Determination of Refrigerant Path Number for Fin-tube Condenser Considering Heat Transfer Performance and Pumping Power

Fin-tube heat exchangers are widely used in air-conditioners and heat pumps, which are constructed with a lot of tubes. Refrigerant circuit of heat exchanger with numerous pipe can be constructed by many methods. Refrigerant circuit design is usually determined designer’s experience and case by case test without guides. The number of path affects largely on heat exchanger performance. In this paper, design methodology for optimum number of path is suggested by relating convective thermal resistance and pumping power. Suggested methodology is described through an example and verified by various refrigerant circuit simulation results

Separatrix modes in weakly deformed microdisk cavities

Optical modes in deformed dielectric microdisk cavities often show an unexpected localization along unstable periodic ray orbits. We reveal a new mechanism for this kind of localization in weakly deformed cavities. In such systems the ray dynamics is nearly integrable and its phase space contains small island chains. When increasing the deformation the enlarging islands incorporate more and more modes. Each time a mode comes close to the border of an island chain (separatrix) the mode exhibits a strong localization near the corresponding unstable periodic orbit. Using an EBK quantization scheme taking into account the Fresnel coefficients we derive a frequency condition for the localization. Observing far field intensity patterns and tunneling distances, reveals small differences in the emission properties. © 2017 Optical Society of America.1

Lymphangiography to treat postoperative lymphatic leakage: a technical review.

In addition to imaging the lymphatics and detecting various types of lymphatic leakage, lymphangiography is a therapeutic option for patients with chylothorax, chylous ascites, and lymphatic fistula. Percutaneous thoracic duct embolization, transabdominal catheterization of the cisterna chyli or thoracic duct, and subsequent embolization of the thoracic duct is an alternative to surgical ligation of the thoracic duct. In this pictorial review, we present the detailed technique, clinical applications, and complications of lymphangiography and thoracic duct embolization

Orphan nuclear receptor Nurr1 induces neuron differentiation from embryonic cortical precursor cells via an extrinsic paracrine mechanism

AbstractNurr1 is an orphan nuclear receptor-type transcription factor (TF) that plays critical roles in midbrain dopamine neuron development. This study demonstrated a novel role for Nurr1 in neuronal/astrocytic differentiation of neural precursor (NP) cells isolated from rat embryonic cortices: overexpression of this TF promoted NP cell differentiation towards neurons at the expense of astrocytic differentiation. Single cell-based lineage analyses and experiments using co-cultures revealed that Nurr1 elicited its neurogenic role in an extrinsic paracrine manner. We defined diffusible factors and downstream neurogenic TFs responsible for the Nurr1-mediated neuronal differentiation

Age-related changes in cervical sagittal range of motion and alignment

Study Design Retrospective cohort study. Objective To compare sagittal cervical range of motion (ROM) and alignment in young versus middle-aged adults. Methods One hundred four asymptomatic adults were selected randomly out of 791 subjects who underwent lateral cervical radiographs in neutral, flexion, and extension positions. They were divided into two groups: young (age 20 to 29, 52 people) and middle-aged adults (age 50 to 59, 52 people). We determined the ROMs of upper cervical (occipital–C2 angle), midcervical (C2–C7 angle), and cervicothoracic spine (cervicosternal angle). We compared the alignment differences of the two groups by calculating the distances between C2 and C7 plumb lines, and C2 central-offset distance. Results In neutral position, there was no significant difference between young and middle-aged adults. However, in flexion, C2–C7 angle, distance between C2–C7 plumb lines, and C2 central-offset distance decreased with age. In extension, C2–C7 angle and C2 central-offset distance decreased with age. During flexion and extension, midcervical ROM and the range of C2 central-offset distance decreased in the middle-aged group. However, there was no difference between the two age groups in the ROM of the upper cervical and the cervicothoracic regions during flexion and extension. Conclusion We found that, despite of the presence of age-related cervical alignment changes, the only difference between the two groups was in the sagittal ROM of the midcervical spine during flexion and extension. Only the ROM of the midcervical spine appears to change significantly, consistent with findings that these levels are most likely to develop both symptomatic and asymptomatic degenerative changes

Chirality of a resonance in the absence of backscatterings

Chirality of a resonance localized on an islands chain is studied in a deformed Reuleaux triangular-shaped microcavity, where clockwise and counter clockwise traveling rays are classically separated. A resonance localized on a period-5 islands chain exhibits chiral emission due to the asymmetric cavity shape. Chirality is experimentally proved in a InGaAsP multiquantum-well semiconductor laser by showing that the experimental emission characteristics well coincide with the wave dynamical ones. (C) 2017 Optical Society of America1