Van der Waals Materials for Atomically-Thin Photovoltaics: Promise and Outlook

Two-dimensional (2D) semiconductors provide a unique opportunity for optoelectronics due to their layered atomic structure, electronic and optical properties. To date, a majority of the application-oriented research in this field has been focused on field-effect electronics as well as photodetectors and light emitting diodes. Here we present a perspective on the use of 2D semiconductors for photovoltaic applications. We discuss photonic device designs that enable light trapping in nanometer-thickness absorber layers, and we also outline schemes for efficient carrier transport and collection. We further provide theoretical estimates of efficiency indicating that 2D semiconductors can indeed be competitive with and complementary to conventional photovoltaics, based on favorable energy bandgap, absorption, external radiative efficiency, along with recent experimental demonstrations. Photonic and electronic design of 2D semiconductor photovoltaics represents a new direction for realizing ultrathin, efficient solar cells with applications ranging from conventional power generation to portable and ultralight solar power.Comment: 4 figure

KNOWLEDGE, ATTITUDE, AND PRACTICE OF GENERIC DRUGS AMONG DOCTORS IN A TERTIARY CARE HOSPITAL

Objectives: Generic medicines constitute an important aspect of affordable health care. “JAN AUSHADHI” campaign was started by the Government of India in 2008 to support generic prescriptions. Recently, medical council of India had requested all clinicians for generic prescriptions. With this background, this study was undertaken to evaluate the knowledge, attitude, and practice of generic medicines among doctors. Methods: It was a cross-sectional, prospective, questionnaire-based study. After obtaining institute permission, validated questionnaires were distributed to different clinical departments at Vydehi Institute of Medical Sciences and Research Centre, Bengaluru. With gentle reminders in between, filled forms were collected after 7 days. Results: Mean age of the participants was 29.05±17.81 years. Out of 250 questionnaires distributed, 156 were returned back without responding. The response rate was 62.4%. Out of 156, 35 (22.43%) were intern medical officers, 89 (57.05%) were post-graduates, and 32 (20.51%) were faculty members. Regarding knowledge, the mean score was 6.24±0.17. 52 (33.33%) participants had good knowledge, 73 (46.79%) had average knowledge, and 31 (19.87%) had poor knowledge about generic medicines. Generics were prescribed by 90 (57.69%) participants. Most of the clinicians (66.02%) felt that prescribing in generics is not a burden on them provided government ensured the quality control of drugs. 121 (77.56%) stated that the socioeconomic status of the patient is an important factor while prescribing generics. 136 (87.17%) felt that generics bring down the treatment costs. Conclusion: This study shows that participants were well aware about generic drugs. As opined by the clinicians, a national level online reference must be made available

ORIF of Radius and Ulna Video Demonstration

Video is an emerging medium that has become an invaluable resource within education. It allows for a multisensory, both visual and auditory, means for students to learn quickly and effectively. We hope to contribute to a growing peer-reviewed video library using this technology

Cosmology with decaying tachyon matter

We investigate the case of a homogeneous tachyon field coupled to gravity in a spatially flat Friedman-Robertson-Walker spacetime. Assuming the field evolution to be exponentially decaying with time we solve the field equations and show that, under certain conditions, the scale factor represents an accelerating universe, following a phase of decelerated expansion. We make use of a model of dark energy (with p=-\rho) and dark matter (p=0) where a single scalar field (tachyon) governs the dynamics of both the dark components. We show that this model fits the current supernova data as well as the canonical \LambdaCDM model. We give the bounds on the parameters allowed by the current data.Comment: 14 pages, 6 figures, v2, Discussions and references addede

Acitretin for the Treatment of Recalcitrant Plantar Warts

Plantar warts caused by human papilloma virus (HPV)may be challenging to treat when conventionalmodalities fail. We report a case of severely recalcitrantplantar warts, successfully treated with oral acitretinand topical 40% urea cream

AVD Tablet Labs: Virtual Chemistry Laboratories, Honors Chemistry, Grade:10

With the increased prevalence of student computers in secondary schools, we created six virtual chemistry laboratories using the virtual lab environment created by Carnegie-Mellon University. Students, using their laptop or tablet computer, can manipulate typical laboratory instrumentation found in an introductory chemistry lab. While not designed to replace traditional wet laboratories, the virtual laboratory environment allows students to examine the nuances of experimental techniques in a low stakes, easily repeatable, environment. The six virtual laboratories developed for this project cover the introductory chemistry subjects of: 1.) density measurements and significant figures, 2.) reaction stoichiometry, 3.) measurements of grams and moles, 4.) limiting reactants, 5.) acid, bases and solution pH, and 6.) molar mass determination of an unknown acid

High Photovoltaic Quantum Efficiency in Ultrathin van der Waals Heterostructures

We report experimental measurements for ultrathin (< 15 nm) van der Waals heterostructures exhibiting external quantum efficiencies exceeding 50%, and show that these structures can achieve experimental absorbance > 90%. By coupling electromagnetic simulations and experimental measurements, we show that pn WSe2/MoS2 heterojunctions with vertical carrier collection can have internal photocarrier collection efficiencies exceeding 70%.Comment: ACS Nano, 2017. Manuscript (25 pages, 7 figures) plus supporting information (7 pages, 4 figures