169 research outputs found
Chasing the Intruder: A Reinforcement Learning Approach for Tracking Intruder Drones
Drones are becoming versatile in a myriad of applications. This has led to
the use of drones for spying and intruding into the restricted or private air
spaces. Such foul use of drone technology is dangerous for the safety and
security of many critical infrastructures. In addition, due to the varied
low-cost design and agility of the drones, it is a challenging task to identify
and track them using the conventional radar systems. In this paper, we propose
a reinforcement learning based approach for identifying and tracking any
intruder drone using a chaser drone. Our proposed solution uses computer vision
techniques interleaved with the policy learning framework of reinforcement
learning to learn a control policy for chasing the intruder drone. The whole
system has been implemented using ROS and Gazebo along with the Ardupilot based
flight controller. The results show that the reinforcement learning based
policy converges to identify and track the intruder drone. Further, the learnt
policy is robust with respect to the change in speed or orientation of the
intruder drone
Controlled coalescence-induced droplet jumping on flexible superhydrophobic substrates
Sessile droplets coalescing on superhydrophobic substrates spontaneously jump
from the surface. In this process, the excess surface energy available at the
initiation of coalescence overcomes the minimal surface adhesion and manifests
as sufficient kinetic energy to propel the droplets away from the substrate.
Here, we show that the coalescence induced droplet jumping velocity is
significantly curtailed if the superhydrophobic substrate is flexible in
nature. Through detailed experimental measurements and numerical simulations,
we demonstrate that the droplet jumping velocity and jumping height can be
reduced by as much as 40 % and 64%, respectively, by synergistically tuning the
substrate stiffness and substrate frequency. We show that this hitherto
unexplored aspect of droplet coalescence jumping can be gainfully exploited in
water harvesting from dew and fog harvesting. Additionally, through an exemplar
butterfly wing substrate, we demonstrate that this effect is likely to manifest
on many natural superhydrophobic substrates due to their inherent flexibility
PENGEMBANGAN BAHAN AJAR ILMU KESEHATAN DAN GIZI PROGRAM SBI PENDIDIKAN BIOLOGI DAN IMPLEMENTASINYA MELALUI LESSON STUDY
Tujuan dari penelitian ini adalah mengembangkan bahan ajar ilmu kesehatan dan gizi (Health and Nutrition) dan mengaplikasikannya dalam pembelajaran melalui lesson study guna meningkatkan kualitas belajar dari aspek interaksi mahasiswa serta hasil belajar mahasiswa.
Penelitian dilakukan dengan kegiatan penyusunan buku ajar Ilmu Kesehatan dan Gizi (Health and Nutrition) serta diimplementasikan melalui lesson study. Proses lesson study melalui tahapan pembentukan tim, perumusan tim apa yang akan dibelajarkan pada mahasiswa, penyusunan disain pembelajaran, pelaksanaan pembelajaran, analisa pembelajaran dan pengulangan tahap pembelajaran dengan perbaikan. Efektivitas adanya buku ajar diketahui melalui aspek pengamatan interaksi mahasiswa dalam proses pembelajaran serta hasil belajar.
