Design and characterization simulation of Ti: sapphire-based femtosecond laser system using Lab2 tools in the NI LabView

We report on the 825-nm center wavelength, 9.17 mJ pulse energy Ti:sapphire-based femtosecond laser system simulation carried out by Lab2 tools in LabVIEW (National Instruments, Inc.). The design investigation and characterization of stretched, amplified and compressed pulses made by intensity module and second harmonic generation (SHG) frequency-resolved optical gating (FROG) module in Lab2. The minimum pulse duration of ~37.80 fs at the output of the compressor end obtained by simulations. The variation of pulse energy, FWHM and central wavelength versus number of passes in the amplifier are computed. The lab2 tools help to design and characterize laser system before to set up on the optical table. The simulation results save time to calculate parameters which are essential in femtosecond laser system designing. The Lab2 simulation tools, along with financial constraints, it is easier, simple and efficient to obtain results in short time

Gas well deliquification : critical rate analysis and artificial lift design & review workflow

Liquid loading is an inevitable phenomenon for most gas wells. Liquid loading occurs when fluids accumulate in the wellbore instead of producing to the surface. This causes additional hydrostatic pressure that lowers formation drawdown and reduces production. The process of de-watering gas wells is commonly known as gas well deliquification. This involves quantifying if liquid production is the source of un-optimization in the well and selecting an appropriate artificial lift system to offload the well. This study presents a gas well deliquification workflow, that quantifies the extent of liquid loading through production analysis, critical unloading rate, and nodal analysis. Once liquid loading is confirmed, a design & review workflow is suggested that compares different artificial lifts to select the most effective choice. Production analysis includes; (a) evaluating decline trend of rate and estimated bottom hole pressure, (b) Nodal analysis, to create a calibrated baseline model that is used as a reference during artificial lift design, (c) VLP Stability, and Flow-point analysis to qualitatively understand unstable flow in the wellbore. A new critical rate calculation workflow is developed to quantitatively confirm liquid loading. This workflow utilizes published critical gas rate correlations and wellhead pressure as a weighing criterion to estimate a weighted average critical rate. A separate data-driven model, where machine learning is used to estimate critical rate for a target well given its well parameters is also formulated. Both workflows are shown to better predict critical gas rate than most published models. If liquid loading is confirmed, applicable lift systems are designed, and their production impact is gauged through nodal analysis. With a direct comparison of all applicable systems, most suitable system is selected that maximizes incremental production. Design & Review workflow is applied to a field in Lower Indus Basin, Pakistan. Several wells are evaluated to check if liquid loading is a problem and artificial lift can improve production. S-field is the largest field in this dataset, where 10 wells are evaluated. Among the technologies suggested for these wells are Gas lift, Coiled Tubing Gas Lift, and Plunger Assisted Gas lifts. Beam lift and velocity strings are found to be less effective in the specific case of S-field. Several artificial lift selection workflows are published that focus on selecting lifts for oil wells. Most only focus on the lift selection and do not include any production analysis to ascertain if liquid loading is the cause of low production. Further, many critical rate correlations are published however most are applicable for specific ranges of well parameters. This study attempts to provide a thorough gas well deliquification workflow. It includes production analysis to quantify root cause, new critical rate calculation that is universally applicable on most wells, and artificial lift selection process, specific to gas well deliquification, to select the most suitable lift systemPetroleum and Geosystems Engineerin

Non-linear propagation effects of intense femtosecond pulses on low order harmonics in solids

The non-linear propagation of the intense near-infrared (NIR) driving field in wide bandgap materials pose a challenge and an opportunity to control the spectral properties of high harmonic generation (HHG) in solids. Here, we have investigated the non-linear propagation effects of the ultrafast intense near-infrared (NIR) driving field at 800 nm of 40 fs pulse duration operating at a repetition rate of 1 kHz focused on the wide bandgap dielectrics such as MgO, Chromium (Cr) doped MgO (Cr: MgO), Sapphire (Sa) crystals and fused silica (FS). Furthermore, we have generated second and third harmonic (TH) in these materials to explore the non-linear response at a strong field. To quantify the non-linear propagation effects, low-order harmonics have been generated in reflection and compared with the harmonics generated in transmission. We observe spectral shifts and broadening of the driving field spectrum which is imprinted on the harmonics. We attribute these effects to strong photoionization, generation of free-carrier density and self-phase modulation effects. We have also studied the polarization dependence of second harmonic generation (SHG) and TH in FS. The linear polarization dependence of below bandgap harmonics in FS and Sa generated in reflection demonstrated the sharp anisotropy than in transmission. This work shows the sensitivity to control the spectral profile of harmonics by manipulating the driving field, showing the possibility of new tailored solid-state XUV sources for optical diagnostics

Prognostically Significant Fusion Oncogenes and Gene Mutations in Pakistani AML Patients

