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A technique is developed for obtaining the solution of second order over-damped non-linear systems based on the Krylov-Bogoliubov-Mitropolskii (KBM) method for small ratio of the eigenvalues. The solution is also useful for large ratio of the eigenvalues. The method is illustrated by an example.

Introduction: Myocardial infarction is one of the most serious pathological condition in which the heart is irritated, inflamed and influenced by multiple factors to cause high mortality and morbidity in the developed and underdeveloped countries. Objectives: To see correlation between Electrocardiographic left ventricular hypertrophy and adverse outcome following acute myocardial infarction in hypertensive patient. Materials and Methods: A Cross sectional analytical study was carried out at the Department of cardiology, Mymensingh Medical College Hospital, Mymensingh Bangladesh from March - 2014 to February- 2015. Patients admitted into cardiology department with Acute Myocardial Infarction with hypertension who fulfill the inclusion and exclusion criteria of the study. Due to time and cost limitation, 65 cases were selected. Results: A total number of sixty five patients were studied of which 56(86.15%) were male and nine (13.84%) were female. The age range was 40 to 70 years. Mean age of male was 52.9±8.4 and female was 56.5±7.5. The patients were divided into two groups on the basis of presence of absence of electrocardiograph left ventricular hypertrophy. All patients had myocardial infarction with evidence of hypertension at admission or known case of hypertension. Group A consisted of 38 patients (58.45%) with ECG-LVH and group B with no ECG_LVH consisted of 27 patients (41.55%). The mean age of group A was 54.25 ±8.9 and group B was 52.55 ± 8.15. Majority patients (34) belonged to 40-50 years age group (52.30%). Twenty one patients belonged to 51-60 years group (32.30%). Ten patients belonged to 61-70 years age group (15.4%), male: female ratio was 6.2: 1. Out of total 68 patients, 43 patients (64.42%) had hypertension on admission and 24 cases (35.38%) had normal blood pressure on admission. Of the 38 patients of group A, 24 had anterior myocardial infarction (63.15%) and 14 had inferior myocardial infarction (36.84%) and 7 had both anterior and inferior myocardial infarction (10.76%). The statistical analysis was highly significant in between group A & group B. The incidence of QMI was highly significant (P=

Background: There are many types of arthritis, but osteoarthritis (OA) is one of the most frequent. IA injections of corticosteroids into the knee joint may improve pain and impairment by relieving joint inflammation. Purpose: To evaluate the effectiveness and safety of hylastan, a novel viscosupplements, with a single intra-articular corticosteroid injection in the treatment of knee osteoarthritis pain (OA). Because of its large molecular weight, the sodium hyaluronate in Hylastan is more likely to stay in the joint for an extended period of time than other viscosupplements. Methods: Multicentered based randomized quasi-experimental comparative study was performed in Shah Mokhdum Medical College, Rajshahi, Bangladesh, from January 2019 to December 2021. Enrolled patients aged ≥40 years. Patients were randomized 1:1:1 to one of three arms: 2 X 4 mL hylastan (n = 129; arthrocentesis then IA hylastan Day 0, same treatment Week 2); 1 X 4 mL hylastan (n = 130; arthrocentesis then IA hylastan Day 0, arthrocentesis only Week 2); steroid (n = 132; arthrocentesis then IA methylprednisolone acetate 40 mg Day 0, arthrocentesis only Week 2). The primary clinical outcome measure was changed from baseline in WOMAC A pain score overall postbaseline visits to Week 26. Results: Statistically significant pain reduction was observed in all three arms, with similar mean (95 % CI) changes in WOMAC A: 2 X 4 mL hylastan -0.9 (-1.0, -0.7); 1 X 4 mL hylastan -0.8 (-0.9, -0.7); steroid -0.9 (-1.0, -0.8); all p < 0.0001 versus baseline. Changes in secondary outcomes were similar in all three arms. Target knee adverse events were comparable for all treatments. Conclusions: An acceptable safety profile and effective pain relief were found with both IA hylastan injection regimens. The hypothesis of better pain relief with IA hylastan was not met compared to IA corticosteroid. The effectiveness and safety of hylastan compared to other viscosupplements require more investigation. Level of evidence Therapeutic study, Level I.

Treatment of infected gap non-union of tibia occurring mostly after trauma and often complicated by infection is difficult to treat. Daily clinical practice in fixation, soft tissue management, and antibiotic therapy, treating infected gap nonunion of the tibia remains a problem for Orthopaedic surgeons. Management includes thorough debridement, stabilization of the fracture, and reconstruction of the bone defect. The study's goal was to evaluate the Ilizarov fixator frame's effectiveness in treating tibial gap nonunion.