Berdasar hasil penelitian dapat disimpulkan bahwa pada akhir penelitian telah dihasilkan luaran buku ajar IKG (Health and Nutrition) yang telah diimplementasikan dalam pembelajaran melalui lesson study dan diketahui efektif meningkatkan kualitas pembelajaran dari aspek interaksi mahasiswa (mahasiswa antar mahasiswa, mahasiswa dengan dosen, mahasiswa dengan media) serta peningkatan hasil belajar (100% mahasiswa tuntas mencapai hasil belajar di atas 70)
Kata kunci : bahan ajar, lesson study, Ilmu Kesehatan dan Gizi, Health and Nutritio
Gradation of Nanoparticle Size by Stokes' Law: A New Approach for Synthesis of CdS Nanoparticles
The synthesis technique and its allied process parameters have a specific effect on the nucleation, growth-dominated microstructure and properties of nanostructure materials. The properties of semiconductor nanoparticles strongly depend on its size, shape, composition, crystallinity and structure. Recently, semiconductor nanoparticles have been extensively investigated and gained much interest due to their unique properties and applications in diverse areas of science and technology. A new controlled technique for synthesis of CdS nanopartlicles by means of kinetic approach using well-known Stokes' law for free body falling in quiescent and viscous fluid has been employed. Nanoparticles of cadmium sulfide (CdS) have been synthesized by simple controlled chemical method using IR radiation heating without using any capping agent and stirring. The desired concentration of aqueous solutions of cadmium chloride (CdCl2.2H2O) and thioacetamide (CH3CSNH2) were reacted in a controlled manner by IR radiation heating at the reaction area (top layer of reactants solution) of solution results the formation of CdS nanoparticles following Stokes' law. The as-synthesized nanoparticles were characterized by XRD, optical spectroscopy and SEM with EDX analysis
Hybrid Spectral-IRDx: Near-IR and Ultrasound Attenuation System for Differentiating Breast Cancer from Adjacent Normal Tissue
OBJECTIVE: While performing surgical excision for breast cancer (lumpectomy), it is important to ensure a clear margin of normal tissue around the cancer to achieve complete resection. The current standard is histopathology; however, it is time-consuming and labour-intensive requiring skilled personnel. METHOD: We describe a Hybrid Spectral-IRDx - a combination of the previously reported Spectral-IRDx tool with multimodal ultrasound and NIR spectroscopy techniques. We show how this portable, cost-effective, minimal-contact tool could provide rapid diagnosis of cancer using formalin-fixed (FF) and deparaffinized (DP) breast biopsy tissues. RESULTS: Using this new tool, measurements were performed on cancerous/fibroadenoma and its adjacent normal tissues from the same patients (N=14). The acoustic attenuation coefficient () and reduced scattering coefficient (s) (at 850, 940, and 1060 nm) for the cancerous/fibroadenoma tissues were reported to be higher compared to adjacent normal tissues, a basis of delineation. Comparing FF cancerous and adjacent normal tissue, the difference in s at 850 nm and 940 nm were statistically significant (p=3.17e-2 and 7.94e-3 respectively). The difference in between the cancerous and adjacent normal tissues for DP and FF tissues were also statistically significant (p=2.85e-2 and 7.94e-3 respectively). Combining multimodal parameters and s (at 940 nm) show highest statistical significance (p=6.72e-4) between FF cancerous/fibroadenoma and adjacent normal tissues. CONCLUSION: We show that Hybrid Spectral-IRDx can accurately delineate between cancerous and adjacent normal breast biopsy tissue. SIGNIFICANCE: The results obtained establish the proof-of-principle and large-scale testing of this multimodal breast cancer diagnostic platform for core biopsy diagnosis
Appearance and disappearance of superconductivity in SmFe1-xNixAsO (x = 0.0 to 1.0)
Bulk polycrystalline Ni-substituted SmFe1-xNixAsO (x = 0.0 to 1.0) samples
are synthesized by solid state reaction route in an evacuated sealed quartz
tube. The cell volume decreases with increase of Ni content in SmFe1-xNixAsO,
thus indicating successful substitution of smaller ion Ni at Fe site. The
resistivity measurements showed that the spin-density-wave (SDW) transition is
suppressed drastically with Ni doping and subsequently superconductivity is
achieved in a narrow range of x from 0.04 to 0.10 with maximum Tc of 9K at x =
0.06. For higher content of Ni (x > 0.10), the system becomes metallic and
superconductivity is not observed down to 2K. The magneto-transport [R(T)H]
measurements exhibited the upper critical field [Hc2(0)] of up to 300kOe. The
flux flow activation energy (U/kB) is estimated ~98.37K for 0.1T field.
Magnetic susceptibility measurements also confirms bulk superconductivity for x
= 0.04, 0.06 and 0.08 samples. The lower critical field (Hc1) is around 100Oe
at 2K for x = 0.06 sample. Heat capacity CP(T) measurements exhibited a hump
like transition pertaining to SDW in Fe planes at around 150K and an AFM
ordering of Sm spins below temperature of 5.4K for ordered Sm spins [TN(Sm)].
