotarsus.

Manual reduction and traction fixation for the treatment of metacarpal neck fractures under ultrasound-guided

To study clinical efficacy of manual reduction and traction fixation for the treatment of metacarpal neck fracture under ultrasound-guided. From April 2013 to August 2016, 30 patients with metacarpal neck fractures were treated with manual reduction and traction fixation under ultrasound-guided, including 26 males and 4 females aged from 14 to 56 years old with an average of (25.6±1.6) years old, the courses of diseases ranged from 7 h to 5 d with an average of (2.7±0.6) d. Twenty patients were the fifth metacarpal neck fracture, 7 patients were the 4th and 5th metacarpal neck fractures, 3 patients were the second metacarpal neck fracture. Fracture healing, angle of bilateral head shaft angle and active range of metacarpophalangeal joints was measured, and DASH score was applied to evaluate function. Twenty-seven patients were followed up from 6 to 11 months with an average of(7.2±0.8) months. Fracture were healed from 5 to 8 weeks with an average of (5.6±0.4) weeks. The affected shaft angle was (15.1±1.8)°, and health head shaft angle was (13.5±2.8)°, while there was no significant difference (t=1.54, P>0.05). The affected range motion of metacarpophalangealjoint was(86.3±2.6)°, health active range motion of metacarpophalangeal joint was(91.8±1.6)°, and no significant difference between both side (t=1.16, P>0.05). DASH score was 4.3±1.5 at 7 months after operation. Manual reduction and traction fixation for the treatment of metacarpal neck fracture under ultrasound-guided could dynamic observe fracture position in time, high patients' acceptability and is a feasible method for the treatment of metacarpal neck fracture.

Young's Modulus and Load Complexity: Modeling Their Effects on Proximal Femur Strain

Finite element analysis (FEA) is a powerful tool for evaluating questions of functional morphology, but the application of FEA to extant or extinct creatures is a non-trivial task. Three categories of input data are needed to appropriately implement FEA: geometry, material properties, and boundary conditions. Geometric data are relatively easily obtained from imaging techniques, but often material properties and boundary conditions must be estimated. Here we conduct sensitivity analyses of the effect of the choice of Young's Modulus for elements representing trabecular bone and muscle loading complexity on the proximal femur using a finite element mesh of a modern human femur. We found that finite element meshes that used a Young's Modulus between 500 and 1,500MPa best matched experimental strains. Loading scenarios that approximated the insertion sites of hip musculature produced strain patterns in the region of the greater trochanter that were different from scenarios that grouped muscle forces to the superior greater trochanter, with changes in strain values of 40% or more for 20% of elements. The femoral head, neck, and proximal shaft were less affected (e.g. approximately 50% of elements changed by 10% or less) by changes in the location of application of muscle forces. From our sensitivity analysis, we recommend the use of a Young's Modulus for the trabecular elements of 1,000MPa for the proximal femur (range 500-1,500MPa) and that the muscular loading complexity be dependent on whether or not strains in the greater trochanter are the focus of the analytical question. Anat Rec, 301:1189-1202, 2018. © 2018 Wiley Periodicals, Inc.

