Modal Frequency Prediction of Chladni Patterns Using Machine Learning

The introduction of machine learning (ML) in the research domain is a new era technique. The machine learning algorithm is developed for frequency predication of patterns that are formed on the Chladni plate and focused on the application of machine learning algorithms in image processing. In the Chladni plate, nodes and antinodes are demonstrated at various excited frequencies. Sand on the plate creates specific patterns when it is excited by vibrations from a mechanical oscillator. In the experimental setup, a rectangular aluminum plate of 16 cm x 16 cm and 0.61 mm thickness was placed over the mechanical oscillator, which was driven by a sine wave signal generator. 14 Chladni patterns are obtained on a Chladni plate and validation is done with modal analysis in Ansys. For machine learning, a large number of data sets are required, as captured around 200 photos of each modal frequency and around 3000 photos with a camera of all 14 Chladni patterns for supervised learning. The current model is written in Python language and model has one convolution layer. The main modules used in this are Tensor Flow Keras, NumPy, CV2 and Maxpooling. The fed reference data is taken for 14 frequencies between 330 Hz to 3910 Hz. In the model, all the images are converted to grayscale and canny edge detected. All patterns of frequencies have an almost 80% - 99% correlation with test sample experimental data. This approach is to form a directory of Chladni patterns for future reference purpose in real-life application. A machine learning algorithm can predict the resonant frequency based on the patterns formed on the Chladni plate.

First contact investigations and compliance to treatment in patients with uveitis

AIM:To ascertain the pattern of investigations at first contact in uveitic patients and evaluate compliance to treatment.METHODS:An observational study comprised of 201 uveitic patients presenting for the first time to our centre from January 2019 to June 2020.Detailed information regarding systemic investigations undertaken by specialists at the time of first contact and the cost of these investigations were reviewed on the first visit to our centre.Compliance with the treatment was determined and reasons behind non-compliance were evaluated on the first follow-up in patients who had no improvement in clinical signs and symptoms.RESULTS:The mean age of the study group was 35.35±14.1y and gender composition was 59.7%males and 40.3%females.Anterior uveitis was observed in 45.3%of patients,intermediate uveitis in 31.8%of patients,posterior uveitis in 14.9%of patients and panuveitis in 8.0%of patients.Association with a systemic disease was evident in 17.9%of patients.When compared with standard guidelines and uveitis patterns,systemic investigations were identified to be relevant only in 38.3%of patients.Non-compliance to treatment was documented in 22.4%of patients.Common reasons for non-compliance were inadequate counselling by the treating physician about treatment in 26.7%of patients and a busy schedule at work/school in 22.2%of patients.CONCLUSION:Significant number of investigations performed at first contact is found to be contrary to standard guidelines and are not contributory to the care.About a quarter of patients in this study are found to be non-compliant with the treatment.Compliance is more challenging to achieve in school-going children and working adults.The availability of comprehensive,periodically updated,evidence-based guidelines on the role of investigations and the use of trained counsellors may help to channelize proper evaluation and improve compliance to treatment,respectively,in patients with uveitis.

Review on the phosphate-based conversion coatings of magnesium and its alloys

Magnesium(Mg)and its alloys are lightweight as well as biocompatible and possess a high strength-to-weight ratio,making them suitable for many industries,including aerospace,automobile,and medical.The major challenge is their high susceptibility to corrosion,thereby limiting their usability.The considerably lower reduction potential of Mg compared to other metals makes it vulnerable to galvanic coupling.The oxide layer on Mg offers little corrosion resistance because of its high porosity,inhomogeneity,and fragility.Chemical conversion coatings(CCs)belong to a distinct class because of underlying chemical reactions,which are fundamentally different from other types of coating.Typically,a CC acts as an intermediate sandwich layer between the base metal and an aesthetic paint.Although chromate CCs offer superior performance compared to phosphate CCs,yet still they release carcinogenic hexavalent chromium ions(Cr^(6+));therefore,their use is prohibited in most European nations under the Registration,Evaluation,Authorization and Restriction of Chemicals legislation framework.Phosphate-based CCs are a cost-effective and environment-friendly alternative.Accordingly,this review primarily focuses on different types of phosphate-based CCs,such as zinc,calcium,Mg,vanadium,manganese,and permanganate.It discusses their mechanisms,current status,pretreatment practices,and the influence of various parameters-such as pH,temperature,immersion time,and bath composition-on the coating performance.Some challenges associated with phosphate CCs and future research directions are also elaborated.