Background: The onset and progression of leukemia is associated with many genetic abnormalities including gene mutations and production of fusion oncogenes. Molecular studies on fusion oncogenes and mutations in different populations have been done. However, not much research on correlation of the fusion oncogenes with acute myeloid leukemia have been done in Pakistan.Methods: Genetic analysis of 105 AML patients was done to investigate AML1-ETOand CBFB-MYH11 fusion oncogenes and mutations in NPM1 and NRAS genes. The genomic DNA and cDNA were subjected to amplification, electrophoresis, and Sanger sequencing.Results: The frequency of AML1-ETO was 26% in AML patients and 34.2% in AML-M2 patients. CBFB-MYH11 was present in 11.4% AML patients. A total of six mutations in 4 regions of NPM1 gene and 2 regions of NRAS gene were detected. 3’UTR of NPMI gene had three variants; g.1128C>T (57.1%), g.1185-/T insertion (80.95%), and g.1163A>T (57.14%) while c.867_871subGTGGA >CAAGTTTGC (2.86%) was present in exon 12. NRAS gene had two mutations c.12C>T (51.4%) and c.33A>T (11.43%) in exon 2. c.867_871subGTGGA >CAAGTTTGC , and g.1163A>T in NPM1 gene and c.33A>T in NRAS gene were the novel findings in this ethnic population.Conclusion: This genetic analysis may help to modulate the treatment strategies and improve survival of patients.Keywords: Acute Myeloid Leukemia; Fusion Oncogenes; AML; AML1-ETO; CBFB-MYH11; AML-M2; Nucleophosmin, NPM1; NRAS

Photocatalytic Denitrification of Nitrate Using Fe-TiO2-Coated Clay Filters

In this work, 3D-structured clay filters were prepared and coated with iron-doped tita- nium dioxide (Fe-TiO2) using 3D printing and sol–gel soaking and calcination techniques. Three- dimensional printing was employed to mold and shape the clay filters before annealing. The coated and uncoated filters were characterized for different properties, i.e., morphology, optical properties, and crystalline structure, using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), UV/Vis diffused reflectance spectroscopy (DRS), and X-ray diffraction (XRD). The FESEM images show uniform coatings of round-shaped Fe-TiO2 on the tiny pore of the clay filter. The optical energy band gap of the obtained coating was around 2.8 eV, estimated by Tauc’s plot, compared with 3.2 eV of pristine anatase TiO2. The XRD spectra data processed through XRD software revealed the coatings of TiO2 on the filter surface with the obtained phase of anatase. The photocatalytic performance of bare and coated filters was initially tested for the degradation of indigo carmine (IC) dye and the obtained results suggested the photocatalytic degradation of IC dye by the Fe-TiO2 clay filter compared with the bare filter. Afterward, the deni- trification of nitrate NO3 at various concentrations was performed using Fe-TiO2-coated clay filters and analyzing the total nitrogen (TN) analysis and reduction of NO3 to nitrite (NO2−), nitrogen monoxide (NO), and nitrogen gas (N2). The TN analysis revealed up to 81% denitrification efficiency of the 30 ppm NO3 solution with the photocatalytic response of the Fe-TiO2-coated filter. The results revealed that the Fe-TiO2-coated clay filter has a high potential for denitrification applications under natural sunlight

Effect of fat contents of buttermilk on fatty acid composition, lipolysis, vitamins and sensory properties of cheddar-type cheese

Cheddar-type cheese produced from buttermilk had softer texture than standard cheddar cheese due to lower fat content of buttermilk. Fat is extremely important for the functional characteristics and optimum textural attributes of cheese. The effect of different fat contents of buttermilk on chemical characteristics of cheddar-type cheese is not previously investigated. This investigation was conducted to know the effect of different fat contents of buttermilk on fatty acids composition, organic acids, vitamins, lipolysis and sensory characteristics of cheddar-type cheese. Cheddar-type cheese was produced from buttermilk having 1, 1.75, 2.50 and 3.25% fat contents (control, T1, T2 and T3). Fat content of control, T1, T2 and T3 were 9.81, 16.34, 25.17 and 31.19%. Fatty acids profile was determined on GC–MS, organic acids and vitamin A and E were determined on HPLC. Free fatty acids, peroxide value and cholesterol were determined. Cheddar-style cheese produced from buttermilk (1% fat) showed that it had softer texture and lacking typical cheese flavor. Gas chromatography–mass spectrometry (GC–MS) analysis showed that long-chain unsaturated fatty acids in control, T1, T2 and T3 samples were 45.88, 45.78, 45.90 and 46.19 mg/100 g. High Performance Liquid Chromatography (HPLC) analysis showed that lactic acid, propionic acid, citric acid and acetic acid gradually and steadily increased during the storage interval of 90 days. At the age of 90 days, lactic acid in control, T1, T2 and T3 was 4,789, 5,487, 6,571 and 8,049 ppm, respectively. At the end of ripening duration of 90 days, free fatty acids in control, T1, T2 and T3 were 0.29, 0.31, 0.35 and 0.42% with no difference in peroxide value. Stability of vitamin A after 90 days storage control, T1, T2 and T3 was 87.0, 80.0, 94.0 and 91.0%. Flavor score of cheddar-type cheese produced from butter milk having 1.0, 2.5 and 3.25% fat content was 81, 89 and 91% of total score (9). Hence, it is concluded that cheddar-type cheese can be produced from buttermilk having 2.5 and 3.25% fat contents with acceptable sensory attributes. Application of buttermilk for the production of other cheese varieties should be studied