Experimental Characterization of Electrical Discharge Machining of Aluminum 6061 T6 Alloy using Different Dielectrics

Electrical discharge machining is a non-traditional machining method broadly employed in industries for machining of parts that have typical profiles and require great accuracy. This paper investigates the effects of electrical parameters: pulse-on-time and current on three performance measures (material removal rate, microstructures and electrode wear rate), using distilled water and kerosene as dielectrics. A comparison between dielectrics for the machining of aluminum 6061 T6 alloy material in terms of performance measures was performed. Aluminum 6061 T6 alloy material was selected, because of its growing use in the automotive and aerospace industrial sectors. The experimental sequence was designed using Taguchi technique of L9 orthogonal array by changing three levels of pulse-on-time and current, and test runs were performed separately for each dielectric. The results obtained show that greater electrode wear rate (EWR) and higher material removal rate (MRR) were achieved with distilled water when compared with kerosene. These greater EWR and MRR responses can be attributed to the early breakage of the weak oxide and carbide layers formed on the tool and alloy material surfaces, respectively. The innovative contributions of this study include, but are not limited to, the possibility of machining of aluminum 6061 T6 alloy with graphite electrode to enhance machinability and fast cutting rate employing two different dielectrics.Peer reviewe

Effect of pregnancy on packed cell volume and total white blood cells count among Sudanese pregnant women attending antenatal care at Ribat University Hospital (Khartoum state)

Background: During pregnancy the women undergo several structural and physiological changes almost in all body systems including the hematological profile. The main reported hematological change is the plasma expansion and haemodilution which affect the red blood cells(RBCs) and white blood cells (WBCs) count in addition to other hematological indices including packed cell volume (PCV). The objective of this study was to assess the effect of pregnancy on packed cell volume and white blood cells among Sudanese pregnant women and derive a formula for the normal values in pregnant women in relation to the packed cell volume.Methods: An analytical case control study was conducted in Khartoum state, Sudan 2017. The study included20 Sudanese pregnant women in the second and third trimesters attending the antenatal care at The National Ribat university hospital and 20 Sudanese non-pregnant women in the same age group as control. A questionnaire was used to collect socio-demographic and clinical data.5ml of venous blood was collected in a container containing EDTA. Complete blood count (CBC) was measured by using automated cell counter Sysmex.Results: There was statistically significant decrease in PCV value during 2nd and 3rd trimesters of pregnancy compared to the non-pregnant control group with p values (0.00 and 0.04 respectively), and statistically significant increase in WBCs count during 2nd and 3rd trimesters of pregnancy compared to the non-pregnant control group with p values (0.04 and 0.00 respectively). Also, a progressive increase in WBCs count with gestational age was demonstrated (second trimester 6.65×103/uL, third trimester 7.43×103/uL). The results showed mean WBCs of 7.79×103/uL, when compared to the estimated values the results showed no significant difference with the mean WBCs in 2ndand 3rdtrimesters (p value 0.06 and 0.39 respectively).Conclusions: During pregnancy there was statistically significant decrease in PCV values, statistically significant increase in WBCs count and by considering the haemodilution factor there was a higher increase in WBCs count

Prevalence of Metallo-β-Lactamase producing Pseudomonas aeruginosa in wound infections in Duhok city, Iraq

Background: Pseudomonas aeruginosa is common pathogen causing nosocomial infection. Acquired drug resistance and Metallo-β-lactamases (MBL) production have recently emerged as one of the most worrisome resistance mechanism that hydrolyze all beta-lactam antibiotics including penicillins, cephalosporins and carbapenems, with the exception of aztreonam. The aim was to find out the prevalence of multi drug resistant (MDR) and Metallo-β-lactamase (MBL) positive isolates of P. aeruginosa in wounds samples which are a serious concern.Methods: Pseudomonas aeruginosa strains were obtained by standard isolation and identification techniques from 307 wound samples of hospital. Strains were then subjected to susceptibility testing for anti-pseudomonas drugs as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Carbapenems resistant strains were selected for the detection of MBL enzyme production by disc potentiation test. Production of MBL was confirmed by enhancement of inhibition zone around imipenem and meropenem discs impregnated with EDTA, as compared to discs without EDTA.Results: Amongst the 71 isolates of P. aeruginosa, 62(87.3%) isolate were imipenem-sensitive, while 9(12.7%) isolates were found to be imipenem resistant and MBL producers. Very high resistance to antibiotics was recorded amongst MBL producers’ P. aeruginosa compared with non-MBL imipenem-sensitive strains.Conclusion: Study indicates that, surveillance for the detection of MBL is necessary. The rapid dissemination of MBL producers is worrisome and necessitates the implementation of proper and judicious selection of antibiotics especially carbapenem.

