Improved sensitivity RF photonics doppler frequency measurement system

An improved sensitivity Doppler frequency measurement system based on microwave photonics technology was demonstrated practically. The system employs a four-wave mixing effect to achieve broad radio-frequency (RF) frequency measurement. In addition, a lock-in amplification technique was utilized to achieve high-measurement sensitivity. The system is, thus, capable of Doppler frequency estimation of radar echoes with a carrier frequency up to 40 GHz and a power level as low as $-$35 dBm. © 2009-2012 IEEE

Neutrino spin oscillations in gravitational fields

We study neutrino spin oscillations in black hole backgrounds. In the case of a charged black hole, the maximum frequency of oscillations is a monotonically increasing function of the charge. For a rotating black hole, the maximum frequency decreases with increasing the angular momentum. In both cases, the frequency of spin oscillations decreases as the distance from the black hole grows. As a phenomenological application of our results, we study simple bipolar neutrino system which is an interesting example of collective neutrino oscillations. We show that the precession frequency of the flavor pendulum as a function of the neutrino number density will be higher for a charged/non-rotating black hole compared with a neutral/rotating black hole respectively.Comment: Replaced with the version accepted for publication in Gravitation and Cosmology, Springer. 10 pages. 4 figure

Nursing Students' Competencies in Evidence-Based Practice and Its Related Factors

Background: Evidence-Based Practice (EBP) is one of the nursing professional roles that can lead them to provide the best and more effective care. However, no studies are available on nursing students’ competencies in EBP. Objectives: This study aimed to investigate the nursing students’ knowledge, attitude and intention to implement EBP and its related factors in two nursing and midwifery faculties in Tehran, Iran. Materials and Methods: In this cross-sectional study, 170 undergraduate nursing students were selected from two faculties of nursing and midwifery in Tehran, Iran. A census sampling method was applied and they were all before graduation in 2013. The Rubin and Parrish questionnaire was used to assess the students’ knowledge, attitude and intention to implement EBP as well as factors affecting the implementation of EBP. Students completed the instrument through self-report. Descriptive statistics, Independent sample t-test and Pearson correlation coefficient were used to analyze the data. Results: The students mean scores of knowledge, attitude and intention to implement EBP was 31.08 ± 5.77, 50.40 ± 9.58, 36.01 ± 4.64, respectively. The students’ age was inversely correlated with their scores of knowledge, attitude and intention to use EBP (P < 0.05). However, the students’ GPA was in direct association with their knowledge, attitude and intention to implement EBP (P < 0.05). No significant differences were observed between the males and females mean scores in the three subscales. However, significant differences were found between the students mean scores in the two subscales of knowledge and attitudes toward EBP in terms of familiarity with statistics and research methods (P < 0.05). Neither familiarity with research methods nor familiarity with EBP could significantly affect the students’ intention to implement EBP. Conclusions: The present study showed that nursing students have not a high mean score in the three subscales of knowledge, attitude and intention to implement EBP. It is essential for faculties and nurse managers not only to focus on education of EBP, but also to support nurses and nursing students to implement it in the process patient care

Audit of Intrapartum Care Based on the National Guideline for Midwifery and Birth Services

© The Author(s) 2018. Providing high-quality maternity care is a worldwide health concern that necessitates regular assessment of intrapartum practice. In an observational study, we aimed to audit intrapartum care based on the National Guideline for Midwifery and Birth Services. Using quota sampling, a total of 200 pregnant women, admitted for normal vaginal delivery, were recruited from four educational hospitals in Tehran, Iran. An observational checklist was developed based on the national guideline to assess the quality of provided care. Content and face validity of the tool were checked and confirmed. Reliability of the observational checklist and questionnaire was confirmed using concurrent observation (intrarater reliability; r =.93) and test–retest (r =.9) methods, respectively. We found that the compatibility of intrapartum care and the national guideline in different domains were as follows: history taking 88.3%, vital sign measurement 64.6%, performing Leopold’s maneuver 38.5%, initial assessment 83.4%, labor care 22.5%, using pain relief methods 63.5%, labor progress assessment 71.5%, process of delivery 89.5%, and postpartum management 89.5%. The findings indicate that additional attention and monitoring are required to align current intrapartum care practices with the national guidelines

