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The Covid-19 pandemic has inherently affected daily lives of people around the world. We, the people, have already started to live in a new-normal way, such as wearing masks, keeping a safe distance from others and maintaining higher level of health & hygiene standards. However, because of this pandemic, the global economy has taken a major blow. Many people have lost their livelihood, and now facing challenges in getting better healthcare facilities and food for survival. Given the serious challenges to the problem, this paper analyzes demographic data to predict vulnerable areas in Kolkata metropolitan city that houses nearly one-third of its population in slums and one-fifth below poverty level, under compromised living conditions. The analysis revealed that the highest risk areas are located in the east and west of the city, the area to a great extent overlapped with wards containing larger share of population below poverty level and are also living in slums. The analysis of publicly accessible Covid-19 case records and containment zones data indicate the hardest hit areas lies in the central Kolkata and several wards along the eastern and northeastern border of the Kolkata Municipal Corporation. The data further revealed that the virus infections have extended to the south Kolkata with increasing number of ‘broad-based’ containment zones with heightened cases. The analysis of demographic characteristics of the hardest hit wards revealed that not a single variables are directly associated with the increase in the number of containments for a particular ward. The ranking of wards based on four intervention criterion have suggested that the ‘lack of social awareness’ along with ‘lack of social distancing’ have dominantly contributed to the increasing number of containments of Covid-19 cases in Kolkata. Determination of optimized ranking and Spearman’s rank correlation coefficient of the wards based on four intervention criterion provided a basis for the policy makers to assess ward-based interventions criterion to control further spread of the disease and/or prevent second wave of infections. Given that the effective antiviral drugs is far away from common publics reach, the application of our study approach would benefit saving lives of many vulnerable populations.

The present study depicts the geospatial relation between basinal geomorphology and heterogeneous arsenic (As) distribution in the Bengal Delta Plain (BDP). The distribution pattern largely varies throughout the study area (higher: Karimpur-II AsT average 214.73 μgL−1; lower: Tehatta AsT average 27.84 μgL−1). Both safe (low As) and unsafe (high As) areas are identified within the single shallow aquifer (

Stress shielding due to difference in stiffness of bone and implant material is one among the foremost causes of loosening and failure of load-bearing implants. Thus far, femoral geometry has been given priority for the customization of total hip joint replacement (THR) implant design. This study, for the first time, demonstrates the key role of bone condition and subject-weight on the customization of stiffness and design of the femoral stem. In particular, internal hollowness was incorporated to reduce the implant stiffness and such designed structure has been customized based on subject parameters, including bone condition and bodyweight. The primary aim was to tailor these parameters to achieve close to natural strain distribution at periprosthetic bone and to reduce interfacial bone loss over time. The maintenance of interfacial bone density over time has been studied here through analysis of bone remodeling (BR). For normal bodyweight, the highest hollowness exhibited clinically relevant biomechanical response, for all bone conditions. However, for heavier subjects, consideration of bone quality was found to be essential as higher hollowness induced bone failure in weaker bones and implant failure in stronger bones. Moreover, for stronger bone, thinner medial wall was found to reduce bone resorption over time on the proximo-lateral zone of stress shielding, while lateral thinning was found advantageous for weaker bones. The findings of this study are likely to facilitate designing of femoral stems for achieving better physiological outcomes and enhancement of the quality of life of patients undergoing THR surgery.

The objective is to make the strain deviation before and after implantation adjacent to the femoral implant as close as possible to zero. Genetic algorithm is applied for this optimization of strain deviation, measured in eight separate positions. The concept of composite desirability is introduced in such a way that if the microstrain deviation values for all eight cases are 0, then the composite desirability is 1. Artificial neural network (ANN) models are developed to capture the correlation of the microstrain in femur implants using the data generated through finite element simulation. Then, the ANN model is used as the surrogate model, which in combination with the desirability function serves as the objective function for optimization. The optimum achievable deviation was found to vary with the bone condition. The optimum implant geometry varied for different bone condition, and the findings act as guideline for designing patient-specific implant.

Homing head of missile or Seeker is having limited gimbal freedom due to physical constraints. For intercepting manoeuvring high speed target with different engagement scenario, it is essential to control and keep this gimbal angle requirement well within the gimbal freedom limit of seeker. This is proposed to be achieved by incorporating gimbal angle constraint in PN guidance law. The gimbal angle constrained PN guidance proposed in this paper avoids seeker track loss by protecting gimbal angle freedom within it's limit and without affecting guidance errors. The performances improvement of the proposed scheme over the basic PN are established through 6-DOF simulations for different engagement scenario and presented in this paper.