Design of an Intelligent Traffic Light Control System

Today, the number of cars is rapidly increasing which creates a real traffic control problem. While the conventional traffic control systems are inconvenient to provide fast and fair solutions for the congestion problem. This research addresses the traffic control problem and hence proposes an intelligent traffic light control system. In particular, the proposed system senses the presence or absence of cars on each lane, and then estimates the time to open each lane, which is proportional to the number of cars on that lane. Practically, the system circuit has been printed on a board with three main components; namely pressure sensors, microcontroller, and traffic lights. Then a C program has been developed to enable the microcontroller for receiving inputs from sensors, calculating the times to open lanes and sending appropriate logic decisions to traffic light. The obtained results prove the accuracy and reliability of the system.    In addition to the practical test, the intelligent traffic light control system has been successfully simulated, where the simulation results are found to be the same as the calculated ones

Design and Development of a Photovoltaic Water Pumping

The theory of design and analysis of experiments has been primarily developed by statisticians engaged mostly in agricultural research. The theory has now found applications in other fields of research, because it is based on general principles concerning the statistical behavior of observations which arise either freely in nature or in artificial laboratory conditions (Badrldin and Kshirsagar,1990). Incomplete block designs were developed to suit experiments where the number of experimental units per block is less than the number of treatments. The concept of incomplete block designs augmented by a control was first introduced by Das (1954). He considered  the case where (q ³ 1) new treatments are introduced into the design and all included in each block. He concluded that  q should be chosen as low as possible to keep the block size to a reasonable level. Pearce (1960) considered the case where a Balanced Incomplete Block (B. I. B.) design is supplemented by a control, where the test treatments are replicated r times except the control which is  replicated r0 times, while all pairs of treatments occurs l times in blocks, the supplemented treatment occurs l0 times with any other treatment(Ture,1982). Pesek (1974) considered the case of a B. I. B. design having an extra control in each block. He utilized Rao’s general formulas to obtain the variances of the elementary treatment contrast between any pair of test treatment and any treatment and the control. He also obtained the efficiency factor of this design and showed that this design is more efficient than a B. I. B. design for comparing treatments with a control, but is less efficient for pair wise comparisons between the test treatments. Many times, for important new drugs and for serious diseases, investigations are carried out simultaneously at various locations under different climatic conditions, for a series of treatments. In such cases, the result of all such investigations need to be combined to produce an overall estimate of the effect of treatment contrast to the control. In this study the case where a control is added to each block in a B. I. B. design is considered. The variances of the elementary treatment contrast between any pair of test treatments and any treatment and the control were obtained. The general theory of inter & intra -block estimates of treatment effect when a B. I. B. design is augmented by a control was investigated, the general theory of a balanced incomplete block design is given where a control is added to each block. The estimation of weight for combining inter and intra-block estimates is also dealt with, and the weight for combining inter-block estimates of treatment contrast was also considered. The object of this study is to get a minimum variance of the treatment contrast between the inter and intra block estimates when a control treatment is added to each block in B. I. B. design

Multimodal 2D-3D face recognition

Up to date, many advances have been made to 2D face recognition (2D FR) due to its broad range of applications in security and commercial areas as well as in smart devices. However, 2D FR is still quite vulnerable under unconstrained conditions of the image acquisition process. To overcome 2D FR limitations, researchers shift to 3D face recognition technology but this technology is computationally expensive and inapplicable to real-world face recognition systems. Multimodal 2D-3D face recognition can combine the strength of both 2D and 3D modalities. In this paper a multimodal 2D-3D face recognition approach has been proposed based on geometric and textural characteristics of 2D and 3D modalities. The conducted experiments show that the proposed approach achieved promising results with illumination and head pose variations. The performance is evaluated using the landmark Bosphorus facial database