Background: Diabetes mellitus (DM) is a complex and heterogeneous chronic metabolic disease caused by elevated levels of blood glucose. Although myocardial ischemia is known to be significantly related to the development of coronary collateral vessels (CCVs), there is considerable variation between patients with ischemic heart disease in the presence of collateral development. Methods: This observational study was done in Department of Cardiology, Mymensingh Medical College Hospital, Bangladesh from January to December 2020. Out of 110 patients who had a stenosis of >95% in any major coronary artery in angiograms were included in the study. Of these patients, 35 patients constitute the diabetic group. Remaining 75 patients were non-diabetic. For case-control matching, 35 non-diabetic patients (mean age, 52.03± 8.69 years) were selected randomly and were included in the control group. The CCVs were graded according to the Rentrop scoring system, and the collateral score was calculated by summing the Rentrop numbers of every patient. Results: There was no statistical difference between patients with and without DM in clinical baseline characteristics. The mean number of diseased vessels in the DM group (2.10±0.76) was higher than that in the nondiabetic group (1.63± 0.72 P.017). The mean collateral score was (1.13± 0.86) in the DM group and (1.97± 1.61) in the control group. After confounding variables were controlled for, the collateral score in the diabetic group was significantly different from that in the nondiabetic group (p=0.015). Conclusion: Our findings suggest that CCV development is poorer in patients with DM than in patients without DM. Thus, we can speculate that DM is an important factor affecting CCV development.

Introduction: An estimated 30% of all general follow-up are due to osteoarthritis (OA). For decades, medical experts have used intraarticular (IA) corticosteroid injections to treat the pain and inflammation associated with osteoarthritis (OA). Objective: To evaluate the patient's functional improvement and clinical result, Evaluations of Intraarticular Steroid Injection Therapy in Osteoarthritis Knee were conducted. Methods: A prospective interventional non-randomized clinical study was conducted in the Department of Orthopaedic surgery, Rajshahi Medical College & Hospital, Bangladesh, from June 2019 to December 2020. A total number (n=54) of patients between 35 and 75 years with knee discomfort for at least three months with radiographic evidence of primary osteoarthritis, male or female, were included in the study. Then, they were split into A and B groups. They had 27 patients in each group, with each group being assigned a random number. There were 6 weeks of follow-up in both groups of patients. Results: 9 (33.3%) were male in group A, and 18 (66.7%) were female. In group B, 10 (37.0%) were male and 18 (63.0%) were female. The mean visual analogue scale (VAS) in group A and group B during pre-treatment were 6.22±1.60 and 7.15±1.56, respectively. The mean age of patients in groups A and B were 52.33±9.62 years and 52.29±9.67 years, respectively. The mean range of motion (ROM) during pre-treatment in group A and group B were 117.33±13.05 and 112.37±19.01, respectively. Meantime taken to walk 50 feet during pre-treatment in group A and group B were 18.22±2.39 and 18.81±2.13 minutes, respectively. After treatment in both groups, visual analogue scale (VAS), range of motion (ROM), time taken to walk 50 feet and range of motion (ROM) gradually increased, which were statistically significant. Conclusion: Steroid injection remains a regular feature in the management of osteoarthritis, particularly osteoarthritis of the knee, despite the lack of strong, ...............

Fusion-bonded epoxy-coated steel is expected to extend the service life of the reinforced concrete structure in chloride-laden environments. However, the effect of coating on the bond-strength between rebar and concrete is not well understood yet. This research, therefore, studied the effect of epoxy-coating on the bond characteristics of reinforcing bars in concrete. The bond characteristics were assessed through pullout test considering variables viz. concrete strength, embedded length and bar diameter. The load was applied to reinforcing bars embedded in concrete until bond strength between the bar and concrete exceeded. Bond strength of epoxy-coated bars was compared with that of the uncoated bars. It was found that epoxy-coating reduced the bond strength approximately 25% for Ø20mm bar and 12% for Ø16mm and Ø12mm bar. As with uncoated bar, bond strength of coated bars were also increased with concrete strength. However, the bond strength ratio between coated and uncoated bars was found almost independent of concrete strength. Based on the test results, a development length modification factor of 1.33 is proposed for Ø20mm bar and 1.15 for Ø12mm and Ø16mm bar to compensate the bond strength reduction due to the epoxy coating.

