An Analytical Approximation for the Excess Noise Factor of Avalanche Photodiodes with Dead Space

Approximate analytical expressions are derived for the mean gain and the excess noise factor of avalanche photodiodes including the effect of dead space. The analysis is based on undertaking a characteristic-equation approach to obtain an approximate analytical solution to the existing system of recurrence equations which characterize the statistics of the random multiplication gain. The analytical expressions for the excess noise factor and the mean gain are shown to be in good agreement with the exact results obtained from numerical solutions of the recurrence equations for values of the dead space reaching up to 20% of the width of the multiplication region

Assessment of risks in conditions of provision of security of economic activities of organizations

The study of the evolution of the economic security of the business entity has shown that at the present stage of economic development it is important to consider the factors of influence on economic security, in particular: the effectiveness of management, personnel and financial safety, a strategic approach to the functioning of the communication system of protection, taking into account the evolution of security and active search for innovative modern domains of development of industrial organizations and increase of the responsibility of performers for the consequences of their work. This allows to reduce the risk of loss of economic safety of the business entity. It was argued that innovative conceptualization of risk as a probable threat of losses lies within the scope of activity of managers of various units and has features of probable economic and objective-subjective nature, as well as a wide range of variability of the impact on the issues of economic safety and is conditioned by the dynamic development of important societal significant economic processes at the global and national levels, which ultimately contributes to enhancement of the organization’s competitive advantages

Viability of Rice Husk Ash Concrete Brick/Block from Green Electricity in Bangladesh

As a developing country, Bangladesh has to face numerous challenges. Self Independence in electricity, contributing to climate change by reducing carbon emission and bringing the backward population of society to the mainstream is more challenging for them. Therefore, it is essential to ensure recycled use of local products to the maximum level in every sector. Some private organizations have already worked alongside government to bring the backward population to the mainstream by developing their financial capacities. As rice husk is the largest single category of the total energy supply in Bangladesh. As part of this strategy, rice husk can play a great as a promising renewable energy source, which is readily available, has considerable environmental benefits and can produce electricity and ensure multiple uses of byproducts in construction technology. For the first time in Bangladesh, an experimental multidimensional project depending on Rice Husk Electricity and Rice Husk Ash (RHA) concrete brick/block under Green Eco-Tech Limited has already been started. Project analysis, opportunity, sustainability, the high monitoring component, limitations and finally evaluated data reflecting the viability of establishing more projects using rice husk are discussed in this paper. The by-product of rice husk from the production of green electricity, RHA, can be used for making, in particular, RHA concrete brick/block in Bangladeshi aspects is also discussed here

Locating target at high speed using image decimation decomposition processing

We develop a decimation-decomposition processing technique that consists of judiciously selecting certain decimation-decomposed components of an image and then performing inter-component processing. For a (kx,ky)-decimation decomposition, there may be up to kxky decimation-decomposed components. The minimal surviving and maximal non-surviving lengths associated with inter-component processing algorithm allows for clutter suppression. By removing detection redundancies, one can locate the target at high speed. A “where-then-what” model is proposed for target tracking and recognition. It locates the target by-image decimation-decomposition processing first and then recognizes the target in question using a suitable image recognition technique

The role of warmed intravenous fluid on intraoperative hypothermia and postoperative shivering during prolonged oral and maxillofacial surgery

Background: Under general anaesthesia, the core temperature may drop up to 6°C. Patients undergoing prolonged maxillofacial surgery frequently experience unintentional hypothermia that causes postanaesthetic shivering which is a common complication of anaesthesia that should be prevented. This study aimed to evaluate the role of warmed intravenous fluid in preventing intraoperative hypothermia and postoperative shivering. Methods: Between January 2022 and December 2022, 322 patients with American Society of Anesthesiologists (ASA) physical status I, II and the age group of 18 to 45 years old scheduled for elective major oral and maxillofacial surgery were evaluated under the Department of Anaesthesiology in Dhaka Dental College and Hospital. The patients were grouped into Room Temperature Group and Warmed Fluid Group. Results: 162 patients received warmed fluid, whereas 160 patients received fluid at room temperature. In Room Temperature Group, there were 89 male and 71 female patients, whereas Warmed Fluid group had 88 male and 74 female patients. At the end of the procedure, the basal core temperature was 36.7±0.2°C in the group receiving warmed fluid versus 35.9±0.2°C in the group receiving fluid at room temperature. The incidence of hypothermia (<36 °C) was much lower in Warmed Fluid Group (n=28, 17.28%) than Room Temperature Group (n=86, 53.75%). Shivering was more common in Room Temperature Group (n = 67, 41.86%) than in Warmed Fluid Group (n = 19, 11.73%) in the postanaesthetic care unit (PACU). Conclusions: The results of this study suggested that intraoperative hypothermia and postoperative shivering are less common when warmed fluid is infused.  

