Evaluating the Wear of Polycrystalline Diamond Compact Drill Bit Cutters using Indentation and Scratch Tests

Abstract–Polycrystalline diamond compact (PDC) drill bits are widely used in oil and gas drilling. The wear of PDC cutters is a major problem during drilling. It leads to severe time losses which affect the overall drilling operation cost. Therefore, it is essential to evaluate the wear tendency for these cutters using predictive approaches. The present research is focused on studying the wear mechanisms of PDC cutters and the effect of their mechanical properties on the extent of wear. The volume of wear for the PDC cutters was determined experimentally using micro- and nano-scratch tests by implementing an approach based on the geometry of the removed material after micro- and nano-scratch tests. The experimental wear results were compared to the predictions from current models in the literature.Various wear models are evaluated for micro- and nano-scratch tests on both layers of the PDC samples. The study shows that the wear of the PDC cutters can be predicted from the material mechanical properties, applied load, sliding distance, and hardness of the PDC cutters. The study could be extended for the evaluation of wear intensity of PDC cutters from various manufactures without using the previous techniques of abrasion testing

The significance of glass transition temperature in processing of selected fried food products : a review

This paper emphasized the significance of the glass transition temperature (Tg) by highliting its applications in drying (hot air and freeze drying) for various food systems such as skim milk powders, rice kernels, starch and sugar products and some freeze-dried products such as strawberries and surimi. The study revealed that the major components of the specified foods (which consist of mixture of ingredients), for example lactose in skim milk powder and sucrose in sugar mixtures, will influence the glass transition temperature of the food. Moreover, Tg is an important parameters for determining the optimum processing conditions of dried products. Thus, it is used in designing drying equipment to meet the purpose. In general, Tg affects the physical properties of food such as stickiness, caking and agglomeration. The effect of moisture content on Tg was covered by almost all studies focusing on Tg of foods. Meanwhile, the effect of pressure on Tg was not well covered due to its scarce availability in the existing literature. In term of test methods for determining the Tg of foods, it seems that not all test methods are suitable for certain type of foods, accordingly, more study on the recommended test methods should be carried out

Recent advances, advantages and limitations of genetically modified foods

Despite the potential benefits of genetically modified foods (GMF), the technology has its limitations and is surrounded by controversy. This review focuses on the recent advances and applications of GM in food production, the present advantages of GMF as well as its limitations and challenges in safety assessment evolving from the recent developments. By summarizing the published information from scattered references in the literature, this paper attempts to contribute to the literature an overall understanding as well as the current status evolution of this field

Lithofacies Architecture of the Gercus Formation in Jabal Haibat Sultan, NE Iraq; New Concept of Lithostratigraphy and Depositional Environmental

Lithostratigraphic analysis of the Gercus Formation reveals four associations based on lithofacies types, petrography and sedimentary structures. The identified lithotypes are shale/claystone, sandstone, carbonate, conglomerate and debrite. Lithofacies association reveals four types arranged from bottom to top; FA1 proximal turbidite (sand dominated), FA2 distal turbidite (clay dominated), FA3 slop-apron turbidite (sand dominated) and FA4 distal deep turbidite (clay dominated). Lithofacies and associated sedimentary structures suggest sedimentation in marine turbidite regime followed the deep marine turbidites of Tanjero and Kolosh Formations in Tethyian foreland basin. The Middle-Late Eocene Gercus Flysch sediments composed of predominant litharenitic sandstones and interbedded mudstones, of turbiditic origin and mostly derived from a NE Arabian Plate margins. The sediments are well exposed in the NE side of Haibat Sultan Mountain, and provide excellent examples of fan sands associated with turbidites and related facies. The examined section indicates that the sandstones were deposited in larger channel complexes, which fed a mud-dominated slope. The more proximal facies have proportion of pebble conglomerates, shale-clast conglomerates and thick-bedded structureless pebbly sandstones, deposited by high-density turbidity currents, debris flows and slump. Other facies, either more distal or with a more uniform sand-rich are dominated by thick-bedded and amalgamated structureless sandstones. The massive sands are thought to originate from the gradual aggradations of sediment beneath or near-steady flows. In this paper, new sedimentological and lithofacies evidences prove for the first time that the Gercus Formation was deposited in gravity-flow regime in marine environment. The identified sedimentary structures display alternative graded and fining upward cycles, load and flute casts, submarine channels, sand and clay balls and pillow structures, convolute and slump beddings, of turbidity origin, which is supported by index glauconite mineral in some sandstone horizons. Keywords: Turbidites, Sedimentary structures, Gravity flow, Flysch, Gercus, Eocene, NE Iraq

The maternal and neonatal outcomes of teenage pregnancy in a tertiary university hospital in Egypt

