Mathematical Modeling of Efficiency Evaluation of Double-Pass Parallel Flow Solar Air Heater

To investigate the influencing range and optimize values of different operational and system parameters on the double-pass parallel flow solar air heater’s (DPPFSAH) thermal, effective, and exergetic efficiencies, an iterative method was used to analyze the governing energy equations using a theoretical model written in MATLAB based on the Nusselt number (Nu) and friction factor (f) correlations developed in the work performed earlier. A comparison between double-pass and single-pass SAHs for mathematical and experimental outcomes was conducted, and the results were found to be fairly consistent. According to the thermo-hydraulic performance indicators, similar to single-pass SAHs, perforated multi-V rib-roughened DPPFSAHs achieve optimum thermal performance for lower Reynolds numbers, which does not change much as the Reynolds number increases above 18,000. This finding can be taken into account when designing any DPPFSAH

Establishment of Trophectoderm Cell Lines from Buffalo (<i>Bubalus bubalis</i>) Embryos of Different Sources and Examination of In Vitro Developmental Competence, Quality, Epigenetic Status and Gene Expression in Cloned Embryos Derived from Them

<div><p>Despite being successfully used to produce live offspring in many species, somatic cell nuclear transfer (NT) has had a limited applicability due to very low (>1%) live birth rate because of a high incidence of pregnancy failure, which is mainly due to placental dysfunction. Since this may be due to abnormalities in the trophectoderm (TE) cell lineage, TE cells can be a model to understand the placental growth disorders seen after NT. We isolated and characterized buffalo TE cells from blastocysts produced by in vitro fertilization (TE-IVF) and Hand-made cloning (TE-HMC), and compared their growth characteristics and gene expression, and developed a feeder-free culture system for their long-term culture. The TE-IVF cells were then used as donor cells to produce HMC embryos following which their developmental competence, quality, epigenetic status and gene expression were compared with those of HMC embryos produced using fetal or adult fibroblasts as donor cells. We found that although TE-HMC and TE-IVF cells have a similar capability to grow in culture, significant differences exist in gene expression levels between them and between IVF and HMC embryos from which they are derived, which may have a role in the placental abnormalities associated with NT pregnancies. Although TE cells can be used as donor cells for producing HMC blastocysts, their developmental competence and quality is lower than that of blastocysts produced from fetal or adult fibroblasts. The epigenetic status and expression level of many important genes is different in HMC blastocysts produced using TE cells or fetal or adult fibroblasts or those produced by IVF.</p></div

Global CDX2 levels in different types of embryos.

<p>Global level of CDX2 in cloned embryos produced using trophoblast cells, adult fibroblasts and fetal fibroblasts as donor cells and those produced by IVF. Bars marked with an asterisk differ significantly from corresponding values (P<i><</i>0.05).</p

Effect of fetal fibroblast CM on growth of TE cells.

<p>Data from 3 trials. Data are Mean ± SEM. Values with different superscripts (a and b) within the same column differ significantly (P<0.05).</p><p>Effect of fetal fibroblast CM on growth of TE cells.</p

Effect of FGF2 on expression level of trophoblast-specific genes.

<p>Bars with different superscripts differ significantly (P<0.05).</p

Derivation of presumptive TE cells.

<p>(A) An IVF-derived blastocyst seeded on buffalo fetal fibroblast feeder layer; (B) A primary colony of TE cells (40X, Scale bar = 500 μm); (C) A primary colony showing inner cell mass and endoderm cells (100X); (D) Endoderm colonies indicated by the arrow mark showing tight colony morphology (100X), Inset: Endoderm colony at 400X (Scale bar = 50 μm); (E) TE cells at passage 20 (200X) and (F) TE cells digested with accutase showing loosening of cells and thread-like structures which are the parts of tight junctions (400X, Scale bar = 50 μm). Scale bar = 100 μm, unless otherwise mentioned in Figure.</p

Immunostaining of CDX2.

<p>(A) IVF-derived hatched blastocysts (100X) and (B) TE cells produced under feeder-free conditions showing positive expression of CDX2 (200X). Scale bar = 100 μm.</p

Growth analysis of presumptive TE cells from different sources.

<p>Growth rate of (A) primary colonies on fetal fibroblast feeder layer and (B) TE cells obtained from IVF-derived hatched blastocysts and HMC-derived cloned blastocysts on MaxGel ECM under feeder-free conditions. Bars/graph points marked with an asterisk differ significantly from the corresponding value. *(P<0.01); **(P<0.001).</p