Analytical Solution to the One-Dimensional Advection-Diffusion Equation with Temporally Dependent Coefficients

In a one-dimensional advection-diffusion equation with temporally dependent coefficients three cases may arise: solute dispersion parameter is time dependent while the flow domain transporting the solutes is uniform, the former is uniform and the latter is time dependent and lastly the both parameters are time dependent. In the present work analytical solutions are obtained for the last case, studying the dispersion of continuous input point sources of uniform and increasing nature in an initially solute free semi-infinite domain. The solutions for the first two cases and for uniform dispersion along uniform flow are derived as particular cases. The dispersion parameter is not proportional to the velocity of the flow. The Laplace transformation technique is used. New space and time variables are introduced to get the solutions. The solutions in all possible combinations of increasing/decreasing temporal dependence are compared with each other with the help of graphs. It has been observed that the concentration attenuation with position and time is the fastest in case of decreasing dispersion in accelerating flow field.

Cameron ulcers:An atypical source for a massive upper gastrointestinal bleed

Cameron lesions represent linear gastric erosions and ulcers on the crests of mucosal folds in the distal neck of a hiatal hernia(HH).Such lesions may be found in upto 50% of endoscopies performed for another indication.Though typically asymptomatic,these may rarely present as acute,severe upper gastrointestinal bleed(GIB).The aim is to report a case of a non-anemic 87-year-old female with history of HH and atrial fibrillation who presented with hematemesis and melena resulting in hypovolemic shock.Repeat esophagogastroduodenoscopy was required to identify multiple Cameron ulcers as the source.Endoscopy in a patient with HH should involve meticulous visualization of hernia neck and surrounding mucosa.Cameron ulcers should be considered in all patients with severe,acute GIB and especially in those with known HH with or without chronic anemia.

Evaluating role of bone marrow-derived stem cells in dry age-related macular degeneration using multifocal electroretinogram and fundus autofluorescence imaging

AIM：To evaluate the role of bone marrow-derived stem cells in the treatment of advanced dry age-related macular degeneration（AMD）using multifocal electroretinogram（mf-ERG）and fundus autofluorescence imaging.METHODS：Thirty patients（60 eyes）with bilateral central geographic atrophy（GA）were recruited.Worse eye of each patient received autologous bone marrow-derived hematopoietic stem cells（BM-HSCs）（group 1）and the fellow eye with better visual acuity served as control（group2）.The effect of stem cell therapy was determined in terms of visual acuity,amplitude and implicit time in mf-ERG and size of GA on fundus autofluorescence imaging.These tests were performed at presentation and first,third and sixth month follow up.Adverse events（if any）were also monitored.RESULTS：At 6mo follow-up there was no statistically significant improvement in median log MAR best corrected visual acuity（BCVA）in either group.Mf-ERG revealed significant improvement in amplitude and implicit time in the intervention group.A significant decrease was also noted in greatest linear dimension（GLD）of GA in the eyes receiving stem cells[6.78±2.60 mm at baseline to 6.56±2.59 mm at 6mo（P=0.021）].However,no such improvement was noted in the control group.CONCLUSION：Electrophysiological and anatomical improvement in the intervention group sheds light on the therapeutic role of BM-HSCs.Further studies are required to determine the stage of disease at which the maximal benefit can be achieved and to standardize the dose andfrequency of stem cell injection.

A novel design approach of charge plasma tunnel FET for radio frequency applications

In this paper, the impact of extra electron source(EES) and dual metal gate engineering on conventional charge plasma TFET(CP-TFET) have been done for improving DC and analog/RF parameters. CP-TFET structure is upgraded to double source CP-TFET(DS-CP-TFET) by placing an EES below the source/channel junction for enhancing the device performance in terms of driving current and RF figures of merit(FOMs). But, in spite of these pros, the approach is having cons of higher leakage current similar to MOSFET and negative conductance(inherent nature of TFET). Both the issues have been resolved in the double source dual gate CP-TFET(DS-DG-CP-TFET) by gate workfunction engineering and drain underlapping respectively. Additionally,for getting the optimum performance of DS-DG-CP-TFET, the device sensitivity has been investigated in terms of position of EES,length of drain electrode and workfunction of gate electrode 1(GE1).

Anesthesia Alert—A Preoperative Safety Concept for the Surgeon

Background: Advances in modern medicine and surgical technique have allowed patients with multiple comorbidities to undergo invasive surgery electively. This places additional stress on hospital resources to anticipate and deal with potential complications. We have introduced a preoperative safety concept called “Anesthesia Alert”. The surgeon or preoperative interviewing anesthesiologist assigns an Anesthesia Alert when booking to denote possible difficulty with anesthesia induction or intubation. As a result, two anesthesiologists and fiber optic equipment are made available on the day of surgery. Methods: A retrospective study of patients from all surgical specialties who were assigned Anesthesia Alerts between January 2012 and November 2012. Records were analyzed for reasons requiring Anesthesia Alerts. Patient demographics, comorbidities, and perioperative complications were reviewed. Results: A total of 112 patients formed this study group. Difficult airway comprised the majority of Anesthesia Alerts (n = 75, 67.0%). Hypertension was the most prevalent comorbidity among patients. There were only 7 patients (6.3%) admitted to the ICU postoperatively and no mortalities. Conclusion: Perioperative patient safety is an evolving concept that requires a team approach amongst the surgeon, anesthesiologist, and operating room staff. An Anesthesia Alert raises awareness for possible complications during anesthesia induction as well as allocates resources to increase patient safety and avoid preoperative delays. Most importantly, this concept places the onus on the surgeon to alert the anesthesiologist for possible complications during induction and extubation.

