1,357 research outputs found
A nano-particle based approach to improve filtration control of water based muds under high pressure high temperature conditions
There have been many attempts to improve the filtration control of water based muds under High Pressure High Temperature (HPHT) condition using a cost effective approach. Nano particles are perhaps the best option considering their successful applications reported in many studies. However, they are often expensive and pose unfavourably changes on the rheology of the muds. In this paper, an attempt was made to show the application of Nano Glass Flakes (NGFs) as a cheap but effective nano particle to control the filtration of water based muds under HPHT conditions. Performing a series of rheology, filtration and conductivity tests on the mud samples with unmodified NGFs revealed that this nano particle increases the mud rheology, yield point and gel strength of the mud with a slight impact on the filtration loss. However, by modifying the surface charges of NGFs with a cationic surfactant, filtration loss was significantly reduced without any severe impacts on the mud rheology. Considering the conductivity of the mud which increases by adding the modified NGF, this nano particle might be a good choice to improve the overall performance of water based muds under HPHT conditions
Tunable Band Structure Effects on Ballistic Transport in Graphene Nanoribbons
Graphene nanoribbons (GNR) in mutually perpendicular electric and magnetic
fields are shown to exhibit dramatic changes in their band structure and
electron transport properties. A strong electric field across the ribbon
induces multiple chiral Dirac points, closing the semiconducting gap in
armchair GNR's. A perpendicular magnetic field induces partially formed Landau
levels as well as dispersive surface-bound states. Each of the applied fields
on its own preserves the even symmetry of the subband
dispersion. When applied together, they reverse the dispersion parity to be odd
and gives and mix the electron and hole subbands within
the energy range corresponding to the change in potential across the ribbon.
This leads to oscillations of the ballistic conductance within this energy
range
Identifying the abilities of biostimulants to improve vegetable production compared with conventional fertilizer
Vegetables are important agricultural products with numerous health benefits. Excessive chemical fertilization to meet the food challenge has resulted in environmental and soil health hazards. Considering this aspect, the current study was conducted with the aim to introduce biostimulants as an alternative to chemical fertilizers to improve soil quality, crop quality, and yield. In the first experiment, the response of radish was noted against the application of glycine (GLY), aspartic acid (ASP), lysine (LYS), vitamin B complex (VBC), and chemical fertilizers (CF). The biostimulants were sourced from Sigma Aldrich and Martin Dow Market Ltd. The results indicated that ASP has significantly improved the phenolic contents in shoot (1.01%) and root (12.23%) compared with CF. Additionally, total protein was significantly increased in shoot with GLY (251.81%) and in root with ASP (57.06%). Shoot ascorbic acid contents were significantly improved with ASP (179.90%), VBC (159.91%), and LYS (139.92%). Plant fresh and dry weight was improved with VBC (478.31%) and ASP (364.73%). The N and P concentrations in radish root were higher in VBC (25.93%) and LYS (100%). Soil organic matter was improved ASP (61.51%), followed by VBC (60.13%). Soil available P concentration was also enhanced with LYS (40.43%), ASP (31.20%), and VBC (23.19%). The second experiment was focused on identifying the response of turnip crop against the following treatments: chemical fertilizers (CF), Isabion® (ISA), 25% CF + LYS + GLY (CLG), 25% CF + ASP + GLY (CAG), and 25% CF + ASP + LYS (CAL). The biostimulants were sourced from Sigma Aldrich Syngenta, Pakistan. The results denoted that CAL and ISA significantly improved the phenolic contents in turnip shoot and root. The ascorbic acid in turnip shoot was improved with CAL (19.27%), CAG (18.13%), ISA (17.68%), and in root with CLG (26.96%). The P concentration in turnip shoot was significantly higher in ISA (19.25%), CLG (16.85%), and CAG (12.26%). Soil total N was improved in all treatments. ISA improved the available P concentration, whereas CF (67.87 mg kg−1) followed by ISA (65.93 mg kg−1) improved the soil available K. Both studies conclude that biostimulants capable of improving vegetable quality
An Internet of Things based bed-egress alerting paradigm using wearable sensors in elderly care environment
The lack of healthcare staff and increasing proportions of elderly population is alarming. The traditional means to look after elderly has resulted in 255,000 reported falls (only within UK). This not only resulted in extensive aftercare needs and surgeries (summing up to £4.4 billion) but also in added suffering and increased mortality. In such circumstances, the technology can greatly assist by offering automated solutions for the problem at hand. The proposed work offers an Internet of things (IoT) based patient bed-exit monitoring system in clinical settings, capable of generating a timely response to alert the healthcare workers and elderly by analyzing the wireless data streams, acquired through wearable sensors. This work analyzes two different datasets obtained from divergent families of sensing technologies, i.e., smartphone-based accelerometer and radio frequency identification (RFID) based accelerometer. The findings of the proposed system show good efficacy in monitoring the bed-exit and discriminate other ambulating activities. Furthermore, the proposed work manages to keep the average end-to-end system delay (i.e., communications of sensed data to Data Sink (DS)/Control Center (CC) + machine-based feature extraction and class identification + feedback communications to a relevant healthcare worker/elderly) below 1 10 th of a second