Bilateral Tibia/Fibula Fractures in Automobile versus Pedestrian Accident

History of present illness: A 25-year-old female presented to the emergency department (ED) with bilateral lower extremity deformities after being struck by a car while riding a skateboard. The patient was not wearing a helmet but did not report a loss of consciousness. She endorses using methamphetamine and crack cocaine on the day of the accident. Examination of the right lower extremity revealed a 10cm x 7cm soft tissue injury with a 5cm segment of exposed tibia on the anteromedial aspect and a deep abrasion on the lateral aspect of the leg just superior to the patella. Examination of the left leg revealed a small 0.5cm x 0.5cm open wound on the anteromedial aspect of the tibia with oozing blood containing fat droplets and superficial abrasions over the knee. Dorsalis pedis and posterior tibial pulses were 2+ bilaterally. There was low suspicion of compartment syndrome, and there was no neurological deficit noted in the lower extremities. Significant findings: Plain film shows severely comminuted and displaced mid tibia/fibula fractures of bilateral lower extremities (red arrows) and comminuted right fibular head (blue arrow) and proximal shaft fracture (yellow arrow).Discussion: Limb trauma is one of the most common injuries seen in emergency medicine and is the most common reason for hospitalization in nonfatal traumas. Approximately 25% of tibial fractures are open, making the tibia the most common long-bone in which an open fracture occurs.1 The largest threat of limb loss is vascular injury. Bleeding can be controlled with direct pressure,2 a tourniquet,3,4 or clamping of the vessel. One should not attempt to clamp a vessel if it cannot be visualized. If there are no signs of vascular injury requiring immediate surgery, nerves, bones, and soft tissues should be assessed. Sensation and strength should be evaluated to assess the integrity of the femoral, sciatic, deep fibular, and tibial nerves. Skin should be evaluated for lacerations, avulsions, penetrating injury, contamination, and open fractures.5 If there is extensive muscle damage, one must also monitor for signs of rhabdomyolysis.6 Extremity radiography is indicated if there is presence of deformity. Assessment should include the joint above and below the site of injury. Comminuted fractures increase the risk of arterial damage and such an injury should lead to a full vascular assessment.5 If the fracture is open, prophylactic antibiotic treatment should be started as the patient is at risk for osteomyelitis.7 Surgery is required for comminuted or open fractures. With casting only, comminuted fractures have an increased risk of nonunion, malunion, or shortening of the limb.8 Furthermore, by stabilizing the fracture, the soft tissues are stabilized, decreasing bacterial spread and inflammatory responses. Debridement of an open fracture is necessary to remove debris and unhealthy tissue from the wound.9 The patient in this case was given intravenous cefazolin and was taken to the operating room the same day by orthopedic surgery for bilateral lower extremity tibia and fibula open reduction and internal fixation. Topics: Tibia/fibula fracture, pedestrian vs. automobile, trauma.

Gloggnitz contract after completion of the intermediate access at Göstritz

AbstractThe intermediate construction access at Göstritz was planned based on the results of a comprehensive geological investigation programme. The intermediate access minimises the risk of the excavation of the Semmering Base Tunnel through the Grassberg‐Schlagl fault system, which is located in the Otterstock area in Lower Austria. The site consists of an approx. 1000 m long access tunnel, a complex system of shaft head caverns, two shafts with a depth of about 250 m down to the level of the tunnel as well as a system of shaft bottom caverns for the four tunnel drives in the directions of Gloggnitz and Mürzzuschlag. During the construction of the access tunnel, a new shaft head layout was proposed by the contractor in form of value engineering to optimize further construction operation, and the optimized layout was adopted to the contract. At the end of the access tunnel, it turned out that the shaft head cavern system could neither be constructed in the original layout as tendered nor in the newly revised layout due to a geological fault zone, which had not been predicted despite extensive geological investigation in advance. Consequently, ÖBB, designer and contractor worked intensively to find a new feasible design to enable further construction of the cavern system, avoid a standstill of tunnelling works and comply with all approvals.

Fatigue and failure mechanism in carbon fiber reinforced plastics/aluminum alloy single lap joint produced by electromagnetic riveting technique

Electromagnetic riveting (EMR) process is suitable for composite joining due to small damage. In this paper, the EMR experiments were conducted to obtain the fatigue samples. Specimens with normalized driven head dimensions were tested to obtain the fatigue behaviors. The experimental results showed that the driven head dimensions had a remarkable effect on fatigue property. The fatigue life increased first and then decreased with the increasing of D/D0 (D and D0 are the diameters of rivet driven head and original shaft, respectively). The electromagnetic riveted specimens with D/D0 = 1.5 had the best fatigue properties. The fatigue failure analysis showed that the specimens had three typical fatigue failure modes: failure in the rivet, failure in the Al sheet and failure in the CFRP and Al sheets as influenced by driven head dimensions and stress levels.