Tobacco Exposed Buccal Mucosa Graft—A Potential Carcinogen for Scrotal Cancer

Squamous cell carcinoma of scrotum is not common. It was the first cancer directly associated with a specific occupation i.e. chimney sweeps. We report a case of squamous cell carcinoma of scrotum developed in a patient of stricture urethra with multiple perineal urinary fistulas treated with lay open urethra with buccal mucosal graft. Tobacco exposed buccal mucosa graft can act as a carcinogen for scrotal cancer in patients with multiple fistula and poor hygiene.

废弃物能量回收技术用于城市固废高效管理的综述(下)

尽管社会经济和技术发展迅速,仍有大约1/4的世界人口依赖传统能源(如煤油、天然气、生物质废弃物、木柴、煤炭、动物粪便等)家庭使用。为了满足逐渐增加的能源需求,矿物资源储量正被大量开采,因此在矿物能源用尽前,需要寻找可替代能源。废弃物能量回收(Waste To Energy,WTE)是一种潜在可替代的能量来源,经济可行,环境友好。本研究综述了目前全球高效能源回收的WTE技术(包括焚烧、热解、煤气化、厌氧消化以及填埋产气)的选择方案,以及发达国家和发展中国家所面临的挑战。本综述基于发达和发展中国家的案例研究为评价WTE技术选择提供了一种整体框架。在发展中国家最常见的垃圾处理选择是非环保的废物填埋,而发达国家已经意识到WTE技术高效管理城市固废(Municipal Solid Waste Management,MSWM)的潜力。本综述可以帮助政策制定、实施机构以MSWM的思路理解城市固废高效管理的当前形势、挑战和阻碍。本综述得出WTE是一种潜在的新能源,将在一定程度上满足能量需求,确保高效管理城市固废管理。

废弃物能量回收技术用于城市固废高效管理的综述(上)

尽管社会经济和技术发展迅速,仍有大约1/4的世界人口依赖传统能源(如煤油、天然气、生物质废弃物、木柴、煤炭、动物粪便等)家庭使用。为了满足逐渐增加的能源需求,矿物资源储量正被大量开采,因此在矿物能源用尽前,需要寻找可替代能源。废弃物能量回收(Waste To Energy,WTE)是一种潜在可替代的能量来源,经济可行,环境友好。本研究综述了目前全球高效能源回收的WTE技术(包括焚烧、热解、煤气化、厌氧消化以及填埋产气)的选择方案,以及发达国家和发展中国家所面临的挑战。本综述基于发达和发展中国家的案例研究为评价WTE技术选择提供了一种整体框架。在发展中国家最常见的垃圾处理选择是非环保的废物填埋,而发达国家已经意识到WTE技术高效管理城市固废(Municipal Solid Waste Management,MSWM)的潜力。本综述可以帮助政策制定、实施机构以MSWM的思路理解城市固废高效管理的当前形势、挑战和阻碍。本综述得出WTE是一种潜在的新能源,将在一定程度上满足能量需求,确保高效管理城市固废管理。

Tandem rapid manufacturing of Inconel-625 using laser assisted and plasma transferred arc depositions

This paper presents an investigation on depo- sition of Inconel-625 using laser rapid manufacturing （LRM） and plasma transferred arc （PTA） deposition in individual and tandem mode. LRM has advantages in terms of dimensional accuracy, improved mechanical properties, finer process control, reduced heat input and lower thermal distortion, while PTA scores more in terms of lower initial investment, lower running cost and higher deposition rate. To quantify the clubbed advantages and limitations of both processes, these were studied individually and in tandem. A number of samples were deposited at different process parameters like power, scan speed, powder feed rate. They were subjected to tensile test, adhesion-cohesion test, impact test and micro hardness measurement. The results of individual tests showed the comparable mechanical prop- erties with i20% variation. The mixed dendritic-cellular and dendritic-columnar microstructures were respectively observed for LRM and PTA deposits with a distinct inter- face for the case of tandem deposition. The interface strength of tandem deposits was evaluated employing adhesion-cohesion test, and it was found to be （325 i 35） MPa. The study confirmed the viability of LRM and PTA deposition in tandem for hybrid manufacturing.