Activation of sperm motility in the euryhaline tilapia Sarotherodon melanotheron heudelotii (Dumeril, 1859) acclimatized to fresh, sea and hypersaline waters

The effects of osmolality and ions were examined on motility of sperm from males of Sarotherodon melanotheron heudelotii acclimatized in tanks at salinities set at 0, 35 and 70 g L-1. The range of osmolality that enabled sperm activation, shifted and broadened as the maintenance salinity of broodfish increased. The requirement of extracellular Ca2+ for activation of sperm motility increased when the maintenance salinity of broodfish was higher

The analysis of phase, dispersion and group delay in InGaAsP/InP microring resonator

The Vernier operation with signal flow graph (SFG) is a graphical approach for analyzing the intricate photonic circuits mathematically and quick calculation of optical transfer function. Analysis of a cascaded microring resonators (CMRR) made of InGaAsP/InP semiconductor is presented using the signal flow graph (SFG) method which enables modelling the transfer function of the passive CMRR. These passive filters are mostly characterized by their frequency response. The theoretical calculations of the system is performed by the Vernier effects analysis. Two MRRs with radius of 100 μm which are vertically coupled together are used to generate resonant peaks. Here, the phase, dispersion and group delay of the generated signals are analyzed

Temporal soliton: generation and applications in optical communications

In general, the temporal and spectral shape of a short optical soliton pulse does not change during propagation in a nonlinear medium due to the Kerr effect which balances the chromatic dispersion. Microring resonators (MRRs) can be used to generate chaotic signals. The smaller MRR is used to form the stopping and filtering system. The employed optical material was InGaAsP/InP, which is suitable for use in the practical devices and systems. The tuning and manipulation of the bandwidth of the soliton signals is recommended to control the output signals. The MRRs can be applied to produce ultra-short pulses, where the medium has a nonlinear condition, thus, using of soliton laser becomes an interesting subject. Therefore, an ultra-short pulse in the scope of pico and femtoseconds soliton pulses can be utilized for many applications in engineering communications. In order to obtain smaller bandwidth of the optical soliton pulses, we propose integrating series of MRRs. In this study, 5 fs soliton pulse could be generated using a series of five MRRs. The soliton signals experience less loss during the propagation, where they are more stable compared to normal conventional laser pulses. Using the series of MRRs connected to an add/drop system, shorter soliton bandwidth and highly multi soliton pulses can be obtained. Therefore, generation of ultra-short multi picosecond (1.2 and 1.3 ps), could be performed, where the radius of the add/drop system has been selected to 50 and 300 μm respectively

Effective Hamiltonian Approach to Hyperon Beta Decay with Final-State Baryon Polarization

Using an effective Hamiltonian approach, we obtain expressions for hyperon beta decay final-state baryon polarization. Terms through second order in the energy release are retained. The resulting approximate expressions are much simpler and more compact than the exact expressions, and they agree closely with them.Comment: 1 Figure Will appear in Phys Rev D 60 Article 117505 (Dec 1, 1999

Burst Out of the Dead Land by the Help of Spirituality: A Case Study of Living with Blindness and Cancer.

Blindness is one of the most complex problems related to health throughout the world. The condition is worse when such stress is accompanied with cancer. The aim of this case study was to introduce a patient with both these conditions who could come over her problems well. A phenomenological hermeneutic approach influenced by Ricoeur was used to explore the experience of the patient. Data were collected through unstructured and deep interview and by checking patient medical records. The patient is an Iranian 58-year-old teacher residing in Kerman who became blind at age 32 due to bloodshed inside the eye and was affected by breast cancer at age 52. The patient could come over these divine tests through the help of spirituality so that she believed blindness and cancer was the best events in her life. Spirituality is one of the human aspects that give meaning and purposes to life. Health care providers are suggested to implement spiritual strategies such as instructional workshops for increasing spirituality in settings, such as oncologic wards for patients to pass stages of adaptation to such great stresses easily and rapidly