Early time dynamics of laser-ablated silicon using ultrafast grazing incidence X-ray scattering

Controlling the morphology of laser-derived nanomaterials is dependent on developing a better understanding of the particle nucleation dynamics in the ablation plume. Here, we utilize the femtosecond-length pulses from an x-ray free electron laser to perform time-resolved grazing incidence x-ray scattering measurements on a laser-produced silicon plasma plume. At 20 ps we observe a dramatic increase in the scattering amplitude at small scattering vectors, which we attribute to incipient formation of liquid silicon droplets. These results demonstrate the utility of XFELs as a tool for characterizing the formation dynamics of nanomaterials in laser-produced plasma plumes on ultrafast timescales

Compressed full-field Fourier transform spectrometry

Imaging Fourier transform spectrometry (IFTS) can be used for hyperspectral imaging in the wide-field mode. Wide-field hyperspectral imaging is a powerful technique for quantifying functional and morphological states of cells and tissues. Multiplexed fluoresce imaging, Multicolor spectral karyotyping of human chromosomes, spectral fluorescence resonance energy transfer(sp-FRET) and spontaneous Raman imaging are few examples. Unlike other hyperspectral imaging modalities, IFTS measures the Fourier transform of the spectrum of light at each pixel in the wide-field image, and traditionally, the inverse Fourier transform is used to extract the spectral information. The spectral recovery process (for each pixel) can be captured by a set of liner equations written in the matrix form below. Please click Additional Files below to see the full abstract

Study of tensile deformation behaviour of M250 grade maraging steel using acoustic emission

Tensile testing of solution annealed and thermally aged (755 K for various durations in the range of 0.25-100 h) specimens of M250 grade maraging steel has been carried out along with acoustic emission (AE) monitoring. Results have shown that strength increases and ductility decreases upon ageing up to 10 h and this has been attributed primarily to the precipitation of Ni3Ti. Continued increase in strength up to 40 h of ageing has been attributed primarily to the precipitation of Fe2Mo in addition to Ni3Ti. Increase in ductility for 10-40 h of ageing has been attributed to dissolution of needle like Ni3Ti precipitates and formation of fine spherical Fe2Mo. Ageing beyond 40 h decreases strength and increases ductility due to the reversion of martensite to austenite and coarsening of the precipitates. The AE generated during tensile deformation depends on the ageing time. Increased occurrence of shearing of the precipitates by dislocations and increased brittleness of the matrix up to 10 h ageing increases the AE. The decrease in the AE beyond 10 h of ageing is due to the occurrence of deformation by Orowan looping, dissolution of Ni3Ti precipitates and austenite reversion. The scanning electron microscopy (SEM) of the fracture surfaces has shown ductile fracture characterized by dimples and changes in the size and shape of the dimples with ageing time

Development of eddy current test procedure for non-destructive detection of fatigue cracks and corrosion in rivets of air-intake structures

Non-destructive detection of defects in countersunk of rivets in multi-layer air-intake structures is essential for ensuring structural integrity and flight safety. This paper presents an eddy current test procedure developed for reliable detection of simulated fatigue cracks and corrosion products in rivets of air-intake structures. This procedure is capable of reliably detecting 0.25 mm deep defects in 4 mm dia rivets and 0.75 mm deep defects in 5 mm dia rivets. Further, it is not influenced by thickness of the multilayers

Effect of temperature and salinity on the infectivity pattern of white spot syndrome virus (WSSV) in giant tiger shrimp Penaeus monodon (Fabricius, 1837)

White spot disease (WSD) caused by the lethal white spot syndrome virus (WSSV) continues to be the major cause of mortality among farmed tiger shrimp in India and elsewhere, resulting in an annual loss of about 4-6 billion US$. Among the environmental variables, temperature and salinity of the rearing water are considered to be major triggering factors for white spot disease outbreak. In order to characterise the effect of salinity and temperature on the pathogenecity of WSSV infection in giant tiger shrimp Penaeus monodon, a laboratory challenge study was conducted at different levels of temperature (16, 25, 27, 28, 30, 32 and 36 ºC) and salinity (0.5, 5, 10, 15, 30 and 45 g l-1) with virulent white spot syndrome virus. Significant influence of temperature (p<0.05) on the percentage mortality and time until death of shrimp affected by the virus was observed, whereas salinity did not show any effect. Significantly higher survival rate was recorded in animals exposed at 32 ºC (37%) and 36 ºC (14%), 21 days post-challenge (dpc). All the shrimp challenged at other temperature levels, however, died after 21 dpc. These results demonstrated preference of WSSV for lower temperatures and higher survival in temperature ranges of 32 ºC to 36 ºC. The present observation may help to develop a management option to control the WSSV inflicted mortalities by selecting favorable hyperthermic rearing conditions for the shrimp

Electroencephalographic assessment of concussive non-penetrative captive bolt stunning of turkeys

