Numerical Study of a Three-Bed Adsorption Chiller Employing an Advanced Mass Recovery Process

The performance improvement of a three-bed (equal bed) adsorption chiller employing an advanced mass recovery process has been numerically studied in this paper. The mass recovery scheme is used to improve the cooling effect and a CFC-free-based sorption chiller driven by the low-grade waste heat or any renewable energy source can be developed for the next generation of refrigeration. Silica gel/water is taken as adsorbent/adsorbate pair for the present chiller. The three-bed adsorption chiller comprises with three adsorber/desorber heat exchanger, one evaporator and one condenser. In the present numerical solution, the heat source temperature variation is taken from 500C to 900C along with coolant inlet temperature at 300C and the chilled water inlet temperature at 140C. In the new strategy, if any one bed (3rd bed) is connect with the evaporator during pre-heating or pre-cooling time then it will give better performance than that of existing system. In this strategy, mass recovery process also occurs in all bed. A cycle simulation computer program is constructed to analyze the influence of operating conditions (hot and cooling water temperature) on COP (coefficient of performance), and CC (cooling capacity)

Methyl 3-[(E,E)-3-phenyl­prop-2-enyl­idene]dithio­carbazate

In the title compound, C11H12N2S2, the dithio­carbazate group adopts an EE configuration with respect to the C=C and C=N bonds of the propenyl­idene group. The atoms of the propenyl­idene and dithio­carbazate unit are essentially co-planar, with a maximum deviation of 0.058 (1) Å; the phenyl ring forms a dihedral angle of 18.3 (1)° with this fragment. In the crystal, mol­ecules form inversion dimers via pairs of N—H⋯S hydrogen bonds involving the terminal S atom

Maternal anaemia and the risk of postpartum haemorrhage: a cohort analysis of data from the WOMAN-2 trial

Background: Worldwide, more than half a billion women of reproductive age are anaemic. Each year, about 70 000 women who give birth die from postpartum haemorrhage. Almost all deaths are in low-income or middle-income countries. We examined the association between anaemia and the risk of postpartum haemorrhage. Methods: We did a prospective cohort analysis of data from the World Maternal Antifibrinolytic-2 (WOMAN-2) trial. This trial enrols women with moderate or severe anaemia giving birth vaginally in hospitals in Pakistan, Nigeria, Tanzania, and Zambia. Hospitals in each country where anaemia in pregnancy is common were identified from a network established during previous obstetric trials. Women who were younger than 18 years without permission provided by a guardian, had a known tranexamic acid allergy, or developed postpartum haemorrhage before the umbilical cord was cut or clamped were excluded from the study. Prebirth haemoglobin, the exposure, was measured after hospital arrival and just before giving birth. Postpartum haemorrhage, the outcome, was defined in three ways: (1) clinical postpartum haemorrhage (estimated blood loss ≥500 mL or any blood loss sufficient to compromise haemodynamic stability); (2) WHO-defined postpartum haemorrhage (estimated blood loss of at least 500 mL); and (3) calculated postpartum haemorrhage (calculated estimated blood loss of ≥1000 mL). Calculated postpartum haemorrhage was estimated from the peripartum change in haemoglobin concentration and bodyweight. We used multivariable logistic regression to examine the association between haemoglobin and postpartum haemorrhage, adjusting for confounding factors. Findings: Of the 10 620 women recruited to the WOMAN-2 trial between Aug 24, 2019, and Nov 1, 2022, 10 561 (99·4%) had complete outcome data. 8751 (82·9%) of 10 561 women were recruited from hospitals in Pakistan, 837 (7·9%) from hospitals in Nigeria, 525 (5·0%) from hospitals in Tanzania, and 448 (4·2%) from hospitals in Zambia. The mean age was 27·1 years (SD 5·5) and mean prebirth haemoglobin was 80·7 g/L (11·8). Mean estimated blood loss was 301 mL (SD 183) for the 8791 (83·2%) women with moderate anaemia and 340 mL (288) for the 1770 (16·8%) women with severe anaemia. 742 (7·0%) women had clinical postpartum haemorrhage. The risk of clinical postpartum haemorrhage was 6·2% in women with moderate anaemia and 11·2% in women with severe anaemia. A 10 g/L reduction in prebirth haemoglobin increased the odds of clinical postpartum haemorrhage (adjusted odds ratio [aOR] 1·29 [95% CI 1·21–1·38]), WHO-defined postpartum haemorrhage (aOR 1·25 [1·16–1·36]), and calculated postpartum haemorrhage (aOR 1·23 [1·14–1·32]). 14 women died and 68 either died or had a near miss. Severe anaemia was associated with seven times higher odds of death or near miss (OR 7·25 [95% CI 4·45–11·80]) than was moderate anaemia. Interpretation: Anaemia is strongly associated with postpartum haemorrhage and the risk of death or near miss. Attention should be given to the prevention and treatment of anaemia in women of reproductive age. Funding: The WOMAN-2 trial is funded by Wellcome and the Bill & Melinda Gates Foundation

Diethyl 4,4′-[octane-1,8-diylbis(oxy)]dibenzoate

The complete molecule of the title compound, C26H34O6, is generated by a crystallographic centre of symmetry and the central octyl chain adopts an extended conformation. In the extended structure, weak C—H...π interactions link the molecules

Crystal structure of bis{S-octyl-3-[(thiophen-2-yl)methylidene]dithiocarbazato-κ2N3,S}nickel(II)

In the title complex, [Ni(C14H21N2S3)2], the nickel(II) atom is located on a crystallographic inversion center and exhibits a square-planar coordination environment, being coordinated by two negatively charged N,S-chelating ligands in a trans configuration. In the crystal, the non-H atoms of the complex are practically coplanar (r.m.s. deviation of fitted atoms = 0.135 Å), and the angle between the thienyl and the chelating rings is 6.7 (1)°. The molecules stack at a distance of 3.623 (2) Å along the b-axis direction

Crystal structure of bis[4-(allyloxy)-N′-(but-2-en-1-ylidene)benzohydrazidato]nickel(II)

In the title complex, [Ni(C14H15N2O2)2], the nickel(II) atom exhibits a square-planar coordination geometry, being coordinated by two negatively charged N,O chelating ligands in a trans configuration, with the metal located on a crystallographic center of symmetry. The X-ray structural characterization showed the complex to be disordered over two orientations with refined occupancies of 0.898 (2) and 0.102 (2). The whole molecule is close to planar, the five- and six-membered rings subtending a dihedral angle of 7.5 (2)°. The crystal packing is supported by C—H...π and C—H...O interactions that form a di-periodic layered network

Crystal structure of S-n-octyl 3-(1-phenylethylidene)dithiocarbazate and of its bis-chelated nickel(II) complex

The nitrogen–sulfur Schiff base proligand S-n-octyl 3-(1-phenylethylidene)dithiocarbazate, C17H26N2S2 (HL), was prepared by reaction of S-octyl dithiocarbamate with acetophenone. Treatment of HL with nickel acetate yielded the complex bis[S-n-octyl 3-(1-phenylethylidene)dithiocarbazato]nickel(II), [Ni(C17H25N2S2)2] (NiL2), which was shown to adopt a tetrahedrally distorted cis-square-planar coordination geometry, with the NiSN planes of the two ligands forming a dihedral angle of 21.66 (6)°. Changes in the geometry of the L ligand upon chelation of Ni2+ are described, involving a ca 180° rotation around the N(azomethine)—C(thiolate) bond