Fem and analytical modeling of the incipient chip formation for the generation of micro-features

This paper explores the modeling of incipient cutting by Abaqus, LS-Dyna, and Ansys Finite Element Methods (FEMs), by comparing also experimentally the results on different material classes, including common aluminum and steel alloys and an acetal polymer. The target application is the sustainable manufacturing of gecko adhesives by micromachining a durable mold for injection molding. The challenges posed by the mold shape include undercuts and sharp tips, which can be machined by a special diamond blade, which enters the material, forms a chip, and exits. An analytical model to predict the shape of the incipient chip and of the formed grove as a function of the material properties and of the cutting parameters is provided. The main scientific merit of the current work is to approach theoretically, numerically, and experimentally the very early phase of the cutting tool penetration for new sustainable machining and micro-machining processes

Effective Models for Predicting Heart Disease Using Machine Learning Techniques – A Comparative Study

Cardiovascular disease is one of the most important causes of death in the modern world, and a significant barrier to clinical information assessment may be the expectation of cardiovascular illness. Machine learning (ML) has proven helpful for forecasting and decision-making in the healthcare industrys large amount of data. Moreover, ML algorithms have been applied in many important fields such as the internet of things and others. In this paper, we applied various ML methods to predict and classify heart patients disease including K-Nearest Neighbor Algorithm (KNN), Naïve Bayes (NB), Neural Network (NN), Decision trees (DT), Support Vector Machine (SVM), Random-Forest (RF), Logistic Regression (LR), Gradient-Boosting GB), Stochastic Gradient Descent (SGD), and Ada-Boost. All models were evaluated, and the most accurate predictive model was chosen to increase the accuracy of heart attack prediction. Compared to other models, our results are efficient, and adequate and could help to predict heart disease more effectively and precisely

An efficient color image compression technique

We present a new image compression method to improve visual perception of the decompressed images and achieve higher image compression ratio. This method balances between the compression rate and image quality by compressing the essential parts of the image-edges. The key subject/edge is of more significance than background/non-edge image. Taking into consideration the value of image components and the effect of smoothness in image compression, this method classifies the image components as edge or non-edge. Low-quality lossy compression is applied to non-edge components whereas high-quality lossy compression is applied to edge components. Outcomes show that our suggested method is efficient in terms of compression ratio, bits per-pixel and peak signal to noise ratio

Effect of Lactobacillus plantarum and Lactobacillus delbrueckii subsp. bulgaricus on growth performance, gut microbial flora and digestive enzymes activities in Tor grypus (Karaman, 1971)

In this study, two main probiotics (Lactobacillus plantarum and Lactobacillus delbrueckii subsp. bulgaricus) were isolated from the intestine of Tor grypus and their effects on growth performance, gut microbial flora and digestive enzymes activities (i.e., α-amylase, lipase, trypsin, chymotrypsin, and alkaline phosphatase) of Tor grypus (Karaman, 1971) were determined. Juveniles of T. grypus (n=480, weighing 45±10 g) were randomly divided into 4 equal groups (with 3 replications) and fed on diets containing 5×10^7 cfu g^-1 of L. plantarum (G1), L. bulgaricus (G2), L. casei (G3) and a control diet (without probiotic) for 60 continuous days. Results showed that probiotic supplementations had generally significant effects on growth performance (p<0.05). The G2 group had the best effect on specific growth rate (SGR) and feed utilization efficiency in T. grypus. The digestive enzyme activities, on day 30 after feeding, significantly increased in G1 when compared with those in the control group (p<0.05). Significant changes in bacterial intestinal flora were observed in all probiotic groups compared with the control (p<0.05). Our results indicated that supplementation of isolated bacteria from the intestine of T. grypus (i.e., G2) can efficiently improve growth performance, intestinal microbiota and some digestive enzyme activities in juvenile T. grypus. Therefore, it can be isolated and used as a growth enhancer just like the commercial probiotics

Hydrochemical characterization of groundwater in the Nekor basin located in the North-East of the Rif of Morocco