1. The aim of this study was to evaluate the electroencephalographic (EEG) and behavioural responses of turkeys stunned with three different concussive non-penetrative captive-bolt guns prior to slaughter. 2. A total of 31 slaughter weight ex-breeding female turkeys (29 weeks of age; mean body weight 13.32 ± SD 0.65 kg) were stunned with the Cash Poultry Killer (CPK) (n = 10), Turkey Euthanasia Device (TED) (n = 10) and Zephyr EXL (n = 11). 3. Mean peak kinetic energy was highest for the CPK compared to the TED and Zephyr EXL (75.9 ± 4.5, 28.4 ± 0.4 and 24.4 ± 0.7 J, respectively). 4. A total of 29 (94%) of the turkeys were rendered unconscious following captive bolt stunning, with total power of the EEG (Ptot) significantly reduced from baseline values (reductions of 67% CPK, 84% TED and 76% Zephyr EXL, p < 0.01) and waveforms becoming isoelectric after periods of transitional EEG. However, two birds shot with the CPK and Zephyr EXL had periods of behavioural/reflexes (rhythmic respiration, nictitating membrane reflex, neck tension) and EEG activity (43–47 and 36–60 + s after the shot, respectively) indicating incomplete concussion and return of consciousness. In one bird, the shot was incorrectly positioned (Zephyr EXL), while the other appeared to be related to a defective cartridge (CPK). 5. In conclusion, all three captive bolt gun models were effective in producing unconsciousness in turkeys, provided they were positioned correctly and power loads performed according to their specifications. KEYWORDS: Animal welfare, behaviour/brainstem reflexes, captive bolt, electroencephalogram (EEG), non-penetrative, stunning, turke

Mentoring the Mentors: Implementation and Evaluation of Four Fogarty-Sponsored Mentoring Training Workshops in Low-and Middle-Income Countries.

A growing body of evidence highlights the importance of competent mentoring in academic research. We describe the development, implementation, and evaluation of four regional 2-day intensive workshops to train mid- and senior-level investigators conducting public health, clinical, and basic science research across multiple academic institutions in low- and middle-income countries (LMICs) on tools and techniques of effective mentoring. Sponsored by the Fogarty International Center, workshops included didactic presentations, interactive discussions, and small-group problem-based learning and were conducted in Lima, Peru; Mombasa, Kenya; Bangalore, India; and Johannesburg, South Africa, from 2013 to 2016. Mid- or senior-level faculty from multiple academic institutions within each region applied and were selected. Thirty faculty from 12 South America-based institutions, 29 faculty from eight East Africa-based institutions, 37 faculty from 14 South Asia-based institutions, and 36 faculty from 13 Africa-based institutions participated, with diverse representation across disciplines, gender, and academic rank. Discussions and evaluations revealed important comparisons and contrasts in the practice of mentoring, and specific barriers and facilitators to mentoring within each cultural and regional context. Specific regional issues related to hierarchy, the post-colonial legacy, and diversity arose as challenges to mentoring in different parts of the world. Common barriers included a lack of a culture of mentoring, time constraints, lack of formal training, and a lack of recognition for mentoring. These workshops provided valuable training, were among the first of their kind, were well-attended, rated highly, and provided concepts and a structure for the development and strengthening of formal mentoring programs across LMIC institutions

Investigation Into the Humaneness of Slaughter Methods for Guinea Pigs (Cavia porcelus) in the Andean Region

Guinea pigs (Cavia porcelus) are an important source of nonhuman animal protein in the Andean region of South America. Specific guidelines regarding the welfare of guinea pigs before and during slaughter have yet to be developed. This study critically assessed the humaneness of 4 different stunning/slaughter methods for guinea pigs: cervical neck dislocation (n = 60), electrical head-only stunning (n = 83), carbon dioxide (CO(2)) stunning (n = 21), and penetrating captive bolt (n = 10). Following cervical neck dislocation, 97% of guinea pigs had at least 1 behavioral or cranial/spinal response. Six percent of guinea pigs were classified as mis-stunned after electrical stunning, and 1% were classified as mis-stunned after captive bolt. Increased respiratory effort was observed during CO(2) stunning. Apart from this finding, there were no other obvious behavioral responses that could be associated with suffering. Of the methods assessed, captive bolt was deemed the most humane, effective, and practical method of stunning guinea pigs. Cervical neck dislocation should not be recommended as a slaughter method for guinea pigs

EVALUATION OF SOLAR PHOTOVOLTAIC WATER PUMPING SYSTEM AND IMPROVING ITS EFFICIENCY FOR DEVELOPING AN ENERGY STORAGE DEVICE

An electricity demand in India is now at an all-time high. Agriculture accounts for 21.5 percent of total electricity use; according to sectoral demand patterns. Technology is becoming increasingly popular. PV cells are utilized to power electrical equipment because of their high energy output. Solar energy is a clean and inexpensive energy source. Solar powered water pumping is an important technology for conserving vital resources such as water and electricity. This experiment is to calculate the efficiency of solar pump and panel. It is evaluated by calculating the input and output energy of the pump and panel. By comparing the efficiencies of pump and panel we can be able to estimate the amount of loss of energy. For conserving the energy, we can also install battery and charge controller for the use of pump in dark without solar energy. It conserves energy even while the pump is working. At the time of 2-3pm the efficiency of solar panel is about 55-60% and for the pump is 50-55%. By installing the storage device, we can save 2-5% of the energy wastage. This proves to be a better implementation for conserving the energy and the use of pump at any time. View Article DOI: 10.47856/ijaast.2022.v09i08.00