Though, the SDW hump for Fe spins disappears for Ni doped samples, the TN (Sm)
remains unaltered but with a reduced transition height, i.e., decreased
entropy. In conclusion, complete phase diagram of SmFe1-xNixAsO (x = 0.0 to
1.0) is studied in terms of its structural, electrical, magnetic and thermal
properties.Comment: 18 pages text + Figures; comments suggestions welcome
([email protected]
In-Vitro anti-inflammatory activity of S. xanthocarpum and A. officinarum herb by Human red blood cell membrane stabilization method
Natural remedies are more acceptable in the belief that they are safer with fewer side effects than the synthetic ones. Herbal formulations have growing demand in the world market. Solanum xanthocarpum herb is highly used by the rural and tribal people in curing various disorders. The aim of the current investigation is evaluation of anti inflammatory activity of solanum xanthocarpum extract and Alpinia officinarum. In-vitro anti-inflammatory study performed by percentage inhibition of Human red blood cell (HRBC) membrane stabilization method. Four different concentration of extract 1mg/ml, 2 mg/ml, 4 mg/ml and 6 mg/ml were used for each extract. Among which ethanolic extract of S. xanthocarpum at concentration 6 mg/ml showed 50.1 % protection of HRBC in hypotonic solution and A. officinarum extract at concentration 6 mg/ml showed 56.89 while combination of extract (1:1 ratio) at concentration 6 mg/ml showed 67.89 % protection of HRBC in hypotonic solution. All the results were compared with standard indomethacin which showed 70.0 % protection at concentration 2.5 mg/ml
Keyword: Natural remedies, anti-inflammatory, Human red blood cell (HRBC) membrane stabilization, hypotonic solution
COVID-19 vaccine hesitancy and attitude toward booster doses among US healthcare workers
Vaccine reluctance among healthcare workers (HCW) can have widespread negative ramifications, including modeling behavior for the general population and challenges with maintaining a healthy workforce so we can respond to a resurgence of the pandemic. We previously reported that only one-third of HCW were willing to take the vaccine as soon as it became available prior to its Emergency Use Authorization (EUA). Here, we re-examine the attitude toward COVID-19 vaccines among HCW several months after the vaccines have been made widely available. In this study, only 7.9% (n = 107) of respondents were hesitant to take the first or second dose of the vaccine. Younger age (18-40 years) and lower level of education attainment (GED or less) were associated with higher vaccine hesitancy, whereas self-identified Asian racial identity was associated with greater acceptance of COVID-19 vaccination. Among the vaccine-hesitant group, more respondents noted mistrust of regulatory authorities (45.3%), government (48.6%), and pharmaceutical companies (50%) than mistrust of doctors (25.4%). Nearly two-thirds of respondents were concerned that vaccination may be ineffective against new strains and booster doses may be required; however, vaccine-hesitant respondents\u27 acceptance of a hypothetical booster dose was only 14.3%. Overall, vaccine hesitancy was observed to have demographic predictors similar to those previously reported; the hesitancy of some US HCW to receive booster doses may reflect a general hesitancy to receive other forms of vaccination
Serum malondialdehyde in different stages of chronic renal disorder
Background: Chronic kidney disease (CKD) is a widespread public health problem, which may have several adverse consequences such as renal failure, cardiovascular disease, and premature death. Kidney-related pathologies have increasing prevalence rates, produce a considerable financial burden, and are characterized by elevated levels of oxidative stress (OS). Several markers emerged as well-suited indicators of OS such as malondialdehyde (MDA) and lipid hydroperoxides. The reduced activities of antioxidant enzymes status and increased production of MDA in the CKD patients confirm the presence of OS. The alteration in antioxidant status and MDA in CKD patients supports the role of OS in CKD patient.
Aims and Objectives: The aim of the study was to compare serum MDA in different stages of CKD with that of control. It is well known that inflammation has an important role in CKD and MDA is an oxidant biomarker.
Materials and Methods: This was a cross-sectional study having 400 participants with 300 known cases of CKD and 100 healthy controls. Serum MDA levels were measured by thiobarbituric acid assay.
Results: There was a significant difference between the groups regarding the MDA values (P<0.001) with that of control. The mean MDA value in Stage III (5.64±1.93 Umol/L), Stage IV (6.14±1.584 Umol/L), and Stage V (10.761±3.347 U moL/L) of CKD patients were high in comparison to healthy control (1.88±0.181 U mol/L).
Conclusion: We concluded that MDA is a useful biomarker in CKD patients. The correlations of serum MDA among different stages of CKD patients were significant. Larger studies focused on CKD severity and antioxidant/oxidant biomarkers are required
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