Nano-confined synthesis of highly ordered mesoporous carbon and its performance as electrode material for electrochemical behavior of riboflavin (vitamin B2) and dopamine

Highly ordered mesoporous carbon (MC) has been synthesized from sucrose, a non-toxic and costeffective source of carbon. X-ray diffraction, N2 adsorption–desorption isotherm and transmission electron micrograph (TEM) were used to characterize the MC. The XRD patterns show the formation of highly ordered mesoporous structures of SBA15 and mesoporous carbon. The N2 adsorptiondesorption isotherms suggest that the MC exhibits a narrow pore-size distribution with high surface area of 1559 m2/g. The potential application of MC as a novel electrode material was investigated using cyclic voltammetry for riboflavin (vitamin B2) and dopamine. MC-modified glassy carbon electrode (MC/GC) shows increase in peak current compared to GC electrode in potassium ferricyanide which clearly suggest that MC/GC possesses larger electrode area (1.8 fold) compared with bare GC electrode. The electrocatalytic behavior of MC/GC was investigated towards the oxidation of riboflavin (vitamin B2) and dopamine using cyclic voltammetry which show larger oxidation current compared to unmodified electrode and thus MC/GC may have the potential to be used as a chemically modified electrode

Effect of phosphorus and potassium on the growth and yield of French bean

An experiment was conducted at the Agronomy Field Laboratory of the Department of Agronomy, Bangladesh Agricultural University, Mymensingh to investigate the yield response of French bean (Phaseolus vulgaris L.) as affected by phosphorus and potassium management. The experiment consisted of two factors. Factor A: Phosphorus fertilizer (4 levels) viz. P1=15Kg P ha-1, P2=20 Kg P ha-1 and P3=25 Kg P ha-1 , P4=35 Kg P ha-1 and factor B: Potassium fertilizer (4 levels) viz. K1=0 Kg K ha-1, K2=20 Kg K ha-1, K3=30 Kg K ha-1 and K4=40 Kg K ha-1. The variety BARI Jharsheem-3 was used in this experiment as the test crop. The experiment was laid out in a randomized complete block design (RCBD) with three replications. In case of phosphorus @ 25 kg ha-1  the highest number of pods plant-1 (4.96), pod length (13.34 cm), number of seeds pod-1 (4.54), weight of 1000-seed (431.21 g), seed yield (1.33 t ha-1), stover yield (1.53 t ha-1), biological yield (2.86 t ha-1) and harvest index 46.50%  were found. In case of potassium @ 40 kg ha-1, he highest number of pods plant-1 (5.80), pod length (14.89 cm), number of seeds pod-1 (4.24), weight of 1000-seed (430.37 g), seed yield (1.53 t ha-1 ), stover yield (1.46 t ha-1 ), biological yield (2.99 t ha-1) and harvest index 51.17% were found. Interaction effect of phosphorus and potassium the highest  number of pods plant-1 (5.18), pod length (13.40 cm), number of seeds pod-1 (4.30), weight of 1000-seed (430.53 g), seed yield (1.40 t ha-1 ), stover yield (1.60 t ha-1 ), biological yield (3.00 t ha-1 ) and harvest index 46.66% were recorded from P @ 25 kg ha-1 and K @ 40 kg ha-1. However, from the study it can be concluded that application of P @ 25 kg ha-1 and K @ 40 kg ha-1 was the most suitable combination for better yield of French bean

Screening for microbial load and antibiotic resistance pattern in Escherichia coli isolated from paper currency circulating in Kushtia, Bangladesh