Pelvic injuries and fractures (abbreviated injury scale > 2) are caused by intrusion of car door structure during motor vehicle side impacts. The objective was to simulate automotive side impact situation for the occupant. This was performed with a computed tomography scan-based three-dimensional finite element (FE) model of human pelvis–femur–soft tissue complex with spring–dashpot–mass representation of whole body, using wide range of mechanical property variations. It was impacted with a 12-kg rigid impactor at 13.54 m s–1 to impart impact energy of 1100 J. The pelvic fracture condition was well-examined by the peak impact force (16.98 kN), peak strain (23.4%) and peak stress (189 MPa). It was concluded that this FE model could reconstruct clinically observed pelvic injury. Moreover, this FE model could reduce the need for modelling the complex whole body with a huge number of elements and nodes when pelvic fracture is the area of focus. Furthermore, this detailed FE model may be used for finding out d...

Objectives: Injuries due to hot-air ballooning accidents are uncommon but may be severe. In this study we examined the factors contributing to ballooning accidents in the UK and the type of injuries sustained. Methods: The post-investigation reports of ballooning accidents from 1976 to 2004 were reviewed. They were analysed to determine type and severity of injuries, phase of flight at time of accident and causative or contributory factors. Results: Sixty-one people were seriously injured in 98 ballooning accidents, with 2 fatalities. The majority of these accidents occurred during the approach and landing phase of flight. Ground collisions and crashes with power lines accounted for the majority of accidents. Adverse weather conditions were present in a significant number of crashes. Equipment failure was an uncommon cause of accidents. Fractures and burns were the most common form of injuries sustained. Conclusions: Changes in design and materials used, as well as adherence to specific recommended safety protocols, may aid to decrease the risk of severe burns in ballooning accidents. We discuss these factors illustrated by our experience of the worst recorded ballooning accident in Britain.

The pelvis is most susceptible to severe fractures in side impacts, arising from motor vehicle crashes. In recent years, car manufacturers are providing more importance to the protection of occupants in lateral impacts. This study was aimed to understand the dynamic response of the pelvis and establish its fracture threshold, using a three-dimensional finite element model, with 13,070 tetrahedral (trabecular bone) and 5,820 shell (cortical bone) elements through 3,704 nodes. These elements take care of bending stress due to out of plane loading. After a detailed modal analysis, thirty-eight load cases were simulated by varying the intensity of impact load, impact duration and density ( i.e . inertia effect) of bones, with 65% of the body weight acting on the sacrum. It was observed that the failure threshold load was near 3 kN. With better design of car-door and hippad, if side impact force was brought down to 3 kN (approximately), then the peak stress (162 MPa at 5 ms of impact time to peak load), within the pelvis, would not exceed the average compressive strength for the cortical bone.

The number of individuals who experience lumbar disease or pain is steadily increasing. Interventions of surgery and implantation are also becoming popular remedial measures. However, the rate of failure after lumbar fusion is also a matter of concern. In this study, finite element models of both the natural healthy lumbar spine (L3-L4-L5) and the implanted lumbar spine were developed. Analyses were performed by using varying implant material, as well as with and without a bone graft between L4-L5. The natural lumbar spine with an intervertebral disc complex showed the expected stress contour for different load cases. We observed that implants made of stainless steel with a bone graft at L4-L5 performed better among the all implantation cases. Titanium alloy may also be an acceptable implant, but has not shown satisfactory results. Without placing a bone graft, implantation led to the generation of a very high stress level at all components for all cases, which was totally unsafe.

A dynamometer was developed indigenously to measure the punching force accurately, especially for all weight groups of boxers. The results were also compared with the help of a computed tomography based finite element simulations.

A coal seam is usually sandwiched between two relatively stronger beds: the roof and floor. Drivage of a rectangular roadway into coal creates a different mining stress situation than that appearing in homogeneous and isotropic rocks with circular, elliptical or rectangular openings. In the present paper, the vertical stress distribution in coal forming the side of a rectangular roadway has been derived, taking into account some assumptions and applying the principle of a “beam on an elastic foundation”. The change of the state of confinement of coal from biaxial at the edge of the roadway to triaxial inbye has been accounted for in the method and the result is the reduction of the maximum vertical stress at the roadway side compared to a continuous biaxial or triaxial confinement. The stress distribution curves using different parameters are presented and the influence of some of parameters on the maximum vertical stress has been analysed.

A case study of an opencast mine is presented where work is being carried out using an interconnected system, with mined ore fed directly to a processing plant. Breakdowns in the mining process or in the plant affect the overall mine production. To separate the two interconnected units, an intermediate stockpile before the primary crusher of the plant has been proposed. The stockpile should be of an adequate capacity to provide the necessary coverage for the breakdowns, but should not be too large or rehandling costs will be too high and it will take up too much space. The minimum size of the stockpile required has been estimated using detailed statistical analysis.