Region-based facial expression recognition in still images

In Facial Expression Recognition Systems (FERS), only particular regions of the face are utilized for discrimination. The areas of the eyes, eyebrows, nose, and mouth are the most important features in any FERS. Applying facial features descriptors such as the local binary pattern (LBP) on such areas results in an effective and efficient FERS. In this paper, we propose an automatic facial expression recognition system. Unlike other systems, it detects and extracts the informative and discriminant regions of the face (i.e., eyes, nose, and mouth areas) using Haar-feature based cascade classifiers and these region-based features are stored into separate image files as a preprocessing step. Then, LBP is applied to these image files for facial texture representation and a feature-vector per subject is obtained by concatenating the resulting LBP histograms of the decomposed region-based features. The one-vs-rest SVM, which is a popular multi-classification method, is employed with the Radial Basis Function (RBF) for facial expression classification. Experimental results show that this approach yields good performance for both frontal and near-frontal facial images in terms of accuracy and time complexity. Cohn-Kanade and JAFFE, which are benchmark facial expression datasets, are used to evaluate this approach

Prevalence of Muscle Dysmorphia and Associated Health Activities in Male Medical Students in Karachi, Pakistan

Background: Muscle Dysmorphia (MD) is a subtype of body dysmorphic disorder (BDD) and is currently classified under anxiety disorders (subheading: Obsessive-compulsive disorder) in DSM 5. MD is hypothesized to affect the self-esteem and social outlook of the younger generation. MD shows a higher rate in males and may influence their self-confidence rendering them more prone towards using steroids, supplementary proteins and other drugs to alter their physical outlooks as shown in previous studies. This problem has been on the rise lately due to revolutionary advancement in the media and film industry and the abrupt changes about the standards of physical good looks and body shapes. With the lack of studies done in our population, our study will be helpful to consider the prevalence of the disease in our setting and increase awareness in the general public and clinicians. We hope to help clinicians/ therapists find better options in managing the disease. Materials: We performed a cross-sectional study with a sample size of 246 medical school students in Karachi to collect data through self-administered questionnaires. We used the DSM 5 criteria for the diagnosis of BDD and additional questions on the presence of MD. Nutritional habits, exercise routines, use of supplements and drugs were also obtained for exploratory analysis. Results: Our study predicted the prevalence of MD to be 25%. Other main findings included statistical significant associations between MD and the thoughts and practice of steroid use for muscularity. Conclusion: MD is an underdiagnosed and often unrecognized disease that we believe has significant consequences for the young male population. Further work is needed on this in our part of the world. Our research, we believe, can be a stepping stone for further studies that would incorporate wider populations

Antibacterial and cytotoxic properties of isoprenoids from the red sea soft coral, Lobophytum sp

Purpose: To evaluate the antibacterial and cytotoxic activities of the secondary metabolites of Lobophytum sp.Methods: Maceration with methanol: chloroform (1:1) was applied to extract the coral material. Chromatographic and spectroscopic techniques were employed for fractionation, isolation and elucidation of pure compounds. Antibacterial activities were performed by well diffusion method against three Gram-positive and four Gram-negative bacteria. Brine shrimp lethality test was employed to predict toxicity, while antitumor activity were tested by 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide (MTT) method against Ehrlich carcinoma cells.Results: Four sesquiterpenes, one cembranoid type diterpenes and two steroids were isolated. 1 exhibited significant antibacterial activity against four tested bacteria (P. aeruginosa, S. aureus, S. epidermis, and S. pneumonia) with MIC value of 15 μg/mL. Moreover, 1 showed high diameter zone of inhibition ranging from 16 - 18 mm against test bacteria. Compounds 4 and 5 displayed moderate antibacterial activity against all test bacteria with inhibition zone diameter (IZD) ranging from 11 – 15 mm and MIC values of 30 μg/mL. 2, 3, 6 and 7 exhibited weak antibacterial activity (IZD, 7 - 11 mm; MIC ≥ 30 μg/mL). In addition, only diterpene compound (4) showed high toxicity against A. Salina and antitumor activity against Erhlich carcinoma cells with the LD50 of 25 and 50 μg/mL, respectively.Conclusion: This study reveals the strong antibacterial activity of sesquiterpene alismol (1) and the potential antibacterial and antitumor activity of cembranoid type diterpene, cembrene A (4).Keywords: Soft coral, Lobophytum sp., Red Sea, Antibacterial, Cytotoxicity, Sesquiterpene Alismol, Cembranoid, Diterpene, Cembren