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A passive eddy current damper (PECD) can be adopted to provide a damping effect and drag force in rotating structure applications. The damping effect is formed as the result of induced eddy current, while the drag force is produced as the result of the repulsive force between the same axially poled magnets. However, modeling and approximating the damping effect, repulsive force, stiffness, the magnetic flux density (MFD) distribution, and eddy current prompted in PECD is a challenging task because of the complicated structure and operational conditions. This paper presents a new method for modeling and estimating the dynamic parameters of novel PECDs such as the damping effect, repulsive force, and stiffness for suppressing vibration in rotating structure applications. This self-powered, cost-effective PECD utilizes four arc-shaped and single ring-shaped permanent magnets with a cylindrical conductor placed between the arc magnets and the ring magnet to generate a damping effect and spring. Eddy currents are generated in the cylindrical conductor as the effect of the relative motion of the ring magnet concerning the arc magnets. An accurate and transient analysis method of the proposed system is carried out by using a three-dimensional finite-element method (3D-FEM). According to the procedures applied in the FE model solution, this new numerical method is appropriate and validated for analyzing PECDs and gaining good results by configuring the conductor and permanent magnets symmetrically. Finally, this novel 3D transient analysis method presents a perfect ability and accuracy for both modeling and calculating the PECD parameters.

BACKGROUND AND AIMS Patients with type 2 diabetes mellitus may present with different macro- and micro-vascular complications including diabetic nephropathy. This preliminary study was designed to evaluate the risk factors for diabetic nephropathy among type 2 diabetic patients at the time of diabetes diagnosis. METHOD A case-control study was done at a tertiary care hospital in Dhaka, Bangladesh from January to September 2017. Adult (≥18 years), type 2 diabetic patients, who were detected as diabetic for the first time within the previous 3 months and who tested, at least, two urine samples for urine albumin-to-creatinine ratio (UACR), at least 6 weeks apart, within a 6-month period, were consecutively enrolled for the study. Pregnant ladies, patients with diagnosed kidney disease, patients having features of glomerulonephritis and systemic diseases including systemic lupus erythematosus and vasculitis, history of recent fever, urinary tract infection and menstruation were excluded. Patients having UACR ≥30 mg/g in at least two (out of 3, if tested) samples were taken as cases and those with UACR RESULTS Total patients were 224 with female predominance (150, 67%). Fifty one (22.8%) patients had diabetic nephropathy (microalbuminuria = 47 and overt proteinuria = 4). Multivariate regression analysis revealed that hypertension {odds ratio (OR) = 3.71 [95% confidence interval (CI) 1.23–4.31], P = 0.003}, smoking [OR = 3.27 (95% CI 2.91–4.79), P = 0.003], family history of diabetes [OR = 2.31 (95% CI 1.84–3.14), P = 0.005] and diabetic nephropathy [OR = 3.34 (95% CI 2.40–4.97), P = 0.001], dyslipidaemia [OR = 2.31 (95% CI 1.98–3.91), P = 0.023], increased body mass index (BMI) [OR = 2.11 (95% CI 1.54–4.87), P = 0.001] and high glycated haemoglobin (HbA1c) [OR 3.21 (95% CI 1.71–5.97), P = 0.034] were significant risk factors for diabetic nephropathy. CONCLUSION Almost 23% of type 2 diabetic patients had diabetic nephropathy during diabetes diagnosis in this study and most patients had microalbuminuria. Presence of hypertension, dyslipidaemia, smoking, family history of diabetes and diabetic nephropathy, increased BMI and high HbA1c were significant risk factors for diabetic nephropathy among patients with type 2 diabetes at diagnosis.

BACKGROUND AND AIMS Emphysematous pyelonephritis (EPN) is an acute and severe form of necrotizing infection of the renal parenchyma, collecting system and/or perinephric tissues, and it is characterized by accumulation of gas within these anatomic locations. Common presenting features are fever, loin pain, vomiting and shock. Risk factors for EPN include diabetes mellitus (DM), renal stone, obstructive uropathy and immunosuppression. In this report, we describe the clinical, laboratory and imaging characteristics of patients with EPN in Bangladesh. METHOD This systematic review included all previously published English literature containing information regarding EPN in/or from Bangladesh. Literature search was conducted via ‘PubMed’ using the key words ‘Bangladesh’ and ‘emphysematous pyelonephritis’. We also searched through Bangladesh Journals Online (BanglaJOL) for articles published in local journals. The search engine ‘Google’ was also used to identify articles. All literature searches were conducted up to 31 December 2021. Unpublished, well-documented EPN cases (six cases) were added. Cases mentioned elsewhere with inadequate information and possible repetition were excluded. RESULTS Twenty two papers were identified from published literature (first case in January, 2012), including 11 case reports, 4 original research articles, 2 images and 5 conference abstracts, and 1 research paper was identified from other source. From them, two case reports were excluded because EPN occurred in non-Bangladeshi nationals; two images and five conference abstracts were excluded because of inadequate information for cases. Finally, a total of 13 papers (total 148 cases) were eligible for analysis, to which six unpublished but well-documented cases were added. Among the total 154 cases, females were 136 (88.3%). The age of the patients ranged between 20 and 85 years. DM was the most common risk factor (146, 94.8%) and nine (5.8%) had renal stones. Patients presented with fever (136, 88.3%), loin pain/renal angle tenderness (102, 66.2%), dysuria (79, 51.3%), altered sensorium (22, 14.3%), anorexia (93, 60.4%), vomiting (111, 72.1%), dehydration (78, 50.6%) and shock (18, 11.7%). Patients had neutrophil leucocytosis (total white cell counts 11 700–54 200/cmm of blood) and 22 (14.3%) patients had thrombocytopaenia. All patients had high erythrocyte sedimentation rate (36–117 mm/1st h) and C-reactive protein (24–199 mg/L). Overall glycaemic status was poor [random blood glucose during admission was 6.8–35.5 mmol/L and glycated haemoglobin (HbA1c) was 6.2–16.1%]. Fifty nine (38.3%) patients were complicated by acute kidney injury (AKI) and 35 (22.7%) patients had hyponatraemia. One patient had EPN in ectopic right kidney, two patients had EPN along with emphysematous cystitis and three patients were complicated by psoas abscess. According to Huang and Tseng classification, 6 (3.9%) patients had class 4 EPN, 41 (26.6%) patients had class 3, 93 (60.4%) patients had class 2 and 14 (9.1%) patients had class 1 EPN. Escherichia coli was the most common (77, 50%) organism identified on urine culture, and 23 (14.9%) patients were complicated by bacteraemia. In one patient, EPN was due to genitourinary tuberculosis. All patients were treated with resuscitative measures, intravenous antibiotics and other supportive measures. Forty four (28.6%) patients required surgery/interventions [nephrectomy in 22 (14.3%), percutaneous drainage in two (1.3%), open drainage in 20 (13%)]. The duration of hospital stay was 6–37 days. Ten (6.5%) patients died in hospital. CONCLUSION EPN occurred predominantly among female diabetic patients with clinical presentation of fever, loin pain, dysuria, vomiting, altered sensorium and shock. Class 2 EPN was the most common. Over one-third of all EPN cases developed AKI. Nearly one-third required surgical interventions including nephrectomy. In-hospital mortality was low, 6.5%.