 In order to evaluate the physicochemical quality of the groundwater of the Nekor watershed (central Rif area in Morocco) and to explain the origin of the mineralization of these waters, we have analyzed the major elements and traces in water samples taken from 17 wells distributed along the basin. This study showed that the samples of water are very charged with a very important mineralization (≥ 1500 mg / l). The Piper diagram allowed us to define dominant Ca-SO4 or Mg-SO4 hydrochemical facies in upstream of the basin. In downstream of the basin Na-SO4 or Na-Cl is the dominant facies. The analyzes of the trace elements show very high levels of manganese, aluminum and iron with contents exceeding those set by the WHO recommendations.The geochemical study shows that the water-rock interaction is predominant in the aquifer. The water saturation indices indicate that these waters are supersaturated in carbonate minerals.The Principal Component Analysis (PCA) and the analysis of the reports of the major elements allowed us the classification of the waters and the determination of the correlation between the various parameters. Two major phenomena in the acquisition of mineralization of water have been put in evidence. The main phenomenon is the dissolution of the rock by the contact water rock due to the important residence time in the aquifer. The second phenomenon is associated to the supply of nutrients and therefore with the exchange and recharge of the aquifer. The use of hierarchical cluster analysis (HCA) technique revealed three homogeneous groups.

Investigation of the Impacts of Social Capital on Organizational Entrepreneurship in Tehran Municipality

Entrepreneurship is the symbol of endeavor and success in business, and entrepreneurs play a crucial role in economic and social development of communities. Since Organizational Entrepreneurship (OE) contribute to earning stable finance required for administration of urban affairs, it is very important in the case of municipalities. For this reason, this study aims to investigate the role of social capital (SC) in the development of entrepreneurship in Tehran municipality. Research method was descriptive and non-experimental, and required data were collected through 204 questionnaires distributed among managers and experts of the organization. Stratified sampling was used, in which 37 managers and 167 experts participated. Number of male participants was 147, and number of female participants was 57. The mean age of participants was 41 years, and its standard deviation was 0.765. In order to test the research hypothesis, structural equation modeling (SEM) was used. The results of the study showed that social capital and its three dimensions (Cognitive, Relational and Structural dimensions) had positive significant effect on organizational entrepreneurship

Policy support for autonomous swarms of drones

In recent years drones have become more widely used in military and non-military applications. Automation of these drones will become more important as their use increases. Individual drones acting autonomously will be able to achieve some tasks, but swarms of autonomous drones working together will be able to achieve much more complex tasks and be able to better adapt to changing environments. In this paper we describe an example scenario involving a swarm of drones from a military coalition and civil/humanitarian organisations that are working collaboratively to monitor areas at risk of flooding. We provide a definition of a swarm and how they can operate by exchanging messages. We define a flexible set of policies that are applicable to our scenario that can be easily extended to other scenarios or policy paradigms. These policies ensure that the swarms of drones behave as expected (e.g., for safety and security). Finally we discuss the challenges and limitations around policies for autonomous swarms and how new research, such as generative policies, can aid in solving these limitations

Detection of Mycoplasma gallisepticum and Mycoplasma synoviae among Commercial Poultry in Khouzestan Province, Iran

Mycoplasmas are important  avian  pathogens,  which  can  cause  both  respiratory  disease  and  synovitis  in  poultry  that  result  in  considerable  economic  losses  to  the  poultry  industry  all  over  the  world.  The  aim  of  this  study  was  to  determine  the  prevalence  of  Mycoplasma  gallisepticum  and  Mycoplasma  synoviae  infections  among  commercial  poultry  flocks  in  Khouzestan  province,  Iran,  using  the  polymerase  chain  reaction  (PCR)  technique. Totally,  290  tracheal  swab  samples  were  collected  from  19  broiler  flocks  and  4  layer-breeder  flocks,  with or  without  respiratory  signs,  in  different  areas  of  Khouzestan  province  within  six  months.  The  PCR  tests  were  applied  for  the  specific  amplification  of  16S  rRNA  (185  bp)  and  vlhA  (392  bp)  genes.  Out  of  100  swab  samples  obtained  from  the  layer-breeder  flocks,  1  and  72  specimens  were  positive  for  M.  gallisepticum and M.  synoviae, respectively.  In  this  regard,  out  of  the  4  layer-breeder  flocks,  1  (25%)  and  4  (100%)  flocks  were  positive  for  M.  gallisepticum and  M.  synoviae,  respectively.  However, none of the studied broiler flocks were M.  gallisepticum- or  M.  synoviae-positive.  According  to  the  results,  the  PCR  technique  could  be  concluded  as  a  rapid  method  for  the  accurate  identification  of  M.  gallisepticum and  M.  synoviae infections  in  commercial  poultry  flocks.  The results were indicative of the low prevalence of M.  gallisepticum in  the  studied  flocks  in  Khouzestan  province.  On the other hand, M.  synoviae  was  widely  distributed  among  layer-breeder  flocks  in  this  province