Background: Paper currency is used for every type of commerce and plays an important role in the life of human beings. They are exchanged and come into contact with different environments and many different individuals during their circulation. Therefore, they can become contaminated with microorganisms and transfer bacteria across environments. The present study was aimed for quantitative assessment of microorganisms in circulated paper currency from Kushtia, Bangladesh and antibiotic resistant profiles of isolated Escherichia coli.Methods: A total of 10 paper currency samples currently in circulation involving three denominations (5, 10 and 500) were randomly collected from individuals involved in various occupations including street beggar, local hotel, bus conductor, poultry seller, vegetable seller, fish seller, commercial bank, ATM booth, tea seller, grocery store in Kushtia city, Bangladesh. Selective culture and biochemical tests were performed for the isolation and identification of microbial pathogens. Antibiotic resistance profiles were evaluated for isolated Escherichia coli using Kirby-Bauer method according to CLSI guidelines.Results: Aerobic mesophilic bacteria, Enterobacteriaceae and Pseudomonas spp. were the highest in paper currency from local hotel and ATM booth. Enterobacteriaceae (including coliforms) were predominantly present in paper currencies collected from local hotel, grocery, fish seller and beggar while Pseudomonas spp. were found in currency notes obtained from ATM booth, poultry farm, vegetable seller and local hotel. Antibiotic resistant profiles of E. coli isolated from local hotel currency showed that 50% of E. coli isolates were multidrug resistant. The highest resistant profile was observed against penicillin (95%) followed by polypeptide (75%), cephalosporin (50%), quinolone (30%) and sulfonamide (5%) groups of antibiotics.Conclusions: Multiple antibiotic resistant pathogenic bacteria are prevalent in paper currency regardless of their sources. Paper currency could contribute in transmission of infectious disease as well as in antibiotic resistance, therefore, should be handled carefully

Case-control study of suicide in Karachi, Pakistan

Background: In recent years suicide has become a major public health problem in Pakistan. Aims: To identify major risk factors associated with suicides in Karachi, Pakistan. Method: A matched case-control psychological autopsy study. interviews were conducted for 100 consecutive suicides, which were matched for age, gender and area of residence with 100 living controls. Results: Both univariate analysis and conditional logistic regression model results indicate that predictors of suicides in Pakistan are psychiatric disorders (especially depression), marital status (being married), unemployment, and negative and stressful life events. only a few individuals were receiving treatment at the time of suicide. None of the victims had been in contact with a health professional in the month before suicide. Conclusions: Suicide in Pakistan is strongly associated with depression, which is under-recognised and under-treated, The absence of an effective primary healthcare system in which mental health could be integrated poses unique challenges for suicide prevention in Pakistan

Spectrum of valvular lesions in newly diagnosed rheumatic heart disease

Background: Rheumatic heart disease (RHD) is the most common acquired heart disease among young adults and an important health problem in developing countries. There is much scarcity of information about echocardiographic evaluation of valvular involvement of RHD in Bangladesh. Objective of this study was to analyze the clinical spectrum and pattern of cardiac valvular lesions in newly diagnosed RHD patients. Methods: This cross-sectional study was conducted from April 2019 to May 2021 in National Center for Control of Rheumatic Fever and Heart Diseases (NCCRF and HD), Dhaka, Bangladesh.  Newly diagnosed 160 RHD patients irrespective of age and sex were enrolled. Medical history was obtained, physical examination was carried out, several investigations were done and standard color Doppler echocardiography was performed. Diagnosis of RHD was made following 2012 World Heart Federation criteria. Results: More than 60% of newly diagnosed patients of RHD were female; mean age of patients was 24.29±9.17 years and 77.5% of patients were between 15-34 years of age. Detected valvular lesions were mostly isolated (65%) and mitral valve involvement was 88.7%. Isolated mitral regurgitation was detected among 56.3% patients and was higher in female. Combination of mitral regurgitation and mitral stenosis were reported in 12.5% cases whereas mitral regurgitation with aortic regurgitation was present in 10.6% cases. Overall, 14 (6.4%) of the newly diagnosed patients were detected with severe forms of cardiac valvular lesion. Conclusions: RHD were common in young adults. Mitral valve was predominantly involved, particularly presenting as isolated mitral regurgitation