In most of the inventory models, a single stock is considered from where items are served for the customers. In this paper, two stocks are considered. One is for fresh items and another is for returned items. The model is more appropriate where warranties are provided for a fixed time duration. Moreover, inventory which are kept to the stock may not have finite shelf-life is also considered here such as milk, meat, vegetables, radioactive materials, volatile liquids. In this current model, we considered the inventory is decayed in a constant rate θ. It is assumed that inventory level for both the fresh and returned items are pre-determined. When inventory level reaches at s, a replenishment takes place with parameter ϒ The demands that arrive for fresh items and returned items follow Poisson process with parameter λ & δ respectively. Service will be provided with Poisson process for returned items with parameter μ. The joint probability distribution for inventory level of returned items and for fresh items is obtained in the steady state analysis. Some systems characteristics of the model are derived and the results are illustrated with the help of numerical examples. The Chittagong Univ. J. Sci. 40(1) : 59-74, 2018

In most of the inventory models, a single stock is considered where items are served for the customers. In this paper, two stocks are considered for efficient stock management, One is for fresh items and another is for returned items. Two models are considered here, first model is developed for non-perishable items where the second one is for perishable items. The models are more appropriate where warranties are provided for a fixed time duration after sale for fresh items. Moreover, inventories whose are kept in the stock may not have finite shelf-life that are also considered here in model-II such as milk, meat, vegetables, radioactive materials, volatile liquids. In model-II, we have considered that the inventory decay in a constant rate $\theta $. It is assumed that inventory level for both the fresh and returned items are pre-determined. When inventory level reaches at re-order point s, a replenishment takes place with parameter $\gamma $. The demands that arrive for fresh items and returned items follow Poisson process with parameter $\lambda $ $\&$ $\delta $ respectively. Service will be provided with Poisson process for returned items with parameter $\mu$. The joint probability distribution for inventory level of returned items and for fresh items are obtained in the steady state analysis. Some systems characteristics of two models are derived here and the results are illustrated with the help of numerical examples.

Transportation problem is an integral part of this competitive world. Minimizing transportation cost of a product from sources to destinations is the main objective of traditional transportation problems. In the present context single objective transportation problem fails to meet the managerial decision making requirements which demands the multi objective transportation problems. Many real life problems can be formulated as multi objective transportation problem, and their solution requires consideration of conflicting objectives. Naturally, these problems have a number of potentially Pareto-optimal solutions. Multi-objective transportation problem refers to a special class of vector minimum linear programming problem, which usually involves multiple, conflicting, and incommensurable objective functions. Solving these complexities, the decision maker has to develop a utility function. In this paper, we develop a utility function to attain the targeted goal for a multi objective transportation problem. This utility function is developed using fuzzy membership functions considering deviations of objective function from the goal value where deviation variable has chosen as fuzzy type. Moreover, fuzzy max-min operator has been included for taking limiting value of the objective functions. Performance of the utility function to achieve proper goal is evaluated and justified by solving numerical examples using fuzzy goal programming.

In this paper, the influence of Joule heating and magneto-hydrodynamics on mixed convection in a lid-driven cavity along with a heated hollow circular plate placed at the centre of the square cavity is investigated. The governing equations which are derived by considering the effects of both Joule heating and magneto-hydrodynamics are solved via the penalty finite-element method with the Galerkin-weighted residual technique. The effects of the Richardson number and Hartmann number arising from the MHD and Joule heating on the flow and heat transfer characteristics have been examined. The results show that the flow behavior, temperature distribution and heat transfer inside the cavity are strongly affected by the presence of the magnetic field. On the other hand, only the temperature distribution and heat transfer inside the cavity are strongly affected by the Joule heating parameter. The results also show that if the Hartmann number is increased from 5 to 100 then the heat transfer detraction is 20%, and if the Joule heating parameter is increased from 1 to 5 then the heat transfer detraction is 58%. In addition, multiple regressions among the various parameters are obtained.

A numerical investigation is performed to study the effect of thermal radiation on magnetohydrodynamic (MHD) free convection flow along a vertical flat plate in presence of variable thermal conductivity in this paper. The governing equations of the flow and the boundary conditions are transformed into dimensionless form using appropriate similarity transformations and then solved employing the implicit finite difference method with Keller-box scheme. Results for the details of the velocity profiles, temperature distributions as well as the skin friction, the rate of heat transfer and surface temperature distributions are shown graphically. Results reveal that the thermal radiation is more significant in MHD natural convection flow during thermal conductivity effect is considered. To illustrate the accuracy of the present results, the results for the local skin fraction and surface temperature distribution excluding the extension effects are compared with results of Merkin and Pop designed for the fixed value of Prandtl number and a good agreement were found.