Currently, Zr-alloys are widely used in nuclear power reactors for fuel cladding and structural components. Many types of zr-based alloys were developed to overcome the challenges encountered in the progress of nuclear reactors (high-burnup and high-duty). Oxygen diffused into the cladding, hydrogen absorbed in the cladding (breakaway oxidation and ruptured balloons) and rapid oxidation rate are results of chemical interaction of cladding material with steam at high temperature. Zirconium alloys seem to be the most suitable for use in fuel cladding, if they can overcome the rapid oxidation at temperature higher than 1200 °C. Previous studies on the oxidation behavior for some Zr-alloys nuclear fuel cladding tubes in steam and steam–air atmospheres at high temperatures are reviewed. The oxidation behavior of zirconium-alloys is strongly affected by the chemical composition of alloys and its surface conditions.

Hydrogen borrowing catalysis serves as a powerful alternative to enolate alkylation, enabling the direct coupling of ketones with unactivated alcohols. However, to date, methods that enable control over the absolute stereochemical outcome of such a process have remained elusive. Here we report a catalytic asymmetric method for the synthesis of enantioenriched cyclohexanes from 1,5‐diols via hydrogen borrowing catalysis. This reaction is mediated by the addition of a chiral iridium(I) complex, which is able to impart high levels of enantioselectivity upon the process. A series of enantioenriched cyclohexanes have been prepared and the mode of enantioinduction has been probed by a combination of experimental and DFT studies.

In this article, a novel algorithm for high-accuracy partial discharge (PD) localization in an oil insulation system is proposed. This study aims to identify the statistics of the dynamics and measurement noise sequences in a PD localization system and employ that information in realizing better estimates. An extended Kalman filter (EKF) is used to estimate the PD location. The performance of the filter is enhanced by identifying the true statistics of the noise sequences using a maximum likelihood estimation approach. The accuracy of the proposed optimal algorithm is verified experimentally by estimating the PD location in an oil insulation system under two experimental settings.

The alkylation of a variety of ketones using 1° or 2° alcohols under hydrogen borrowing catalysis is described. Initial research focused on the α-alkylation of cyclopropyl ketones with higher 1° alcohols (i.e. larger than MeOH), leading to the formation of α-branched products. Our search for additional substrates with which to explore this chemistry led us to discover that di-ortho-substituted aryl ketones were also privileged scaffolds, with Ph∗ (C6Me5) ketones being the optimal choice. Further investigations revealed that this motif was crucial for alkylation with 2° alcohols forming β-branched products, which also provided an opportunity to study diastereoselective and intramolecular hydrogen borrowing processes.

An enantioconvergent method for the alkylation of o-disubstituted aryl ketones with racemic secondary alcohols is described. This process is mediated by a commercially available iridium catalyst and proceeds via hydrogen borrowing catalysis. The highly enantioenriched β-substituted ketone products were readily cleaved to a wide range of functional groups via retro-Friedel–Crafts acylation.

As con-rod is a critical component in an engine, its reliability overwhelmingly directly affects the performance of the whole diesel engine. The fretting wear of con-rod bushing mainly occurs on the contact surface with con-rod small end and con-rod small end cap. In the proposed study, the contact process of con-rod small end, con-rod small end cap and bushing under maximum combustion pressure condition was analyzed, and the distribution of contact pressure and friction stress was analyzed. Then the orthogonal simulation test was designed. According to the contact mechanics theory, the interference amount and friction coefficient of the contact surface were taken as the test factors, and the maximum contact pressure and friction stress under the maximum combustion pressure condition were taken as the objective functions. The influence of the test factors on the objective function was analyzed, and the most reasonable interference amount and friction coefficient were found, so as to slow down the fretting wear of the con-rod bushing.