Aerospace structures are highly vulnerable to impact loads whose damage tolerance, and its resistance vary over the range of impact velocity. Honeycomb sandwich structures are used in aerospace industries where mass efficient and impact resistant structures are needed. However, the structural integrity of these structures is reduced by impact load due to tool drop, runway debris, hailstones and improper handling of the structure. A thorough investigation of the damage behaviour of honeycomb sandwich under low-velocity impact and the post-impact residual strength determination is required to design a crashworthy lightweight structure. This paper presents the experimental evaluation of specific energy absorption using Charpy impact, residual compressive strength by Compression after impact and damage evaluation of honeycomb sandwich structures having composite face sheets. Parametric studies on composites and honeycombs are carried out by varying the cell size, cell thickness, core height, impact velocity, thickness and orientation of lamina. Densely packed thick honeycombs provide higher fracture energy. Under transverse compressive loading, the honeycomb core undergoes cell wall buckling, crushing and densification. Load-displacement history under in-plane Compression and Compression after impact for different impact energies is observed. The present study contributes for the understanding how various parameters affect the characteristics of face sheet indentation and plastic buckling of honeycomb sandwich structures with composite face sheets, thereby providing useful guidelines for its potential applications in impact engineering.

Introduction: Bleeding, hematoma and cyanosis in the arterial catheter site are considered the most important complications after coronary artery angiography. A method in which homeostasis can result faster and patient can walk sooner should be found. Therefore, this study aimed to compare two methods of sandbags and transparent film dressings to reduce complications after coronary artery angiography.Methods: This quasi-experimental study was conducted on 80 eligible patients at Shafa Hospital in Kerman, Iran. after angiography, the patients were randomly divided into two groups (n=40), a transparent film dressing and traditional dressing with sand bags groups. Transparent Talc and ECG paper, a 10-cm ruler, in the range of zero to ten, and the blood-soaked film weight (weight before and after angiography), were respectively used to measure cyanosis, the pain intensity and the amount of bleeding.Results: No bleeding was observed in patients using transparent film dressing. after coronary angiography, the intensity of back pain and groin pain in patients using traditional dressing with sand bags was higher than in those using the transparent film dressing. Cyanosis was the same in both groups.Conclusion: Transparent film dressing is advised because of its impact of on reduction of complications after angiography, and also flexibility, semi-permeability, convenience, simplicity of usage and visibility.

Background: Chronic diabetes is substantially associated with circulatory disorders in lower limbs. Vacuum-Compression Therapy (VCT) has been commonly used in treatment of peripheral circulatory disorders. VCT is based on intermittent alteration of Positive- Negative pressure phases. The purpose of this study was to determine effects of VCT on diabetic subjects' peripheral blood flow.Methods: In this Before-after and case-series study, 18 type 2 diabetic subjects with diabetic neuropathy and/or peripheral vascular disease (PVD) completed the study. Subjects received 45 min of VCT for 10 sessions three times weekly. Blood flow (calf+foot) was measured via venous occlusion plethysmography.Results: Among Variables of "Arterial Inflow", "Venous Outflow", "Venous Capacity", "Postischemic Reactive Hyperemia" and "Peak Flow of Reactive Hyperemia", only "Venous Outflow" significantly improved after 10 sessions treatment via VCT (P<0.05).Conclusions: Arterial blood inflow, which was the most important determinant evaluated in this study, was not increased via VCT. Additional studies are required to investigate the effective VCT parameters and duration of each session and number of sessions, considering progressive and deteriorative natural history of diabetes.

Background: In the patients with osteoporotic vertebral Compression fracture (OVCF) treated conservatively, significant progressionof the local kyphosis due to an impaired healing leads to reduction in the quality of life. Thus, it is of critical value to identifythe predictors of this major complication. Objectives: The current prospective cohort study aimed at evaluating the predictors of progression in the local kyphosis in a seriesof patients with acute OVCF undergoing conservative treatment. Methods: Eligible patients with OVCF were identified and local kyphosis progression was evaluated after four months of conservativetreatment. Demographic characteristics such as gender, age, and body mass index (BMI), as well as radiographic characteristicssuch as the location of fracture, bone mineral density (BMD), andserum25 (OH) vitaminDlevel were compared between the patientswith local kyphosis angle (LKA) progressed 30° (group A) and the patients with LKA remained < 30° (group B). Results: From a total of 60 patients with OVCF, LKA progressed  30° in 19 patients (31. 7%). The mean change of LKA was 16. 2°  7. 2° in group A and 1. 92°  2. 7° in group B (P < 0. 001). Higher age, lower BMI, and lower spinal BMD were significantly associatedwith LKA progression  30° (P = 0. 013, P < 0. 001, and P = 0. 037, respectively). The involvement of thoracolumbar junction (T11-L1)was more frequent in group A (P = 0. 049). Anterior cortical wall fracture was more frequent in group A as well (P = 0. 007). afteradjustment of confounding factors, the association of LKA progression with the age, BMI, and the level of fractured vertebra stillremained significant. Conclusions: Significant progression of LKA following conservative treatment of OVCF is correlated with the level of fractured vertebra, BMI, and age of the patients. These factors could be used to select patients most benefit from conservative treatment.

Protective steel doors are widely used in buildings due to their high resistance against the impact loads. However, its heavy weight has been always considered as a major drawback for these doors. In this paper, a new optimized stiffened impact-protective steel door incorporating sandwich panel with aluminum foam core (OSSA) is examined. This door consists of two face sheets, main and secondary stiffeners, and aluminum foam as the inner core. In order to optimize the door, at first the rigidity and weight functions of the stiffened steel door were extracted. Then an optimal door weighing 42% less than the primary door was obtained. Due to the high energy absorption capacity of the combined foam core and stiffened steel door structure, the use of aluminum foam core in the optimized steel door was proposed. By doing numerical analysis, and depending on the thickness of the face sheet of OSSA, 20 to 32% reduction in the maximum displacement was observed. The results also showed that, with 67% increase in the peak overpressure, OSSA has kept almost the same maximum displacement as that of the steel door without an aluminum foam. In other words, by using aluminum foam core in the optimized stiffened door, the door will resist 67% more impact load.

Percutaneous vertebroplasty is a promising therapeutic technique for pain control in patients with pathologic fractures of vertebral bodies. Percutaneous vertebroplasty is an appropriate treatment for vertebral pathologic fractures, which is resistant to other usual treatment. It is a useful and only choice in special cases, because of less tissue damage and there is no risk of open surgery and patient's embolization is rapid. Herein we described the first case of percutaneous vertebroplasty in Yazd shahid sadoughi teaching hospital, which was done in ordybehesht 1386 in a 72 years old male with pathologic fracture of 2 lumbar vertebrae. He was suffered from pain and disability and open surgery was not appropriate treatment for him.