In this study, ductile mode cutting of silicon wafer materials has been carried out using an ultra-precision lathe with single crystal diamond cutters and the wear characteristics of the tool and the effect of its different diamond crystal orientations were investigated. Experimental results indicated that wear occurred mainly on the flank face of the tool and the wear pattern was typically mechanical abrasive wear, adhesive wear and possible thermo-chemical wear. At higher cutting distance, crater wear with small grooves in the vicinity of cutting edge was observed on the tool rake face. However, given the highly anisotropic nature in properties of diamond, wear resistance of a diamond tool varies with the crystal planes as well as crystal directions on the same plane. From this study, it is found that in terms of tool flank wear (VBmax) resistance, the tool life of the diamond cutter with crystal orientations {1 0 0} as the rake and {1 1 0} as the flank planes, was much longer than those of the diamond cutters with other crystal orientations as the rake and flank planes.

Wear in diamond tools is a crucial factor in ultra-precision machining. However, as is well known, single crystal diamond possesses strong anisotropy. Its mechanical and physical properties vary with crystallographic orientation. In this study, tool wear investigation was carried out on nano-scale ductile cutting of silicon using an ultra-precision lathe with single crystal diamond tools. The wear characteristics of single point diamond tools and the effect of diamond crystallographic orientation were investigated. Experimental results indicate that gradual wear occurred mainly on the flank face of the tool. A very smooth wear mark on the rake face was also seen. The machining data show that wear resistance of the tool and tool life were greater when the crystallographic orientation of the rake face was {1 1 0} than when it was {1 0 0} or {1 1 1}. The thrust force on the diamond tool was lower when the rake face crystallographic orientation was {1 1 0} than when it was some other orientation. For all the crystallographic orientations studied in the diamond tools, gradual tool flank wear had no significant effect on the surface roughness of machined silicon work material.

The process of learning the alphabet of a language can be made interesting to the young learners by adopting an audio-visual approach. This paper describes the development of an audio-visual alphabet learning system using a sound card in a PC. The advantages of this approach are outlined, and some possible extensions to this work are suggested.

Kinematic errors due to geometric inaccuracies in five-axis machining centers cause deviations in tool positions and orientation from commanded values, which consequently affect geometric accuracy of the machined surface. As is well known in the machine tool industry, machining of a cone frustum as specified in NAS979 standard is a widely accepted final performance test for five-axis machining centers. A critical issue with this machining test is, however, that the influence of the machine's error sources on the geometric accuracy of the machined cone frustum is not fully understood by machine tool builders and thus it is difficult to find causes of machining errors. To address this issue, this paper presents a simulator of machining geometric errors in five-axis machining by considering the effect of kinematic errors on the three-dimensional interference of the tool and the workpiece. Kinematic errors of a five-axis machining center with tilting rotary table type are first identified by a DBB method. Using an error model of the machining center with identified kinematic errors and considering location and geometry of the workpiece, machining geometric error with respect to the nominal geometry of the workpiece is predicted and evaluated. In an aim to improve geometric accuracy of the machined surface, an error compensation for tool position and orientation is also presented. Finally, as an example, the machining of a cone frustum by using a straight end mill, as described in the standard NAS979, is considered in case studies to experimentally verify the prediction and the compensation of machining geometric errors in five-axis machining.

Kinematic errors due to geometric inaccuracies in 5-axis machine tools cause deviations in tool positions and orientation from commanded values, which consequently affect geometric accuracy of the machined surface. The present research work studies the prediction of machining accuracy of a 5-axis machine tool with its kinematic errors. First, kinematic errors associated with linear and rotary axes of a 5-axis machine tool with tilting rotary table types, are identified by a DBB method. By using an error model of the machine tool, erroneous tool position and orientations are computed. Then, machining error with respect to the nominal geometry is predicted and evaluated. With the aim to improve the geometric accuracy of a machined surface, an error compensation for tool position and orientation is also presented. As an example, the machining of a tilted taper cone by using a straight end mill, as described in the standard NAS979, is considered in a case study to experimentally verify the prediction and the compensation of machining errors in 5-axis machining.