Identification of parvalbumin interneurons as cellular substrate of fear memory persistence
Parvalbumin-positive (PV) basket cells provide perisomatic inhibition in the cortex and hippocampus and control generation of memory-related network activity patterns, such as sharp wave ripples (SPW-R). Deterioration of this class of fast-spiking interneurons has been observed in neuropsychiatric disorders and evidence from animal models suggests their involvement in the acquisition and extinction of fear memories. Here, we used mice with neuron type-targeted expression of the presynaptic gain-of-function glycine receptor RNA variant GlyR {beta}3L(185L) to genetically enhance the network activity of PV interneurons. These mice showed reduced extinction of contextual fear memory but normal auditory cued fear memory. They furthermore displayed increase of SPW-R activity in area CA3 and CA1 and facilitated propagation of this particular network activity pattern, as determined in ventral hippocampal slice preparations. Individual freezing levels during extinction and SPW-R propagation were correlated across genotypes. The same was true for parvalbumin immunoreactivity in the ventral hippocampus, which was generally augmented in the GlyR mutant mice and correlated with individual freezing levels. Together, these results identify PV interneurons as critical cellular substrate of fear memory persistence and associated SPW-R activity in the hippocampus. Our findings may be relevant for the identification and characterization of physiological correlates for posttraumatic stress and anxiety disorders
Typhoid and paratyphoid cost of illness in Pakistan: Patient and health facility costs from the surveillance for enteric fever in Asia project II
Background: The objective of this study was to estimate the cost of illness from enteric fever (typhoid and paratyphoid) at selected sites in Pakistan.Methods: We implemented a cost-of-illness study in 4 hospitals as part of the Surveillance for Enteric Fever in Asia Project (SEAP) II in Pakistan. From the patient and caregiver perspective, we collected direct medical, nonmedical, and indirect costs per case of enteric fever incurred since illness onset by phone after enrollment and 6 weeks later. From the health care provider perspective, we collected data on quantities and prices of resources used at 3 of the hospitals, to estimate the direct medical economic costs to treat a case of enteric fever. We collected costs in Pakistani rupees and converted them into 2018 US dollars. We multiplied the unit cost per procedure by the frequency of procedures in the surveillance case cohort to calculate the average cost per case.Results: We collected patient and caregiver information for 1029 patients with blood culture-confirmed enteric fever or with a nontraumatic terminal ileal perforation, with a median cost of illness per case of US 72.89-496.40). The median direct medical and nonmedical costs represented 8.2% of the annual labor income. From the health care provider perspective, the estimated average direct medical cost per case was US 52.24 at Hospital B, and US $11.73 at Hospital C.Conclusions: Enteric fever can impose a considerable economic burden in Pakistan. These new estimates of the cost of illness of enteric fever can improve evaluation and modeling of the costs and benefits of enteric fever prevention and control measures, including typhoid conjugate vaccines
Biometric identification using global discretezation
Biometrics is the science and technology that involves the measurement and analysis of the human body’s biological data. Biometrics involves the extraction a feature set from the obtained data. The feature set is then compared against the template set stored the database. Identification of people must demonstrate reliability and accurately especially in the domains of business transactions and in the access to confidential information. The currently available fingerprint biometric Identification concentrates on feature extraction and task of classification for authorship identification. In fingerprint, the random representation may cause degradation to the performance of classification. Thus, prior to the classification task, certain standards should be present to denote these unique features. In relation to this, the application of the discretization technique would be beneficial. Hence, a new framework for fingerprint biometric identification is proposed. This paper particularly shows the outcome of discretization process on fingerprint samples to attain individual identification. In this paper, the new proposed framework and classic framework were compared using samples. Based on the results, classification accuracies of 90% were obtained when using discretization process with fingerprint biometric identification
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