Aim: To highlight the grave complications among teenage mothers in Assiut Woman\u27s Health Hospital compared with the adult mothers. Methods: This study was a prospective case control study, conducted at the Labor Ward of Assiut Woman\u27s Health Hospital from 1st of January 2016 to 30th of June 2016. We included teenage pregnant women (13-19 completed years at delivery) as case and adult mothers (20-29 years) formed the control group. The primary outcome of the study is the rate of pregnancy complications among teenage mothers. Results: Obstetric complications were higher among the teenage mothers (p=0.0001). The teenage mothers had a higher proportion of normal vaginal delivery (p=0.005). The adult mothers reported a higher rate of elective cesarean section (CS) and operative vaginal delivery (p=0.0001, p=0.002; respectively). The infants of teenage mothers tended to have a lower birth weight and Apgar score than the adult ones. Conclusion: This study clearly states that the teenage mothers and their infants were more liable to complications during pregnancy and labor compared to adult mothers

The maternal and neonatal outcomes of teenage pregnancy in a tertiary university hospital in Egypt

Aim: To highlight the grave complications among teenage mothers in Assiut Woman\u27s Health Hospital compared with the adult mothers. Methods: This study was a prospective case control study, conducted at the Labor Ward of Assiut Woman\u27s Health Hospital from 1st of January 2016 to 30th of June 2016. We included teenage pregnant women (13-19 completed years at delivery) as case and adult mothers (20-29 years) formed the control group. The primary outcome of the study is the rate of pregnancy complications among teenage mothers. Results: Obstetric complications were higher among the teenage mothers (p=0.0001). The teenage mothers had a higher proportion of normal vaginal delivery (p=0.005). The adult mothers reported a higher rate of elective cesarean section (CS) and operative vaginal delivery (p=0.0001, p=0.002; respectively). The infants of teenage mothers tended to have a lower birth weight and Apgar score than the adult ones. Conclusion: This study clearly states that the teenage mothers and their infants were more liable to complications during pregnancy and labor compared to adult mothers

Epidemic Spreading and Digital Contact Tracing: Effects of Heterogeneous Mixing and Quarantine Failures

Contact tracing via digital tracking applications installed on mobile phones is an important tool for controlling epidemic spreading. Its effectivity can be quantified by modifying the standard methodology for analyzing percolation and connectivity of contact networks. We apply this framework to networks with varying degree distributions, numbers of application users, and probabilities of quarantine failures. Further, we study structured populations with homophily and heterophily and the possibility of degree-targeted application distribution. Our results are based on a combination of explicit simulations and mean-field analysis. They indicate that there can be major differences in the epidemic size and epidemic probabilities which are equivalent in the normal SIR processes. Further, degree heterogeneity is seen to be especially important for the epidemic threshold but not as much for the epidemic size. The probability that tracing leads to quarantines is not as important as the application adoption rate. Finally, both strong homophily and especially heterophily with regard to application adoption can be detrimental. Overall, epidemic dynamics are very sensitive to all of the parameter values we tested out, which makes the problem of estimating the effect of digital contact tracing an inherently multidimensional problem

Multifocus Images Fusion Based On Homogenity and Edges Measures

Image fusion is one of the most important techniques in digital image processing, includes the development of software to make the integration of multiple sets of data for the same location; It is one of the new fields adopted in solve the problems of the digital image, and produce high-quality images contains on more information for the purposes of interpretation, classification, segmentation and compression, etc. In this research, there is a solution of problems faced by different digital images such as multi focus images through a simulation process using the camera to the work of the fuse of various digital images based on previously adopted fusion techniques such as arithmetic techniques (BT, CNT and MLT), statistical techniques (LMM, RVS and WT) and spatial techniques (HPFA, HFA and HFM). As these techniques have been developed and build programs using the language MATLAB (b 2010). In this work homogeneity criteria have been suggested for evaluation fused digital image's quality, especially fine details. This criterion is correlation criteria to guess homogeneity in different regions within the image by taking a number of blocks of different regions in the image and different sizes and work shifted blocks per pixel. As dependence was on traditional statistical criteria such as (mean, standard deviation, and signal to noise ratio, mutual information and spatial frequency) and compared with the suggested criteria to the work. The results showed that the evaluation process was effective and well because it took into measure the quality of the homogenous regions

Therapeutic Efficacy of Lotus (Nelumbo nucifera) Leaves Extract to Manage Diabetes mellitus

Natural bioactive compounds that target pancreatic cells for the prevention and treatment of diabetes mellitus are gaining popularity. The purpose of this research was to investigate the physiologic effects of Lotus leaves on insulin and sugar levels in order to improve diabetes control. The Soxhelt apparatus was used to extract the Lotus ethanol extract, which was diluted with distilled water at two concentrations: 5 mg/ml (5 percent) and 10 mg/ml (10 percent).. Thirty female white albino rats were randomly separated into three groups: G1(n=10) was given distilled water 1ml, G2(n=10) and G3(n=10) were given a single dosage of 5% and 10% extract solution, respectively, daily for ten days. The results showed significant decrease of glucose level in serum after 10 days of treatment G2= 87.36±1.5 and G3=69.7±1.7 and significant increase of insulin level in serum G2= 78.92±1.03 and G3= 89.36±1.46