A major worldwide health problem is hip fracture due to sideways fall among the elderly population. The effects of sideways fall on the hip are required to be investigated thoroughly. The objectives of this study are to evaluate the responses to trochanteric soft tissue thickness (T) variations and hip impact velocity (V) variations during sideways fall based on a previously developed CT scan derived 3D non-linear and non-homogeneous finite element model of pelvis-femur-soft tissue complex with simplified biomechanical representation of the whole body. This study is also aimed at quantifying the effects [peak impact force (F(max)), time to F(max), acceleration and peak principal compressive strain (epsilon(max))] of these variations (T,V) on hip fracture. It was found that under constant impact energy, for 81% decrease in T (26-5mm), F(max) and epsilon(max) increased by 38% and 97%, respectively. Hence, decrease in T (as in slimmer persons) strongly correlated to risk for hip fracture (phi) and strain ratio (SR) by 0.972 and 0.988, respectively. Also under same T and body weight, for 75% decrease in V (4.79-1.2m/s), F(max) and epsilon(max) decreased by 70% and 86%, respectively. Hence, increase in V (as in taller persons) strongly correlated to phi and SR by 0.995 and 0.984, respectively. For both variations in T and V, inter-trochanteric fracture situations were well demonstrated by phi as well as by SR and strain contours, similar to clinically observed fractures. These quantifications would be helpful for effective design of person-specific hip protective devices.

Burns as a consequence of non-suicidal self-harm are commonly small-localised burns due to varied aetiology [1,2]. We report an unusual case of a self-inflicted burn caused by the inappropriate administration of a bronchodilator inhaler. A 22-year-old Caucasian woman deliberately discharged approximately 40 blasts of her Salbutamol inhaler in rapid succession, with the nozzle of the inhaler placed directly onto the skin of her left hand. She had a past history of deliberate self-harm and admitted intent to self-harm on this occasion. On presentation to hospital the next day she had a 3 cm diameter area of blistered, insensate skin with surrounding erythema on the dorsum of the first web space. (Fig. 1) A diagnosis of full thickness burn was made. The patient was referred to the deliberate self-harm psychiatry liaison team. The wound was treated successfully with regular dressings over a period of 4 weeks.

Pelvic injuries and fractures, caused by intrusion of car door structure due to car side impacts, are a serious problem worldwide. A 'car door padding', modelled with expanded polystyrene foam (EPS), is suggested in this study. This padding, formed with five layers of foams with different stiffness, is to be incorporated between the car door interior and outer body surface, around greater trochanter location of the occupant for protection from pelvic fracture (pubic rami fracture). To simplify the situation, in this finite element study the padding was fitted with a rigid impactor to hit the previously developed finite element model of the pelvis-femur-soft tissue complex with simplified representation of the whole body in occupant posture. It was observed that this padding has the capacity to reduce the risk of pubic rami fracture in case of car side impact for the occupants with the attenuation of peak impact force by 63% and a considerable reduction in peak strain by 91%. For the five-layered padding, the non-linear stiffness variations of EPS ('high to low' or 'low to high' across the pad thickness) also have an effect on the peak impact force, though less pronounced and it can be concluded that 'low to high' combination is preferred over 'high to low' combination.

An experimental validation with the pelvic bone or human cadaver has always been considered as a gold standard to assess the accuracy of the finite element predictions. The present study provides an approach in mechanical testing of pelvic bone and human cadaver under side impact load for the purpose of validating the previously developed finite element models of pelvis-femur complex and pelvis-femur-soft tissue complex, respectively. An experimental setup was designed and developed, instrumented with miniature piezoelectric load cell and miniature charge amplifier. PC based data acquisition system was used to record the impact force-time data. The support conditions of the experiments were applied on the finite element model and simulated under similar impact load. Considering all the load cases with pelvic bone and human cadaver, high correlation (r² = 0.966) and significance level (p < 0.0001) were obtained between the experimental and finite element results. It strongly suggests that the numerical results calculated by the finite element models could be used as a valid predictor of the actual results.

The lumbar inter-vertebral joint (L4-L5) performs a very important role in transferring load from the upper portion of the body to the lower part, especially during bending activities. Failure such as bone fracture, tissue damage, disc rupture, etc. occurs very often in this region. Stress distribution patterns are very useful for evaluation of such failure. A three-dimensional finite element model of lumbar vertebral joint (L4-L5) along with an intervertebral disc was created. The geometry was based on standard literature and compared physically. For meshing cortical bone, 8-noded shell elements were used and 10-noded tetrahedra were used for meshing cancellous bone and intervertebral disc. The finite element model contained different isotropic material properties for different regions. The finite element model contained 105,876 elements, connected through 136,974 nodes. Stress analyses were done for different loading conditions such as axial compression of 2,000 N, bending moments for flexion with magnitudes of 5, 10, 15 and 20 Nm and lifting weight in hand with varying magnitude (20-80% of the body weight) and inclination (15°-90°) of the body with the vertical axis (0° for vertical body and 90° for horizontal body). The results were compared with previous similar type of studies, carried out by different researchers. This finite element model may be useful in clinical application for fracture assessment and spinal instrumentation.